ilxltViVN'i.*:-,:-1.^ ,;l M^ ELEMENTS A -* $ T PATHOLOGICAL ANATOMY, ILLUSTRATED BY NUMEROUS ENGRAVINGS. 1 IN MORBIS, SIVE ACUTIS, SIVE CHRONICIS, VIGET OCCULTUM, PER HDMANAS SPECULATIONES FERE INCOMPREHENSIBILE.'—BAGLIYI. By SAMUEL D. £ROSS, M. D. LATE PROFESSOR OF GENERAL ANATOMY, PHYSIOLOGY, AND PATHOLOGICAL ANATOMY, IN THE MEDICAL DEPARTMENT OF THE CINCINNATI COLLEGE. IN TWO VOLUMES. VOL.1. /''b^Mf-'.f' • ^ %-| BOSTON: -~±~*^ MARSH, CAPEN, LYON, & WEBB, AND JAMES B. DOW. 1839. V I Entered according to Act of Congress, in the year 1839, by SAMUEL D. GROSS, M. D. the Clerk's Office of the District Court of the District of Massachusetts. (5 We / W v. i WILLIAM A. HALL & CO. PRINTERS. TO DANIEL DRAKE, M. D. PROFESSOR OF CLINICAL MEDICINE AND PATHOLOGICAL ANATOMY IN THE LOUISVILLE MEDICAL INSTITUTE, ETC. Distinguished alike as an accomplished and successful teacher, an erudite and skilful physician, a zealous pro- moter of science and literature, and an ardent friend of pathological anatomy, the following pages, intended to illustrate one of the fundamental branches of medical science, are respectfully inscribed, as a testimony of esteem for his exalted talents and attainments, and as a token of sincere regard for his character, By his obliged Friend and Servant, THE AUTHOR. t I i I PREFACE. The acknowledged want, in our country, of a work on pathologi- cal anatomy precludes the necessity of any apology, on the part of the author, for offering to the public the following volumes. The only native production of the kind, which has yet appeared, is the Treatise of Professor Horner, of the University of Pennsylvania, which, from the narrow limits within which it is restricted, can lay no claim to the character of a system, or be considered as exhibit- ing a correct view of the existing state of the science, reformed, as it has recently been, by new discoveries and improvements. As presenting a record of facts, collected with indefatigable industry, and detailed with great candor and impartiality, it is a valuabie fund of information, which can never be consulted without interest and instruction. Of foreign publications that have found their way to the United States, there are only two, those of the late Dr. Matthew Baillie, of London, and of Professor Andral, of Paris. Concerning these productions, which are both highly honorable to their authors, as well as to the nations to which they respectively belong, it need only be remarked that the one, besides being entirely out of print, is altogether in arrear of the present condition of pathological anatomy ; and that the other, from the introduction of new and perplexing terms, for which there is so extraordinary a fondness on the part of the French writers, and from a singular want of systematic arrange- ment, can never subserve the purposes of a text-book. To supply these deficiencies, therefore, is the object of the present treatise. It has been the constant aim of the author, in the composition of the following pages, to express himself in plain, intelligible language, to abstain from every thing like pedantry, in the use of new terms, and to furnish, as far as practicable, a comprehensive view of the existing state of the science. How far he has succeeded, in these and other respects, he leaves to the candid judgment of his reader to determine. It is sufficient to say that he has been fully sensible VI PREFACE. of the responsibility of the enterprise, and that nearly four years have been devoted to its accomplishment. In regard to his materials, the author may be permitted to state, that, whilst he has freely availed himself of the usual sources of information from books, as every one who wishes to present any thing like a connected view of the science necessarily must, lie has not omitted, whenever occasion offered, to incorporate the results of his personal observation and experience. Although much less extensively engaged in necroscopic examinations than many of his European brethren, or even, perhaps, than some of his more imme- diate neighbors, his position, as Professor of Pathological Anatomy in the medical department of the Cincinnati College, has given him unusual advantages, and induced him to devote a much greater share of attention to the subject than is ordinarily allotted to it. The average period he is in the habit of spending upon such dissections is from two to three hours; and it has been his constant practice, moreover, for many years, to carry away, for subsequent and more thorough inspection, every morbid structure of interest. In this manner has been formed the nucleus of a museum of pathological anatomy, embracing already a large number of the most valuable specimens. True it is, the author has not, like Monsieur Andral, examined the thoracic duct in six hundred subjects, nor has he, like Dr. Bizot, of Geneva, performed several hundred dissections, to ascertain the relative frequency of disease in different parts of the arterial system — which is all well enough — but he has done what, in his opinion, is of much greater" utility, directed particular attention to the lesions of the more important organs. It is certainly an anomaly in the history of our profession, that a science which admits of such extensive application as the present, and which may be regarded as constituting the very foundation of the grand edifice of medicine, should still be so much neglected as a branch of elementary study in the United States. This is so much the more surprising when we consider the successful efforts which have been made, of late years, for the diffusion of general knowl- edge, and the absolute importance, in a pursuit like ours, of availing ourselves of every source of information, whether of a direct or collateral bearing. It displays a degree of apathy, to say the least, on the part of our schools, which is alike disreputable to them as seminaries of learning, disgraceful to the American profession, whose dignity and usefulness they ought to have at heart, and inju- rious to the progress of medical science. The utility of an extended knowledge of this science cannot, indeed, be any longer a matter of doubt or dispute. Without the light which it furnishes, our views of disease must necessarily be limited and confused; whilst, by its help, the nature and seat of every lesion is comparatively easily comprehended. The history of pathological anatomy may be said, not unaptly, to be a register of observations, not of a single individual, but of many, to ascertain the PREFACE. Vll power of morbid action; and precisely in proportion as they are based on fact, is their tendency to advance the healing art to the rank and dignity of a certain science. From the successful manner in which they have been conducted within the last twenty years, and from the immense flood of light which they have shed upon the nature, seat, and diagnosis of disease, it is obvious that they alone can yield any substantial trophies ; and they should therefore at once serve to guide and encourage our future researches. To dis- criminate between different lesions ; to be able to locate, or give them " a habitation and a name ;" to know the nature of their products and their effects, — these are some of the qualities which distinguish the medical philosopher from the routine practitioner, the scientific physician from the mere symptomatologist. It is certainly a matter of deep regret that the investigation of diseased structure was not conducted in a more diligent and en- lightened manner by our medical ancestors: had this been done, comparatively little would have remained to be accomplished by the present race of physicians: diagnosis, the grand object of our preparatory studies, would be much more perfect, and the funda- mental prkpciples of our profession repose upon a more firm and immutable basis. But, as it is, our heritage unfortunately amounts to little else than a detail of individual facts, drawn up, for the most part, in so loose and slovenly a manner, as to render it difficult, if not impossible, to derive from them any profitable results. The appearance of Bichat, towards the close of the last century, on the great theatre of active life, constitutes a new epoch in the history of medicine, pregnant with the most important events. From the thorough revolution which has been effected by his writings, in the total subversion of the various artificial systems of nosology which flourished up to the period adverted to, we may justly award to him the honorable and well-merited title of the " father of modern pathological anatomy;" and to his influence and example, more than to those of any other individual or sect in medicine, are unquestionably to be ascribed all the discoveries and improvements which have been achieved, in different quarters of the civilized world, since the time in which he wrote. The admirable works of his countrymen, Laennec, Bayle, and Corvisart; Broussais, Louis, Andral, and Cruveilhier; of J. F. Meckel, of Germany, of Abercrombie, of Scotland, and of Hope, Mayo, and Carswell, of England, are all traceable, directly or indirectly, to the extraordi- nary impulse transmitted by this illustrious man: they are enter- prises of the highest utility to medicine, and afford a happy illustra- tion of the spirit of inquiry and philosophy which actuates the physicians of the age in which we live. But to return from this digression. It will be perceived that considerable space is occupied with discussions relative to the normal characters of the various organs and tissues of the body. Disquisi- tions of this sort, though they trench upon another but kindred vm PREFACE. department, are indispensable to a clear and intelligible comprehen- sion of the fundamental principles of pathological anatomy. AX'ith- out a knowledge of the natural color, weight, volume, and consist- ence of a structure, how is it possible to obtain distinct conceptions of the numerous and diversified alterations induced in it by disease ? The thing is utterly impossible. Without, therefore, a competent share of information of this kind, it is obvious that no physician, whatever may be the extent of his attainments in other respects, can successfully execute the duties of a pathological anatomist. So numerous, indeed, are the sources of fallacy and deception, that even the most enlightened members of the profession frequently commit the most egregious errors, assuming for morbid what is perfectly normal, or, conversely, for healthy what is diseased, or the result solely and exclusively of cadaveric mutations. Miscon- ceptions such as these, abstractly considered, arc of no great moment; but, when principles are deduced from them, as is most generally the case, and applied to practice, their mischievous tendency be- comes too obvious to require any comment in this place. The same remarks are equally true of hasty and superficial examinations, which can never be productive of any good, but, on the contrary, often lead to a great deal of harm. These are topics upon which the author would not dwell, were he not fully convinced, from daily observation, of their injurious effects upon the practice of medicine and surgery. They lie at the very foundation of the discordant statements which disfigure so many of the treatises of the present day, and which are annually inculcated, with so much zeal and eloquence, in the lecture-rooms of the Western continent. The embarrassments which the author has had to contend with, in the execution of this branch of his subject, can only be appreciated by those who are acquainted with the meagre and contradictoiy statements which are to be found in our various treatises on general and descriptive anatomy. Confident, from an attentive perusal, that no satisfactory account could be gleaned from these sources, relative to the dimensions, weight, and physical properties of the different viscera, the author has been induced, in most instances, to substitute the results of his own observations, in preference to what, in his opinion, appeared to be information of equivocal authenticity. Al- though his examinations of individual parts have not been so nu- merous as could be desired, yet he ventures to predict, from the rectitude with which they were conducted, that future researches will not essentially contradict them. It would be well if a standard of comparison could be established, by which to judge of the normal character of every organ in the body; but, to be complete, it is obvious that it must be constructed in reference to the varying cir- cumstances of age, sex, and stature. Until this be accomplished, our statements must necessarily be devoid of that precision which is so indispensable in all pathological investigations. Nor can a standard of this sort be determined by a single individual: to be preface. JX worthy of implicit confidence, and susceptible of general application, it must be the joint labor of numerous inquirers in different parts of the world. Some apology may be thought necessary for the manner in which the author has expressed himself in relation to the subject of inflam- mation. Disclaiming to be the follower of any man, or school, in medicine, the sentiments he has avowed are the results of his con- scientious conviction, grounded upon personal observation and re- flection ; and, as such, he does not hesitate to submit them to the scientific scrutiny of his professional brethren. Those who have been in the habit of contemplating disease, as revealed by the phenomena of the living system, and by the knife after dissolution, will agree with him, at least, that, if disease be not, like life itself, a unit, it has few elements, and that these elements are so modified by internal and extrinsic causes, or, in other and more appropriate terms, by texture, age, sex, constitution, climate, season, and other circumstances, as to produce those multiform features which are a source of so much difficulty and perplexity to the nosological physi- cian. In every science some system is required ; and in no one is this more necessary than in pathological anatomy. The most natural arrangement that suggests itself is that unquestionably which relates to the affinities existing between the different structures; but, how- ever desirable it might be in some respects, it is evidently not suffi- ciently specific, and has therefore not been adopted in the present work. After presenting an account of the general principles of the science, the author proceeds to consider the lesions of each organ and tissue individually, indicating their anatomical characters, and also, as far as they are known, their diagnostic signs. In thus treating the subject, although some repetition is unavoidable, yet much greater order is attained, as well as wider scope afforded for minute discussion, than by the adoption of any other classification. How far the attempt to blend the description of diseased action with the study of pathognomonic symptoms, which is, in great degree, peculiar to the work, will meet the sanction of the profession, time alone can determine. Without being altogether unobjectionable, it has a direct tendency to augment the utility of pathological science, by pointing out its true connection, and cannot fail, therefore, if properly carried out, to be of the greatest practical benefit to the physician. The drawings illustrative of the heterologous formations, and of the lesions of the gastro-enteric mucous membrane, are from the pencil of Mr. Henry Brown, a young artist of uncommon merit. They are, with few exceptions, taken from nature, and their accuracy is such as to entitle them, in all respects, to the confidence of the reader. Of the wood cuts, some are original, but the greater part are collected from other sources, with no little trouble and ex- pense. VOL. I. 2 X PREFACE. Before bringing these prefatory remarks to a close, the author would tender his sincere acknowledgments to Dr. J. Wyman, of Boston, who kindly offered his aid in bringing this work before the public, taking upon himself the labor of superintending the passage of the sheets through the press. Finally, the author is not without the hope that the present treatise, imperfect, as it is, will contribute, in some degree, towards the abolition of ancient errors, extend the boundaries of useful knowledge, and diffuse a taste for the cultivation of pathological anatomy. Cincinnati College, July 1, 1839. CONTENTS. PART I. GENERAL principles of pathological anatomy. CHAPTER I. of inflammation. Preliminary Observations. — Fluids and Solids. — Different kinds of Sym- pathy.— Disease, functional and organic. — Inflammation, how modified by Temperament, Age, Sex, Habit, Climate, Season, the nature of the ex- citing cause, and the character of the Tissue; acute and chronic; does not occur with equal frequency in all parts of the body; common and specific. — Nature, Symptoms, and Seat of ordinary Inflammation; Redness, Heat, Pain, and Swelling; Derangement of the Vital Actions; Structure of the Capillaries; joint agency of the Vascular and Nervous Systems; altered Sensibility; preternatural influx of Blood; Experiments and Opinions of Kaltenbrunner. — Congestion; Theories of Boerhaave, Cullen, Vacca, and others. — Terminations and Conditions of Inflammation, - - - - CHAPTER II. OF THE EFFUSION OF SERUM. Occurs to a greater or less extent in almost every Inflammation. — (Edema, Anasarca, and Dropsy. — Color, Consistence, Quantity, and chemical Composition.— Usually the result of a mild degree of Inflammation.— Conclusion,.....-............... CHAPTER III. OF LYMPHIZATION. Always the result of Inflammation. — Physical properties of Lymph. — Quan- tity. — Varieties of Form. — Chemical Constitution. — Period at which the Deposition commences. — Has a tendency to become organized. — How this is effected. —Analogous Tissues. — Use of Lymph as a means of Res- toration.— Adhesive Action,............... CHAPTER IV. OF SUPPURATION. Definition. — Organs in which it is most easily effected. — May take place without Solution of Continuity.—Varieties of Form.— Abscesses. — Phys- ical and Chemical Properties of Pus. — Distinguishing Tests. — How produced,...................... xu CONTENTS. CHAPTER V. OF HEMORRHAGE. The subject still involved in obscurity. — Causes.— Opinions of Morgagni and of Bichat. —Exhalant Vessels. — Aptitude of different Structures.— Nomenclature. — Predisposition. — Hereditary Proclivity. — Hemorrhage sometimes vicarious. — Active and passive. — Critical. — Quantity of Blood effused.— Changes and final Disposition,.........76 CHAPTER VI. OF SOFTENING. One of the most unequivocal signs of Inflammation. — Structures most lia- ble to be affected by it. — In what anatomical Element is the Lesion seat- ed 1 — Causes. — Opinions of Rostan and other writers. — Degrees of Softening,......................84 CHAPTER VII. OF GANGRENE. Definition. — Parts most apt to suffer. — Color and Consistence. — Extent. — Manner in which Nature guards against the occurrence of Hemorrhage. — Causes, of two kinds.— Malignant Pustule. — Gangrene from the use of Ergot. — From the exhibition of Tartar Emetic. — Senile Gangrene, - - 87 CHAPTER VIII. OF ULCERATION. Definition; intricate nature. — Most common in the Skin, Cellular Tissue, and Mucous Membranes. — May be slow or rapid. — Manifests a tendency to extend towards the nearest surface. — Produced by Inflammation. — Ulcers sometimes heal; the process by which this is accomplished. — Ul- ceration a sanative effort, -----............96 CHAPTER IX. OF GRANULATION. Importance of the Subject. — Nature of Granulations.— Difference in re- gard to their Vascularity and Sensibility. — How modified by Texture. — Are secreting and absorbing Organs,............-- 100 CHAPTER X. OF CICATRIZATION. Nature of the Process. — Different Steps. — Do Ulcers ever heal from the Centre 1 — Process of Cicatrization influenced by the Form and Situation of the Sore. — Meaning of the term Cicatrice. — Reproduction of the original Tissues,....................103 CHAPTER XI. OF INDURATION. Definition. — Historical Notice. — Color, Size, and Degree. — Period neces- sary for its Production. — Causes, -----......._. jgg CHAPTER XII. OF HYPERTROPHY. Meaning of the Term. — Liabilities of different Structures.— Causes.—May be general or local. — Color, Weight, and Volume, of the Part affected, 111 CONTENTS. Xlll CHAPTER XIII. OF ATROPHY. Definition. — May be general or partial. — Causes: want of Exercise; dim- inution of the Nervous Influence; deficient supply of Blood, .....116 CHAPTER XIV. OF TRANSFORMATIONS. The Body in a state of constant Mutation. — Number of Transformations : the Cellular, Mucous, Cutaneous, Fibrous, Cartilaginous, Osseous and Adipous, -------...............121 CHAPTER XV. OF HYDATIDS. Historical Outline. — Where found. — Classification of Hydatids. — The Cysticercus, Polycephalus, Diceras, Echinococcus, and Acephalocystis. — Their Origin and Organization. — The manner in which they are nour- ished. — The Changes which they experience by Age, and the Alterations they induce in the Organs in which they are developed,......131 CHAPTER XVI. OF SEROUS CYSTS. Have the form of shut Sacs.— Organs in which they are most frequently found. — Classification : the simple, multilocular, and the included. — Na- ture of the contained Fluid. — Are either new products, or formed out of the preexisting Textures.— Are liable to Inflammation and its conse- quences, >...............-'.....143 CHAPTER XVII. OF THE HETEROLOGOUS FORMATIONS. Preliminary Observations.— Classification: Tubercle; Melanosis; Scirrhus; Eucephalotd. Section I. Tubercle.—Definition. — Great frequency.— Occurs nearly in all Tissues, and at all Periods of Life. — Is common in the lower Animals. — Chemical Composition. — Varieties of Form. — Concrete and semi-concrete Tubercular Matter. — Notions respecting its Origin, Developement, and Organization.— Softening and Excavations. Section II. Melanosis. — Historical Sketch. — Occurs in Man and Animals. — Chemical Analysis.— Color and Consistence. — Varieties of Form.— Tissues most liable to suffer from Melanotic Diathesis. — States of the Sys- tem which predispose to its formation. Section III. Scirrhus.— Difficulty of the Subject. — Definition.—Varieties of Form. — Chemical Constitution. — Rarely appears before the age of thirty. — Most common in Glandular Organs. — Proximate Cause. — Opinions of Adams, Carmichael, Hodgkin, and others. — Is apt to Ulcerate and involve the general System. Sec- tion IV. Encephatoid. — Is intimately allied to Scirrhus. — Terms by which it has been designated.— More frequent in some Structures than in others.— Varieties of Form.— Color, Consistence, and Composition. — Organization and Mode of Origin. — A Disease of early Life. — In- volves the whole System. —Termination,...........148 XIV CONTENTS. PART II. SPECIAL PATHOLOGICAL ANATOMY. CHAPTER I. OF THE BLOOD. Physical Properties.— Chemical Analysis.—Division into Serum, Fibrin, and Hematosine. —Lesions of the Blood.—Nature and Formation of the buffy Coat. — Cupped appearance of the Blood. — Want of Coagulability.— Relative quantity of Fibrin in healthy and diseased Blood. —Alterations of the Hematosine.—Lesions of the Serum, in Inflammation, Dropsy, and other Maladies. —Changes of the Blood, from acceleration of the Circulation and Division'of the Pneumo-gastric Nerves. — Appearances in Cholera, Fever, Chlorosis, and Scurvy,...........197 CHAPTER II. OF THE CELLULAR TEXTURE. Distribution. — Physical Characters. — Organization. — Physiological Prop- erties. — Lesions. — Acute Inflammation. — Suppuration. — Gangrene. — Chronic Inflammation. — Induration. — Serous Infiltration. — Emphyse- ma. — Degenerations. — Foreign Substances. — Guinea Worm, - - - - 228 CHAPTER III. OF THE ADIPOUS TEXTURE. Organization. — Exists only in particular regions of the Body. — Office of the Adipous Vesicles. — Nature and Uses of the Fat.— Lesions of the Adipous Tissue. — Wounds. — Liability to Inflammation.— Hypertrophy, general and local. — Adipous Diathesis. — Atrophy, -------- 239 CHAPTER IV. OF THE MUSCULAR SYSTEM. Section 1. Of the Muscles.— Different Classes. — Structure.— Color and Con- sistence. — Chemical Analysis. — Sensibility. — Reunite when divided. — Inflammation. — Suppuration. — Mortification. — Chronic Irritation. — Softening. — Induration. — Ossification. — Fibrous and Fatty Transforma- tions. — Heterologous Deposits. — Hypertrophy. — Atrophy. — Parasitic Animals. — Sanguineous Effusions. Section II. The Tendons. — Appear- ance and Organization. — Reunite when divided. — Inflammation. — Ossi- fication.— Atrophy. — Diseases of the Sheaths of the Tendons. Section III. The Aponeuroses.— Structure. — Acute and Chronic Inflammation. — Section IV. Tlie Synovial Burses.— Situation and Structure. — Are liable to Disease. — Fibro-cartilaginous Concretions. — Hypertrophy. — Hyda- told Bodies,.....................247 CHAPTER V. OF THE ARTERIES. Their Tunics. —Nutrient Vessels. —Nerves.— Cellular Sheath.—Lesions. — Wounds.— Inflammation.— Suppuration. — Ulceration. — Aneurism. — Contraction. — Hypertrophy. — Morbid Deposits,........271 CHAPTER VI. OF THE VEINS. More numerous and capacious than the Arteries. — Tunics and Valves proper Vessels and Nerves.—Lesions. —Acute Inflammation. —Suppu- CONTENTS. XV ration. — Ulceration. — Chronic Inflammation. — Dilatation. — Oblitera- tion. — Calcareous Deposits. — Phlebolites. — Admission of A ir, - - - 291 CHAPTER VII. OF THE LYMPHATICS. Organization. — Liability to Inflammation and Suppuration.— Tubercular Deposits.— Dilatation. — Aneurism of the Thoracic Duct. — Situation and Structure of the Lymphatic Ganglions. — Lesions.— Inflammation and its ordinary consequences. — Hypertrophy. — Encephaloid Disease. — Tubercle.— Ossification. — Melanosis,............301 CHAPTER VIII. OF THE JOINTS. Section I. The Articular Cartilages. — Structure and Chemical Composi- tion. — Vascularity. — Lesions. — Reparation. — Inflammation. — Soften- ing. — Suppuration. — Ulceration. — Ossification. Section II. The Syno- vial Membranes.— Organization, Appearance, and Office.—Diseases: In- flammation — Effusion of Lymph and Pus — Ulceration —Chronic Irrita- tion — Loose Cartilages — Chalky Concretions. Section III. The Liga- ments.— Structure and Sensibility. — Adhesive Inflammation. — Atrophy. — Calcareous Concretions,................311 CHAPTER IX. OF THE OSSEOUS SYSTEM. Section I. The Bones. — Notions of the older Writers respecting their Organ- ization.— Vessels and Nerves. — Chemical Constitution. — Effects of Heat and Acids. — Classification. — Compact, Areolar, and Canaliculated Textures. — Diseases of the Bones. — Reparation. — Inflammation. — Suppuration. — Ulceration. — Gangrene. — Softening. — Fragility. — Hy- pertrophy. — Atrophy. — Hydatids. — Aneurism. — Carcinoma. — Mela- nosis.— Tubercle. Section II. The Periosteum.— Its fibrous structure liable to the same kinds of Diseases as the fibrous Membranes generally. — Hypertrophy. — Ossification. — Is seldom, if ever, affected by the Heter- ologous Formations. Section III. The Medullary Membrane. — Situation and Character. — Diseases few, but important,.........324 CHAPTER X. OF THE CUTANEOUS SYSTEM. Section I. The Skin. — Number of Layers. — Epidermis. — Mucous Web. — Dermis. — Papilla;.— Sudoriferous Glands. — Sebaceous Follicles. — Re- productive power of the different lamellae of the Skin.— Diseases. — (r.) Unclassifiable Lesions. — Keloid. — Melanosis. — Encephaloid. — Carti- laginous Tumors. — Eiloid. — LepoTd. — Hypertrophy. — Corns. — Warts. — Horny Excrescences. — Gangrene. — Sebaceous Tumors. — Hemor- rhages.— (n.) Classifiable Lesions. 1. Exanthematous Diseases.—2. Pustular. — 3. Papular. — 4. Bullar. — 5. Tubercular. — 6. Scaly. — 7. Syphilitic Diseases. — 8. Stains. Section II. The Nails. — Situation, Composition, and Arrangement. — Growth. — Reproductive Power. — Inordinate Length. — Absence. — Malformation.— Vicious Situation.— Onyxitis. Section HI. The Hairs. — Similarity to the Nails. — Situation. — Consist each of a Follicle and Stem. — Organization. — Polish Plait. — Regenerating Power. — Hypertrophy. — Female Beards. — Softening. — Fragility. — Changes of Color. — Accidental developement of Hair, - - 355 CHAPTER XI. OF THE NERVOUS SYSTEM. Section I. General Observations. — Cerebral Envelopes. — Cephalo-spinal Li- quid.—White and Gray Substances. — Chemical Composition. —Con- XVI CONTENTS. sistence. — Color. — Sensibility. — Vascularity. — Absorbent Vessels. — Speculations of Kellie and Abercrombie, respecting the Compressibility of the Cerebral Tissue. — Weight of the Encephalon and Form of the Spi- nal Cord. Section II. Lesions of the Cerebral Envelopes. — Inflammation of the Dura Mater.— Suppuration. —Fibrous Tumors. — Bony Deposits. — Hypertrophy of the Glands of Pacchioni. — Arachnitis. — Hydrocepha- lus. — Tubercles. — Stages and Symptoms of Arachnitis. — Diseases of the Pia Mater. Section III. Lesions of the Brain. — Wounds. — Encephalitis. — Suppuration. — Abscesses. — Gangrene. — Softening.—Chronic Inflam- mation. — Induration. — Ulceration. — Sanguineous Effusions. — Tuber- cles. — Melanosis. — Encephaloid. — Cartilaginous Formations. — Calca- reous Deposits. — Cysts and Hydatids. — Hypertrophy and Atrophy. — Section IV. Lesions of the Spinal Cord. — Inflammation. — Heterologous Formations. — Hydro-rachitis. Section V. Lesions of the JVerves. — Clas- sification. — Form. — Distribution. — Connection and Structure. — Res- torative Power. — Neuritis. — Suppuration. — Ulceration. — Hypertrophy and Atrophy. — Diseases of the .Nervous Ganglia,.....- - -419 CHAPTER XII. OF THE EYE. Section I. Lesions of the Lacrymal Apparatus. — Preliminary Observations.— Lacrymal Gland. — Ducts and Sac. Section II. Lesions of the Ball of the Eye. — The Conjunctiva. — Pterygium. — Lacrymal Caruncle. — Acute Corneitis. — Ulceration and Ossification of the Cornea. — Fleshy Excres- cences.— Alterations of Form. — Diseases of the Sclerotica. — Choroid Tunic. — The Retina. — Amaurosis. — Optic Nerve.— Membrane of De- mours. — Haemophthalmus. — Lesions of the Iris. — Alterations of the Pu- pil. — Capsule of the Crystalline Lens. — Liquor of Morgagni. — Varie- ties of Cataract. — Vitreous Humor. — Heterologous Formations, - - - 485 CHAPTER XIII. OF THE EAR. Preliminary Remarks. — Malformations of the external Ear. — Polypous Growths. — Lesions of the Tympanum. — Bones of the Ear.— Eustachian Tube. — The Labyrinth and Vestibule. — Diseases of the Auditory Nerve,.......-...............512 PART I. GENERAL PRINCIPLES OF PATHOLOGICAL ANATOMY. PATHOLOGICAL ANATOMY. CHAPTER I. Of Inflammation. Preliminary Observations. — Fluids and Solids. — Different kinds of Sympathy. — Disease, functional and organic. — Inflammation, how modified by Tem- perament, Age, Sex, Habit, Climate, Season, the nature of the exciting cause, and the character of the Tissue; acute and chronic; does not occur with equal frequency in all parts of the body; common and specific. — Nature, Symptoms, and Seat of ordinary Inflammation ; Redness, Heat, Pain, and Swelling; De- rangement of the Vital Actions; Structure of the Capillaries; joint agency of the Vascular and Nervous Systems; altered Sensibility; preternatural influx of Blood ; Experiments and Opinions of Kaltenbrunner.— Congestion; The- ories of Boerhaave, Cullen, Vacca, and others. — Terminations and Condi- tions of Inflammation. The human body is composed of solids and fluids, which are intimately blended together, and mutually dependent up- on each other for their origin and preservation. Both classes are resolvable into a number of proximate constituents, differ- ing widely in their color, their consistence, and their chemi- cal properties. Of the fluids, the blood is by far the most important, as it is out of it that the solids are formed, and by it that they are nourished and sustained. The quantity of this liquid, on an average, is about eighteen pounds; but it may be observed that it is liable to vary not only in different persons, but likewise in the same individuals at different pe- riods. Not only its amount, but also its quality, is much in- fluenced by the kind of food and drink, the exercise, the climate, and mode of life to which the individual is subjected. It is not my design, in this place, to say any thing of the chemical constituents of the blood, further than to declare that this fluid contains all the elements of the solid parts of the body, that the latter are constantly permeated by it, and that there can be no secretion, whether healthy or morbid, that is not derived from it. The diseases to which it is lia- ble will be made the subject of separate consideration. 20 INFLAMMATION. [CHAP. I. The solids consist of what have been called, since the time of Bichat, the tissues; of which the number has been variously stated by different writers, scarcely any two agreeing on the subject. Without occupying the attention of the reader with any discussion of this sort, which would be out of place here, I shall merely remark concerning them, that they all differ from each other in their appearance, their composition, their structure, and the purposes which they are designed to fulfil in the economy. With the exception of the muscular and nervous fibres, they all seem to be derived from the cellular element, — a substance which enters so large- ly into the composition of the animal machine, cementing together its various parts, and forming myriads of meshes for the reception of its nutrient and recrementitious par- ticles. Combined in various ways, these tissues constitute the dif- ferent organs, whether parenchymatous, pulpy, glandular, or erectile. The parenchymatous structure is well exemplified in the lungs, which are composed of a soft, spongy, cellular substance, freely pervaded by vessels. Of the pulpy texture, a good illustration is afforded by the brain: here there is very little cellular matter, and the consistence of the organ appears to depend principally upon the presence of a large proportion of albumen. The glandular structure is still imperfectly un- derstood. The liver, which forms the type of this system, is made up of myriads of granules lodged in distinct cells, the walls of which are evidently fibrous; but, what the pre- cise nature of the contained substance is, whether essentially vascular, or of a character altogether peculiar to itself, is a point which is yet to be determined. The erectile texture, the most perfect example of which occurs in the penis, is composed mainly of arteries and veins, closely interwoven with each other, and susceptible of temporary erection, from the influx of blood. The tissues, whether they be regarded individually, or as united together to form compound organs, are differently sup- plied with vessels, with nerves, and with lymphatics; and, consequently, although they are all important, each in its own way, to the well-being of the general system, some are much more so than others. Whole limbs, containing ev- ery variety of texture, may be removed, even in the human subject, without being necessarily followed by the dissolution of the economy; whereas, scarcely a single one of the inter- CHAP. I.] SYMPATHY. 21 nal organs, properly so called, with the exception of the spleen, can be extirpated without the destruction of life. Connected together by vessels and nerves, as well as, in some instances, by continuity of surface, there subsists be- tween the various parts of the body the closest fellow-feeling. In health, this sympathetic action is carried on so impercep- tibly as to escape the attention of the physiologist; but no sooner is the system deranged, than it manifests itself at al- most every point of the compass, serving at once to show the nature of the lesion, and the particular tissue, or set of tex- tures, which it implicates. Every one is familiar' with the k powerful sympathy existing between the uterus and the stom- ach ; the stomach and the lungs ; the lungs and the heart; the heart and the brain. Nor is this fellow-feeling less marked in some of the other viscera. In duodenitis, nothing is more common than to see the liver disturbed in its functions ; or, if the disease continue long, even its structure. The ex- planation of this is obvious. These two organs, the duo- denum and the liver, are not only near neighbors, but the mu- cous membrane, which lines the former, is extended into the latter, by means of its excretory ducts, into the very cen- tre of each granule. There is thus a direct continuity of structure, in consequence of which, disease cannot exist long, or in any considerable degree, in the one without being prop- agated to the other. So, also, with the urethra and urinary bladder ; the vagina and uterus ; the fauces and tonsils ; the larynx and trachea ; the nose and frontal sinuses; the eusta- chian tube and middle ear. All these cases are examples of what Mr. John Hunter has termed continuous sympathy. In other cases, again, this sympathy displays itself in parts very remote from the one originally affected. In mumps, that is to say, in inflammation of the parotid gland, a not un- frequent occurrence is a swelling of the testicles, proceeding sometimes to such an extent as to destroy the structure and function of the organ. In what manner, or in accordance with what law of the animal economy, this association is es- tablished, it is impossible to say, as there is no similarity of texture any more than a direct, nervous connection. The parotid is supplied with filaments from the ascending cervical nerves, and with branches from the fifth cranial; the testicle, with filaments from the spermatic plexus, formed by the sympathetic. Thus, then, there is no immediate tie be- tween these organs, and yet, as has been stated, they often 22 INFLAMMATION. [CHAP. I. display the strongest fellow-feeling. The sympathy exist- ing between the uterus and the breast, and which is so conspicuous both in the healthy and diseased states of these parts, has been endeavored to be explained by the anastomosis of the internal mammary and epigastric arte- ries ; but it need scarcely be remarked that this mode of accounting for the phenomenon is far-fetched and unsatisfac- tory, the vessels adverted to having by no means the inti- mate connection which some have ascribed to them. The same difficulty occurs when we attempt to ascertain the cause of the well-known sympathy between the cerebellum and genital organs. In regard to all of these organs, all that we know is, that there is such a bond of connection, and this, surely, for all practical purposes, is sufficient. Writers have long since noticed the sympathy between parts of the same structure, situated remotely from each other. In gout, a disease which is seated in the fibrous textures of the extremities, it often happens, especially when the attack is violent, that the pericardium is involved, — the affection being transferred from its original situation to the chest. This is effected by what is called metastasis, — a term which only exposes our ignorance. The transfer must take place solely on account of the similarity of structure, not through any direct communication ; for every anatomist knows that there is no connection whatever between the fibrous envelopes of the voluntary muscles and the fibrous covering of the heart. The serous and synovial membranes, the cutaneous and mucous tissues, strongly sympathize with each other, no doubt from the anatomical elements which enter into their composition, being so much alike. The liver and the skin are intimately associated by fellow-feeling ; but how this is brought about, we have no means of determining. I have thus briefly adverted to the relationship subsisting between the principal organs of the body, and endeavored to account for it upon anatomical principles. Much* time might be occupied in the discussion of the subject; but I am not certain that it would result in much good. What is most worth knowing, is soonest learned, and least subject to dis- pute. The relationship which I have described should be carefully studied by the physician, as it will be impossible for him, without.an extensive acquaintance with it, to com- prehend some of the most extraordinary phenomena that are to be observed at the bedside of the sick. CHAP. I.] DISEASE : WHAT IS IT ? 23 Having made these desultory remarks, we may now pro- ceed a step further, and inquire what constitutes disease ; for every body knows what is meant by health. Disease may be defined to be a departure from the sound state, whether this departure consist simply in a derangement of function or structure. So long as the solid and fluid mate- rials of the body act in concert, there cannot, of course, be any lesion; health, in all its vigor and perfection, must be the result; but when the blood and the tissues are arrayed, as it were, against each other, the harmony of the system is interrupted, unnatural action is set up, or, in other words, there is disease. This deranged action, it need scarcely be stated, may be limited, or it may involve a considerable num- berof organs and tissues at the same time. ^Jf the essence of disease, very little is known; indeed, nothing at all; nor can the utmost ingenuity hope to re- move the veil which still envelopes the subject, until the physiology and pathology of the muscular and nervous systems shall be better understood. The proximate cause of morbid action, and the immediate cause of life in the healthy state, are as inscrutable to the human mind as the cause of gravitation, of attraction, and repulsion. All we can boast ,of is, that we know something of their effects; beyond this, it is extremely problematical whether we shall ever be able to penetrate. With this, indeed, every philosophical inquirer after truth should be contented, remembering that the secrets of nature are not easily detected, and that to God alone belongs the knowledge of the intrinsic property of things.^N It has been already intimated, that diseases are functional or organic. As it is of the latter class that we shall more par- ticularly treat in the following pages, it will be proper that we should speak of them somewhat at length. Before pro- ceeding further, however, it behoves me to explain what I comprehend by the term organic. By pathological anato- mists, the word is generally employed to denote some perma- nent change in the textures of an organ; but, in the sense that I would use it, I would not only include under it all such lesions, but also every temporary alteration which the tissues experience when in a state of disease. The term organic will then have a wider latitude; and, as expressing the same thing, we shall often have occasion to use the word structure. If this acception be adopted, it may perhaps be 24 INFLAMMATION. [CHAP. I. doubted whether, under any circumstances, there can, strictly speaking, be a functional disease, or, in other terms, a mere aberration of the physiological state of a part, without some change in its anatomical elements. The question, at all events, is not settled. Bearing in. mind the above definition, it may be assumed, as a general proposition, liable to few exceptions, that all organic diseases, whatever be their seat or extent, are the result of inflammatory action, either of an acute or of a chronic kind. To many, this proposition may be startling ; nevertheless, if it be carefully examined, it will be found, I doubt not, to be grounded on fact. The truth of this remark will appear more evident as we proceed. The second proposition that may be stated is, that every inflammation, irritation, or morbid action, is originally of a local nature; that is to say, it makes its impression in the first instance always upon some particular part, texture, or organ. After this inflammation has continued for a longer or shorter period, it often happens that it extends to and impli- cates other structures. If the mucous membrane of the stomach, for instance, be fretted, the morbid action accruing from this cause will be confined at first to that lining; or, in more comprehensive terms, the disease will be strictly local in its character : by degrees, however, as the disorder pro- gresses, the adjacent parts, such as the submucous cellular tissue, become affected; and, spreading still further, it next invades the muscular fibres of the organ, and, finally, the peritoneal covering. It is in this manner that most affec- tions, which are originally local, extend their sphere of action, so as to become general, whether they be considered sim- ply in reference to one organ, to several, or to a great number of them. Inflammation of particular organs and textures is usually designated by adding the Greek term itis to the anatomical name of the part affected, as gastritis, laryngitis, pleuritis. In some instances, the old nomenclature is retained. Thus, inflammation of the tonsils is called quinsy; of the eye, ophthalmia; of the urethra, gonorrhoea; of the parotid gland, mumps. In regard to its progress, intensity, and mode of termina- tion, inflammation is greatly modified by temperament, age, sex, habit, climate, and season, by the nature of the exciting cause, and, above all, by the character of the tissue in which CHAP. I.] MODIFIED BY AGE, SEX, CLIMATE, &C 25 it is developed. The time of life which seems to be most obnoxious to this disease, is from the first to the tenth year, nearly one half of the entire mortality occurring during this interval. Affections of the cutaneous, mucous, and lym- phatic systems, are particularly rife during this period, and carry off an immense number of children. Scarcely less common is inflammation of the arachnoid membrane. Pleu- ritis, pneumonitis, cerebritis, and hepatitis, with carditis, phlebitis, and arteritis, are comparatively frequent before the age of manhood; from thence on, however, they are by no means unusual, and prove a fruitful source of destruction. Diseases of the genital organs are rarely observed before the age of puberty ; anterior to this period, these structures seem, indeed, in a great degree, to lie dormant in the system. Once roused into action, however, they deeply sympathize with the other viscera, and hence the frequency of organic mala- dies of the uterus, the ovaries, breasts, and testicles, towards the decline of life. Affections of the urinary bladder are comparatively rare in the young, whilst they are very common in the old. Considered in reference to sex, some organs and tissues are more liable to be affected with inflammation than others. Cerebritis and splenitis, as well as carditis and arteritis, are infinitely more common in men than in women, probably, from the organs of the former being more exposed to perturbating agents, both of a physical and a mental kind. On the other hand, it is a well-established fact, that the female sex is much more obnoxious to inflammation of the peritonaeum, of the veins, and lymphatics, than the male. The seasons of the year in which inflammation is most prevalent, are winter and spring ; it is also more common in moist than in dry situations, and in cold and hot climates than in such as are temperate. In northern latitudes, the parts most frequently involved are the lungs, the air-passages, and the fibrous textures; in tropical ones, the mucous mem- brane of the large bowel, the liver, and the skin. The above are circumstances in the history of inflamma- tion which, of course, we can only glance at; the subject is certainly one of vast interest to the practising physician, and the attentive study of it cannot fail to be of the greatest benefit to him. The rapidity with which this disease may run its course, is subject to a considerable number of circumstances, amongst 4 26 INFLAMMATION. [CHAP. I. which the most important are the nature of the exciting cause and the structure of the part affected. As a general rule, it may be stated, that the more liberally an organ is furnished with vessels and nerves, the more easily will it be disorganized. Thus, an inflammation of the mucous mem- brane of the bowels will usually terminate much more rapidly either in health, or in death, than the same disease seated in a fibrous membrane, a tendon, ligament, or bone. When an acute inflammation, after having existed for some time, does not terminate in the usual manner, it is said to become chronic. Paradoxical as it may at first sight appear, there are some varieties of this disease that assume a chronic form at the very moment of their outset. The irri- tation which accompanies the tubercular deposition, and some species of pure uncomplicated pneumonitis, are of this de- scription. Considered in regard to its degree of intensity, inflamma- tion presents a great variety of forms, from the slightest possible derangement to the most intense morbid action. In this respect, therefore, the disease may be said to be mild, moderate, or violent. For the purpose of designating the first of these conditions, some writers are in the habit of em- ploying the term sub-acute ; a word which seems to me to be ill-chosen, and consequently conducive, to error. The terms mild, slight, or moderate, are free from this objection, and will, therefore, be retained in the following pages. The disease before us does not occur with equal frequency in all the organs and tissues of the body. There are some parts, in fact, in which it has been doubted, though, as I think, without any foundation in truth, whether this affection ever takes place. Such are the nails, the epidermis and the hairs. These structures are supposed, by general anatomists, to be destitute of vessels, and, therefore, incapable of per- forming any vital action. This7 however, is merely a con- jecture ; the fact remains to be proved, and, for my own part, I feel as certain that these textures are susceptible of inflam- mation, as that the liver is, the stomach, or any other organ. The cellular, -mucous, serous, and dermoid textures are particularly prone to inflammation. In children, this is different. In them, the cutaneous and mucous textures are infinitely more liable to inflammation than the cellular tissue and serous membranes, — the frequency of their attack being, as nearly as can be, in the order here stated. It is here that CHAP. I.] COMMON AND SPECIFIC. 27 the disease can be studied with the greatest advantage, both as it respects its phenomena and modes of termination, inasmuch as it is usually well marked, intense in degree, and rapid in its progress. The synovial membranes, the fibrous envelopes, the bones, ligaments, and cartilages, with the muscles and their tendons, inflame with difficulty; but when the disease has once fastened upon them, they readily yield to its influence, the sufferings are often excessively severe, and the consequences very serious. The blood- vessels, nerves, and absorbents, are all more or less liable to phlegmasia. The conservative powers of these structures, especially of the former, is remarkable, and is strikingly evinced in cases of gangrene, where, as will be shown here- after, they frequently retain their vitality amidst the half putrefied mass. Of the organs, some are more ready to take on inflamma- tion than others. Those which are most frequently affected, at least in this country, are the lungs, spleen, liver, uterus, and brain. The heart, ovaries, thyroid body, pancreas, pros- tate gland, testicles, and kidneys, are comparatively rarely the seat of this disease. Respecting specific inflammation, some parts, again, are more prone to this disease than others. Thus, erysipelas commonly attacks the skin; anthrax, the subcutaneous cellular tissue; rheumatism, the fibrous envelopes of the extremities; tubercle, the lungs; scirrhus, the glandular organs. In the skin, numerous varieties of inflammation, both of an acute and. chronic kind, are observed, that never occur in any other of the elementary textures and systems of the body. To this category specially belong the different species of eruptive and scaly diseases, which have their seat, for the most part, in the superficial portion of the dermis, the net-work of Malpighi, and the cuticle. Although we have employed here the term " specific," yet it must be confessed that it is one of very equivocal signifi- cation ; and, in order to remove all ambiguity respecting it, it will be necessary to determine, if possible, the sense in which it is understood by professional men. Almost all sur- gical authors agree in stating that there are two descriptions of specific inflammation; one of which is produced, it is alleged, by a peculiar condition of the constitution, and the other by the action of a special virus. Under the influence of the first are developed what are denominated the heterolo- 28 INFLAMMATION. [CHAP. I. gous formations, such as tubercle and scirrhus, together with gout, rheumatism, and erysipelas; under that of the latter a disease which manifests a particular train of phenomena, which exerts its effects only upon a particular set of struc- tures, and which can only be excited by particular causes. In such a classification, surgically considered, there is no special objection ; but, viewed philosophically, or in reference to the laws of healthy and abnormal action, there is no ground whatever for such a distinction. All morbid action, indeed, whether acute or chronic, is, properly speaking, specific, or, what is the same thing, exerts a particular influence in rela- tion to the particular structure which it implicates, being accompanied by particular symptoms and particular products. Let us now proceed to investigate the nature of inflamma- tion, its seat, and the phenomena which characterize it. In the w'hole range of medical science there is no topic which has attracted so much attention, and been the source of so much discussion, as the one now under consideration. Theory after theory has been framed, each in its turn to live for a while, and then give way to some other, either more ingenious, or fostered and protected with more talent and per- tinacity by its author. To review the various notions that exist on this subject would be a task as irksome to the in- quirer as it would be unprofitable to the student of pathologi- cal anatomy. At every step the mind would be bewildered with idle conjecture, and at the close of the investigation it would be no better off, so far as real and substantial informa- tion is concerned, than at the outset. We can only express our regret that so much time should have been misspent, so much talent wasted, in the construction of hypotheses, which, although sometimes plausible, do not, in the majority of in- stances, embrace a single well-ascertained fact to repay us for the trouble of examining them. Pathological anatomy is emphatically a science of observation and induction : in pur- suing our inquiry, we shall therefore limit our remarks to a simple analysis of what is known respecting it; referring such of my readers as are fond of speculative reasoning to the va- rious works that have been published on the subject within the last two centuries. He will there find a melancholy illustration of the fact that genius, however often it has wan- dered in quest of truth, has rarely succeeded in detecting it. The symptoms usually enumerated as marking inflamma- tion are redness, heat, pain, and swelling. These signs, CHAP. I.] SYMPTOMS. 29 however, are not constantly present, and, as might be sup- posed, they are liable to vary according to the nature of the exciting cause and the character of the part affected. But these are not the only circumstances which occur in inflam- mation : in every case there is a perversion of the vital actions, attended with an altered state of the nutritive and secretory functions. To affix to these several conditions their respective value, it will be necessary to allot to each of them a considerable share of attention. Most writers, it seems to me, have attached too much importance to some of them, and too little to others; whilst they have entirely overlooked the fact that they are always greatly modified by the nature of the tissue in which the malady, of which they are the indices, is located. If we regard the four phenomena, redness, heat, pain, and swelling, referred to above, as being essential to the process, it will be at once perceived that there can be but few inflammations; and we shall therefore be obliged, in describing diseases, to invoke other names, such as irritation and fever ; a blind adherence to which has un- fortunately tended too much to retard the progress of patho- logical science. Boerhaave enumerated one hundred and fifty varieties of fever: had he enumerated a thousand more he would have been much nearer to the truth, for he might then have specified nearly every form of inflammation, whether occurring in the external parts of the body, or in the interior organs. The word " fever" is a conventional one, and is employed to designate not the nature or seat of a disease, but simply the phenomena which it manifests. So also with the term irritation. Mr. Travers and others have written extensive treatises on this subject; but have they pointed out any thing concerning the essential character of this disease ? have they told us any thing of the peculiar condition of the nervous and vascular systems which accom- panies it? So far as I am acquainted with their labors they have not done this ; and yet men continue to talk about irritation, with its numerous varieties, as if they had the most perfect knowledge of its nature, seat, causes, and symptoms. A course such as this cannot but have a most dangerous ten- dency in practice; for what one physician describes as a fever, another will consider simply as an irritation, a third as an inflammation, and in this way no principles can ever be introduced as standards of treatment. The practice of medi- 30 INFLAMMATION. [CHAP. I. cine must continue to ebb and to flow with every tide of professional opinion. The time, however, cannot be far off, when the term fever must be entirely discarded from our books, and diseases named according to the tissues which they implicate. Then, and not till then, can it be expected that the laws of de- ranged action will be properly interpreted, or fully compre- hended. All diseases, I feel confident, will ultimately be found to have a local origin and habitation ; and if this should ever be proved to be true, the whole class of febrile maladies, with its hundred varieties and subdivisions, will cease to have a place in our medical treatises. The artificial nosology of Sauvages, of Hoffmann, Cullen, Hosack, and a host of minor worthies, has had its day; its authority is at an end, its sceptre is departed ; philosophy has usurped its place, and derides its aid. For the mighty changes which have been effected, and which are still going forward, in relation to the doctrine of morbid action, we are mainly indebted to a pro- found cultivation of pathological anatomy, which, since the time of Bichat, a period of scarcely thirty years, has advanced with such rapid strides, and reduced the healing art to a de- gree of certainty, which could scarcely have been anticipated. But this is a digression. The redness of an inflamed part presents various shades, from the slightest rose to the deepest purple. There are some tissues which naturally contain little blood, or which convey only serosity, and these, of course, are never much dis- colored when affected with disease. The tendons, ligaments, and cartilages are seldom reddened, no matter what may be the intensity of the inflammation. In the fibrous membranes, such as the pericardium, the dura mater, and sclerotic coat of the eye, the discoloration is usually of a lilac or purple hue, with a shade of blue. In the mucous lining of the alimentary tube, the redness, in the early stage of the disease, is bright and florid, like that of arterial blood ; but, as it progresses, it often assumes a dark violet, or black appearance, especially when it is about to pass into gangrene. A striking exempli- fication of the truth of this remark is afforded by the mucous membrane of the fauces in the malignant form of scar- latina. In the beginning of this disease, the tonsils and ad- jacent parts are of a bright red, which is often, in the course of a few hours, converted into a deep purple. In the skin, the redness is sometimes of a scarlet color; at others, it has CHAP. I.] REDNESS--HEAT. 31 a yellow tinge, with various shades of mahogany. The yellow color is most commonly witnessed along with derange- ment of the liver; hence the frequency of its occurrence in the latter stages of erysipelas and anthrax. In inflammation of the pleura and peritonaeum, the redness is, at first, of a lilac hue; afterwards of a scarlet, brownish, or violet. In the ar- achnoid there is rarely, if ever, any perceptible discoloration. Inflammation of the spleen and liver is attended with a purple hue : when the brain is affected, the color is generally rosaceous, cineritious, or like the lees of wine. The salivary glands are usually of a pink complexion ; the kidneys, of a deep violet; the testicles and ovaries, of a reddish yellow. In the lungs the color varies from the slightest rose to the deepest purple. The redness is generally greatest at the centre of the in- flamed part, from which it gradually diminishes in intensity until it reaches the natural standard of the tissue or organ in which it is located. It may be superficial or deep-seated ; circumscribed or diffuse ; arborescent or capilliform : punctu- ated or blotch-like. In some instances, as in the lining mem- brane of the arteries, the color is uniform, having the appear- ance as if it were dyed into the part. Whatever form it may assume, the immediate cause of it is an unnatural influx of blood into the capillaries, — the red globules being admitted in much greater numbers than in the sound state. So long as the circulation in these vessels is carried on vigorously, the redness in many of the tissues will be of a bright scarlet tint; but no sooner does the blood begin to stagnate, than the part assumes a darker hue, from some chemical change, probably, which the fluid experiences under such circumstances. When a part is inflamed, is there really a preternatural devel- opement of heat ? Mr. John Hunter thought there was not; and, in corroboration of this opinion, he adduces some exper- iments which he performed on the inferior animals. He made a wound in the right side of the chest of a dog, and, pushing the thermometer in contact with the diaphragm, ascertained that the temperature of the part was 101°. A large dossil of lint was then put into the opening, and its surface covered over with adhesive strips. On the following day, when the parts were in a state of inflammation, the foreign substance was re- moved, and the instrument being again introduced, the heat was found to be exactly the same as before, namely, 101°. Similar experiments were made on the rectum and vagina of 32 INFLAMMATION. [CHAP. I. an ass, with the same results. There would thus seem to be no real increase of temperature. As a general r"le, this is no doubt the case. Nevertheless, it has been clearly ascer- tained that, under certain circumstances, the reverse obtains. The difference is certainly not so great in the external as in the internal parts of the body. Yet here there is reason to believe, that the temperature of the inflamed structure is frequently higher, by several degrees, than that of the blood. In the natural state, the average heat of this fluid, as I have ascertained by numerous experiments, is 96°, whereas, in disease, the thermometer sometimes falls as low as 92°, or rises as high as 104°.* Every one knows how extremely hot the breath is in in- flammatory affections of the throat, which can only be ex- plained on the assumption that there is a partial increase of temperature. That the heat of the body, like every other physical endowment, is liable to be modified, is a fact which has been clearly established by the researches of physiolo- gists. Sir Everard Home states that the oviduct of a frog ready to spawn, is two degrees hotter than the heart; and it is asserted by Dr. Granville, that, during labor, the tempera- ture of the uterus sometimes rises to 120°, — the elevation appearing to bear a direct proportion to the action of the organ. A similar phenomenon has been observed to occur in plants. M. Huber found that, when the heat of the atmos- phere stood at 21° of the centigrade thermometer, the in- strument surrounded with spadices of the arum cordifolium, during the process of fecundation, rose as high as 42°. f From the foregoing facts, it clearly appears that there is occasionally a considerable extrication of heat, even when there is no inflammation, or when there is merely a slight approximation towards it. The subject of animal heat is still somewhat enveloped in doubt: that it is dependent, in great measure, upon the nervous system, appears, however, sufficiently obvious ; and if this point be conceded, no diffi- culty will be in the way in accounting for the alterations of temperature which occur in different states of the body. A deranged state of the nervous function would be accompanied, of course, with a corresponding modification of the heat of the part, whether this was higher or lower than the natural stand- ard ; and this, indeed, is precisely what happens when in- * See " The Western Medical Gazette," vol. i. t Ellis on Respiration, p. 204; also, Mayo's Physiology, p. 79, 4th ed. CHAP. I.] SYMPTOMS--PAIN. 33 flammation is seated in parts remote from the central organ of the circulation. In cases of erysipelas, furuncle, and an- thrax, the thermometer has been observed, in numerous experiments made since the time of Mr. Hunter, to rise as high even as 107°. Similar results have been noticed in tetanus and acute rheumatism. There can, therefore, be no doubt whatever, as was before intimated, that, in certain cases of inflammation, whether occurring in the interior or- gans or in the external parts, there is a real augmentation of temperature, over and above what is observed at the heart, the great fountain of the circulation. In some parts of the body, such as the ligaments, bones, cartilages, fibrous membranes, and tendons, the extrication of heat must necessarily be very slight. Pain is one of the most important symptoms of inflamma- tion. Like redness, it varies in degree according to the nature of the affected part. As a general rule, it may be stated, that it is most keenly felt in those structures which are most liberally endowed with vessels and nerves. There are some tissues which, in the healthy state, are perfectly void of sensation, but which are exquisitely sensitive when laboring under disease. Thus, for example, a sound bone may be sawed, rasped, and even burnt, without the animal evincing the least uneasiness ; but no sooner does it become inflamed than it gives rise to the most excruciating torture, leading often rapidly to hectic, with its whole train of evils. «. Similar phenomena occur in the fibrous membranes, the ten- dons, ligaments, and cartilages. In regard to the different viscera, it is a singular fact, that they generally experience much more pain when their coverings are affected than when their proper structure is involved. In hepatitis, the inflam- mation often proceeds to a most destructive extent before the individual is aware of his danger. Cerebritis is seldom so painful a'malady as arachnitis; and a pleuritis, it is well known, is invariably attended with more suffering than a pneumonitis. The degree of consciousness evinced by the mucous mem- branes, in a state of inflammation, is subject to much variety. In some situations the pain is excessive, whilst in others it is literally latent, — the disease proceeding in its work of disor- ganization without giving the individual, so to speak, the slightest intimation of it. In pulmonary phthisis, nothing is more common than to find ulcers in the ileum and colon, 5 34 INFLAMMATION. [dlAP. I. sometimes of great size, where there was no sign whatever of their presence during life. It is a singular fact, in relation to this subject, that the pain is usually much greater when the inflammation is seated at the extremities of the mucous membranes, or at their junction with the skin, than when it involves the intermediate points. Bichat has endeavored to explain this difference, with perfect success, as I conceive, by referring it to a difference of organization. The mucous lining of the intestinal tube, and of the air-passages, which often manifests very little consciousness when inflamed, receives its nerves almost entirely from the ganglionic sys- tem ; whereas the reverse is the case with the conjunctiva, the fauces, the urethra, and urinary bladder, the vagina and rectum, these parts being liberally supplied by filaments derived from the cerebro-spinal axis.* Not only does the pain vary in degree, but also in its character. In the cellular tissue it is acute and pulsatile ; in the pleura, sharp and lancinating ; in the lungs and glandular viscera, obtuse and heavy ; in the skin, prurient and smart- ing ; in the bones, dull and gnawing. Sometimes the pain is persistent, sometimes intermittent, sometimes periodical; but, what is more remarkable than all is, that it is not unfre- quently felt at parts very remote from the one originally and mainly affected. We have a familiar instance of this pecu- liarity in the hip disease of children, in which the earliest symptom complained of is pain in the knee. In hepa- titis, the right shoulder is often the seat of the suffering ; in cystitis, the head of the penis. We are sometimes enabled to account for this by the direct nervous commu- nication, but more frequently the matter is entirely inexpli- cable. When inflammation is about to pass into suppu- ration, the pain usually becomes throbbing, and the pa- tient is seized with shivering, with fever, and, in some instances, with delirium. After this process is fairly estab- lished, it almost always diminishes in intensity, or even wholly subsides. Pressure generally increases the pain, and in some cases the slightest touch of the finger produces intolerable suffering. The proximate cause of this symptom has been variously accounted for. It is usually supposed to be owing to the unnatural influx of blood, the increased size of the capilla- * See Bichat's General Anatomy; also, Horner's Pathological Anatomy, p. 81. CHAP. I.] SYMPTOMS--SWELLING. 35 ries, and to the quantity of effused fluids, which compress, it is said, the delicate nervous filaments of the part concerned. This seems to me, however, to be taking only a partial view of the case. To complete the theory, it is necessary to assume that the nervous filaments themselves are affected, altered, or deranged, independently of the causes just ad- verted to ; and in this idea there is nothing that is in the least repugnant to the laws of pathology. What the precise nature of the change is, we cannot, of course, define ; nor is this a matter of much importance. The effect of augmented circulation in producing aug- mented sensibility, is strikingly evinced in what occurs in inflammation of the hand. If the part be allowed to hang down, severe throbbing pain is instantly felt, which is as instantly relieved, in many cases, by putting the limb in an elevated position. Cold applications, by constringing the vessels, lead to the same result, and hence their beneficial effect in the treatment of external inflammation. The fourth and last symptom of inflammation, which has been particularly specified by writers, is swelling. This is occasioned partly by the enlargement of the vessels, but chiefly by the effusion of serosity, lymph, blood, or pus, into the cellular tissue. In its degree it varies according to the laxity and vascularity of the part concerned. It is always well marked in the subcutaneous cellular substance, whilst the skin itself is generally little if at all affected by it. In- flammation of the serous and fibrous textures, the ligaments, tendons, muscles, cartilages, and bones, is usually unattended with swelling. The same remark is applicable to the inter- nal viscera. The mucous membranes are rarely the seat of tumefaction. Hitherto, this symptom has been chiefly no- ticed in the vulva, at the mouth of the larynx, and in the conjunctiva of the eye. Although the swelling generally comes on gradually, yet, in some instances, it proceeds with astonishing rapidity, at the same time that it spreads over a large extent of sur- face. The bite of the common bee, wasp, hornet, yellow- jacket, and rattlesnake, is often attended with the most frightful tumefaction, which makes its appearance sometimes in a few minutes, and speedily diffuses itself over an entire limb, or even over the whole body. From the hasty survey which has been taken of these symptoms, we are authorized to conclude that they are by 36 INFLAMMATION. [CHAP. I. no means entitled to the stress which has been generally placed upon them by writers. In many instances there is an entire absence of at least one or two of them, and yet the part is absolutely in a state of higher inflammation. How often does it not happen, that enteritis is high up, and goes on to destructive disorganization, without even the slightest indication of its presence ? In arachnitis, the only symptom, frequently, is merely a severe cephalalgia, with delirium and partial paralysis. The patient dies, and, on examination, the membrane is found to retain its natural thinness, and to be as free from injection as in the sound state. In such a case, should there be but little effusion of serum and fibrin, a super- ficial observer might conclude that there never had been any inflammation, or that what he saw was the result solely of irritation. The injurious tendency which such a mode of procedure would exert on the practice of medicine is too obvious to require any comment in this place. In reasoning- on this subject, the physician should constantly bear in mind the important fact, that the symptoms which have been enu- merated above, although they are frequently all present, are not necessarily so, and that the absence of some of them is not a sufficient proof that there does not exist inflammation. By such course alone can he expect to escape error. Besides these phenomena, there is always, in well-estab- lished inflammation, a perverted state of the vital action. In none of the tissues is this state, perhaps, ever entirely absent; yet, as might be expected, it is much more conspicuous in some than in others. It is sometimes, indeed, the only symp- tom present, or the only one which can be recognized. In gastritis, the only manifestation of which is frequently irrita- bility, without heat or pain, or uneasiness on pressure, the digestive function is entirely suspended, gastric juice is no longer secreted, and the organ is oppressed by the mildest arti- cles of food. In the duodenum the process of chylificatino is interrupted, retarded, or perverted; in the liver, bile is either no longer deposited, or it is furnished in small quantity, and vitiated in quality. In high degrees of inflammation of both kidneys, there is sometimes a total want of urine, and the individual dies under all the symptoms which characterize the retention of that fluid in the bladder. It should be ob- served here, that, as a general rule, this derangement of the functional action is always greatest when the irritation is at its height, and that, from this period on, it gradually dimin- CHAP. I.] SYMPTOMS. 37 ishes until the disease subsides. When the office of an organ is to receive some external impression, it does either not so at all, or very imperfectly. The inflamed eye is no longer able to take cognizance of light; the schneiderian membrane does not notice odors ; and the ear is incapable of distinguish- ing sounds. When the brain is affected, the intellectual faculties are deranged, and the individual raves with deliri- um, or lies like an automatic mass, dead to all surrounding impressions. The function of absorption is often very much impaired in this disease. A solution of strychnine applied to an inflamed serous membrane, as the pleura, will not. result in any injury to the animal, or only in a very long time after the contact has been effected. In some experiments made by Dr. Gen- drin, of Paris, and which I shall hereafter notice more par- ticularly, prussic acid was applied with impunity to the conjunctiva of the eye, the schneiderian membrane of the nose, and the mucous lining of the vagina, which had been previously inflamed by hot oil and tincture of cantharides. Notwithstanding the results of these experiments, correctly stated, no doubt, by the French philosopher, experience daily teaches us that, whilst some substances are rejected by the organs and tissues, when in a high state of inflammation, there are others, the absorption of which is still, to a certain extent, carried on. In the stomach, for example, mild dilu- ent drinks, such as gum-water, slippery-elm tea, or arrow-root, are rapidly conveyed into the circulation, and are usually employed more or less by the practitioners of different coun- tries. If the quantity given, however, be so great as to oppress the affected organ, absorption will cease, and the fluid will be ejected. In the serous cavities, nearly the same circumstance is observed. When the fluid that is effused in these situations exceeds several quarts, the absorbents appear to be incapable of taking it up, and the surgeon is obliged to evacuate it. Acetate of morphia, applied to a piece of skin that has been inflamed by a blister, will tranquillize the sys- tem nearly in as short a period as when it is introduced in the ordinary way. Not less remarkably altered is the nutritive function. If an organ remain for a considerable time inflamed, the parti- cles which are requisite for its growth and nourishment are withheld, and, in consequence, it gradually sinks into a state of atrophy. In more rapid cases, the part retains its natural 38 INFLAMMATION. [CHAP. I. bulk, but undergoes a change of color and consistence,, from the imperfect admission of blood, and from some derange- ment of the molecular structure. This state is remarkably conspicuous in several of our organs and tissues, and will be described hereafter under the name of softening, mollescence, or ramollis sement. The next subject which we have proposed to discuss is the seat of inflammation. That this is in the capillary vessels is a fact concerning which there exists, I believe, no dispute. Of the nature of the vessels themselves, however, different views have been expressed by anatomists, and it will be necessary, therefore, before proceeding further, to examine briefly their situation, structure, and functions ; for in this way alone can we expect to throw any real light upon the nature of the present disease. The capillaries are those minute tubes which are every where interposed between the arteries and the veins. It was at one time imagined that they formed a distinct set of ves- sels by themselves, perfectly independent of the -rest of the vascular system, — an opinion which had been abundantly dis- proved by the researches of modern anatomists. It is now well known that they not only communicate directly with the arteries and the veins, but likewise 'that they are, as it were, merely so many prolongations of them. What their precise structure is we have no means of determining; nor is it known where the arterial capillaries terminate, or the ve- nous begin. The transition is too gradual, perhaps, to enable us ever to arrive at any positive conclusion in relation to the subject. The walls of the capillaries, as may be imagined, must be extremely thin, delicate, and transparent, otherwise it would be much easier to discern them. Bichat states that they are formed entirely out of the inner arterial and venous mem- brane, the other tunics being excluded, as he alleges, from their composition. An opinion precisely similar to this is advanced by Beclard. He asserts that the parietes of the ca- pillaries are scarcely to be distinguished from the substance of the organs in which they are situated, and thence draws the inference that they are rather formed out of this substance than that they possess walls of their own, acknowledging, however, at the same time, that it is not impossible that the internal tunic of these vessels is uninterruptedly continued from the arteries to the veins. Admitting, as we have already CHAP. I.] ITS SEAT. 39 done, the utter impossibility of determining the precise point at which the arterial tubes in question terminate, and that at which the venous tubes commence, it would seem that the doctrine of the two French anatomists is entirely too exclu- sive in its bearings to entitle it to our confidence and regard. It is true, neither dissection nor microscopic observation can afford us much aid in solving the difficulty ; for the vessels are altogether too minute to enable us to investigate their structure with any degree of accuracy; still, where these means fail us, we are warranted in going to analogy, and in availing ourselves of its assistance. Taking it for granted that the privilege above alluded to properly belongs to us on the present occasion, let us extend our examination to other tubular structures, and see if we cannot find a more philosophical method of disposing of the question than that resorted to by the French anatomists. Let us take the excretory duct of the liver, and follow it along its ultimate ramification in the organ whose secreted fluids it is intended to carry off from the system. In the early part of its course it consists, plainly enough, of two tunics, which, as they extend into the substance of the viscus, become so excessively attenuated that it is quite impossible not only to separate them from each other, but even to distinguish them from the surrounding textures. Now that the inner mem- brane is prolonged as far as the very point at which the tube terminates, or rather where it takes its origin, no one can for a moment doubt, for the bile is a highly acrid fluid; and hence nature, in order to guard against suffering, has wisely furnished the canal with a mucous lining. But is it reasona- ble to presume that, because we can no longer discern the external tunic, it must necessarily be wanting? Is it not more philosophical to suppose that both membranes exist, than to say that one is preserved and the other lost ? This conclusion involves nothing that is either absurd or improba- ble ; and, although not founded on actual observation, it is much more in conformity with sound anatomy and physiolo- gy than any other that has been framed in relation to the subject. If, now, we apply this mode of reasoning to the ca- pillaries, it will at once be perceived that the theory of Bichat and Beclard is untenable ; and that these vessels, instead of possessing, as they imagined, only one tunic, have precisely the same number as the arteries and veins, between which they are situated. If this idea be adopted, it follows, as a 40 INFLAMMATION. [CHAP. I. necessary corollary, that the capillaries are nourished and animated, like the rest of the vascular system, by vessels still more minute, and by nerves so excessively delicate as to elude even the most powerful microscope. Viewed in reference to their caliber, the capillaries are di- visible into two classes. The one embraces those minute tubules which, though invisible to the naked eye, are found, when examined with the microscope, to be capable of carry- ing a continuous stream of blood, so as to give the part in which they are located a red appearance ; the other includes those delicate vessels, the cavity of which is so small as to admit only a single globule at a time, and which it is ex- tremely difficult to detect even with a good magnifier. By reflecting for a moment on the size of the red particles of the blood, estimated by most writers to be about the three thou- sandth part of an inch, the reader will be struck with the great tenuity of these vessels. That the capillaries do not abound equally in all the organs and tissues, is a fact which was rendered sufficiently obvious when speaking of the phenomena of inflammation. The parts which form the basis of the skeleton, together with the tendons, the cellular substance, the epidermis, nails, and hairs, have, comparatively, few of these vessels after the body has attained a certain degree of developement. In the early stages of life, however, most of these structures are highly vascular, and can be readily injected. The serous membranes appear to possess very few capillaries; in the healthy state, in fact, none can be discerned in them; yet, when inflamed, they are rendered highly vascular, and thousands of minute ves- sels, which before were invisible, are now perfectly distinct, giving the affected part a beautiful reddish aspect. The capillaries abound in the mucous membranes, the skin, the liver, spleen, lungs, and kidneys. They are also very numerous in the heart, the muscles of voluntary life, in the brain, and in the pia mater. Thus situated, and thus constituted, the capillaries form by far the most interesting as well as the most voluminous portion of the vascular system. To it are confided the im- portant functions of nutrition. Secretion, calorification, and perhaps also, at least in part, that of absorption. Whilst the larger vessels perform the office merely of sangui-ducts, it is in the capillaries that the fluid and solid materials are brought into those intimate relations which precede the conversion of CHAP. I.] AGENCY OF VASCULAR AND NERVOUS SYSTEMS. 41 the one into the other, and which are necessary to their vi- tality and support. In inflammation the capillaries play a most important part: blood is sent into them in an unnatural quantity; their action is perverted, and, in consequence, va- rious fluids are poured out which are foreign to the normal condition of the economy. These, however, are not the only structures that are affected. It is highly probable, I think, that the nervous filaments are equally engaged in the morbid enterprise, though this is a point concerning which our infor- mation is extremely slender. The fact is certain that neither of these tissues can be long involved without the other par- ticipating in the derangement. The joint agency of the nervous and vascular systems, in the production of inflammation, has been happily illustrated by the researches of Magendie, Brodie, and Philip. The first of these distinguished physiologists ascertained that, when the opthalmic branch of the fifth pair of nerves is di- vided in the cranial cavity of a rabbit at the Varolian bridge, inflammation is speedily lighted up in the surface of the eye, which eventuates in opacity of the upper segment of the cornea. What is still more remarkable is, that, when the nerve is cut on the petrous portion of the temporal bone, so as to involve the destruction of the ganglion of Gasser, the resulting irritation is not only more violent in degree, but much more deeply seated, as well as more deplorable in its effects, the consequence being nothing less than a complete disorganization of the organ. Analogous effects follow the division of the pneumo-gastric nerves. When these cords are cut high up in the neck, the lining membrane of the air-passage assumes a dark color, the lungs are engorged with black blood, and an abundance of serosity is poured out into the parenchymatous texture, a3 well as into the pulmonary vesicles and the minute branches of the bronchiee. The pleura generally participates in the irri- tation, and there is almost always more or less inflammation of the stomach, with a suspension of the secretion of the gastric juice. The investigations of Mr. Brodie have successfully eluci- dated the phenomena which ensue upon tying the brachial plexus of nerves. Animals that have been subjected to this experiment are seized, in a short time, with inflammation of the integuments of the remote parts of the limb, which gradually progresses until all the soft structures are invaded vol. i. 6 42 INFLAMMATION. [CHAP. I. by gangrene. The results of this experiment enable us to account for certain circumstances that have long since been noticed by practitioners in particular morbid states of the system. It is a remarkable fact that a part affected with pal- sy is much less capable of withstanding the ordinary impres- sions of physical agents, than one receiving its customary supply of nervous influence. A burn in a paralytic person creates much more serious mischief than in one that enjoys perfect health ; and the same is true in regard to blisters and other irritants, the injudicious application of which often leads to the destruction of large portions of the skin and sub- jacent cellular tissue. There is little doubt that the in- flammation of the bladder, which always supervenes upon serious injury of the spinal marrow, is caused in the same way; that is, by the interruption of the natural supply of the nervous influence. In whatever manner parts are deprived of their nervous influence, it is presumable that they are brought under rela- tions somewhat analogous to those of a frozen limb. The temperature is lowered, the sensibility impaired, the process of nutrition perverted, — in a word, the natural connection be- tween the vessels and nerves is broken up, and hence ensues that series of phenomena known under the name of inflam- mation. Let us pursue this subject a little further. The very first step in the process of inflammation is an altered sensibility of the part, produced by some hurtful agent, which the system makes an effort to dislodge. To effect this, the local impression is reflected upon the cerebro- spinal axis, and through this again upon the heart, which, being sympathetically incited to increased action, more blood flows to the part concerned than it is accustomed to receive, at the same time that the capillaries are perceptibly dilated. Those who maintain that the capillaries possess an inherent contractility, by virtue of which they aid in the circulation, will probably feel disposed to deny the agency of the heart in bringing about this preternatural determination of blood ; to such I Avill only say, that if they will carefully study the subject, they will arrive at a different conclusion. That these vessels do contract and dilate, no one will dispute : for the experiments of Hunter, Wilson Philip, Thompson, Hast- ings, and other writers, have fully decided this point ; all that I contend for is, that the capillaries have no vermicular movement, and therefore they are incapable of carrying on CHAP. I.] STATE OF CAPILLARIES. 43 the circulation without the direct influence of the heart. In the inceptive stage of inflammation, this sympathetic action of the heart is no doubt so slight as frequently to escape the attention of the observer: as the disease progresses, it as- sumes a more distinct character, and can always be easily recognized. The phenomena above alluded to, namely, the preternat- ural influx of blood, and the dilatation of the capillaries, can be easily detected by exciting irritation in the mesentery of a rabbit, the tale of a tadpole, the fin of a fish, or the web of a frog's foot,—parts which are perfectly transparent, and therefore well calculated for the purpose. On viewing these structures with a microscope, in the sound state, nu- merous channels will be observed filled with blood, the red globules of which roll along in the most regular and beauti- ful order. If they be now irritated with spirits of wine, hot water, or diluted acid, the little rivulets just referred to will be found to become dilated, from the manner in which the blood is crowded into them by the heart, which, in order to remove the local difficulty, is excited into sympathetic action. In a few minutes hundreds of vessels, which were previous- ly invisible, will be seen shooting out in different directions, and connecting themselves with the sides of those that ap- peared in the first instance. These are not new channels, but old ones appertaining to the second class of capillaries, which are rendered evident by the intromission of red particles, which are either excluded in the healthy state, or pass along them in so slow and gradual a manner as to elude the eye of the beholder. The little bodies which are thus introduced do not circulate, at first, with the same facility as in the other parts of the body; for, as the dilatation of the little rivulets takes place by degrees, they have to force their way, and hence, after having advanced a short distance, they retreat slightly immediately after each pulsation of the heart, re- bounding, as it were, upon each other. In this manner they travel on, surmounting every obstacle, until they finally reach the corresponding capillary veins, into which, as they are considerably more capacious, they rush, as into a vortex. Such are the initial steps of inflammation. If the process be now checked by the removal of the exciting cause, the phenomena referred to gradually disappear, and the part re- covers its natural tone and condition. If, on the other hand, the inflammation be allowed to pro- nn 44 INFLAMMATION. [CHAP. I. ceed, another series of changes may be witnessed, surpassing, if possible, in point of interest, those we have just described. The circulation now completely ceases ; the blood assumes a dark modena color, and the coats of the vessels are ren- dered so soft as to be liable to give way on the slightest force. With these alterations the healthy functions of the part are suspended: it is red, hot, painful, and tumid ; and its molecular intervals are filled with serosity or coagulating lymph. In this stage of the malady, the capillaries contain thick, viscid, partially clotted blood, which adheres with great tenacity to their inner surface, and opposes an effectual barrier to artificial injection, or to the removal of the fluid by pressure or ablution. In violent cases the blood escapes from the diseased vessels, and, forcing its way along the pellular tissue, forms new channels, through which it afterwards con- tinues to circulate. This interesting phenomenon, which has been frequently noticed by Kaltenbrunner in the inflamed mesentery of the rabbit, is strictly analogous to what occurs in the organization of adventitious membranes,—a subject to which the attention of the reader will be subsequently di- rected. Inflammation, it will thus be seen, is a gradual process, which is preceded and accompanied by certain stages. Of these, three are recognized by Kaltenbrunner. The first he denominates the stage of incubation ; the second, the stage of congestion ,• the third, the stage of inflammation, properly so called. Each of these is characterized by particular phe- nomena, the most important of which have been already de- scribed, in the order, as nearly as may be. in whjch they appear. To this arrangement I can see no special objection: it should be recollected, however, that it is altogether artificial, and that the stages which it recognizes are frequently so blended as to render it impossible to distinguish them from one another. Contrary to what might be inferred from analogy, Kaltenbrun- ner has ascertained the singular fact, that more time is usually required for inflammation to be developed in highly vascular organs, as the lungs and peritonaBum, than in parts in which the circulation is more tardy and less perfect, as the liver and kidney. It is worthy of remark, however, that when the disease is once fairly established, it progresses much more rapid in the former than in the latter of these structures. Another striking phenomenon is the distended condition of the larger vessels leading to the inflamed part. When the CHAP. I.] CONGESTION. 45 disease is at its height, the congestion often extends to a con- siderable distance ; the blood is unnaturally dark, thick, and viscid, and artificial injection is difficult, sometimes impracti- cable. It has been alleged that the larger arteries in the im- mediate neighborhood of the lesion occasionally pulsate with preternatural force and frequency; but this is an assertion which is unsupported by proof, and which is, moreover, in di- rect opposition with every principle of physiology. The intensity of the morbid action is generally greatest at the centre of the inflamed part, from which it gradually, and, in some instances, suddenly diminishes, until it loses itself in the circumjacent textures. Having thus finished the notice which I proposed to take of the anatomical characters of inflammation, it will only be necessary, in concluding this part of the subject, to allude to the principal circumstances which are capable of producing congestion and discoloration of the different organs and tis- sues, immediately prior to, during, or subsequently to, the extinction of life. In a practical point of view, no less than in a pathological, this is a matter of no trifling moment, yet one concerning which there still prevails a great deal of mis- apprehension in. the minds of medical men. The causes under the influence of which congestion and discoloration may be produced before death, are referable, first, to mechanical obstructions, interfering with the free return of the venous blood; and, secondly, to the effects of stimulating agents, introduced into the body either as food, drink, medicine, or poison. The latter of these will be ex- amined in another place, and'it will therefore only be necessary, on the present occasion, briefly to inquire into the character of the former. Whatever has a tendency to interrupt the passage of the blood to or from the heart, must be a cause of congestion in the organ where the accumulation takes place. The obstruc- tion, which may exist in any part of the body, may be pro- duced by a great variety of circumstances, as the presence of a tumor, some morbid deposit, or the obliteration of a large vessel. But the more common source of the difficulty, per- haps, is organic lesion of the heart, particularly of its valves, of the auriculo-ventricular apertures, or of the mouth of the aorta or pulmonary artery, opposing the progress of the blood, and throwing it back upon other organs, which thus receive an undue supply of it. That congestion may, and often is,. 46 INFLAMMATION. [CHAP. I. produced in this manner, is a fact too well known to admit of dispute; but it is by no means so clear that it does not, inasmuch as it is of a permanent nature, give rise to results very different from those we are now contemplating, — in a word, that it does not lead to inflammation, or to what An- dral has termed active hyperaemia. However this may be, it seems to me that pure, uncomplicated congestion, in what- ever parts of the body occurring, must uniformly depend upon one or other of the following circumstances: 1. Ob- struction of the heart and great vessels, by the formation of fibrinous concretions during the last struggles of life. 2. Par- tial paralysis of the heart, disqualifying it, to a greater or less extent, for carrying on the circulation. 3. Asphyxia, whether induced by actual strangulation, the inhalation of deleterious gases, or difficult dissolution in ordinary sickness. The congestion produced by the first two classes of cases is generally partial, and almost always limited to the more dependent situations; that, on the contrary, which results from asphyxia usually pervades the whole body, and is par- ticularly conspicuous in the skin, the conjunctiva, the mouth and lips, in the lungs, the heart, and the great vessels, which are often distended, to their very utmost, with black fluid blood. In either case, the resultant discoloration is of a dull bluish tint, as well as much more uniform than in inflammation. The causes which operate in the production of congestion and discoloration after death, are the gravitation of the blood, and the transudation of this fluid, or of some of its component elements, through the parietes of the vessels. It is a well-ascertained fact, that, with the cessation of life, the blood, in obedience to the laws of gravity, gradually sub- sides to the more depending structures, distending their ves- sels, both large and small, and imparting to them its peculiar color. Under ordinary circumstances, these appearances are most conspicuous in the posterior parts of the body; but ob- servation has fully shown that they may be produced in any situation, laterally, in front, or behind, simply by placing the subject in a particular position, and keeping it there until it - is deprived of its warmth. The congestion thus arising is limited, in great degree, to the veins, which are often as thoroughly distended as if they had been filled with injecting matter: they spread out in an arborescent manner, and are generally traceable to large trunks, which are themselves fre- quently quite full of blood. Their contents are of a dark CHAP. I.] DISCOLORATION AFTER DEATH. 47 modena color, perfectly fluid, or partly fluid, and partly coagu- lated, and easily pressed from one place to another; the re- verse of which, as was before stated, is the case when the congestion depends upon inflammation. At what period the injection begins has not been accurately determined : there is reason, however, to believe that it frequently commences several hours, or even days, prior to dissolution. In the generality of instances, as is well known, the approaches of death are gradual, one organ fails, as it were, after another, and whilst some parts are still actively engaged in the dis- charge of the duties which nature has assigned to them, others have either ceased to act, or have become so crippled as to be able to perform their functions only in a tardy and imperfect manner. Under such circumstances, observation warrants the presumption that the blood, from the feeble im- pulse exerted upon it by the heart, the central organ of the circulation, accumulates in the more dependent parts of the organ, in a mode calculated to produce local congestion, with a corresponding augmentation of color, long before the solids and fluids are consigned to the influence of decompos- ing agents. The structures which are more particularly liable to be affected by this kind of injection, are the posterior portions of the lungs, of the liver, and of the kidneys, for the reason not only that these organs are highly vascular in the normal state, but that the individual usually lies upon his back, both after and for some time previously to death. For the same reason, the skin of the back part of the neck, trunk, and extremities is always much more filled with blood than at the sides or in front, where the cutaneous vessels are comparatively empty. The accompanying discoloration varies with the nature of the affected tissues, from slight rose to deep red, as in the most intense inflammation. Ordinarily, however, it is very faint, more uniform, and diffuse than in disease, and much more easily removed by pressure and ablution. The second cause capable of imparting an abnormal color to the animal textures after death, is the transudation of the blood through the parietes of the vessels. It is a law of the healthy economy that the vessels should retain the fluid which is destined to pass along them without suffering per- meation ; but no sooner is the vital principle withdrawn than the body is brought under the influence of surrounding agents, which speedily change the relations of its various 48 INFLAMMATION. [CHAP. II. component elements, and impress upon them a total alteration of character. Amongst these, the most important, in con- nection with the present topic, is the percolation of the blood through its vessels, and its diffusion through the solids, by which the latter are rendered unnaturally red and moist, as if they had been steeped in some coloring liquid. The redness thus produced, as it almost always depends upon pjtrifactive decomposition, rarely appears within the first four and twenty „ hours after death, unless there is a very high degree of sum- mer heat conjoined with atmospheric humidity. Nor does it occur with equal facility or frequency in all parts of the body: the structures which are soonest and most extensively affected are, the endocardial lining of the heart and the in- ternal tunic of the arteries and veins, where it is often mis- taken for that of inflammation. To this, however, it bears only a very remote resemblance. It is usually a mere scarlet stain, as if it were attached to the free surface of the mem- brane, over which it is generally uniformly diffused, without any particular alteration in the subjacent parts, or any de- posit upon the interior of the tube. Sometimes the redness occurs in bands, patches, streaks, points, or arborescent lines, with intervals retaining the ordinary appearance. The latter variety is frequently observed along the course of the larger veins of the stomach and bowels, in warm, wet weather, when the examination is delayed beyond twenty-six hours. Similar phenomena are occasionally witnessed, under like circumstances, in the skin of the back part of the body, par- ticularly in those regions which are subjected to pressure. Finally, as the process of decomposition advances, the dis- coloration, losing its scarlet character, assumes a muddy, brownish aspect, with various tints of green, and, at the same time pervades, to a greater or less extent, all the softer tex- tures of the body. These changes take place, all other things being equal, much sooner in warm than in cold weath- er, and in full, plethoric individuals, than in such as die in a state of general anaemia. Exposure to the air is another cause of cadavaric colora- tion, which demands brief consideration in reference to the present subject. This variety of redness, which generally begins to appear within a very short time after the removal of the organs from the body, always proceeds with great rapidity in warm weather, especially when the part is brought under the direct influence of the solar rays. The CHAP. I.] DISCOLORATION AFTER DEATH. 49 structures in which it is most commonly observed, are the spleen, liver, kidney, and heart, the internal tunic of the arte- ries and veins, and the mucous membrane of the alimentary tube. In nearly all these situations, the color is of a bright scarlet, like that of arterial blood, and uniformly diffused over the whole, or the greater portion, of the organ in which it occurs. In the stomach and bowels, it occasionally presents itself in small florid specks, as if the surface of the lining membrane had been dusted over with vermilion. Absorption of the oxygen of the air, and the admixture of this gas with the blood, are the causes, undoubtedly, under the influence of which this species of coloration is established. Hence, by exposing the affected organ, for a few minutes, to a gentle stream of water, or immersing it in diluted vinegar, it almost instantly changes its florid appearance, and assumes a dark purple hue, similar to that of venous blood. Such are the varieties of congestion and discoloration, re- sulting from causes which exert their influence during the last moments of existence, or within the first few days after death. Although, in general, easily distinguishable from those of inflammation, yet it must be confessed that the diagnosis is sometimes extremely difficult, if not impossible, so closely do they run into each other. Under such circum- stances, a careful analysis of the symptoms of the case, with the effects of the remedies employed, and an attentive con- sideration of the ordinary products of morbid action, are absolutely indispensable to a correct appreciation of the nature and character of the supposed lesion. Should there be merely some degree of redness, with ramiform injection, traceable to some large venous trunk, unaccompanied by effusion, softening, opacity, induration, thickening, or ulcer- ation, the presumption is strong that these appearances are the result solely of congestion, produced by some one or more of the causes previously pointed out. If, on the other hand, the discoloration and vascularity are associated with some, or all, of the anatomical characters here indicated, it must be concluded that they are dependent upon inflamma- tory irritation, since they afford the best possible evidence of the existence of that lesion. Can inflammatory redness exist during life, and yet en- tirely disappear after death? This is a question, undoubt- edly, of no little moment, in a practical point of view, which will be duly considered when we come to speak of the vol. i. 7 50 INFLAMMATION. [cilAf. I. anatomical characters of inflammation of the mucous mem- brane of the alimentary tubes. After what has been here stated, it will not be expected that we should say much respecting the various theories, or, rather, hypotheses, that have been projected in relation to the proximate cause of inflammation. A few only of the more prominent will be noticed. The first which I shall mention is that of Boerhaave, which supposes that the dis- ease essentially consists in an obstructed state of the capilla- ries, produced by some morbid lentor of the blood, or by the entrance of the red globules into vessels not fitted to receive them. This opinion rested on the belief, that the sanguine- ous particles are remarkably complicated in their structure, each red one consisting of six serous, and each serous of six lymphatic ones, for the conveyance of which three kinds of tubules were imagined, as channels of communication be- tween the arteries and veins. By getting into a wrong vessel, the globules might very readily produce obstruction, and thus excite inflammation. The late Dr. Cullen, of Edinburgh, no less distinguished for his eloquence as a teacher than his ability as a writer, conceived the idea that inflammation was merely a sort of spasmodic contraction of the small vessels, interrupting the passage of the blood. This state, he supposed, was some- times the effect of direct debility; and he imagined, more- over, that there was frequently a peculiar condition of the whole vascular system, which predisposed to this affection, and which received from him the name of the phlogistic diathesis. This theory, notwithstanding the favorable man- ner in which it was for a long while regarded, has the disadvantage of being unsupported by a single fact. So far from the vessels being contracted in inflammation, it is now well ascertained, as was before mentioned, that they are invariably dilated, and that, in consequence of this, they always admit an unusually large amount of blood, which could not happen were the reverse of this the case. Dissatisfied with the crude conjectures of Boerhaave, of Cullen, and other writers, another theory was proposed by Dr. Vacca, an eminent Italian pathologist, soon after the middle of the last century. In his treatise on inflammation, published at Florence, in 176-'), he maintains the opinion, that this disease invariably results from sanguineous conges- tion, attended with more or less debility of the affected part. CHAP. I.] THEORIES OF THOMSON, HUNTER, AND OTHERS. 51 The first step in the process is relaxation of the capillary vessels, which allow them to be abnormally distended by the blood that passes through them. To this increased quantity of fluid he ascribes the redness, heat, pain, and turgescence, which are always more distinctly marked in proportion to the dilatation of the minute arteries and veins, the violence of the exciting cause, and the natural vascularity of the part concerned. Since the time of Vacca, the theory of diminished power of the vessels has been warmly advocated by a considerable number of pathologists, especially by Dr. P. Wilson, Dr. Hastings, and Dr. Thomson. The experiments which were performed by these distinguished writers, although they are at variance as respects some trifling points, all tend to show that inflammation essentially consists in a weakened action of the capillaries, by which the balance between them and the large vessels is destroyed, and congestion is the result. Opposed to these views, again, are those of Mr. Hunter and Dr. Gendrin, of Paris. These pathologists have both minute- ly investigated the subject of inflammation in all its depart- ments, and they adopt the belief that the primary cause of the disease is an increased action of the vessels. Amidst such a discrepancy of opinion, it might seem, at first sight, extremely difficult, if not impossible, to arrive at any satisfac- tory conclusion. To me, both views appear to be correct, but not in the sense advocated by their respective authors. In the early stage of the disorder, we have every reason to believe, from the phenomena which are exhibited under the microscope, that the vessels have an augmented action ; sub- sequently, however, when the disease is fully established, the capillaries are partially paralyzed, the blood ceases to circulate, the function of nutrition, of secretion, and absorption, is in- terrupted, and every thing indicates the diminished power of the part. Finally, inflammation ends in different ways. When it gradually subsides, without any untoward occurrence, it is said to terminate in resolution. In some cases it relieves itself by an effusion of serum and of lymph, by suppuration, by hemorrhage, and by softening. At other times, the part loses its vitality; and it is then said to end in gangrene. Philosophically speaking, some of these states are merely conditions, not terminations of inflammation. Thus, suppu- ration is absolutely, from first to last, a phlegmasial process ; 52 INFLAMMATION. [CHAP. I. and so of softening, of the effusion of serum, and of the de- position of lymph. It is therefore rather in compliance with professional usage than with the sound principles of patholo- gy, that we should continue to employ this vague expression. If this fact be borne in mind, the reader will not be likely to fall into error. With respect to acute inflammation, the following termina- tions may be recognized : 1. resolution ; 2. effusion of serum ; 3. deposition of lymph ; 4. suppuration ; 5. hemorrhage ; 6. soft- ening ; 7. gangrene. These different terminations constitute merely so many degrees of inflammation. Thus, suppuration indicates a higher grade of action than lymphization, and a milder one than hemorrhage, softening, or gangrene. We might thus construct a sort of phlegmasial scale, the index of which would be the product of the disease, or the mode in which it terminates. Chronic inflammation has fewer terminations or conditions than the acute. The principal ones may be thus stated : 1. ulceration; 2. granulation; 3. cicatrization; 4. induration. Besides these conditions, chronic inflammation may occa- sionally be attended with hemorrhage and softening, or even terminate in gangrene. These occurrences are, however, ex- tremely rare, and are seldom witnessed except when there is a sudden supervention of acute phlegmasia. Let us now pro- ceed to describe these different states, in the order in which they have been enumerated. CHAPTER II. Of the Effusion of Serum. Occurs, to a greater or less extent, in almost every Inflammation. — CEdema, An- asarca, arid Dropsy. — Color, Consistence, Quantity, and chemical Composi- sition.— Usually the result of a mild degree of Inflammation. — Conclusion. An effusion of serum, to a greater or less extent, occurs in almost every inflammation. There are some varieties of this disease in which, indeed, it forms the chief if not the only symptom. It is seen most frequently in the interstices of the cellular tissue, on the surface of the serous membranes, in the parenchymatous texture of the lungs, in hydatids, and serous cysts. There are some structures which, from their dense and compact nature, do not seem to allow of this infil- tration. Of this description are the liver, kidney, womb, prostate gland, and spleen, together with the tendons, apo- neuroses, ligaments, cartilages, and bones. Very little serum is effused in the brain, spinal cord, nerves, vessels, and mu- cous membranes. With respect to the latter, the parts most frequently and extensively affected, are the margins of the glottis, the conjunctiva, and the nymphae. Considered in reference to the subcutaneous cellular tissue, the effusion oc- curs much more frequently in the inferior extremities than in the superior; in the genital organs than in the trunk; in the eyelids than in the face, head, or neck. The lymphatic ganglions and the inter-fibrilar substance of the muscles are often the seats of considerable serous infiltrations, especially in weak cachetic subjects, or those who are worn out by se- vere and protracted diseases. Large quantities of this liquid are frequently discharged by the mucous membrane of the bowels, in diarrhoea and cholera. In the skin the most strik- ing exemplification of this effusion is seen in the vesication of an ordinary blister, in burns and scalds, and in the eleva- tion of the cuticle which announces mortification. Various names are employed to designate these effusions. When the fluid is poured out into the interstices of the sub- 54 EFFUSION OF SERUM. [CHAP. II. cutaneous cellular tissue, it forms a smooth, pale, glossy swelling, which pits on pressure, and is seldom painful, un- less there be considerable inflammation. This is called aide- ma. When this affection occurs in the extremities, it gen- erally varies with the position of the body, being very slight or entirely absent when the limb is elevated, most promi- nent when it is dependent. The reason of this is obvious. In many cases the fluid is not developed in these parts, but gravitates thither from other regions, making passages for it- self through the cellular tissue. As meaning the same thing, the term anasarca is sometimes used. The word, however, it should be observed, is generally employed in a more com- prehensive sense, to designate the effusion of serum into the meshes of the cellular tissue, in whatever part of the body this structure exists. When the collections occur in the se- rous sacs, they are called dropsies. These, again, are named according to the particular cavities in which they are found. Thus, an accumulation of water in the arachnoid is denom- inated hydrocephalus ; in the spinal canal, hydrorachitis; in the pleura, hydrothorax ; in the pericardium, hydropericardi- um ; in the peritonasum, hydroabdominalis; in the vaginal tunic, hydrocele ; and hydrarthrosis in the articulations. The color and consistence of this fluid are liable to consid- erable diversity. In some situations, as in the arachnoid membrane and subcutaneous cellular tissue, it is clear and limpid, like the purest spring water; in others, it is more or less viscid, of a pale yellowish tint, and contains flakes of fibrin. A lemon-colored serum is not of unfrequent occur- rence in the chest, the vaginal tunic of the testicles, and in the articulations of the extremities. Occasionally the fluid is of a pale reddish color, from the admixture of haematosine, and cases are witnessed where it has the aspect and consist- ence of coffee-grounds. The latter variety is particularly common in inflammation of the peritonaeum, caused by stran- gulation. In jaundice, it sometimes contains a yellow color- ing matter, like that of the bile : it has also been found to be impregnated with cholesterine and uric acid. Of the chemical composition of this fluid very little was known until within the last thirty years. For the most im- portant information concerning it, we are principally indebted to Dr. Marcet, of England, to whom animal chemistry gen- erally is under so many obligations. This distinguished phy- sician has developed the interesting fact, that serous liquids, CHAP. II.] CHEMICAL COMPOSITION. 55 no matter what may be the structure of the organ or tissue furnishing it, is essentially of the same nature. According to the statement which he has published in the second vol- ume of the London Medico-Chirurgical Transactions, the prevailing animal substance is albumen, with a minute quan- tity of muco-extractive matter, which is uncoagulable, but soluble in water and other fluids. In none of his experiments did he detect any gelatine. The proportion of albumen is subject to much variety, being very abundant in some situa- tions, and almost entirely wanting in others. The principal saline ingredients are soda and potash, in the form of muriates and sulphates, with phosphate of lime, iron, and magnesia. The specific gravity of the effused liquids is generally less than that of the serum of the blood, and their coagulability is always in direct ratio to the amount of albumen. In the fluid of hydrocephalus and spina bifida the quantity of this substance is frequently so small as scarcely to be rendered visible by heat, alcohol, or acids. From all, then, that we know concerning this matter, it may be legitimately inferred that it is perfectly identical with the serum of the blood from which it is derived, differing from it only in specific gravity, and in the relative proportion of its constituents. The amount of fluid varies, under different circumstances, from a few drops to several gallons. The rapidity with which it is poured out, even in large quantity, is sometimes surprisingly great. In persons bit by venomous serpents, the whole body often attains an enormous size in the course of a few hours from this source, and some of the internal organs are literally inundated. Usually, however, the effusion takes place more gradually, and, as might be inferred from our pre- vious remarks, never to any extent until the inflammation has attained a certain point. Let me be comprehended. In the serous membranes, which afford this fluid in greatest abundance, one of the first things that happens, when they are irritated, is the suspension of the natural secretion, which is restored and augmented only after the violence of the in- flammatory impulse has somewhat abated. If this should not occur, lymph, not serum, will be furnished, either alone or combined with pus or blood ; or the individual, the subject of the disease, will perish from its effects; or the part will fall into a state of sphacelus. It has been already hinted that serous effusion is the result of inflammation, usually of a very mild grade. That this is 56 EFFUSION OF SERUM. [CHAP. II. true, as a general rule, very few will attempt to dispute; the exceptions, if there be any, are certainly very rare, and have not hitherto been satisfactorily pointed out. A few facts, clearly and concisely stated, will assist in determining this problem. It has been alleged, in the first place, that serum is occa- sionally effused when there is an obstacle simply in the cir- culation, without any concomitant inflammatory action. It is a matter of common observation with the physician, that ana- sarca of the lower extremities often arises from obliteration of the femoral, external iliac, and ascending hollowvein ; and the face, neck, and arms are frequently loaded with serum from compression of the vessels whose duty it is to return the blood to the right side of the heart. When the portal vein, or any one of its principal branches, is obstructed, abdominal dropsy, or ascites, follows. Contraction of the right auriculo- ventricular orifice, or disease of the valves of the pulmonary artery, impeding the passage of the blood, and compelling it to regurgitate into the inferior cava, produces the same result, together with oedema of the legs and feet. These examples will be sufficient for the subject which they are intended to illustrate. Let us now endeavor to ascertain how far they are dependent upon inflammation, or whether they are the result merely of mechanical obstruction? It is frequently extremely difficult to ascertain the condition of the seat of the effusion by anatomical inspection. In ascites how often does it not happen that there is the most copious accumulation of water, caused obviously by inflammation ! and yet, on exami- nation after death, there is scarcely a well-marked trace of the latter malady. That there are cases, then, of serous effusions, in which the ordinary phenomena of phlegmasia, particularly the discoloration, entirely vanish on the approach of death, or during the last struggles of life, cannot be doubted; indeed, it is not improbable, I think, that there are instances in which this disposition occurs a long time before the individual ex- _ pires. The absence of redness, therefore, does not prove that there was no inflammation; for the existence of this lesion is sufficiently evinced by the presence of the watery accumu- lation, and the opacity of the affected membrane. Should there be, in addition, specks, patches, or bands of fibrin, all doubt on the subject must vanish. Such, then, being the difficulty of recognizing the presence of inflammation, where every symptom during life gives in- CHAP. II.] CAUSES. 57 dubitable evidence of its existence, can it be wondered at that, in the instances above referred to, pathologists should still consider the effusion of serum as the result merely of mechanical obstruction ? The question may now be asked", — can such an obstruction exist, to any considerable extent, without producing a state of parts analogous to, if not really identical with, inflammation ? I would answer, no. Let it be supposed that the obstacle exists in the ascending hollow vein. This vessel is destined to return the blood from the inferior extremities, the pelvis and abdomen, to the right side of the heart. But, failing in the accomplishment of this ob- ject, from the difficulty adverted to, the blood is interrupted in its passage upwards, and congestion of all the vessels, both large and small, is the result. This congestion is not tran- sient, but permanent; and it is scarcely reasonable to presume, judging from our knowledge of the circulation, that this state could exist long without producing an altered condition of the sensibility of the parts affected, attended with more or less redness, and effusion of serosity. The peritonaeum and cellular tissue of the limbs are the structures which receive the brunt of the difficulty, and these are parts, it is well known, which are most liberally supplied with serous capilla- ries. But, it may be said that the effusion may result from perverted action, from irritation, or disturbed function: all this may be true, and yet not in the least invalidate our posi- tion. Every body knows that in inflammation there is per- verted action, or deranged function, with irritation, or altered sensibility. These terms, therefore, if they mean any thing at all, only denote certain conditions — not the cause of these conditions ; as redness, heat, pain, and turgescence are not inflammation, but only so many symptoms of it. The preceding remarks are equally applicable to the wa- tery effusions of the serous textures, which occur in associa- tion with organic diseases of the glandular and parenchymatous viscera. A large scirrhous tumor of the liver, seated so su- perficially as to encroach upon and fret its serous investment, is often attended with ascites, although the portal circulation is in no wise obstructed or embarrassed. In the same manner hydrothorax is sometimes induced by tubercles of the lungs; hydrocele by carcinoma of the testicle; hydrocephalus by heterologous growths of the brain. In all these instances the effusion of water is the result, unquestionably, of inflamma- tion, lighted up in the serous covering of the respective vol. i. 8 58 EFFUSION OF SERUM. [CHAP. II. organs, by the morbid deposit acting in the capacity of a for- eign substance. The dropsical accumulations which super- vene upon scarlet fever, measles, and other eruptive diseases, can be traced, in most cases, directly to phlegmasial irritation of the serous membranes. Taking into consideration the preceding facts, and the reasoning founded upon them, the conclusion is obvious that the effusion of serosity, no matter in what part, organ, or .,__region it occurs, is the result, invariably, of a process analo- gous to, if not strictly identical with, inflammation. This process, we repeat, is often very imperfectly marked, both during life and after death, so that the ordinary phenomena of phlegmasia are in no way manifest to our senses. That this conclusion is fully borne out by the premises, is, I think, sufficiently evident; and we shall, therefore, dismiss the sub- ject, in the hope that what has been stated will have a ten- dency, at least, to arouse the attention of the profession to further investigation respecting it. CHAPTER III. Of Lymphization.* Always >the result of Inflammation. — Physical properties of Lymph. — Quan- tity. — Varieties of Form. — Chemical Constitution. — Period at which the Deposition commences. — Has a tendency to become organized. — How this is effected. —Analogous Tissues. — Use of Lymph as a means of Restoration. — Adhesive Action. If there be still some doubt as to the question, whether effusion of serum is invariably of inflammatory origin, there can surely be none respecting that of fibrin. So true is this,» in reference to the latter product, that it may be assumed as a law, than which there is none more satisfactorily estab- lished in pathological science. Yet, as in the former case, examples not unfrequently occur where the fibrin constitutes the only sign which is to be observed after death, of the pre- vious existence of inflammation. In arachnitis, large quanti- ties of this matter are often poured out, without our being able to detect the slightest redness, opacity, or thickening of the serous membrane. Nevertheless, would it not be the height of absurdity to say that, because any of the ordinary phenomena are wanting, there had been no inflammation ? But we forbear making further comments on this topic, having dwelled upon it, at sufficient length, in the preceding pages. We only beg the reader to remember that the effusion of fibrin, gluten, or coagulating lym,ph, as it is variously termed, is uniformly the result of inflammation, and that it forms, occasionally, the only necroscopic sign which we have of the existence of this lesion. With the appearance of this substance, every one is famil- iar. In the majority of instances, it is of a light opaline cast ; in others, it is of a pale straw color, cineritious, of a * As this term is not to be found in any of our pathological treatises, it is ne- — cessary to observe, that it i~> employed here in the same sense as " effusion of lvmph" or "deposition of fibrin." We say a part is in a state of suppuration when it is secreting matter : with the same propriety we may say that a structure is in a state of lymphization, when it is pouring out lymph, gluten or fibrin. 60 LYMPHIZATION. [dlAP. III. milky white, or reddish, from the admixture of hoematosine. When first deposited, it is soft, fluid, and somewhat ropy. allowing itself to be drawn out into little filaments : after a while, however, as its watery particles are being removed, it assumes greater consistence, and is finally converted, in many cases, into firm, dense structure, having all the attributes of the cellular tissue, fibrous membrane, or even cartilage and bone. The period required for these transformations varies from a few weeks to as many months. Lymph is effused under a considerable variety of forms, depending upon the peculiar shape of the part which supplies it. In the subcutaneous cellular tissue it usually occurs in small amorphous masses, sometimes in disseminated globules. In the larynx and trachea, it accurately moulds itself to those cavities. In the peritonaeum, it forms bands, occasionally of considerable length, which extend from one coil of bowel to the other ; and in the pleura it is commonly laminated. To these statements there are, of course, numerous exceptions, which Avill be particularly adverted to in a subsequent part of the present treatise. The amount of fibrin poured out is subject to much di- versity. As a general rule, it may be stated, that it is fur- nished most abundantly by the serous sacs ; yet, under cer- tain circumstances, large quantities are effused by the mucous membranes of the respiratory and intestinal tubes, as well as by that of the oesophagus and uterus. Happily, however, this substance rarely remains long in these outlets; otherwise the most serious consequences might ensue. As it is, in the trachea it often produces death, by preventing the ingress of the atmosphere ; the lachrymal passages, and many of the minute bronchial canals are sometimes obliterated by it; in the urethra it lays the foundation of permanent stricture; and in the chest, by tying down and compressing the lun^-s, it has been known to give rise to atrophy, or otherwise em- barrass the respiratory function. Considerable quantities of fibrin are not unfrequently found on the inner surface of the arteries, and the largest sized trunks are occasionally obliterated by it. The muscles, fibrous membranes, the tendons, ligaments, cartilages, and bones yield very little when in a state of inflammation. The skin, the veins, and absorbents furnish it also very sparingly. A good deal is generally effused in phlegmasia of the subcutaneous cellular tissue, around abscesses, and upon CHAP. III.] FIBRIN J ITS COMPOSITION. 61 the walls of fistulous passages. With respect to the paren- chymatous and glandular organs, the effusion of fibrin may be said to be in direct proportion to the amount of cellular substance which enters into their composition, being always very small where their structure is dense and compact, more or less copious where it is soft and lax. The chemical composition of this substance, like that of serum, is essentially the same in whatever part of the body it is found. Professor Andral states that in the pleura and peritonaeum it consists exclusively of fibrin : this, however, I presume, is an error, its constituents here as elsewhere being albumen and water, in union with the substance just mentioned. Immersed in alcohol, or a strong solution of cor- rosive sublimate, it becomes dense, firm, and assumes a whitish, shrivelled aspect. In water it is gradually decom- posed, breaking up into small, dirty, rotten-looking fragments, which readily yield under the pressure of the finger. This substance, then, is identically the same with the buffy coat of the blood, being separated from the vessels by some secre- tory process, which rejects the coloring and saline principles pies of that fluid, whilst it permits others to escape along with it. The period at which the deposition of lymph commences is influenced by different circumstances, the principal of which are referable to the intensity of the inflammation and the nature of the affected structure, tissue, or organ. In some experiments which Dr. Thomson, of Edinburgh, made on the inferior animals, a distinct layer of lymph was seen covering the incisions within less than four hours after they had been inflicted; * and in a young man who died last summer of a gun-shot wound, which penetrated the liver and diaphragm, I found both the pleura and peritonaeum extensively coated with this substance, nine hours after the reception of the injury. In many cases there is reason to believe that the effusion in question takes place almost at the very onset of the inflammation, and proceeds with greater or less rapidity until the disease either abates, passes into suppuration, as- sumes achronic form, or destroys the life of the individual. If this substance be allowed to reuiain undisturbed, it man- ifests a disposition, sooner or later, to become organized. The period at which this occurs varies from a few hours to sev- * Lectures on Inflammation, p. 168. Phila. 1831. 62 LYMPHIZATION. [cHAP. III. eral weeks : in some instances, indeed, it never takes place at all. The serous sacs are the situations in which the process is accomplished Avith the greatest ease and rapidity, whilst the mucous membranes are parts in which, if it happen at all, it is effected very imperfectly, aiid only after a long pe- riod. It likewise takes place with much facility in the skin, cellular tissue, and bones, after injuries. How this organization is brought about, is an interesting subject of inquiry, and one which has excited much discussion among pathological anatomists. That it is effected in one of two ways, is sufficiently obvious, — either by the vessels of the natural tissues shooting into it, or spontaneously by powers residing within itself. Proofs are not wanting in sup- port of both views. In removing, for example, a recently formed adventitious membrane, we not unfrequently find that its adherent surface is marked by numerous bloody points, caused evidently by the rupture of the elongated capillaries of the inflamed normal membrane. What renders this supposi- tion more probable, is the fact that the free surface of the se- rous membrane — for it is to this class of textures that these remarks are more particularly intended to apply — is studded with very minute granulations, which are highly vascular, and accurately correspond in their situation with the red dots observable on the attached surface of the new membrane. In process of time, these granulations become more and more distinct, both on the original and on the adventitious struc- ture ; and, by means of a magnifying-glass, very delicate slender vessels, arterial as well as venous, may be seen pass- ing from the substance of the one into that of the other. As the penetrating vessels increase in volume and number, the lymph adheres more firmly to the inflamed surface of the natural membrane, until at length the circulation between them is fully established, being carried on with the same free- dom and vigor as in other regions of the body. The second opinion — that, namely, which supposes the lymph to possess a self-organizing power — ranks amongst its advocates some of the most distinguished pathologists of the last and present centuries; and the facts which they have adduced in favor of their position go far, it must be confessed. in leading us to doubt whether this substance, in whatever form it may appear, is ever vitalized in any other way. They have shown, most conclusively, as it seems to me, that por- tions of exuded lymph contain vessels, and perform the fiiuc- CHAP. III.] ORGANIZATION OF FIBRIN. 63 tions of nutrition, secretion, and absorption, before it is possi- ble to trace the slightest vascular connection between them and the surrounding textures. In the pleura, it has often occurred to me to see as many as three, four, five, and even six distinct layers of this substance, arranged so as to inter- cept cavities of various sizes, filled with serum, flakes of fibrin, pus, or even blood. In some of the cases, the circum- stances were such as to render it perfectly certain, that the developement of these adventitious membranes must have taken place with so much rapidity as to preclude the idea that their organization could be effected through the agency of the subjacent serous structure. There is therefore reason to believe, that lymph possesses, in many instances, an inherent self-creating power, in virtue of which it forms blood which gradually prepares its own vessels. What the precise nature of this vitalizing influence is, we cannot, of course, deter- mine : the difficulty, surely, cannot be solved by invoking the agency of the electric fluid, as has been done by Andral. Of the intimate character of this fluid we know as little as of life itself; and the notion just alluded to is therefore ill cal- culated to enlighten us on a subject concerning which we must necessarily remain forever ignorant. The primordial traces of the organizing process consist, ac- cording to the theory under consideration, in the appearance of a few red dots, which have been happily compared to the " salient point " in the vitelline membrane of the chick, — the fibrin being endowed, as was before stated, with a similar prop- erty of generating blood.* Red furrows, streaks, or lines, are sometimes perceived, shooting out in various directions, which gradually assume the character of distinct vessels, in every respect analogous to those in other parts of the body. In other cases the small sanguineous trains take on a ramiform arrange- ment, and are ultimately converted into real vascular tubes. Examined at an early period of their developement, the trains here adverted to are found, according to Laennec, who has carefully described them, to contain minute filaments of fibrin, permeable at their centre, which soon assume a cylindrical shape, and thus constitute the rudiments of the future vessels. These new channels, composed both of arteries and veins, the latter of which, however, predominate as well in volume * Dr. Adair Crawford, Cyclop. Pract. Medicine, art. Inflammation, p. 765. 64 LYMPHIZATION. [CHAP. III. as in number, gradually extend towards the neighboring parts, with the capillaries of which they finally inosculate, the blood passing freely from the one to the other. It should be observed that, in their mode of arrangement, many of these vessels resemble the vena porta ; that is to say, they consist each of a single trunk, usually of considerable length, from each extremity of which are detached a certain number of branches, twigs, and filaments. Such is an abstract, — too rapid and imperfect an one, I fear, to do justice to the subject, — of those two principal theories that have been advanced in relation to the manner in which this substance is organized, and rendered " part and parcel " of the living system. Both of them are highly plausible and ingenious, and both of them are, perhaps, equally entitled to our confidence and regard. The probability is that neither the one nor the other is exclusively applicable to all cases. To be at all susceptible of organization, it is necessary that the lymph at the time of its deposition should be endued with a certain amount of vitality ; for where this is withheld, it will soon be broken down and converted into puriform matter. When, therefore, the exudation is very feebly vital- ized at the moment of its secretion, it may be inferred that it can become organized only by the vessels of the surrounding textures sprouting into it; whilst, on the other hand, if it be highly impregnated, if I may so express myself, with the living principle, it may be supposed to be capable of effecting this object by its own inherent powers, without any assist- ance whatever from the original structures. Be this as it may, it is impossible to avoid the conclusion that coagulating lymph is susceptible of spontaneous organization. Independ- ently of the facts already adduced, the experiments of John Hunter and Everard Home, in which the vessels formed in a clot of blood were successfully filled with injecting matter, place this subject in a most incontrovertible light. Nothing is known, with any certainty, concerning the nerves of this organized matter. So far as my knowledge extends, I am not aware that any anatomist has succeeded in detecting these structures in the adventitious membranes , that they exist, however, may be legitimately inferred from the fact that they are capable of executing the highly impor- tant function of nutrition, secretion, and absorption, which, but for this circumstance, they could not possibly accomplish. CHAP. III.] TISSUES RESULTING FROM IT. 65 My own opinion is, that plastic lymph, in whatever part of the body it may occur, in its progress towards organization, either generates its own nerves, or receives them from the neighboring tissues, in the coats of the vessels. I am the more inclined to adopt this view from the analogy afforded by some of the primitive textures, as the osseous and carti- laginous, which, there is every reason to believe, obtain their nervous supply in this way. Absorbent vessels also probably exist, and, as I should suppose, in great numbers. Their presence, however, like that of the nerves, is a matter merely of inference, not of actual observation, which has hitherto failed in detecting them. Whether the plastic lymph, when once organized, remains during life, or whether it is partially or totally absorbed, are points respecting which there still exists a difference of opinion. Most generally it maintains its parasitic existence, though occasionally there is just ground for believing that it disappears. This, at least, would seem to have occurred in the interesting case of a maniac, dissected by the late Professor Beclard, of Paris. In some of his paroxysms, this individual inflicted upon himself a considerable number of stabs, several of which penetrated the abdomen. In the most recent, the intestine adhered directly to the wounded spots; in another, evidently of longer standing, the union was effect- ed by a small, narrow band ; whilst in that which was in- flicted first, the bridle was absorbed at the middle, and thereby broken.* Plastic lymph, organized in the manner now described, forms the basis of all the analogous tissues, and the bond of union of divided parts. It may become the seat of inflamma- tion, both acute and chronic; pour out serum, lymph, pus, or even blood; and undergo various transformations precisely in the same manner as any of the natural textures. It should also be remarked here, that this substance is the source of what is termed indurations, and probably, also, of scirrhus and tubercle. The analogous tissues formed, as I have just stated, out of the plastic element of the blood, are nearly as numerous as the natural, to which, as their name imports, they bear the closest resemblance in the threefold respect of physical, * General Anatomy, by Dr. Togno, p. 156. vol. i. 9 66 LYMPHIZATION. [CHAP. III. chemical, and vital properties. The following arrangement includes the different kinds of textures pertaining to this class which have hitherto been described by authors : Cellu- lar ; serous; mucous; cutaneous; vascular, including the erectile; adipous; horny, including the cuticle, hair, and nails; fibrous; fibro-cartilaginous; cartilaginous; osseous. These tissues will be described in their appropriate places. In the mean time, it may be remarked concerning them, gene- rally, that they do not occur with equal facility; that they are more prone to arise in old people than in the young ; and that whilst some most closely resemble the tissues from which they have received their names, the likeness of others is faint and imperfect. It has been already intimated that coagulating lymph per- forms a most conspicuous part in the reunion of divided parts. Without the assistance of this substance, no wound, however trifling, could possibly get well. The little incision made in the operation of venesection would either prove fatal, or become a source of permanent inconvenience and suffering. Ulcers would not heal, and fractured limbs would dangle about "in wild uncertainty." Formerly surgeons seemed to be entirely ignorant of the utility of this substance as a means of repairing injuries, whether occurring in the soft or in the hard parts of the body. It remained for Mr. Hunter to ex- hibit the subject in its true light, by which he created an epoch in the history of our science, amongst the most inter- esting that have occurred. As admitting of the most easy examination, the attention of the reader may be here directed for a few moments to the part which this substance performs in the reparation of wounds of the cutaneous and cellular tissues. If these struc- tures be simply incised, the edges of the cut surface, if kept in close apposition with each other, are united by what was for- merly denominated first intention, or, since the time of John Hunter, union by adhesive inflammation. In a case of this description, the first thing that nature does is to set up a new action in the part; that is, the wound becomes red, painful, hot, and tumid, — phenomena which clearly indicate that her workmen are busily engaged in repairing the injury which has been sustained. Plastic lymph is now thrown out, by which the contiguous surfaces of the incision are gradually and effectually agglutinated together. Whilst this secretion is in CHAP. III.] UNION OF DIVIDED PARTS. 67 operation, the vessels of the part are elongated, and, passing through the bond of union thus set up, they finally inosculate with each other, transmitting thereby the blood through the new substance, which, at the same time, increases considera- bly in firmness and density. Similar changes take place with respect to the nerves and absorbents. Thus the lymph that is poured out becomes a living intermedium; and it is in this way that the restoration of divided parts, no matter what may be their structure, is effected. It should be observed, how- ever, that in order that the process may go on kindly, the concomitant inflammation should not transcend certain limits ; for, where this happens, purulent matter will be effused, not fibrin. This, then, is a point which should always be guard- ed against by the judicious surgeon. It is upon a knowledge of this property of coagulating lymph, that are founded some of the most astonishing im- provements that have been achieved by modern surgery. Amongst these the most remarkable are the operations for tying arteries, in cases of aneurism, so much perfected, if not devised, by John Hunter ; and for repairing mutilated organs by transplanting parts from one region of the body to the other. Much good has also resulted in respect to the treatment of incised wounds, whether produced by accident, by the re- moval of a tumor, or the amputation of a limb. In all these instances it is customary, in every part of the civilized world, with the exception, perhaps, of France, to endeavor, if possi- ble, to bring about union by the first intention ; the surgeon well knowing that if this can be effected he will save him- self much trouble, and the patient no little suffering and inconvenience. When we reflect upon this subject, it is ex- tremely difficult to account for the great apathy and silly hesitancy which the Parisian practitioners exhibit, with re- gard to this plan of treatment, about the propriety of which there ought to be but one opinion. In this respect they cer- tainly are fifty years behind the present state of the science, — a circumstance which is so much the more surprising, when it is recollected that they have decidedly the best schools of pathology in the world. The effusion of lymph is a means which nature sometimes employs to obviate accidents. A striking exemplification of this conservative process is witnessed in cases of tubercular phthisis. In this disease, abscesses generally form in the 68 LYMPHIZATION. [CHAP. III. superior lobes of the lungs: these are sometimes seated quite superficially; at other times they are exceedingly capacious, and extend their dimensions until they make their way com- pletely through the pulmonary tissue, and even the pleura. But does the softened tubercular matter usually escape ? By no means. Long before the event alluded to takes place, in- flammation is set up in the surrounding serous membranes, followed by a copious secretion of lymph, by which a barrier is formed that effectually opposes the extravasation of the contents of the cavity. Similar phenomena occur in ulcera- tions of the bowels, and in abscesses of the abdominal and pelvic viscera. CHAPTER IV. Of Suppuration. Definition. — Organs in which it is most easily effected. — May take place without Solution of Continuity. — Varieties of Form. — Abscesses. — Physical and Chemical Properties of Pus.— Distinguishing Tests. — How produced. A third mode by which inflammation relieves itself is by suppuration. This consists in the formation of purulent matter, and constitutes, strictly speaking, merely the third stage of inflammation, inasmuch as pus is never developed when there is an entire absence of this state. That this position is correct, no one at all acquainted with the subject will doubt. Mr. Hunter, it is true, is of opinion that collections of extraneous matter, as he terms them, may form in various parts of the body, without being preceded by inflammation; but in this notion he has not been followed, so far as I know, by any respectable authority since he promulgated it. This idea, that pus might be formed without previous inflammation, originated, it would appear, with De Haen, a celebrated German physician. He uses the term inflammation as synonymous with ulcerative absorption. Indeed, if any one will take the trouble to peruse the chapter which this great pathologist has published on this subject, he will be struck, at almost every line, with the vagueness of his expressions and the inconclusiveness of his reasonings. In what is called a cold abscess, the formation of which is sometimes the work of months, inflammation has just as much to do as in a phleg- monous boil that is developed in two or three days. The only difference is, that, in the one the process goes on slowly, almost imperceptibly; whereas in the other it proceeds rap- idly, and is accompanied with symptoms so well marked as not to be mistaken by the most superficial observer. But to discuss this topic at any length at the present day, when every thing relating to it is fully admitted, might justly be considered a matter of supererogation; and I will therefore conclude this branch of the subject by laying down the 70 SUPPURATION. [chap. IV. proposition, that the formation of pus, in whatever part of the body occurring, is the result of inflammatory action, either acute or chronic, simple or specific. The formation of purulent matter does not take place with equal facility in all the organs and textures. Of the viscera, those which are most prone to take on suppurative action are the liver, lungs, and brain ; of the tissues, the cellular, the cutaneous, mucous, and serous. In the fibrous textures, the cartilaginous, tendinous, and osseous matter forms with diffi- culty, and is seldom of a thick, consistent nature. Of the mucous system some portions are more liable to be affected with suppuration than others. Thus, it is much more common to find pus in the colon than in the stomach or ileum, in the vagina than in the uterus, in the urethra than in the urinary bladder, in the nose than in the mouth, in the fauces than in the oesophagus, in the bronchia than in the larynx. So, like- wise, in the serous system, suppuration is more frequent in some situations than in others ; as, for example, in the pleura, the vaginal tunic of the testicle, and the lining membrane of the larger joints. In the subcutaneous cellular texture, pus is most readily formed in parts which are remote from the cen- tral organ of the circulation. The blood-vessels do not often suppurate, except when they are wounded; and the same, so far as we know, is the case with the absorbents. The lymphatic ganglions, however, are very frequently affected in this way, especially those of the axilla, the groin, the mesentery, and at the base of the lower-jaw, in persons who are predis- posed to scrofulous disease. The nervous tissue seldom suppurates, and still more rarely the osseous and the muscu- lar. From all these facts we may deduce this axiom, that those structures are most prone to form matter which contain the largest amount of loose cellular substance, and, conversely, that those which possess this tissue sparingly always suppu- rate with difficulty, requiring in general a much longer period, and elaborating a less perfect fluid. It is a singular circumstance that pus may be formed with- out any solution of continuity. We owe to Mr. John Hunter the suggestion of this fact, which, as he states, first occurred to him soon after the middle of the last century, in examining the body of a young man who died of disease of the pleura. It need scarcely be observed that this mode of suppuration is a very common one, not only in all the serous cavities, but throughout nearly the whole of the mucous system. Nor is CHAP. IV.] ABSCESS. 71 it confined to these textures. In the cellular substance, in the lungs, brain, liver, and other viscera, nothing is more frequent than suppuration, without any breach whatever, in the first instance, of continuity. Pus, when first effused, generally appears in the form of distinct globules, which are dispersed through the affected structure, and can be easily recognized by their pale yellow- ish color. As the purulent particles increase in number, they gradually become confluent by the absorption of the part con- cerned, and in this way the matter is at length collected into an abscess. The time required for the formation of an abscess depends a good deal upon the constitution of the patient, the nature of the exciting cause, and the anatomical elements of the various organs. In the lungs, brain, spinal cord, and spleen, death usually takes place before the matter is allowed to concentrate itself into a focus, and hence, in examining subjects who die of acute diseases of these viscera, it is extremely rare to meet with an abscess, even of small size. On an average, the period necessary for the formation of visceral collections of this kind may be stated at fifteen days ; whereas, in the subcutaneous cellular substance, abscesses often make their appearance in less than a week, — sometimes, indeed, in less than forty-eight hours from the commencement of the inflammation. Superficial abscesses have always a tendency to work their way to the surface : such, on the contrary, as are deep seated, discharge their contents into some hollow viscus, burst into a splanchnic cavity, or they become lined with a layer of coag- ulating lymph. This substance, which is poured out by the neighboring vessels, is of a pale, cineritious color, and is arranged so as to form a distinct cyst, sac, or bag, by which the matter is effectually prevented from diffusing itself through the surrounding parts. In process of time the mem- brane that is thus developed, becomes organized, and in abscesses of long standing it often acquires considerable thick- ness, say from two lines to half an inch. Internally it is either perfectly smooth, or, as more frequently happens, villous, or granulated; externally it is rough, fioeculent, and firmly united to the neighboring textures, which are at the same time preternaturally dense and vascular, from the presence of inflammatory irritation. The cyst, it may now be observed, is both a secreting and an absorbing texture, resembling, in this respect, the organized adventitious membranes of the serous cavities described in a preceding page. 72 SUPPURATION. [CHAP. IV. Abscesses, whether encysted or not, present much variety with respect to their size. As a general rule, it may be stated, that their dimensions are in direct ratio to the spongy structure of the affected part. Thus, abscesses of the glandu- lar organs are seldom so large as those that are developed in the groin, the axilla, the lumbar region, and in the retro-peri- tonaeal cellular substance, where they not unfrequently attain a magnitude capable of holding many quarts of pus. Not less variable is their number. Whilst in some cases there is only one, in others, as, for example, in the liver, there are as many as twenty, forty, or even fifty. This subject necessarily brings us to the consideration of the physical and chemical properties of pus. When genuine, or, as it is not improperly termed, healthy, pus is of a pale yellowish tint, opake, nearly of the consistence of cream, of a sweetish taste, without any particular smell, and of the specific gravity of 1050. Being neither alkaline nor acid, it does not affect vegetable colors until it has been for some time exposed to the air, when it becomes slightly sour. It readily combines with water, which, when pure, it uniformly whitens, emits a faint mawkish odor on being heated to the normal temperature of the body, resists putrifaction for a long time, and is coagulated by heat, alcohol, and muriate of ammonia. When examined with the microscope, it appears to be com- posed of a prodigious number of globules suspended in a thin transparent fluid, which has been found, on analysis, to con- sist of albumen, fibrin, extractive and fatty matter, muriate of soda, phosphate of lime, and other salts. Examined by the eye, this liquid has all the appearances of the serum of the blood, but differs from it by a peculiar state of the albu- men and of the extractive matter just referred to. The globules, which are of a spherical figure, and of a light yel- lowish tint, are the two thousandth part of an inch in diame- ter, or about a third larger than those of the blood. When matter possesses the foregoing characters, it is said, in surgical language, to be healthy, in reference to the process by which it is produced, which, it is supposed, is of a sanative nature. If it be thin, watery, and sanguinolent, it is termed sanious pus ; if thick and curdy, scrofulous pus; if firm and concrete, lymphy pus. Sanious matter is generally of an irritating nature, producing not unfrequently erosion of the parts with which it comes in contact: it contains a super- abundance of salts and albumen, together with red particles, CHAP. IV.] CHARACTERS OF PUS. 73 is often quite offensive, and is observed principally in suppu- ration of the cutaneous and osseous textures. Scrofulous pus is mostly seen in tubercular disease of the lungs, and in chronic inflammation of the lymphatic ganglions : granules of calcerous matter are occasionally blended with it; and if it be allowed to remain at rest for a short time it usually sepa- rates into two parts, — the one being thick, straw-colored, and inodorous; the other thin, ropy, and mixed with small, opake, cheesy flakes. When scrofulous pus is long retained, it has been known to be excessively foetid, from the extrica- tion, probably, of sulphuretted hydrogen gas. Various attempts have been made by writers, with the hope of discovering some test by which pus might be distinguished from other secretions, especially from mucus, which it is known to resemble more closely than any other. From some experiments performed by Mr. John Hunter, he was induced to recommend the muriate of ammonia, which, as we have seen, readily coagulates the fluid in question, whilst no such effect is produced on blood or mucus. The younger Dar- win proposed a double test of sulphuric acid, and a solution of pure potash. If, on the addition of water to pus dissolved in either of these liquids separately, there be a copious precip- itate, the matter made use of is judged to be purulent ; but, if there be no such deposit, it must, as is alleged, be of some other character. But the most unexceptionable test, perhaps, is that which was suggested by the late learned Dr. Young, of England. It is founded on the globular particles of the pus, and consists simply in holding a small quantity of this fluid, placed between two thin pieces of glass, between the eye and a candle, a little way off. If the matter be purulent, it will be encompassed by a bright halo of colors, not unlike those of the rainbow, the light being at the centre, and the tints so much the more intense as the particles are more nu- merous and more equably diffused.* Concerning the mode of production of this fluid, patholo- gists have expressed very different views. Boerhaave and some of his followers attributed the formation of pus to a dissolution of the solids ; Pringle and Gaber, to putrifaction of the serum; Gorter and Q,uesnai, to changes induced in the coagulating lymph. But all these singular notions, with many others, have been fully refuted, or deemed unworthy of * Young's Medical Literature, p. 571. VOL. I. 10 74 SUPPURATION. [chap. IV. this trouble. The first consistent theory on this subject was advanced by Dr. Morgan, of Philadelphia, in his inaugural dissertation published at Edinburgh, in 1763. In this tract, he threw out the hint that pus is a peculiar morbid secretion, which is always preceded and accompanied by inflammation of the affected part ; and a somewhat similar view was short- ly afterwards adopted by Mr. Hudson, of England. The way which was thus prepared by these and other writers, was subsequently more successfully explored by John Hunter. It remained for the penetrating genius of this great man — great in everything which he attempted — to remove the flimsy veil which still shrouded this curious process, and to place it in a light at once so clear and conspicuous, that very little has been added to the subject since the time in which _ he wrote. Pus, then, is not produced, as was contended by the older authors, by a breaking down of the solids, or by changes wrought in the serum or fibrin, but by a peculiar secretion, not unlike that in kind, though more intense in degree, which is concerned in separating the nutritious parti- cles from the vital fluid. _y That pus itself is merely an altered state of the blood, seems to be equally true, more especially Avhen it is remem- bered that it includes alt the essential ingredients of that fluid. How it is deprived of the coloring matter, it is not easy to determine; it is one of those hidden and mysterious circumstances, the efficient cause of which is locked up in the bosom of the Creator, and concerning which it would be absurd to speculate. If any reliance is to be placed in the well-conducted observations of Gendrin, it must be con- cluded that the formation of pus bears a very great analogy to the separation of the serum or fibrin. On inspecting the capillaries of a frog's foot, which had been for some time in a state of inflammation, this distinguished philosopher states that he repeatedly observed the changes which the globules of the blood undergo preparatory to their conversion into pus. At first, the minute vessels are merely dilated from excessive sanguineous engorgement; but, in the course of a few days, sooner or later, according to the nature of the ex- citing cause, the circulation becomes remarkably tardy, and they are then seen to be distended with a pale grayish fluid, inclining somewhat to yellow. In its character, this fluid is essentially globular, the particles of which it consists being considerably larger than those of healthy blood, and differing CHAP. IV.] FORMATION OF PUS. 75 in their aspect according to the degree of the metamorphosis which they have experienced. Thus, at the centre of the inflamed part, they are of the color of cream, a little farther on, of a grayish appearance, whilst towards the periphery, where the elaboration is still very imperfect, they are partly red, and partly yellow, with various intermediate shades which are more easily perceived than described. A similar effect ensues, says Gendrin, in the coagulum which is formed subsequently to the tying of an artery. If a ligature be placed round the vessel above the obliteration, and a seton be passed through the clot, suppuration is ob- served in a short time to occur, the inspissated blood becom- ing gradually softened, and converted into purulent matter, in the same manner as in an inflamed tissue.* These and ,— other observations, which we have not room to dwell upon, conclusively show that pus is directly derived from the blood, by a peculiar process, which may be considered as a degree higher than that which is concerned in the separation of coagulating lymph.f * Histoire Anatomique des Inflammations, t. ii. p. 471. t " II n'y a done," says Gendrin; " entre le fluide purulent des tissues en- flammes et le fluide coagulable organisable qu'un degre de plus." Op. Cit. This remark is very similar to one made long before by Mr. John Hunter. His lan- guage is substantially this, — that the new-formed matter peculiar to suppuration is a remove further from the nature of the blood than the matter formed by adhesive inflammation. See his excellent chapter on suppuration, in his work on the Blood. CHAPTER V. Of Hemorrhage. The subject still involved in obscurity. — Causes. — Opinions of Morgagni and of Bichai; Exhalant Vessels. — Aptitude of different Structures. — iN'omencla- tnre. — Predisposition. — Hereditary Proclivity.— Hemorrhage sometimes vi- carious— Active and passive. — Critical. — Quantity of Blood effused.— Changes and final Disposition. In the pathology of hemorrhage there is much that yet remains to be elucidated. This is not surprising, when we consider the ignorance which still exists in relation to the capillaries in which this lesion is, for the most part, located. We have no means, except by analogy and induction, of as- certaining the habits, if I may so express myself, of these small tubes whilst engaged in the discharge of their various functions. We are acquainted, however, with certain facts, and these, scanty as they are, must guide us in the discussion of the subject. Although inflammation is not unfrequently attended by a discharge of blood, this is by no means the only condition in which this phenomenon is observed. In many instances it would seem to be the result purely of over distention of the capillaries, from obstruction in the heart or large vessels, by which the sanguine fluid is prevented from pursuing its accustomed route with its accustomed freedom. Nor is it necessary, in order to bring about this congestion, that the system should be in a state of plethora: most commonly, in- deed, the reverse is the case, the quantity of blood being unusually small. In some diseases, again, such as scurvy and typhus, in which hemorrhagic effusions are by no means infrequent, it is exceedingly probable that the blood itself is morbidly affected, by which it is enabled the more readily to percolate through the relaxed parietes of the minute vessels, carrying with it its different component elements. Formerly the idea prevailed that all sanguineous effusions depended invariably upon a rupture of the blood-vessels. Nor is this notion, even at the present day, fully eradicated from the CHAP. V.] HOW EFFECTED. 77 minds of some physicians and pathologists. Morgagni seems to have been the first to throw out the hint that hemorrhages might be the result merely of a process of exhalation, without the slightest appreciable lesion of the vessels from which it emanates. This opinion, so well calculated to elucidate this interesting piece of pathology, was afterwards embraced by Xavier Bichat, who has fully discussed it in his great work on the tissues. He explains the phenomenon through the instrumentality of a set of open-mouthed vessels, known un- der the name of the exhalants. Of these he has described not less than three distinct orders, the excrementitious, nu- trient, and recrementitious. The existence of such vessels was long ago admitted by Boerhaave and Haller ; and, since their time, they have formed a favorite subject of speculation with many highly respectable anatomists. Unfortunately, however, much labor has been wasted which might have been turned to more profitable account; for it is now well known that there are no exhalants, in the true sense of that term; none, at all events, have ever been demonstrated, and probably never will be. How, then, if the open-mouthed vessels, so minutely de- scribed by Bichat and others, have no existence, are we to explain the exhalation of blood ? Are we to suppose, with Mascagni, that the arteries are every where furnished with pores through which the contained fluids merely percolate ? That there are apertures in the tunics of the vessels, of some kind or other, is a circumstance concerning which there can no longer be any dispute. The experiments of Dutrochet, of France, repeated and modified by our countrymen, Dr. John K. Mitchell, of Philadelphia,* and Dr. Edwin D. Faust, of South Carolina,! satisfactorily prove that all animal tissues are permeable to fluids and gases; which could not be the case if they were destitute of pores. What the nature of these openings is, it is not my design to inquire, nor is it im- portant that it should be known. The fact that they exist is sufficient for my purpose. Assuming, therefore, that all vessels are porous, the most plausible theory that suggests itself is, that all hemorrhages, not dependent on rupture, are caused by a sort of exosmose, * On the Penetraliveness of Fluids. American Journal of the Med. Sciences, vol. vii. p. 36. t Experiments and Observations on the Endosmose and Exosmose of Gases, ib. vol. vii. p. 23. 78 HEMORRHAGE. [chap. V. diapedesis, or transudation, by which the elements of the blood are forced through the coats of the vessels, and made to occupy situations, in which they are not naturally found. How far this process differs from that of ordinary secretion, or what the precise conditions are on which it depends, are circumstances which it is not in our power to explain. Ana- logically, it may be inferred that the vessels are in a state of morbid activity, whereby fluids are suffered to escape, that were appointed to be retained ; or it may be supposed, as we have reason to believe, is often actually the case, that the capillaries, being in a state of debility and relaxation, their pores are rendered unnaturally patulous, and thus allow the blood to have a more ready egress. Nor is it probable that the change, whatever it may be, is confined to the minute vessels. To give rise to the phenomenon in question, the nervous system must be involved, by which, if it do not ex- cite, it promotes and countenances, the perverted action. The idea of Morgagni and Bichat, that hemorrhage proceeds from exhalation, embraces no error, further than that it as- cribes this process to a set of vessels which, so far as is at present known, have no real existence. In all other respects, the term exhalation expresses the same thing as that of exos- mose, transudation, oozing, or diapedesis. The theory propounded by Morgagni and Bichat will not ;appear so difficult, if we take into account the results of some ireeent experiments in relation to the subject of venous ab- sorption. The doctrine that this function is exclusively ex- ecuted by the lymphatics, has been completely subverted by the researches of Magendie and other physiologists. If, then, it be admitted, as certainly it must, that the veins absorb or imbibe fluids, it does not require much stretch of imagination to conceive that the arteries, which so much resemble them in structure, should exhale blood, especially when they are in a state of disease. This process, indeed, takes place, ap- parently, even within the limits of health, as in the uterus, where it constitutes the menses. How far hemorrhage, not dependent upon rupture, is con- nected with inflammation, is a question, for the solution of which we have no accurate data. That mere congestion will produce this result, has been sufficiently established by experiments on the inferior animals. Boerhaave excited hem- orrhage in the intestinal mucous membrane of dogs, by placing a ligature on the portal vein ; and similar effects have CHAP. V.] HOW PRODUCED. 79 since been produced by tying the vessels of the stomach, spleen, and other organs. Nevertheless, it is doubtful, even in these instances, whether the parts from which the blood flowed were not in a state approximating to, if not identical with, inflammation, as characterized in its earlier stages. As affording analogical evidence, we may here refer to the phe- nomena which take place in the uterus. After the period of puberty, it is the duty of this organ, at every lunar month, to elaborate a fluid, which, in every respect, resembles pure blood, save that it has a stronger odor, and does not coagu- late. The discharge that is thus set up is a natural one, as it is common to all women; yet how comparatively few are there who do not experience more or less constitutional derange- ment during its existence ? Many, indeed, undergo great suf- fering, laboring under all the symptoms which indicate the presence of inflammation. Taking into connection, therefore, these and similar facts, it is extremely difficult, I say, in many cases, to determine how far the exhalation of blood is concerned with, or independent of, inflammation. The rela- tionship, so far as it goes, can only be ascertained by further observations and experiments. Having made these remarks, it may now be stated that, so far as the immediate causes of hemorrhage are concerned, they may result, first, from exhalation; and, secondly, from direct injury of the vessels. In regard to the former of these divisions, enough has been said to render it unnecessary to add any thing more in this place ; as respects the latter, I shall only observe, that the most frequent source of hemor- rhage is a rupture of the vessels, in consequence of disease of their tunics, or from the violence with which the blood is impelled into them by the action of the heart or by extrane- ous force. The structures in which hemorrhage is most frequently ob- served, are the mucous, the cellular, and the serous. Every organ and texture of the body, however, is liable to be thus affected. Concerning the mucous system, it may be remarked that some portions are much oftener involved than others. It is asserted by some, that all parts of the alimentary tube are equally subject to this effusion, which, however, is a mistake. Beyond all doubt hemorrhage is most common in the large bowel; next, in point of frequency, it occurs in the stomach ; and, finally, in the inferior third of the ileum. The jejunum and duodenum, together with the oesophagus, mouth, and 80 HEMORRHAGE. [CHAP. V. fauces, are rarely affected. A discharge of blood from the nose and bronchial tubes is not an infrequent event, whereas it is very unusual in the larynx and the trachea. In regard to the genito-urinary division of the mucous system, consid- erable difference obtains in the two sexes. In the male, the urethra and bladder are oftener involved ; in the female, the uterus and vagina. Of the serous membranes, the parts most liable to sanguin- eous effusion are the pleura and pericardium. The cutaneous texture is very rarely affected, except in scurvy and typhus fever. With regard to the viscera, the brain and lungs are much oftener the seat of hemorrhage than any other. In- deed, it is doubtful whether some of them, owing to the pe- culiarity of their structure, are susceptible of this lesion. Be this as it may, effusions of blood, whether from rupture or otherwise, are exceedingly uncommon in the liver, spleen, kidney, pancreas, uterus, and other organs. In the fibrous, cartilaginous, ligamentous, and osseous textures, they seldom, if ever, occur. Eruptions of blood have received different names, accord- ing to the parts in which they occur; but these it is not necessary to specify. This lesion, it may also be stated, is sometimes described under the term apoplexy. This word was orignally restricted to hemorrhagic effusions in the brain : at the present period, however, it is employed in a wider sense, being applied to all extravasations of blood, no matter where occurring. The predisposition to hemorrhage to different organs va- ries remarkably in the different periods of life. During child- hood expistaxis is most common ; between twenty and thirty- five, there is an extraordinary proclivity to hemorrhage of the lungs and of the rectum ; about the age of forty, bleeding of the uterus is most usual; from fifty to sixty, apoplexy and hematuria are most frequent, especially in men of irregular, dissolute habits. The exciting causes of hemorrhage are extremely numerous, but as they do not particularly concern the pathological anatomist, they need not be enumerated in this place. A plethoric state of the system, especially in the young, and a nervo-sanguineous temperament, are circum- stances which powerfully predispose to its occurrence. Cli- mate also appears to determine some difference in the erup- tion of blood in different situations. In cold regions, for ex- ample, hemorrhage is most frequently observed in the nose, CHAP. V.] HEREDITARY--VICARIOUS. 81 bronchial tubes, and urinary bladder; in tropical, in the rectum and uterus. On the whole, it may be said, also, to be more common in the female than in the male ; though, as respects this point, we have no positive facts from which to deduce any just conclusion. One of the most remarkable circumstances in the history of this lesion, is its hereditary tendency. The facts which are in our possession, in relation to this subject, are too nu- merous and well authenticated to admit of the slightest doubt, in the mind even of the most skeptical. Almost ev- ery practitioner must have noticed cases of this description. Dr. Krimer, a German physiologist, records a curious in- stance in which this hereditary proclivity displayed itself in the male descendants of a family in four successive genera- tions ; and two similar cases have recently been reported by Dr. J. N. Hughes, of the State of Kentucky.* What is more singular than all, is, that the disease may cease in one gener- ation and reappear in another. In a most remarkable case of this mode of transmission, mentioned by Dr. Riecken, the pa- rents, who both attained to old age, had never been subject to hemorrhage. The couple had twelve children — five boys and seven girls — of whom three of the former and one of the latter died of the lesion in question. The youngest daugh- ter, who never suffered from the affection, married a stout, healthy man, by whom she had six children — four boys and two girls— two of the former of whom fell victims to hem- orrhage.! Not less singular is that variety of hemorrhage to which the term vicarious has been applied. As its name imports, it is supplemental of a similar natural or morbid state in a re- mote organ, and is most frequently observed in young fe- males, in consequence of the tardy appearance of the men- strual flux, or from its suppression after it has been estab- lished. In the great majority of cases, it is located in the mucous membrane of the nose, and recurs with considerable regularity every lunar month, until the difficulty, of which it is the result, has subsided. Occasionally the blood oozes from the skin, the eye, ear, lung, anus, and even the nip- ple, either simultaneously or successively. What particular * Transylvania Journal of Medicine, vols. iv. and v. t Edinburgh Medical and Surgical Journal, No. 108; also, Cyclop. Pract. Medicine, vol. ii. p. 480. VOL. I. 11 82 HEMORRHAGE. [(.HAP. V. changes, if any, the capillaries, which are the seat of these vicarious effusions, undergo, is not ascertained : we only know that they are the chief agents which are concerned in their production : beyond this all is doubt and uncertainty. That they are effected under the immediate influence of the func- tional operation of the minute vessels, as has been suggested by some, appears not improbable ; but this, I apprehend, does not explain the matter, or bring us any nearer the truth than we were before. Hemorrhages are usually divided into two classes, the ac- tive and the passive. The former occurring in strong robust persons, the latter in such as are naturally feeble, or who have become so by disease, impoverished diet, or excessive evacu- ations. This distinction, however, is not of much value, in a practical point of view, as it is often extremely difficult to refer the cases that are met with to the one or the other of these forms; nor is it of any importance in reference to the proximate causes of the disease, inasmuch as they are usually the same in both varieties. By others, again, hemor- rhages have been divided into acute and chronic, — an arrange- ment which is, perhaps, on the whole, the least objectionable of the two. Hemorrhages are not always announced by precursory symptoms. In some cases the individual experiences obscure pains in different parts of the body, with a sensation of weight and fulness in the organ from which the effusion is about to occur, and chilliness of the extremities, particularly the feet. The blood, which often escapes with great rapid- ity, oozing out at innumerable points, is generally of a florid hue, and, although it readily coagulates, it seldom separates into serum and crassamentum, as happens when it is drawn from a vessel at the arm. Sanguineous effusions sometimes occur as a critical dis- charge, especially in cases of protracted fever. Nature, in such cases, is said to make an effort to get rid of the original disease, by establishing an efflux in some remote part, which, in most instances, is the nose. Nevertheless, as the occur- rence is not constant, it can be regarded in the light merely of an accidental circumstance, produced by some disruption in the balance of the circulation. The quantity of blood varies in different cases, from a few drops to several quarts. Generally speaking, it will be likely to be much greater when it proceeds from the rupture of a CHAP. V.] QUANTITY. 83 vessel, — than when it is the result of exhalation. In no part of the body is hemorrhage so apt to be profuse as in the mucous system. In the uterus, the bronchial tubes, the stomach, and intestines, an immense quantity of blood is frequently discharged in the course of a few minutes. When blood is effused, one of four circumstances happens in regard to its final disposal. In the first place, it may be entirely rejected. This is generally witnessed when the hemorrhage occurs in the oesophagus, the stomach, or bowels. In all these situations, as well as in the urinary, genital, and respiratory passages, the blood is voided either in a pure state, or blended with such substances as may happen to be lodged there at the time. Secondly, the fluid may be absorbed. This frequently takes place in the subcutaneous cellular tissue, and sometimes, also, in the brain, lungs, and other viscera. Tliirdly, the blood may remain, and become organ- ized ; or, fourthly, it may act as a foreign substance, and induce fatal inflammation. The above account would be imperfect were we to pass by the charges which are wrought in the effused blood. When it is poured into the pulmonary organs, it is usually quite fluid, and of a bright florid hue, from the influence of the atmosphere. In the stomach, on the contrary, it is usually more or less coagulated, and of a black color, from the ac- tion of the acid and gaseous contents of the organ. In most of the other viscera, properly so termed, it is of a dark com- plexion, and for the first day or two of a fluid consistence. Subsequently, by the action of the neighboring absorbents, the coloring and serous portions of the blood are in great measure removed, and the consequence is that it not only becomes lighter but likewise more dense and firm. At a still more remote period, the clot becomes organized, and not unfrequently also encysted. To these important changes, with which every physician should be thoroughly acquainted, we shall revert when treating of cerebral apoplexy, a disease in which they are generally most conspicuous. CHAPTER VI. Of Softening. One of the most unequivocal signs of Inflammation.— Structures most liable to be affected by it. — In what anatomical Element is the Lesion seated! — Causes. — Opinions of Rostan and other writers. — Degrees of Softening. One of the most singular effects of inflammation is soften- ing of the affected parts. This lesion was first pointed out by the late distinguished Professor Dupuytren, of Paris. The term which is here used to designate it is synonymous with that of mollescence or ramollissement, so much in vogue among the French pathologists. Next to redness, softening may be regarded as decidedly the most unequivocal sign of the existence of phlegmasial irritation, and it will therefore be necessary to speak of it somewhat in detail. Softening does not occur with equal frequency in all the organs and tissues of the body, yet there is perhaps not a single one that is not sometimes affected with it. The parts in which it is most common, as well as most strongly marked, are the brain, the spinal cord, and the mucous membrane of the alimentary tube, together with the spleen and liver. It is occasionally seen in the tendons and cartilages, where it forms the principal, if indeed not the only, character of in- flammation, both the redness and turgescence being, in most cases, entirely wanting here. The blood-vessels, the serous and fibrous textures, the ligaments, the voluntary and invol- untary muscles, and the external teguments are among those parts of the body which are least liable to be affected with this disease, owing, no doubt, to the peculiarity of their nervous and vascular endowments. In the bones, softening is by no means uncommon, and, what is remarkable, it seems sometimes to pervade nearly the entire skeleton. When this is the case, the other organs and textures of the body usually participate in the lesion, although so slightly, perhaps, as to be scarcely observable in making the dissection. The interesting question here arises, — what is the particu- CHAP. VI.] SOFTENING : ITS CAUSE. 85 lar anatomical element in which the lesion now under consid- eration resides ? As might be expected, observations have been made with a view of deciding this point, and the result would seem to be, that, in nearly all cases, the structure most at fault is the interstitial cellular. In the liver, for example, the diminution of cohesion is never so strongly marked in the granulations as in the cellular substance by which they are surrounded. So likewise in the muscles, the fleshy fibres frequently retain their healthy consistence long after the connecting tissue is converted into a soft shreddy mass. In the stomach and bowels, also, the mucous mem- brane is never softened by inflammation without the cellular structure beneath participating in it. Indeed, it may well be doubted, I think, when the lesion takes place in this situa- tion, whether it be not always seated in the first instance in the submucous substance. This, however, is a point con- cerning which we have no positive data. The most common cause of softening, as has been already stated, is inflammatory irritation, generally of an acute, but sometimes of a slow, chronic character. It should also be remembered that it is sometimes the result of causes which exert their influence after death. In making examinations, nothing is more common than to find the posterior parts of the lungs much softer than the anterior, simply, it would appear, from the stagnation of the blood ; and, in the stomach, molles- cence, it is well known, is frequently produced by the action of the gastric juice. These facts should be kept in mind by the pathologist; otherwise he will be in danger of confounding these phenomena with such as are caused by inflammation. There is a species of softening, particularly frequent in the brain and spinal cord, which is supposed by Rostan and others, to proceed from an obliteration of the arteries. That mollescence may be brought about in this way, I do not feel disposed to deny ; at the same time it must be confessed that it is far from being certain, that, when the nutrition of an organ is thus interrupted, the changes which it experiences are not of a character which assimilate it to inflammation. This opinion will not appear less plausible when it is recol- lected that there is always more or less effusion of serosity, of lymph, or even of purulent matter. There can, indeed, strictly speaking, be no such thing as dry softening; and whenever, therefore, the fluids here referred to are found, 86 SOFTENING. [CHAP. VI. there is reason to believe that they are poured out as an effect of inflammatory irritation. The degree and consistence of a softened organ cannot be very well defined in a general way, and the consideration of it must therefore be postponed until we come to speak of the mollescence of individual structures. In its color it may vary from a milky white, as in the brain, to deep red, as in the lung, with every intermediate shade of ash, brown, and yellowish. What is singular, the blood-vessels in many cases seem as if they had entirely disappeared, whilst in others they are so weak as to be incapable of withstanding the slightest pressure, or receive the finest injecting matter. CHAPTER VII. Of Gangrene. Definition. — Parts most apt to suffer.— Color and Consistence. — Extent— Manner in which Nature guards against the occurrence of Hemorrhage. — Causes, of two kinds.—Malignant Pustule.— Gangrene from the use of Ergot.—From the exhibition of Tartar Emetic. — Senile Gangrene. The last termination of inflammation, of which we shall speak, is gangrene. In the United States and Great Britain, the term gangrene is used to denote that condition of a part which immediately precedes its death. In France, however, a more considerable latitude has been given to its significa- tion, the physicans of that country regarding it as synonymous with mortification and sphacelus. It is in this latter accepta- tion that the word will be employed in the present work. Gangrene, mortification, or sphacelus, then, may be defined to be the extinction of the vitality of a part of the body, the rest of the organism retaining its life. When this event is about to take place, the affected structure loses its sensibility, it becomes cold, the blood ceases to circulate, and absorption is suspended. The process by which these changes are accomplished is generally progressive, its rapidity varying with the con- stitution of the patient, the violence of the exciting causes, and, above all, the nature of the suffering structure. Thus, gangrene, in some cases, takes place in the course of a few hours, whilst, in others, it does not make its appearance for several weeks or even months from the commencement of the inflammation. Much diversity prevails amongst the different organs and tissues in regard to their liability to be- come affected with this lesion. The cellular, cutaneous, and mucous, may be enumerated as the textures which are more frequently seized with mortification than any other ; and it is worthy of remark that these are parts which are extremely well supplied with blood, especially the two latter. Nevertheless, in the skin and cellular substance, this event takes place most 88 GANGRENE. [CHAP. VII. frequently in situations which are remote from the central organ of the circulation, as on the hands, feet and posterior portions of the trunk. In the mucous system, the parts most liable to mortification are the gums, the inside of the cheeks, the tonsils, the colon, the inferior third of the ileum, the urinary bladder, and the lining membrane of the vulva. The serous membranes, muscles, ligaments, tendons, aponeuroses, and cartilages are rarely affected in this way; and the same remark holds good in reference to the arteries, veins, and absorbents. The three latter of these structures, indeed, seem to possess a most astonishing conservative power, and hence it is not uncommon to find them retain their integrity in the midst of the sphacelated part. In malignant scarlet fever, attended with mortification of the tonsils and upper part of the neck, I have several times seen the common carotid go on in the performance of its function, and the individual recover, notwithstanding the detachment of immense sloughs of the skin and cellular substance ; and similar phenomena have often been witnessed in gangrene of the inferior ex- tremities. It seems doubtful from the cases on record whether spha- celus has ever been actually observed in the uterus, kidneys, ovaries, supra-renal capsules, the thyroid body, the testicles, pancreas, and salivary glands. The occurrence, at any rate, is extremely rare, and further observations are wanting to settle the question. Gangrene of the lungs is by no means so uncommon as was formerly supposed by pathologists: in the liver and the spleen it is also sometimes observed, as also in the brain and spinal cord. The nerves are rarely affected; the heart, perhaps, never, although, as will be shown hereafter, several cases are on record in which the reverse seems to have been true. The bones are often destroyed by gangrene, especially those of the inferior ex- tremities, from causes which often seem to be originally seated in their own structure, or in the fibrous membrane which surrounds them. The color of the mortified part varies with the nature of the affected tissue. In the lungs it is frequently greenish, black in the spleen, cineritious in the cellular tissue, livid in the skin, brownish or pale yellow in the mucous membranes, and like the leas of red wine in the brain and spinal cord. This statement, of course, is liable to numerous exceptions, to which reference will be made, particularly in their appropri- CHAP. VII.] CHARACTERS--SEAT. 89 ate places. Ligaments, tendons, and fibrous membranes rarely undergo much change of color, unless there is at the same time an abundant effusion of sero-sanguinolent fluid, in which case they occasionally have a reddish, macerated appearance. It need scarcely be remarked here that the consistence of a mortified part must depend, in great measure, upon the mode of aggregation of its anatomical elements, and upon the amount of blood by which they are nourished. In gan- grene of the lung, which contains a large quantity of cellular substance, pervaded by myriads of the finest capillaries, the affected part is generally very soft — sometimes, in fact, a mere diffluent putrilage, in which it is impossible to discern the slightest trace of the primitive structure of the organ. Nearly similar phenomena are occasionally observed in gangrene of the brain, spleen, and liver. In mortification of the cellular tissue, especially in the carbuncular variety of it, the loss of cohesion is likewise very considerable; so that this substance can be torn and cut with much more facility than in the normal state. The harder solids, as they are denominated, on the contrary, undergo very little change of consistence, as is exemplified in tendon, ligament, and bone. Much of this loss of cohesion is owing to chemical decom- position. The period at which this begins is greatly influenced by the structure of the affected part, the quantity of effused fluid, the season of the year, and the nature of the dressings. There are several species of gangrene, where, as will be seen presently, the affected part is perfectly dry, hard and shriveled, approaching to the condition of a rotten pear. In other cases the mortified mass is remarkably soft and baggy, exuding, on being divided, a large quantity of thin, turbid, sanious matter. It is on the absence of this fluid, on the one hand, and on its presence, on the other, that is founded the distinction made by some writers, of dry and humid gangrene. The exhalation which arises during the progress of the decomposition, and which gives to gangrene its characteristic fetor, has not been thoroughly investigated, I believe, by any chemist: probably it is of the nature of hydrogen gas, holding a certain quantity of carbon, sulphur, and phosphorus in solution. The gangrene may effect a single tissue, or appear simul- taneously in a considerable number. This latter occurrence is well exemplified in severe inflammation of the lower ex- tremity : commencing in the subcutaneous cellular tissue, it vol. i. 12 90 GANGRENE. [CHAP. VII. gradually extends to the skin, the aponeurosis, muscles, periosteum, and bones, which, together with the vessels and nerves, it sometimes converts into one common sphacelated mass, of a dark livid color. In a case of this description, should the patient's constitution be good, the gangrene, after having proceeded a certain distance up the limb, manifests a disposition to stop, or, more properly speaking, the surround- ing structures make an effort to resist its further encroach- ment. This attempt is generally indicated by the appear- ance of a red line, for which the surgeon, as is well known, always anxiously looks, as it forms a circumvallation around the dead parts, and shows that the morbid action is arrested. The next step which nature takes in this enterprise is to set up an ulcerative absorption, by which the mortified mass, now called a slough, is gradually detached, the structures that give way first being the cutaneous and cellular, then the muscular and fibrous, then the nervous and vascular, and, finally, the ligamentous and osseous. The absorption by which this important change is effected is confined exclu- sively to the living parts, and the rapidity with which it takes place is influenced by a great variety of causes, which it would be needless to enumerate. One of the most interesting phenomena, in connection with this sloughing process, is the manner in which nature guards against the occurrence of hemorrhage. Long before death has accomplished its work, the blood in the vessel of the affected limb begins to coagulate, and, by the time the parts are ready to be detached, the inspissated fluid is firmly glued to the inner surface of the tubes by adhesive inflammation. The arteries and veins, however large, are thus, as it were, hermetically sealed, so that, on amputating the limb, particu- larly when the plug extends high up into the sound parts, there is frequently not the slightest hemorrhage. We now proceed to speak of the causes of gangrene. These may be divided into two great classes, —into those, namely, which act directly upon the part, and into those which exert their deleterious influence through the constitu- tion. Of the former, it is not necessary to say any thing in a work of this kind, further than that they are either of a mechanical, chemical, or physical character : of the latter, however, as they involve some highly interesting circum- stances in relation to the operation of internal poisons, it will be proper to give a more comprehensive account. CHAP. VII.] CAUSES. 91 Among the internal causes of gangrene, are organic dis- eases of the heart, leading to deficient circulation in remote parts of the body, imperfect supply of the nervous influence, habitual intemperance in eating and drinking, want of nu- tritious diet, and the inordinate use of spurred rye. That an impoverished state of the blood, with lesion of the innervation, is a frequent cause of gangrene, is a fact which is now pretty generally admitted by medical men. In the lower orders of society, mortification from this source some- times manifests itself in the mucous membrane of the mouth and vulva, in the groin, axilla, and feet. The influence which a diseased state of the blood exercises in the produc- tion of this lesion is well exemplified in scurvy. Persons who labor under this affection are extremely prone to inflam- mation from the slightest accident, followed frequently by gangrene. The state of general debility, too, as has been justly remarked by Carswell, which prevails during pro- tracted fevers, is well known not only to favor the develope- ment of inflammation, but to give this disease a peculiar tendency to end in mortification. The malignant pustule, as it is termed, a disease which is not uncommon in certain provinces of France and Germany, and which will be noticed more particularly hereafter, seems to be often produced by causes which exert their influence through the medium of the circulating fluids. In the ex- periments of Hamont and Leuret, blood taken from the veins of an affected animal and transfused into those of a sound one, readily induced this singular malady. Even the flesh appears to be strongly impregnated with the septic agent, numerous examples being on record where death was occasioned by using it as food. There is a singular species of gangrene which is very rare in this country, but sufficiently common in certain districts of France, Switzerland, and Germany, where it sometimes prevails endemically. Many of the inhabitants of these countries, it is well known, use rye almost exclusively as an article of food. In very moist seasons, this grain often con- tains a large quantity of blighted matter, which has re- ceived the name of ergot, secale cornutum, or cock-spur, and which, when employed for a considerable length of time, is supposed to give rise to the disease in question. The attention of the profession was first called to this affection by M. Dodard, a French physician, in 1676: it was examined 92 GANGRENE. [chap. VII. with considerable accuracy by M. Noel, surgeon to the Hotel Dieu, of Orleans, and, since his time, has been frequently made the subject of investigation ; but, for the latest and most correct account of it, we are indebted to M. Lessier. This species of gangrene is, in every respect, a most sin- gular affection. In the cases described by M. Noel, it always began in the toes, from whence it gradually extended along the foot and leg, until, in some instances, it reached the upper part of the thigh, or even the trunk. In the majority of the patients, the gangrene was preceded by redness, pain, and burning heat, which subsided in the course of four or five days, leaving the parts cold, hard, dry, insensible, and black like charcoal. After some time, sloughing commenced, and, if the system was not too much exhausted, nature alone was frequently sufficient to effect the separation of the affected limb. In one of the cases, both thighs were detached at the ilio-femoral articulation. In a second series of cases, delineated by Gassoud, the dis- ease is described as occurring in the feet and legs, together with the hands and arms. The symptoms which accom- panied it varied in different individuals. In some, there was considerable swelling, with great pain and heat; in others, the tumefaction was combined with redness, and the patient labored under fever and delirium ; in others, again, the suf- fering was entirely local, and was sometimes intermittent, sometimes constant. The separation of the black mortified mass commonly took place spontaneously, and was often at- tended with the most excruciating pain. Neither in these, nor in the cases mentioned by Noel, was there any of the foetor which is so generally present in ordinary gangrene. M. Bossau, however, met with some instances of this affection in which the parts exhaled an insupportable stench ; but. it is worthy of remark, that, in most of them, the gangrene was not of the dry kind. The disease, it would seem, attacked, indiscriminately, men, women, and children. For a long time doubts were entertained whether ergot was really the cause of this disease. With a view of settling this point, M. Lessier, an eminent French physician, was re- quested by the Royal Academy of Medicine of Paris, to in- vestigate the matter experimentally. The subjects of his researches were ducks, turkeys, and pigs. Without going into details, which would be foreign to my design, it may be briefly stated, that these animals were strictly subjected to CHAP. VII.] CAUSES--ERGOT--EMETICS. 93 the use of spurred rye ; that most of them died between the tenth and twenty-fourth day, and that distinct marks of spha- celus were perceived in different parts of the body, both ex- ternally and internally. How, it may now be asked, does ergot operate so as to pro- duce this singular effect ? On this point we are still in com- plete ignorance. The only idea I can form of the influence of this substance is, that it exerts its deleterious influence, in the first instance, on the blood, and, through it, upon the capillaries, causing inflammation in them, followed by gangrene. This opinion, indeed, seems to be fully borne out by the phenom- ena which precede this event, not only in the human subject, but likewise in the inferior animals. That the blood and its vessels are alone implicated, we do not assert: the nervous system, no doubt, is seriousl}7 involved : all that is contended for is, that these are the parts which receive the primary im- pression ; and, in this view, as before hinted, we are amply sustained by the facts of the case. This affection, as was before intimated, is very rare in the inhabitants of this country. It has been several times no- ticed by our eastern practitioners ; but I am not acquainted with a single instance that has occurred in the Valley of the Mississippi; though such, no doubt, has been the case. In Chester county, Pennsylvania, it prevailed extensively among the horned cattle in 1819, and, in the following year, in Orange county, in the State of New York. In these in- stances the disease seems to have proceeded from the use of the green grass, the poa viridis, the seeds of which, as was ascertained by Dr. Mease, of Philadelphia, were affected with the ergot.* A very curious circumstance, in relation to the present sub- ject, has been recently brought to light by some of the French pathologists. I allude to the fact that emetic substances, when taken in excess, will give rise, not unfrequently, to in- flammation of the extremities, rapidly followed by gangrene. Several cases, illustrative of this effect, are recorded by Dr. Barbier, of Paris, in his excellent work on the materia medi- ca.f One of them came within his own knowledge, in a woman, who, after having taken a dose of drastic cathartic medicine, was seized with violent vomiting and purging, * Domestic Encyclopedia, vol. ii. p. 5-2, and vol. iii. p. 196. t T. iii. p. 327, quatrieme edition, Paris, 1837. 94 GANGRENE. [CHAP. VII. which, in a short time, produced the most alarming prostra- tion of the vital energies. In this condition she was con- veyed to the H'tel Dieu. Next day the point of the nose, the ears, and cheeks, assumed a deep purple color, and simi- lar spots appeared on the feet and hands. All these parts were now rapidly attacked with gangrene, and one of the feet sloughed entirely off. In the other case, the particulars of which are detailed in the " Journal de Medicine," of Paris * the patient, also a female, was attacked with severe cramp, spasm of the extremities, and extreme anguish. These symptoms were followed, in a short period, by lancinating pains in the limbs, with dark blotches in different regions of the body. Gangrene appeared in the lower lip, the chin, the car- tilaginous part of the nose, and in several of the toes, — all of which successively dropped off. Are these effects produced in the same manner as when the system is laboring under the influence of ergot ? To me, I must confess, the modus op- erandi of these substances is quite incomprehensible; yet the circumstance is certainly a curious one, and will no doubt receive further attention. The lesion may be said to be owing to the great and rapid reduction of the powers of life, giving rise to inflammation of the capillaries; but, if this be true, how happens it that all cases of general debility are not fol- lowed by gangrene ? The parts are placed in the same rela- tion as one that is deprived of its nervous supply. Closely allied to the disease now described, is that affec- tion which was so well portrayed by the celebrated Pott, of England, under the name of mortification of the toes and feet. As has been justly remarked by this great surgeon, the lesion is most common in aged persons, though the young are by no means exempt from it. Its progress is generally slow and insidious, commencing sometimes without the slightest pain, uneasiness, or swelling. In the majority of instances, it makes its first appearance at the inside of one of the small- er toes, by a circumscribed bluish spot, which is more or less painful, and is soon followed by a separation of the cuticle, leaving the skin beneath of a dark red color. In some in- stances the gangrene begins at a number of points at once, and when this is the case, it is usually more rapid in its march, as well as accompanied with more urgent symptoms. In its progress, it gradually involves the whole foot, and not un- * T. xxxviii. CHAP. VII.] SENILE GANGRENE. 95 frequently the leg, and even the thigh, the soft parts of which are converted into a black, bluish, or brownish mass, often extremely offensive to the smell. The sloughing process generally goes on rapidly, and the bones occasionally drop off at the joints. Mr. Pott, who observed this disease chiefly in gouty persons, states that it is much more common in men than in women, in the proportion nearly of twenty to one. In France, how- ever, it seems to occur with equal frequency in both sexes, for the reason, probably, that their mode of living is more alike than in England.* In this country, the disease is of very rare occurrence, some of our most experienced surgeons having never witnessed a case of it. The cause of this va- riety of mortification has been variously explained by differ- ent writers. Mr. Cowper, an old English author, threw out the idea that it might depend upon ossification of the arteries of the inferior extremities, — a view which has since been embraced by Mr. Hodgson and other writers. Numerous ex- amples, in fact, might be cited in corroboration of this opin- ion ; yet, that it is not exclusively true, is apparent, when it is remembered that the disease occasionally occurs in subjects in whom the arteries are perfectly free from the degeneration in question. In these cases, it is not improbable, I think, that the capillaries, both arterial and venous, are the original seat of the affection, inflammation being set up in them by some stimulating property of the blood, or by other causes, the precise nature of which is unknown to us. * Begin, Diet, de Medicine et de Chirurgie Pratiques, art. Gangrene. CHAPTER VIII. Of Ulceration. Definition; intricate nature. — Most common in the Skin, Cellular Tissue, and Mucous Membranes.— May be slow or rapid. — Manifests a tendency to ex- tend towards the nearest surface. — Produced by Inflammation. — Ulcers sometimes heal: the process by which this is accomplished. — Ulceration a sanative effort. By this term I understand the solution of continuity of a texture from the absorption of its molecules. It is synony- mous with what was anciently called erosion, and with what some modern pathologists, with Mr. Hunter, denominate ul- cerative absorption. Of the intimate nature of this lesion nothing is known with any certainty, beyond the fact that it is usually connected with inflammation. Although there are few parts which are not susceptible of ulceration, yet that this occurrence is much more frequent in some textures than in others, is a fact of which every one is convinced by daily observation. The cutaneous, mucous, and cellular tissues are infinitely more often affected than all the rest put together. This is exemplified in the numerous blotches which sometimes cover almost the whole body, and in the erosions which are so frequently noticed in the bowels, the mouth, the throat, the vagina, the gall-bladder, and the larynx. The heterologous formations, the bones and teeth, with the articular cartilages and their coverings, come next in order. The serous membranes, properly so called, the fibrous and muscular structures, rarely suffer from ulceration; and the same is true of the internal viscera, excepting the uterus. Nature seems also to have endowed the vascular system with a remarkable power of resisting this process. Vessels, even of large size, are occasionally completely ex- posed, from the destruction of the surrounding parts, and yet entirely escape the disease. It is a remarkable fact, that parts even of the same struc- ture will take on ulceration much more readily in some situ- CHAP. VIII.] ITS SEAT--CAUSES. 97 ations than in others. This is well exemplified in the di- gestive mucous membrane. Thus, for one erosion in the stomach, we find at least a thousand in the ileum and the colon ; and so also with the skin, though not in the same ratio, of the upper as compared with that of the lower extremity. Newly-formed parts are extremely prone to ul- ceration. A cicatrix is rapidly destroyed by this process, be- cause it is much more feebly organized than structures that have existed longer. The same thing happens in the callus of a fractured bone. The ulceration occasionally proceeds with great rapidity, destroying as much of the body in a few days as nature can repair in as many months. It is sometimes limited to one texture; at other times invades a considerable number of them. In the bones, although it usually progresses very slowly, it is often remarkably destructive, whole pieces of the skeleton being, in some instances, literally eaten away. In the skin and mucous membranes, it occasionally persists for years, without greatly impairing the health of the indi- vidual. In the articular cartilages, although it may be equally protracted, it generally induces anchylosis, or death from constitutional irritation. Ulceration always manifests a tendency to extend towards the nearest surface. This is a law which is attended with the most salutary effects ; for, if there were no such pro- vision, the individual, the subject of this process, would often fall a victim to its ravages. This tendency is well exempli- fied in the tibia. Ulceration commencing in the interior of this bone, generally works its way through the part which is covered merely by the skin and periosteum, nature thus greatly economizing her time, and saving the surrounding structures from much mischief. Another beautiful illustra- tion of this law is afforded by the liver. Wlien an abscess is seated in this organ; inflammation is gradually set up in its peritonaBal covering, followed by an effusion of lymph, by which the viscus is glued to the stomach, the colon, or duodenum. Ulcerative action now begins, and, in process of r time, a communication is established between the adherent parts, affording a ready outlet for the purulent fluid. In this manner nature effects, in a few days, what, if the opening were made through the skin and muscles, it would require weeks to accomplish. The great cause of ulceration is inflammation conjoined vol. i. 13 98 ULCERATION. [CHAP. VIII. with pressure. In many instances, however, it follows sup- puration and gangrene. Nor is pressure always essential to the process. In many situations, indeed, as in the cutaneous and mucous textures, ulceration occurs without the slightest aid from this source. On the other hand, there are examples in which pressure appears to be the principal agent, as in caries of the bones produced by the presence of a large aneu- rismal tumor. The same disease disproves the idea, formerly so current amongst pathologists, that ulceration can never happen without the formation of pus. Were any further illustration necessary of the fallacy of this opinion, we might refer to the mucous textures, where this process often occurs, unaccompanied by the slightest deposition of matter. The question here comes up, — what is the nature of this concomitant inflammation ? Is it of that description to which Mr. Hunter has applied the term adhesive ? or does it possess a character altogether peculiar to itself ? The latter supposi- tion seems to me to be the most plausible, — certainly most in accordance with what we know of the subject. Every practitioner is acquainted with the fact, that an inflammation, apparently of the same kind and degree, produced by the same cause, and affecting the same tissue, will, at one time, end in ulceration, at another, pass off without any such oc- currence. This can only be explained on the assumption that the inflammation which precedes and accompanies the ulcerative process is of a specific character, or, in other words, that it is modified by circumstances, either local or constitu- tional, or both conjoined, which the pathologist cannot appre- ciate. This opinion is the more plausible, as there are some erosions which invariably result from particular causes, and none other. The venereal ulcer has its peculiar features, not less than the tubercular, the herpetic, or the scirrhous. All these are specific affections, induced by specific agents, ac- companied by specific inflammation, and followed by specific results. The ulcerative process is usually accompanied with more or less pain. In the majority of cases, it is of a dull aching or gnawing character, as if insects were feeding on the part. Occasionally, it is entirely latent, or the patient experiences merely a slight degree of uneasiness. In some instances, it is continued; in others, intermittent; in others, periodical. With this symptom, there is often irritation, or hectic fever, with rapid emaciation, and great failure of the powers of the system. CHAP. VIII.] ITS NATURE. 99 The inflammation, which precedes the ulceration, always continues until this process is completely arrested. Andral supposes that it may entirely disappear, and still the erosion go on. This, however, seems to me to be altogether a gra- tuitous assumption. We must unquestionably, I think, re- gard this disease as essentially inflammatory in its nature; and, although the part may be perfectly blanched, yet this does not prove that this process is not, to a certain extent, present. Ulcers sometimes heal. This takes place much more readily in some tissues than in others; but the process by which it is accomplished is the same in all; namely, by granulation. The different steps of this process, together with various other circumstances connected with ulceration, will be described in detail under the head of the different organs and tissues. Ulceration may be regarded, in some degree, as a sanitary process, or as a means employed by nature to rid the animal economy of extraneous materials. We have already seen that collections of purulent fluids have a disposition to escape by the nearest and easiest route ; and this is uniformly effect- ed by the agency of ulceration. A ball lodged under the skin is removed in the same way ; or it travels from one region to another, and is finally cut out at a great distance from the place where it was originally situated. It is useful also in the expulsion of tubercular matter, in the exfoliation of the bones, and in the sloughing of the soft parts. In other cases, again, as in old drunkards, the process seems to be designed to relieve the system of hurtful fluids; which it does by establishing extensive sores on the legs, attended with a perpetual flow of irritating matter. Thus we see that ulceration, although apparently a very unpleasant, is in many instances a most fortunate event, and one for which the prac- titioner often anxiously looks. CHAPTER IX. Of Granulation. Importance of the Subject — Nature of Granulations.— Difference in regard to their Vascularity and Sensibility. — How modified by Texture. —Are secret- ing and absorbing Organs. Leaving the subject of ulceration, I now come, by an easy transition, to speak of that of granulation. This process, like that of union by the first intention, is one of the grand opera- tions employed by nature for the cure of wounds, and the filling up of ulcers. To the surgeon, a knowledge of this process is of indispensable importance ; whilst to the inquisi- tive physiologist it discloses a series of changes, which, in point of interest, are not surpassed by any in the animal frame, whether in a sound or diseased state. A granulation is a small, vascular body, generally somewhat mammillated in shape, more or less red, sensitive, and capable of secreting pus. It consists, in the first instance, essentially of coagulating lymph ; and the process by which it is formed is very similar to that which is concerned in union by the first intention. Let me be understood. An individual re- ceives a wound involving the skin and cellular tissue. The edges, instead of being brought into contact, are allowed to remain apart. Immediate adhesion being thus prevented, another process, more complex and tardy, is instituted. The sore now becomes painful, and, in short, exhibits all the ordinary phenomena of inflammation. A thin, watery fluid oozes from its surface; and, after some hours, — generally from six to twenty-four, — it is found to be slightly incrusted with lymph, by which its interstices are filled up, and the whole is made to assume a smooth, uniform appearance. The lajp;r thus formed is of a whitish color, somewhat ropy in its consistence, homogeneous, and easily wiped away. If it be allowed to remain, in the course of a short time, varying from one to two days, sooner or later, according to the activity of the sore, the exudation becomes organized by the subjacent old vessels extending into it, or, if we adopt the opinion of some, by the formation of new ones, which inosculate with CHAP. IX.] STRUCTURE -- SENSIBILITY. 101 those of the divided parts. The surface of the sore is now of a red color, readily bleeds if it be touched, and is elevated into a great number of little rounded bodies, closely aggre- gated together, which are the rudimentary granulations. Another layer of plastic lymph is next effused, the vessels are still further elongated, and thus incrustation after incrust- ation is formed and organized, until the cavity is finally filled up. Not only does each granulation receive one or more arterial and venous branches, but, in all probability, also a small nerve and an absorbent. Such, at least, must be our conclu- sion, when we reflect upon the fact, that this little body not only bleeds when roughly handled, but that it often becomes highly sensitive, and that it readily absorbs such substances as are placed in contact with it. The vascularity of these little bodies is much greater, I am disposed to think, than is usually imagined. That they are liberally supplied with vessels is at once indicated by their florid complexion, by the astonishing rapidity of their growth, by the facility with which they bleed when touched, and by the fact that they become hard and tumid if filled with in- jecting matter. The arteries, the precise number of which is not known, having entered the base of each elevation, soon separate into arborescent branches, which freely anasto- mose with each other, as well as with those in the granula- tions immediately around. Accompanying these arteries are corresponding veins, which carry away the blood which is not required for the nourishment of the part, the effusion of lymph, and the secretion of pus, with which the abraded surface is usually covered. Whether the nerves and absor- bents are of new formation, or merely elongations of those that previously existed, it is impossible to determine. The latter supposition is probably the true one. Granulations are often very sensitive. This, however, is not the case every where, or under all circumstances. In the cutaneous and cellular tissues, the granulations are, all other things being equal, infinitely more sensitive than in the tendons, aponeuroses, and ligaments. The same Jhing is true with respect to the granulations of the bones, except when they spring from the cancellated structure ; then they are frequently so tender that it is impossible to touch them without inducing severe pain. These little bodies are also more sensitive when there is much inflammation, and in per- sons of an irritable and worn-out constitution than in such as 102 GRANULATION. [CHAP. IX. are healthy and robust. In some instances, especially in old ulcers of the leg, they are more than triple the ordinary size, extremely pale, cold, apparently infiltrated with serosity, and so completely insensible that they may be cut without the least pain. Granulations are absorbing as well as secreting bodies. These properties, however, are not equally well marked in all the tissues. A great difference, for instance, exists in this respect between the granulations which arise from the skin and those which arise from the bones, the former absorb- ing and secreting with great rapidity, while the latter per- form these offices very slowly and imperfectly. A knowledge of this fact is of no little value in the practice of surgery, as it enables us, on the one hand, to avoid stimulating dress- ings, and, on the other, the application of such substances as have a tendency, when absorbed into the system, to give rise to dangerous results. Not a few cases are on record where arsenic, corrosive sublimate, and other articles of the materia medica, placed in contact with a granulating sore, have de- stroyed life. The extract of belladonna, used in this way, will produce temporary amaurosis, mercury will salivate, and opium, it is well known, will occasion sleep nearly as soon as when introduced into the stomach. Thus, granulations are a very interesting and important set of textures, extremely complex in their structure, and per- forming the triple office of pouring out lymph, secreting pus, and absorbing such substances, to a greater or less ex- tent, as are brought in contact with them. The facility with which they are developed is much greater in some tissues than in others, depending on the degree of laxity and vascularity of the part from which they spring. The con- comitant inflammation appears also to be of a mixed charac- ter, as it is attended with the simultaneous effusion of lymph, and purulent matter ; and it is important that the phlogistic action should not transcend certain bounds, otherwise the process will be interrupted, retarded, or wholly suspended. The skin and cellular substance appear, of all other tissues, to be most susceptible of granulation. Mucous membranes, aponeuroses, ligaments, tendons, cartilages, and bones, to- gether with the internal viscera, excepting, perhaps, the brain, rarely heal in this way, and then only after a long time. CHAPTER X. Of Cicatrization. Nature of the Process. — Different Steps. — Do Ulcers never heal from the Cen- tre 1 — Process of Cicatrization influenced by the Form and Situation of the Sore. — Meaning of the term Cicatrice. — Reproduction of the original Tissues. The subject next in order is cicatrization. The remarks . which I shall offer here must necessarily be brief, as a great deal of what might be said will more appropriately come in under the head of the different organs and tissues. Cicatrization is the process which nature employs to heal wounds and ulcers. It is the finishing stroke, if the expression be allowable, of granulation, — the labor which is necessary to polish the surface of the sore, to contract its diameter, and to bring it as nearly as possible to a level with the surround- ing structures. This process, although it is not limited to the skin, as might be inferred from reading some modern treatises on surgery, is yet most advantageously studied there, as it enables us to follow nature as it were in the different steps which she employs with a view of accomplish- ing her enterprise. The first step in the healing of an ulcer seems to be the subsidence of the inflammation, which becomes gradually less and less, until the surrounding parts regain their natural color, form, and consistence. The sore at the same time sensibly diminishes in diameter, by the contraction and coa- lescence of its granulations ; and its surface, instead of being rough and uneven, assumes a smooth, glassy appearance, its centre, however, being still considerably depressed; or, if the granulations have been very exuberant, unnaturally elevated. Cicatrization is now observed to begin, the first indication of it being a thin, delicate, bluish pellicle, placed along the margin of the breach, where it soon unites with the old skin by an interchange of vessels, nerves, and absorbents. If the part be inspected at a later period, the substance that was 104 CICATRIZATION. [chap. x. thus deposited and organized, will be found to have increased in thickness and density, and to be gradually extending itself towards the centre of the ulcer by the addition of new mat- ter. It is in this manner, by this successive experipheral action, that the denuded surface is eventually covered over. But do ulcers and wounds never heal from the centre ? This is a topic concerning which pathologists have expressed different sentiments — some maintaining the affirmative, others the negative side of the question. From an inspection of numerous cases, I am convinced that the process of cicatri- zation takes place only in one way, namely, in that which I have described. To this remark there is but a single exception. In extensive wounds, especially of the lacerated kind, it often happens that portions of the original skin remain, form- ing so many little patches in the midst of the abraded sur- face. In such cases, the cicatrization goes on simultaneously around these parts and along the principal edges of the solu- tion of continuity. There is, however, no new law in operation here, the old skin being the starting point of the new one in both instances. The process of cicatrization is much influenced by the form and situation of the sore. Circular-shaped breeches of continuity heal much slower, cceteris paribus, than such as are longitudinal, for the obvious reason that it takes the new skin a much longer time to reach the centre in the former than in the latter. A sore in the leg cicatrizes with more difficulty than one on the trunk; and a callous ulcer than a soft one. When the cure is completed, a cicatrice is left, or, as it is called in familiar language, a scar. This is, of course, always much smaller than the original sore, and still further diminishes by the contraction of the new skin. When the breach of continuity has been of great extent, as when it has been produced by a burn, this contraction is often a source of great mischief and deformity. At first, the cicatrix is ex- tremely vascular, soft, and of a bluish color: afterwards the vessels decrease in size and number, and the part becomes dense, bloodless, and whiter than the original skin. This is well seen in persons who have had confluent small-pox, or in those who have been covered with venereal blotches. Are the original textures, in the formation of cicatrices, always regenerated ? and, if so, in what respect, if any, do they differ from them ? Cartilages and muscles are said to chap, x.] cicatrix. 105 be the only parts which are not susceptible of being repro- duced. But even of this I feel extremely doubtful; certain am I that I have seen muscles, which were almost entirely torn asunder, unite through the medium of fleshy matter. Very recently, I had under my charge a healthy lad, eleven years old, who had a large piece of the great pectoral and broad dorsal muscles torn away by a steam-engine, in which the breach of continuity was repaired by a substance perfectly identical with the original. The granulations were unu- sually florid, highly sensitive, and grew with astonishing rapidity. In old subjects, it is not improbable that the junc- tion is sometimes effected by tendon. The cartilages of the ribs generally unite by osseous matter, as certain pieces of the skeleton, such as the patella, the olecranon process, and the neck of the femur, do by cartilaginous. In most instances, however, the reproduction is imperfect. This is the case even with the skin. The cutis is never so strong or so capable of resisting the effects of disease, as in the normal state ; its inner surface is not reticulated, nor is it provided with sebaceous follicles. The mucous network is but imperfectly regenerated, and the epidermis drops con- stantly off in thin, dry, furfuraceous scales. No hairs are to be seen in the scar; for their roots having been destroyed, they cannot of course be reproduced. The same imperfect developement is observed in the cicatrization of the mucous or some other tissues. VOL. I. 14 CHAPTER XI. Of Induration. Definition. — Historical Notice. — Color, Size, and Degree. — Period necessary for its Production. — Causes. By this term I wish to designate that peculiar pathological condition of an organ which is characterized by an increase of its consistence, whether arising from the deposition of a new product, from a deficiency of the natural secretion, or simply from the transformation of its elementary tissues. This definition does not include, of course, the induration produced by the heterologous formations, such as tubercle, encephaloid, and scirrhus, with the latter of which the present disease is unfortunately too often confounded. Until recently, induration, considered as a special disease, does not seem to have attracted much attention. Professor Andral has investigated it with his usual patience and inge- nuity ; and a few years ago Dr. Carswell, of London, pub- lished a very able article on it in the British Cyclopedia of Practical Medicine, a work which, from its rare excellence, should be in the hands of every intelligent physician. In the United States most of our knowledge in relation to the subject has been derived, as usual, from European sources, and, if I mistake not, the lesion in question has not yet found a place even in our best medical and surgical treatises. This, however, is not very surprising, when it is recollected that the same is true of hypertrophy, softening, and hydatid, with numerous other highly important and interesting topics, in respect to many of which we are still greatly behind the present state of the science, mortifying as it is to be obliged to make the confession. Induration is an extremely common lesion, and may occur in any tissue of the body, but is most frequently seen in the spleen, the liver, the lymphatic ganglions, and subcutaneous cellular substance; next to which the lungs, heart, brain, ovaries, breasts, and prostate gland, are the most common seats of it. No age, nor sex, nor condition of life is exempt from it; and, in France and Germany, it is often witnessed as CHAP. XI.] COLOR-- SIZE --DEGREE. 107 an intra-uterine affection, or as occurring within a few days after birth. Like many other diseases that are described in the course of this work, induration may exist alone, or in association with other alterations ; may affect a part of an organ, its whole substance, or only one of its anatomical elements. The color of the affected part usually partakes, to a greater or less extent, of the natural complexion of the organ. The most ordinary tints are red and gray, with numerous inter- mediate shades of white, yellow, brown, and black. As a general rule, it may be stated, that the intensity of the color is in proportion to the vascularity of the affected part, and the violence of the exciting cause. Thus, in acute pneumon- itis, the induration — hepatization — is almost always charac- terized by deep redness, often verging on purple, whilst, in the chronic form of the disease, it is commonly of a dirty pale color, grayish, or dappled. When the induration occurs in structures that are naturally light, as in the subserous, sub- mucous, and subcutaneous cellular tissue, there is always more or less concomitant opacity. The size of a part in a state of induration may be natural, augmented, or diminished. An increase of bulk is by far the most frequent, and is sometimes very considerable in in- duration of the liver, the spleen, and the lymphatic ganglia. A diminution of size is by no means unusual, but cannot be regarded as a necessary consequence of the disease : the same remarks are applicable to the weight of the affected organ, which is much more frequently above than below the normal standard. There are other physical changes attend- ant on this pathological condition, which need only be al- luded to in this place, such as diminished humidity, altered sonorousness, and loss of elasticity. These changes are strikingly exemplified in inflammation of the pulmonary tissue, which becomes dry, hard, increpitous, sinks in water, and emits a dull sound on percussion of the chest. The degree of induration is liable to considerable variety, depending upon a number of contingent circumstances. Parts that are naturally soft and flaccid, are often, when thus affected, rendered quite dense, firm, and unyielding. Of this the lung affords a remarkable illustration. In the sound state, this viscus is soft, spongy, and elastic, but, when in a state of induration, it is sometimes almost incompressible, and cuts like old cheese, occasioning a peculiar grating sound under the knife. In induration of the heart, again, the walls of 108 INDURATION. [ciIAP. XT. this organ are at times found so hard and unyielding as not to collapse when pressed, and to emit a sound, on being struck, similar to that of a horn. Considered in a general point of view, induration may be said to present three degrees, which it is of some importance to distinguish. In the first, the part still retains its moisture, and feels only a little unnaturally dense ; in the second, it is already firm, dryish, and considerably altered in color; and, in the third, its consistence is so much increased as to resem- ble the white of a hard-boiled egg, old cheese, or fibro-carti- lage, every trace of its original softness, juiciness, and pliancy being gone. As to the time requisite for the production of these several degrees of induration, no definite rule can be established, as it is influenced by a variety of circumstances, the considera- tion of which must be deferred until we come to speak of the special pathology of this affection. I shall therefore con- tent myself, in this place, with observing that, in the great majority of instances, the process is remarkably slow, — weeks, months, and even years elapsing before it reaches its full developement. In other cases, on the contrary, it forms with great rapidity, a few days being sufficient for the alteration of a tissue from its normal consistence to that of a firm, dense mass. Thus, then, if we consider the disease in refer- ence to the period necessary for its developement, it may be said at one time to be chronic, at another acute, the former being infinitely the most frequent. This necessarily brings us to inquire, in the next place, into the causes of this pathological state. These are refera- ble, for the most part, to inflammation, followed by an effu- sion of coagulating lymph into the interstitial substance of the affected organ. In the lungs there is frequently, in addition to this, more or less blood poured out, which, com- bining with the natural structures, gives them a red color. It is thus that red hepatization is established. In chronic cases, on the other hand, the induration is commonly effected by the lymph alone ; and hence it is that the organ is usu- ally of a much lighter hue. In the hardening of the subcu- taneous cellular tissue of infants, a disease of pretty frequent occurrence in certain districts of Europe, the effected matter is generally impregnated with two coloring principles, the one of an orange red, the other of a bluish shade, both of which are stated by M. Chevreul to exist in the blood. From the foregoing considerations, it is certain that one va- CHAP. XI.] CAUSES. 109 riety, at least, of induration is dependent upon inflammatory irritation. In a second series of cases, the lesion, if such it can be called, appears to arise from a deficiency merely of the natural secretion. In this category belongs the indura- tion of the various organs and tissues observable in old peo- ple. As we advance in life, the whole body experiences an astonishing change in its consistence : many of the vessels are obliterated, the juices are dried up, the solids are rendered hard and rigid, and, as a consequence, the movements are difficult and imperfect. An increase of consistence from this cause is generally most considerable in the cellular tissue, the mammae, the ovaries, the prostate gland, the muscles of vol- untary life, and the bones, the latter of which sometimes acquire a degree of hardness equal to that of ivory. Were I asked what is the proximate cause of this condition, I should say that it consisted in a diminution of the vascularity of the affected part, attended with a deficiency of the normal secre- tion, and perhaps, also, a partial absorption of its more tender anatomical constituents. The part thus becomes hard, dry, and, where the circumstances are favorable, shriveled and corrugated. In a third series of cases the induration is traceable to a real transformation ; that is to say, some of its anatomical ele- ments disappear, leaving nothing but the original frame-work of the affected part. Examples of this description are occa- sionally seen in the liver, spleen, and lungs, around hydatids, serous cysts, tubercles, and other tumors. The irritation caused by the presence of these adventitious growths pro- duces a partial absorption of the natural structures, leaving those which remain in a dense and indurated state. Similar effects are sometimes brought about by protracted compres- sions, whether occasioned by bands of false membrane, or by large accumulations of fluid. Of this, a striking illustration is furnished by the lung. In chronic pleuritis, attended with copious effusion, this organ is often reduced to the size of a small cake, by the approximation simply of its solid textures, which are thus rendered unnaturally dense and hard. If the compression is not kept up too long, these textures may be made to resume, in time, their natural bulk, form, and consistence ; and so the respiratory function is gradually re- stored. This variety of induration, it may now be observed, is almost constantly associated with atrophy. Such are the several forms of induration which have been 110 INDURATION. [CHAP. XI. noticed in the different organs and tissues of the body, and the causes under the influence of which they are produced. Let us next proceed to inquire, whether parts thus affected can regain their natural consistence, and, if so, under what circumstances ? The former of these queries can be easily answered ; the latter properly belongs to therapeutics, and need not, there- fore, be particularly discussed on the present occasion. That induration is susceptible of being cured, daily observation abundantly testifies. This remark is especially true in rela- tion to the chronic form of the lesion: in the acute it is not so common, the disease usually reaching a fatal height before the system can properly react; yet even here recovery is far from being infrequent. As the induration of which I am now speaking is caused by the deposition of a new product, it is obvious that whatever has a tendency to remove this, must be instrumental in bringing about the restoration of the af- fected part. It is with a view of accomplishing this object, that the practitioner resorts to the exhibition of iodine and other kindred articles, when the disease is located in some in- ternal organ; that he uses friction and other stimulating means, if it happen to be seated externally. In either case he is desirous of producing the same effect, namely, the ab- sorption of the affected substance, the incorporation of which with the natural textures gives rise to the lesion under notice. The time required for effecting this object cannot be speci- fied, as it must be influenced by a great variety of circum- stances which it would be out of place to consider here. In acute cases, the induration frequently subsides in the course of a few weeks, even when it involves a very large extent of surface and a multiplicity of tissues : in chronic ones, on the contrary, the process is usually very tardy, — months elapsing before this event is brought about. In the mean time, the function of the part is imperfectly executed, and the longer the case is protracted the greater will be the danger that the organ will never recover its original consistence. Under such circumstances the affected textures frequently undergo the cartilaginous, the fibro-cartilaginous, and osseous transformations; and, it is even thought by some, that they are apt to degenerate into malignant disease. This, however, is doubtful : at all events, I have never seen a case in confir- mation of it. CHAPTER XII. Of Hypertrophy. Meaning of the Term. — Liabilities of different Structures.— Causes—May be general or local. — Color, Weight, and Volume, of the Part affected. The word hypertrophy is derived from the Greek u«rep-Tpo structure it may be either homogeneous, radiated or reticulated ; but noAvhere, so far as I have been able to observe, does it present an inter- nal cavity corresponding with the medullary canal of the long bones. Chemically examined, it is found, like the original osseous tissue, to be composed of the phosphate and carbonate of lime, in combination with gelatine. The relative propor- tions of these constituents are extremely variable, and it not unfrequently happens that one of them is totally absent. It has been already seen that the osseous transformation is most common in the cellular tissue. This tissue, however, is not equally liable to suffer in all parts of the body. It is seldom Avitnessed in the subcutaneous cellular tissue, whilst it is very frequent in that of the muscles, and still more so in that of the serous membranes, especially in that of the ar- teries and of the left side of the heart. The submucous cel- lular tissue appears to be almost exempt from this transforma- tion ; at all events, I have never seen an instance of it; and this accords with the experience of Andral, and other writers. The fibrous membranes, the cartilages, and fibro-cartilages, are rarely affected except as the consequence of old age, and, what is remarkable, the latter are generally much more fre- quently involved than the two former, out of which they are constructed, and between Avhich they form the connecting link in the textural scale. Is the osseous transformation ahvays preceded, Avhen it takes place in the cellular tissue, by the fibrous and cartilaginous states ? Upon this point pathological anatomists are still at variance. If the process be carefully examined, as it occurs in the subserous cellular tissue in different parts of the body, it will be found that it involves a series of successive stages corresponding Avith those that are observed in the ossi- fication of the foetal skeleton. The first change which this substance experiences is a diminution of its natural transpar- ency, accompanied with a slight degree of thickening of the part, and a deposition of turbid, cream-like matter, which is diffused through its areolar texture. As the morbid process advances, the part becomes more and more opaque, is ren- dered flexible and elastic, assumes a grayish color, and grates under the scalpel. It is now distinctly fibro-cartilaginous; it is next converted into cartilage, and finally into bone, the particles of osseous matter being deposited at different points, 128 TRANSFORMATIONS. [CHAP. XIV. Avhich gradually augment in diameter, and at length, running into each other, thus completely change the primitive char- acter of the part. The period required for the perfection of each of these changes cannot be determined: in some in- stances there is reason to believe that it is very short, Avhilst in others it embraces several months, or even years. Such, in a few words, is the process Avhich nature ordi- narily employs in order to accomplish this transformation. I say ordinarily, for there are cases, as every one must be sen- sible, in Avhich the process is much less complicated, and in which the osseous matter is deposited Avithout any antecedent alteration in the structure of the part. This mode of ossifi- cation is most common in the cellular tissue of the arteries, and in that of the valves in the left side of the heart: it is also occasionally seen in the parietes of serous cysts, and in the cellular tissue of the muscles. Accidental ossification is frequently an effect of old age. There are very few persons, beyond the fiftieth year, in Avhom the arteries, to say nothing of the mitral and aortic valves, together Avith the costal and laryngeal cartilages, are not thus affected, and this often to a surprising extent. In other cases, it is directly chargeable to inflammation, sometimes of an acute but mostly of a chronic nature. The ossification of the pleura in pulmonary phthisis, of the vaginal tunic in old hydroceles, and of the arachnoid in chronic hydrocephalus, is unquestionably to be referred to this cause and to no other. So also with regard to the ossification of the periosteum during the formation of callus, of the Avails of old abscesses, and the linings of tubercular excavations of the lungs. Hoav far the examples of senile transformations above adverted to are influenced by, or unconnected Avith, inflammation, is a question concerning which Ave have no positive information. For my oAvn part, I am disposed to believe that it is not altogether absent even here, although it may not be charac- terized by the phenomena that physicians are in the habit of ascribing to it. The most remarkable transformation, perhaps, of all, is the adipous, concerning Avhich very little appears to have been known until Avithin the last fifteen or tAventy years. Not- Avithstanding the great attention that has been bestOAved upon it by some of the European pathological anatomists, it must be acknoAvledged that Ave are still entirely in the dark, both as respects its intimate nature and its exciting CHAP. XIV.] ADIPOUS. 129 cause. By some the alteration is supposed to consist essen- tially in the superaddition of fatty matter to the existing tissues, Avhilst others consider it as the result of a true trans- formation, the same in principle as the fibrous, cartilaginous, or osseous. Whatever doubts may still exist upon the sub- ject, it seems to me that both views are, to a certain extent, correct. At all events, my OAvn observations have fully con- vinced me, that there are cases in Avhich the fatty matter is literally infiltrated into the interstices of the different organs, imparting to them a greasy color and consistence. On the other hand, I am equally certain that a transformation, prop- erly so called, of this kind takes place in different structures, especially in the liver, kidneys, pancreas, heart, and muscles, — parts in Avhich it is most frequently witnessed. An organ that is thus affected, is generally of a pale straw-color, diminished rather than increased in consistence, is easily torn, receives the impression of the finger, greases the scalpel which is used in cutting it, is of lighter specific gravity than in the natural state, and contains from one third to one half its own weight of yelloAv concrete oil. Such are the changes Avhich ordinarily attend this transformation, and the question now presents itself, — how are they brought about ? In the liver of the inferior animals, as will be shown in another place, this degeneration can often be produced at Avill, simply by subjecting them to rest in a dark apartment, and cramming their stomachs with rich, stimulating food, which, by creating obstruction in the portal circle, in all probability induces inflammation in the hepatic tissues. In the human subject, it is occasionally connected Avith general hypertrophy of the adipous tissue, and instances have been observed in which it appeared to depend upon the Avant of exercise of the affected part. The latter opinion is entitled to consideration chiefly from Avhat occurs in the muscles of the inferior extremities of old persons who have for a long time labored under paralysis. In such cases, the muscles often assume a pale color, are remarkably soft and flaccid, and exude a clear, oily fluid, on pressure, their fibres, hoAvever, remaining perfectly distinct. But are these effects really attributable to the repose in which these parts, under these circumstances here referred to, are placed ? Would it not be more philosophical, in the absence of more satisfactory evidence, to conclude that some- thing was due to the Avant of nervous influence, and to the vol. i. 17 130 TRANSFORMATIONS. [CHAP. XIV. a^ered state of the circulation thence arising? Be this as it may, I feel perfectly convinced, in my OAvn mind, that the transformation in question, like the cartilaginous and the osseous, indeed, like every other, is uniformly the result of inflammatory irritation. The subject, however, requires to be further investigated, and, until this be done, it will be Avell enough to avoid all speculation concerning it. The preceding subjects might all have been extended much further, but what has been already said must suffice. In discussing the pathological anatomy of the various tissues and organs, ample opportunity will be afforded me for supply- ing deficiencies, and entering into details which could not well have been noticed in the present section. CHAPTER XV. Of Hydatids. Historical Outline. — Where found. — Classification of Hydatids. — The Cys- ticercus, Polycephalus, Diceras, Echinococcus, and Acephalocystis. — Their Origin and Organization. — The manner in which they are nourished.— The Changes which they experience by Age, and the Alterations they induce in the Organs in which they are developed. The combined researches of naturalists and pathologists have fully shown that many of the higher orders of animals, as well as some of the lower, are infested Avith a class of beings which are generally known, at the present day, by the name of hydatids. The account of these singular bodies by the ancients is extremely slender and imperfect; nor did the scanty stock of knowledge Avhich they left us receive much accession until after the middle of the last century. Since that period much light has been thrown upon the his- tory, developement, and organization of the different kinds of hydatids, principally by the researches of Rudolphi, Zeder, Laennec, Ludersens, Cuvier, and Cloquet, the latter of Avhom published a very lucid and elaborate article on the subject, in 1818, in the French Dictionary of the Medical Sciences. Much, hoAvever, as these distinguished anatomists have done, it must be confessed that there are a great many interesting circumstances concerning Avhich Ave are still in complete un- certainty. In this country the subject can scarcely be said even to have begun to attract the attention of the physicians; indeed, I venture to affirm that there are not fifty members of the whole American profession who have any knowledge of it. Hydatids occur in the serous cavities, the alimentary canal and the passages which open into it, the cellular tissue, be- tAveen the muscles, and in the proper substance of the differ- ent organs. Nevertheless, there are, as will be seen here- after, some parts that are more frequently affected than others. They have been found in nearly all classes of animals, — in birds, reptiles, and fishes, as Avell as in a great many of the 132 HYDATIDS. [CHAP. XV. mammalia. Whether they exist in insects, is a point which has not been ascertained. ' No period of life is exempt from them. Portal, indeed, mentions an instance of their having been detected in the foetus. They are most common, how- ever, in adults and old people. So far as can be ascertained, these parasitic beings possess no genital organs, no apparatus for respiration, no trace of a circulation, and apparently no nerves. They can live and propagate their species only in the interior of other animals, and their existence is usually very brief, most of them per- ishing Avithin the first year or two after they are developed, often much earlier. A few of them only are capable of per- forming distinct movements, under the influence of external stimulants. The cysticercus, for example, Avhen put in luke- warm water, not only Avhirls itself about, but alternately protrudes and retracts its suckers. The acephalocyst, on the contrary, remains perfectly quiescent, and may therefore be said to be void of irritability and contractility. In describing these singular animalcules, I shall divide them, with Cloquet and others, into five genera: 1. the cysticercus; 2. the polycephalus; 3. the diceras; 4. the echinococcus ; and, 5. the acephalocystis. Differing from each other in many essential points, it Avill be necessary to devote to each of these genera a separate consideration. It may be premised, however, concerning them, that they all consist of a thin, pellucid vesicle, varying in size between a clover-seed and an orange, Avhich is filled with a clear, watery fluid, and surrounded by a dense, fibrous capsule, uf)on which they depend for their nourishment and support. The cysticercus is nearly cylindrical in shape, terminating behind in a caudal vesicle, whence its name. The whole animal is somewhat Avrinkled, and its head, Avhich strongly resembles that of the tape-Avorm, is furnished with hooks and suckers. This genus is more frequently met with in the in- ferior animals than in man, and is particularly common in the liver and brain of the sheep. Its size rarely exceeds a small walnut, and in most cases it is not near, so large. It generally exists singly in the enclosing cyst, which is almost always thin, delicate, and transparent, except in old cases, or where the hydatid has lost its vitality, Avhen it is apt to be thick, dense, semi-cartilaginous, or even bony. In the sheep, in which this genus often acquires a large size, the caudal vesicle presents an infinite number of minute elevated lines, running nearly at right angles with the body of the CHAP. XV.] CYSTICERCUS. 133 animal. Five species of the cysticercus have been recog- nized by authors, — the cellular, vesicular, dicystic, speckled, and Fischerian. The cellular cysticerce (see Figs. 1 and 2) is met Avith almost ex- clusively in the hog, in which it occasions the disease commonly known under the name of measles, or Avhat the German Avriters call finnen. It has been observed but once or tAvice in the human sub- ject. The body is conoidal, from four to ten lines in length, and composed of a thin, transparent membrane, without any perceptible fibres : the caudal bladder is of an oval shape, and the head, Avhich is tetragonal, is furnished Avith four suckers, together Avith thirty-two hooks divided into two toavs. The vesicular species, which is also very rare in man, having been found only in a single instance, in the choroid plexus of an apoplectic subject, has hitherto been chiefly observed in the ox, sheep, 'swine, goat, stag, and gazelle. The peritonaeum, the pleura, and the arachnoid, are the situ- ations in which it delights to dwell. Its head, which is almost tetragonal, is armed Avith a cylindrical and slightly curved snout: the neck is quite short, the body small, and the caudal vesicle nearly spherical. Such are its distinguish- ing features. The third species is the dicystis, or, as this term literally signifies, the double-bladder hydatids. Laennee is the only person who has observed this Avorm. He found it in the lateral ventricles of a man Avho died of apoplexy. It consists of two large vesicles, of Avhich one is caudal, whilst the other, which is annulated and of a conical shape, forms the body. Both are traversed by a wide canal, which terminates ante- riorly in a cul-de-sac. The head has four suckers, and a certain but undeterminate number of hooks. The speckled cysticerce has a head with one sucker and * a, the head ; b, the neck; and c, the dilated vesicular tail. t Magnified head of the same: d, the proboscis; e, e, e, the suctorious discs. t A portion of human muscle, with the cysticerces : a, the cyst cut open ; b, the parasite; c, the muscle. 134 HYDATIDS. [CHAP. XV. six hooks; the body is conical, nearly transparent, and from four to eight lines long ; the caudal bladder is spherical, and irregularly dotted Avith very small Avhite points. It has been met with only in one instance, by M. Trentler, in the choroid plexus of a young Avoman. The Fischerian species, the fifth and last Avhich I shall describe, has a rounded, slender, annulated body, and a large head furnished Avith an indeterminate number of hooks and suckers. The caudal bladder, which is pear-shaped, is about the fourth of an inch long, and terminates in a small point, Avhich adheres to the organ which the animal inhabits. It is said to have no enclosing cyst. Dr. Fischer, of Leipsic, after whom it is named, detected it tAvice in the choroid plexus of the human subject. The second genus, the polycephalus, is extremely rare, and has not, up to the present time, so far at least as I am aware, been found in man. It is composed of a semi-transparent cyst, speckled with minute, opaque, Avhitish spots, of a some- what oval figure, is generally very small, and is provided, as the derivation of the name indicates, with a great number of heads. The situations Avhich it generally occupies in the inferior animals are the brain, the liver, and the intermuscu- lar cellular tissue. Two species have been noticed by authors, the cerebral and the granular, Avhich, however, as they never occur in the human subject, need not be described. The diceras, a genus established by Sulzer, infests the alimentary canal of animals, and also occasionally that of the human subject. The German author here mentioned, first observed it in the alvine evacuations of a young Avoman after having taken some purgative medicine. This genus, which embraces only one species, the rough diceras, is distinguished by its flat, oval body, which is about a line and a half long, and terminated in a point posteriorly, and by the rough, bifid horn which surmounts its head, and from which the animal derives its name. It is loosely enclosed by a capsule. As yet it has not been discovered in the substance of any of the viscera. Of the diceras, I have never seen any specimens, and suspect that it is extremely uncommon. Rudolphi, indeed, appears altogether to doubt its existence, Avhilst others suppose that it may be a variety merely of acephalocysts, presently to be described. The fourth genus is the echinococcus, (Figs. 4 and 5,) first suggested by Rudolphi, but not admitted by Cuvier. Occurring principally in the brain, liver, spleen, and omentum, it consists CHAP. XV.] ECHINOCOCCUS--ACEPHALOCYSTIS. 135 of a capsule, analogous in structure to that of the acephalocyst, attached to the inner surface of which are numerous animal- cules, of an ovoidal shape, extremely fine, Fio, A granulated, and provided with four suck- ers and a crown of hooklets. The echino- coccus is very rarely found in the human subject. Zeder discovered some in the brain of a young woman, occupying the third and fourth ventricles: they were about tAvelve in number, pyriform, and quite small. Miiller has recently described an instance in which they were voided by a man laboring under renal disease. with the urine, But the most is that published by Fig. 5. extraordinary case, perhaps, on record Rendtorf. The sac containing the hyda- tids was developed in the brain: it Avas of large size, and weighed upwards of two pounds. The walls of the right ven- tricle, in which it was situated, were so at- tenuated as to be scarcely a line and a half in thickness. It should not be forgotten, that the name by Avhich this genus is designated has reference to the rounded form of the body, and to the little asperities Avhich cover it. The fifth genus, the acephalocystis, (Fig. 6,) by far the most interesting and common of all, Avas founded by the celebrated Laennec, who published a very accurate account of it, in 1804, in his excellent " Memoir on Vesicular Worms." Occurring both in the human subject and in many of the inferior animals, the individuals of this class of parasites infest some organs much more frequently than others. They seem to have a remarkable predilection for the liver, OAving, probably, to some peculiarity of struc- ture favoring their developement. The brain, ovary, uterus, mammary gland, spleen, and kidney, are also sometimes their Fig. 6. 136 HYDATIDS. [chap. XV. seat; in fact, they have been found in every part of the body, except the alimentary canal, the urinary bladder, and the respiratory passages. Varying in size between a mustard-seed and a large orange, they are generally of a spherical figure, and com- posed of a Avhite, semi-opaque, pulpy vesicle, filled Avith a clear, limpid fluid. This vesicle, Avhich forms the hydatid, properly so called, is from the sixth of a line to the eighth of an inch in thickness, and is often separable into tAvo or more layers, and is so exceedingly delicate as to yield under the slightest pressure of the finger. So Aveak is it, indeed, that it is frequently incapable of withstanding the pressure even of its own contents, as I have had repeated opportunities of witnessing, after the partial removal of the enclosing cyst. On being ruptured, it shrinks up into a soft, irregular, pulpy mass, of an opaline color, Avhich readily sAvims in water, and bears the greatest resemblance to coagulated Avhite of egg. M. Collard, a French chemist, Avho has recently examined this substance, states that it consists of tAvo principal ingre- dients, one of Avhich is essentially albuminous, whilst the other, the precise nature of which is not knoAvn, has a con- siderable analogy with mucus.* To the inner surface of the vesicle noAV described are often attached extremely minute bodies, (a and b,) not bigger than the finest grain of sand, of a grayish color, and a spherical shape, Avhich are supposed to be young hydatids. In some instances they are said to be connected Avith the exterior of the parent sac ; but this, I presume, is very rare, and I have never seen an example of it. It has been made the basis, hoAvever, of the division of acephalocysts into tAvo species, the endogenous and exogenous, the former being most common in the human subject, the latter in the ox and other ruminant animals. In what manner these animalcules originate, hoAv they are attached, or at Avhat time, after their formation, they are cast off, are circumstances in their history, concerning Avhich Ave are still perfectly in the dark. All that is knoAvn with any certainty is, that they may often be seen floating about in great numbers, while they are scarcely the two hundredth part of an inch in diameter, Avhich would lead us to infer that they are generally detached at a very early period of their existence. When the hydatid consists of several coats, as often happens, the generation sometimes takes place be- * Diet.' de Medicine et de Chirurgie Pratiques, art. Acephalocyslis, 196. CHAP. XV.] ACEPHALOCYSTS. 137 tween them, or even in their substance. In Avhatever way it be accomplished, a small opaque elevation, easily distin- guishable by the eyes, usually indicates the spot where the young have been developed. It sometimes happens, though not very often, that a large acephalocyst contains seA^eral that are smaller, one within the other, all of the same shape and structure. As many as three, four, and even five, have been found thus enclosed, like so many pill-boxes. This arrangement, which occurs much oftener in the human subject than in the inferior ani- mals, is explained by the endogenous mode of generation previously adverted to, by Avhich one acephalocyst, after hav- ing arrived at maturity, produces another, each successive one being smaller than its parent. The enclosing cyst of this species of hydatid is usually semi-transparent, very strong and dense, and has no connec- tion Avhatever Avith the parasite within. In fact, there is usually interposed between them a soft, pulpy, dirty-looking substance, arranged in a thin, unequal lamella, which is re- garded, by Dr. Hodgkin, as a sort of excrementitious secretion, furnished by the hydatid itself. * The thickness of this outer capsule varies a good deal with the size and age of the tumor : it can be separated occasionally into several layers, and may be iid to possess all the properties of the fibrous tissue, without any of its linear disposition. Professor Cruveilhier, of Paris, who has Avritten an able article on acephalocysts, in the French Dictionary of Prac- tical Medicine and Surgery, divides them into two specie *, the solitary and the social, — a distinction which he appea s to regard as of no little practical importance. The first vari- ety is of most frequent occurrence in animals, and is rarely developed singly, or only in one organ. In the sheep and the ox it has been found simultaneously in the lungs, the spleen, the heart, brain, and kidneys. The social hydatid, on the other hand, is not common in man; and seldom co- exists in several viscera, or in several parts of the same organ. The structures in which it is most frequently de- veloped are the ovary and the Uterus, Avhere hundreds, nay thousands, from the volume of a clover-seed to that of the fist, are occasionally found Avrapped up by one common pouch. Against this division there can be no particular ob- * Lectures on the Morbid Anat. of the Serous Membranes, p. 187. London, 1838. VOL. I. 18 138 HYDATIDS. [CHAP. XV. jection, provided it be borne in mind that the distinction rests solely upon the manner in Avhich the hydatids are isolated or grouped together, not upon any difference of form, texture, or organization. Such is a rapid sketch of the most common genera and species of hydatids. Let us noAV inquire briefly into their origin, their organization, the manner in Avhich they are nourished, the changes they experience from age, and the alterations they induce in the tissues in Avhich they are developed. With regard to the origin of hydatids, all is doubt and conjecture. The idea of Vitet, adopted by Iveger and others, that they are the result of inflammation, although not gener- ally embraced by pathologists, seems, on the whole, less objectionable than any other that has yet been suggested. This opinion derives considerable plausibility from Avhat occurs in the inferior animals. In many ruminants hydatids may be produced, almost at pleasure, by confining them in moist situations and restricting them to very juicy, unripe vegetables. Cruveilhier informs us that, during several years in Avhich he resided at Limoges, in France, comparatively few cattle Avere killed there that had not acephalocysts in the liver, lungs, or some other organs; and in Cincinnati, where there are annually slaughtered upAvards of one hundred thou- sand hogs, probably not a tenth part are free from this disease. Whole droves, consisting of three or four hundred heads, are sometimes thus affected. These animals, most of Avhich are young, are raised in the prairie districts of Ohio, Indiana and Kentucky, and are literally stuffed, for six or eight weeks before being sent to market, Avith fresh corn. The conse- quence is, that the portal circle is kept in a state of constant congestion, which finally leads to inflammatory irritation and the developement of acephalocysts in the liver and other viscera. The irritation thus set up is of a specific nature, and is followed by the deposition of a fibro-albuminous sub- stance, or, Avhat is the same thing, a sort of plastic lymph, the particles of which arrange themselves in such a manner as to create an inferior being, an entozoic parasite. Whilst this formative process is going forward, the parasite takes care to isolate itself from the parts in Avhich it is devel- oped by means of a capsule, Avhich surrounds and protects it from injury. This capsule is supposed, by Dr. Hodgkin and others, to be derived from the circumjacent cellular tissue, — an opinion respecting Avhich I feel myself obliged to dissent, as CHAP. XV.] STRUCTURE. 139 being no less unphilosophical than unsupported by facts. Were there no other reason, the circumstance that hydatids are often found where there is almost an entire absence of this substance, Avould be sufficient to convince any one of its fallacy. Whilst there is a possibility that the opinion may sometimes hold good, it is certain that, in the great majority of cases, the capsule is a neAV formation, as much as the parasite itself, both being developed simultaneously out of the same substance, the only difference between them being the manner in Avhich the particles of each are grouped to- gether. This point may be illustrated by Avhat occurs in an abscess of the liver. When the matter is deep seated, espe- cially when it is considerable, there is usually an effusion of lymph, by which a sac is formed, provided with all the neces- sary'appurtenances of organization. This external, adventitious envelope, formed, as we have just supposed, out of the plastic lymph of the blood, is fur- nished with appropriate vessels, as Avell as, in all probability, with nerves and absorbents. Many of these vessels are of large size, can be readily injected, spread out in beautiful arborescent lines. So far as I have had an opportunity of ex- amining them — and I have often done this in the acephalocyst of the hog — they appear to me to be derived principally from the surrounding textures. Nevertheless, there are cer- tain situations in which they are plainly the result of new formation, as in the ventricles of the brain, the serous sacs, the ovaries, and the uterus. Nowhere can any of their branches be traced from the outer covering into the walls of the hydatid itself. The reverse of this has, I knoAv, been asserted by authors, but without, there is reason to believe, any foundation in truth. The proper hydatid contains, as was before intimated, a thin, aqueous fluid, which, as long as the animal remains healthy, is generally perfectly clear and limpid, like the purest spring-water. Under opposite circumstances, it is frequently turbid and discolored, or it is entirely replaced by purulent matter, blood, or other substance. Be this as it may, the fluid is usually remarkably saline in its taste, pos- sesses little or no odor, and rarely, if ever, coagulates by exposure to heat, or on the addition of alcohol, corrosive sublimate, or the dilute acids. In several experiments which I made on the contents of some very large acephalocysts found in the liver of the hog, heat produced not the slightest change; and similar results ensued in a trial which I made 140 HYDATIDS. [CHAP. XV. on a hydatid taken from the same organ of a man forty years old. These results accord with the researches of Marcet, Cruveilhier, and other writers ; and they point out the great resemblance of the fluid in question, to that of hydrocephalus, in its want of coagulability, in consequence of the almost total destitution of albumen. As hydatids, then, do not possess any vessels, so far at least as we can discover, Avhence is the fluid just mentioned derived, and in what manner are these parasites nourished ? Deeply interesting as these questions are, we must acknowl- edge our utter inability to give a satisfactory or even a plau- sible answer to them. Is there any animal, however minute, which furnishes a secretion, and yet is destitute of vessels ? If there be, I must confess I am not acquainted Avith it: the very idea, it seems to me, involves an absurdity. That the fluid in question is the product of the hydatid itself, no one can doubt, for it could not be derived from any other source; and, if this be admitted, it is obvious that it must be the result of vascular action. But it may be said that the fluid is secreted by the containing capsule, and that it finds its way into the proper cyst by a sort of endosmose. The only circumstances which at all countenance this supposition, are some experiments performed by Professor Cruveilhier, of Paris, and Mr. Owen, of London, in Avhich, on placing recent acephal- ocysts in a colored liquid, they found that little streams of it were gradually transmitted through the parasites, so as to mingle with their contents. These researches, however, besides being incomplete, only prove that this phenomenon may take place here as in other parts, without showing in any wise that the fluid is thus actually imbibed by the animal in the natural state. Let us now recur to the question, — how are hydatids nourished ? or, rather, whence do they derive the materials necessary for this purpose ? It has been already seen that these entozoa are completely isolated from the tissues in which they are developed by means of a capsule which has no immediate connection with them ; and the inner surface of which, moreover, particularly in the acephalocystic genus, is generally lined by a thin, pulpy, fragile lamella, which adds still further to the insulation. This intervening sub- stance has been supposed, by Dr. Hodgkin, to be a sort of excrementitious secretion from the hydatid itself: I should presume that it was an important structure, and that it Avas designed to assist in the elaboration of a fluid for nourishing CHAP. XV.] MODE OF TERMINATION. 141 the parasite. This fluid, Avhich is probably of a sero-albu- minous character, is furnished by the vessels of the enclosing capsule, is filtered through the soft, pulpy matter here ad- verted to, and is finally imbibed by the proper cyst of the hydatid, which it thus enables to live and to execute its humble functions, — those, namely, of secreting a thin, watery liquid, and of propagating the species. Much of all this, of course, is conjectural; nevertheless, most of the arguments might be sustained by analogy; and this is the only kind of proof that can ever be adduced in illustration of an inquiry environed by so many difficulties. Many hydatids appear to enjoy but a short period of life. This is especially true of the acephalocysts of some of the inferior animals, as the sheep and SAvine, in Avhich they are said to be produced in the spring, and to perish the folloAving winter. In others, again, as well as in the human subject, they live for years, and often acquire a very large size. The duration of their existence is greatly influenced by the nature of the tissues in Avhich they are developed, and by various other circumstances which will readily suggest themselves to the reader. Not unfrequently an old hydatid is destroyed by its young, which press upon and finally rupture it. In a second series of cases, death comes on Avithout any assigna- ble cause; the contained fluid gradually disappearing, and the proper cyst, as well as the enclosing capsule, becoming collapsed, opaque, corrugated, and of a yellowish amber color. In a third series the parasite is attacked with inflammation. When acute, this disease sometimes ends in a species of gangrene ; but more generally it leads to suppuration. Of both these terminations I have had occasion to observe a considerable number of instances. In the former case, the fluid is of a turbid appearance, and the cysts, both proper and adventitious, are converted into a soft, brownish mass, which is sometimes quite offensive. In the latter, that is, Avhen the inflammation ends in suppuration, the contained liquid is often entirely absorbed, its place being occupied by a yellowish, gold-colored pus, of a thick, plastic consistence, slightly saline to the taste, and of a faint animal odor. This occurrence is most frequently Avitnessed, according to my OAvn experience, in old acephalocysts, and in most of the cases that I have examined the internal membrane was either Avholly destroyed, or broken up into fragments, which were mixed with the abnormal secretion. When the inflammation is of a chronic kind, it is not un- 142 HYDATIDS. [CHAP. XV. common for the enclosing capsule to become thickened, in- durated, and fibrous, from the deposition of lymph. Occa- sionally it puts on exactly the appearance of the interior of a large aneurismal sac ; and cases have been observed where it was rendered cartilaginous, and even bony. The ossifica- tion usually begins by a few central points, which gradually augment in diameter, until, in some instances, they coalesce with each other, and form considerable sized patches. A hydatid has been known to be the seat of apoplexy. The only instance of this kind that I remember to have read of, is that mentioned by Dr. Hodgkin, in his morbid anato- my of the serous membranes, as occurring in a man forty years old. The hydatid Avas seated in the neighborhood of the spleen, and Avas externally of a dark color, which arose from a thin layer of blood that was interposed between the proper and the enclosing cyst. Hydatids may prove mischievous in two ways; first, by their great number, and, secondly, by their large size. In either case, they are apt, sooner or later, to excite inflamma- tion in the parts in Avhich they are situated, which may ter- minate in suppuration, in softening, in gangrene, in indura- tion, or, finally, in ulceration. The hardest structures are sometimes incapable of withstanding their progress. Thus, Andral records a case in which they perforated the scapula. When seated in the abdominal viscera, they are often passed by stool, ejected by vomiting, or discharged externally through a fistulous aperture. In the lungs, hundreds are sometimes coughed up by the same patient; and in the kid- neys they have been known to be voided with the urine, either entirely, or in small fragments. In the brain, they may become a source of epilepsy, paralysis, or destructive softening ; and, in the serous cavities, their escape is occa- sionally attended Avith fatal inflammation. I need scarcely allude here to the doctrine of Adams, Baron, and others, that hydatids are essentially connected with the origin of tubercles and carcinoma. This theory, to which I shall particularly advert in another page, Avas found- ed on the frequent coexistence of these diseases in the cow, sheep, and hog, — a circumstance Avhich is very rarely wit- nessed in the human subject, and which has led to the gen- eral abandonment of the vieAvs of the distinguished writers above named. CHAPTER XVI. Of Serous Cysts. Have the form of shut Sacs.— Organs in which they are most frequently found. — Classification: the simple, multilocular, and the included. — Nature of the contained Fluid. — Are either new products, or formed out of the preexisting Textures.— Are liable to Inflammation and its consequences. Much more simple in their structure, as well as much less obscure in their mode of origin, than hydatids, are those membranous pouches which have received from the morbid anatomists the name of serous cysts. Deriving their generic distinction from their contents, which are usually of an aque- ous character, they constitute a class of adventitious textures, which, like those naturally existing in the splanchnic cavities, form perfectly shut sacs, rough and adherent on one surface, smooth and in contact Avith a fluid on the other. Their shape is globular, ovoidal, pear-like, or pediculated, and in size they observe every intermediate degree between a grain of mustard and a large melon. As far as can be ascertained, they are the result, with feAV exceptions, of an entirely neAv formation, dependent upon the effusion and organization of plastic lymph. With the mechanism of this creative process, as Avith that of hydatids and other accidental groAVths, we are altogether unacquainted; nor is it possible ahvays to appreciate the different morbid lesions Avhich precede and accompany it: that it proceeds, however, under the influence of causes Avhich excite inflammation in the normal tissues, is a fact that is borne out both by observation and analogy, and con- cerning which it Avould therefore be absurd to entertain the slightest doubt. Like hydatids, Avith which they are often confounded, serous cysts are found either upon free surfaces in natural cavities, or in the substance of the organs. They have been observed in almost all classes of animals; and, although no period of life can be said to be exempt from them, yet they are much more frequently seen in the old than in the young, 144 serous cysts. [chap. xvi. and, according to my own experience, in the female than the male. Like hydatids, they may be considered as a species of parasites that live at the expense, and in the interior, of other beings, more perfectly organized than themselves, Avhich afford them protection, and the means of subsistence. Their occurrence is extremely common, both in man and in ruminat- ing animals ; and it has even been contended that they occa- sionally manifest a hereditary tendency, the greater portion of a large family having been known to be thus affected during several successive generations. They have been found in near- ly every structure and cavity of the body, but particularly in the ovaries, the liver, kidneys, the mamma?, and the testicles. They are also not unfrequent in the brain of old persons ; but very seldom have they been seen in the spleen, heart, lungs, or pancreas. In the vessels, the fibrous membranes, liga- ments, cartilages, and mucous outlets, they have not, I believe, been noticed. Viewed in reference to their structure, these adventitious sacs may be divided into three classes, — the simple, the multi- locular, and the included. Before we proceed to speak of these in detail, it will be proper to offer a few remarks con- cerning their contents. Like the natural serous membranes, the sacs in question, when once formed, or even whilst they are in progress of developement, enjoy a life of their OAvn, and are susceptible of various morbid actions, either set up in their substance or propagated to them from the surrounding normal textures. So long as they remain healthy, or in the exercise of the functions Avhich nature has assigned to them, the fluid Avhich they secrete, and Avhich occupies their inte- rior, is of a thin, watery consistence, clear and limpid, some- what saline in its taste, and more or less coagulable by heat, alcohol, or acids. As to quantity, it must vary, of course, according to the size of the morbid growth, in every grada- tion, from a single drop to many ounces or even quarts. When affected Avith disease, the contents of the cysts are differently altered, and, Avhat is remarkable, often present appearances Avhich are not to be observed under similar circumstances in the normal serous textures. The most interesting of these changes Avill be adverted to in another paragraph. The simple cyst, the type of the whole series, consists of a thin, delicate sac, generally of a globular figure, the inte- rior of which, in the healthy state, is occupied by a pellucid fluid possessing all the properties of the serum of the blood. CHAP. XVI.] MULTILOCULAR CYSTS. 145 Composed of a single lamella, it is usually perfectly transpa- rent, seldom bigger than an orange, and is supplied with very long, slender vessels, Avhich are evidently derived, in all cases, from the circumjacent parts. It is from these vessels, Avhich are often extremely numerous, and spread out in the most beautiful arborescent manner, that the cyst obtains its nutriment and the materials from Avhich it prepares its con- tents. They are accompanied, very probably, by nerves and absorbents ; but these, if they exist, are so excessively minute as to elude our closest scrutiny ; for no anatomist has ever succeeded, I believe, in tracing them. The parts in Avhich this variety is most frequently developed are the internal organs of reproduction of the female, particularly the ovaries and the fimbriated extremities of the fallopian tubes, the liver, and the brain, in the lateral ventricles of Avhich, along the choroid plexus of old subjects, they often occur in clus- ters of ten, twenty, or thirty at a time, the largest not ex- ceeding a common currant. Advancing a step higher in the scale of complexity, we come to the second division of our subject, the multilocular cyst. The principal difference between this and the preceding variety consists in the cellulated structure Avhich is to be found in the former, whilst there is an entire absence of it in the latter. This arrangement, from which the present acci- dental groAvth derives its name, is produced by a variable number of membranous processes, which are attached to the inner surface of the main cyst, and extend inward so as to intersect each other in different directions. In this way numerous compartments are formed, varying in size and shape, Avhich sometimes communicate together, at other times are perfectly distinct. The most curious circumstance con- nected Avith these chambers is, that they often contain dif- ferent kinds of substances. Thus, one may be occupied by perfectly limpid serum, a second by pure blood, a third by pus, and a fourth, perhaps, by fatty, melicerous or atheroma- tous matter. The reason of this cannot be easily explained : Ave might naturally expect to find it in some difference of structure ; but, in the majority of cases, no such difference exists ; and Ave are therefore forced to conclude that the phe- nomenon depends upon a modification of secretion. This variety of cyst is most commonly found in the cere- bral substance around old apoplectic effusions. It is also fre- quently seen in ovarian tumors, and in the subcutaneous vol. i. 19 146 serous cysts. [chap. xvi. cellular tissue, in parts Avhich are constantly subjected to pressure, as the shoulders of porters and the knees of chamber- maids. In its shape, the multilocular cyst is generally irregu- lar, its Avails are of unequal thickness, and its internal pro- cesses are often rough and uneven. The third variety, much less frequent than either of the others, is characterized by the circumstance of the main cyst, which is commonly of an irregular shape, containing clus- ters of smaller ones attached to different points of its inner surface. The number of included vesicles is sometimes truly surprising, many hundreds being found in the same specimen, from the volume of a grain of mustard to that of a hickory- nut, but mostly of a globular form : they are composed each of a single lamella, Avhich is continuous Avith, and appears to be merely a reflection from, the original sac, Avhich not un- frequently contains several series of these junior cysts. On cutting into them, they are found to be occupied, in the great majority of instances, by a serous fluid, in others by a matter resembling the Avhite of eggs, thin starch, or a solution of gum arable ; or all these substances may occur at the same time, filling different cavities. When the interior vesicles are large or numerous, they sometimes completely distend the main cyst, rendering it rough and protuberant, and occasion- ally even bursting it; after Avhich, being no longer repressed, they often grow Avith extraordinary rapidity. These cysts, Avhich I shall denominate the included, are apt to be confounded with hydatids ; but may be readily dis- tinguished by the fact of their being all intimately connected with the parent sac, and by the circumstance of vessels pass- ing from the one to the other. The parts in Avhich these cysts are most frequently met with, and in which they acquire the largest size, are the ovaries and the broad ligaments of the uterus. In most cases, as was previously stated, they are of a globular form; but it is by no means unusual for them to present a pediculated appearance, especially the binary and tertiary orders. Thus, there are three distinct varieties of serous cysts, all referable to three general modes of formation, the first being the most simple, the third the most complicated, the other being intermediate betAveen them. In other words, the first consists of a simple sac, filled with a serous fluid ; the second, of a sac which is intersected by more or less numerous pro- cesses ; and the third, of a sac which contains clusters of CHAP. XVI.] INCLUDED CYSTS. . 147 smaller ones, precisely of the same shape and structure Avith itself. It will be recollected that these different classes of cysts are the result, in most instances, of an entirely new forma- tion, dependent upon a perverted state of the nutritive func- tion. In other cases, they appear to be formed out of pre- existing textures, sometimes of a serous, at other times of a mucous nature. To the former category belong the cysts, Avhich are so often found in the ovaries, in consequence of the enlargement of the vesicles of De Graaf; to the latter, those Avhich are developed in the kidneys and in the female breasts, from obstruction of the excretory ducts. In these situations it is not uncommon for the adventitious growth to receive an accidental covering from the organ in Avhich it is located. In the ovaries, for example, we accordingly find that the cyst is usually provided Avith very thick, dense parietes, separable into three distinct layers, the internal of which con- sists of the capsule of the vesicle of De Graaf, the second of the albugineous, and the third of the peritonasal coat of the organ. The same thing is sometimes observed in the spleen and liver. It is worthy of remark here, that, Avhen the cyst is formed out of preexisting mucous membrane, as in the instances above referred to, it generally, in the course of a short period, assumes all the properties of the serous textures. Serous cysts, Avhether of neAV formation, or constructed out of preexisting tissues, are liable to inflammation, and, when thus affected, they may present all the phenomena which characterize this disease in other parts of the body. The contained fluid, in such cases, is generally thick, turbid, and discolored, oAving to the presence of substances Avhich do not naturally belong to it. Occasionally, it has the aspect and consistence of coffee-grounds, thin treacle, or tar; and the instances are by no means unusual in which it possesses all the characters of genuine pus. A fatty matter has also been found in it, and a substance resembling cholesterine. The cyst itself may be variously affected. Generally speak- ing, it is opaque, grayish, dense, and fibrous, being thicker and stronger at some points than at others. The examples, I believe, are rare in which the cyst is eroded, or transformed into cartilage or bone. The alterations which it creates in the parts in Avhich it is situated need not be particularly de- scribed, as they do not differ from those induced by hydatids. CHAPTER XVII. Of the Heterologous Formations. Preliminary Observations. — Classification: Tubercle; Melanosis; Scirrhus; Encephalo'fd. — I. Tubercle. — Definition. — Great frequency. — Occurs nearly in all Tissues, and at all Periods of Life.— Is common in the lower Animals. — Chemical Composition. — Varieties of Form. — Concrete and semi-concrete Tubercular Matter. — Notions respecting its Origin, Developement, and Or- ganization. — Softening and Excavations. — II. Melanosis. — HistoricaljSketch. — Occurs in Man and Animals. — Chemical Analysis.— Color and Consist- ence. — Varieties of Form. — Tissues most liable to suffer from Melanotic Dia- thesis. — States of the System which predispose to its formation. — III. Scirrhus. — Difficulty of the Subject. — Definition.—Varieties of Form. — Chemical Con- stitution. — Rarely appears before the age of thirty. — Most common in Glan- dular Organs. — Proximate Cause. — Opinions of Adams, Carmichael, Hodg- kin, and others. — Is apt to Ulcerate and involve the general System.— IV. Encephaloid.—Is intimately allied to Scirrhus. — Terms by which it has been designated.— More frequent in some Structures than in others. — Varie- ties of Form.— Color, Consistence, and Composition. — Organization and Mode of Origin. —A Disease of early Life. — Involves the whole System.— Termination. By the term heterologous are understood certain morbid products, of a solid or semi-concrete consistence, Avhich have no resemblance whatever, or, at most, only a very remote one, to the natural, normal, or preexisting tissues of the body. It is of Greek deriv-ation, literally signifying unlike, dissimilar, or Avithout analogy, and is employed by many as synonymous with the Avord heteroclite, first devised, I be- lieve, by some of the German anatomists. The number of heterologous products has been variously stated by writers, but it admits of much doubt, I think, whether there are really more than four, namely, the tuber- cular, the scirrhous, the encephaloid, and the melanotic. To these might, perhaps, be added the parasitic animals which are developed in different parts of the body, such as Avorms and hydatids, and the calcareous concretions which are found in certain cavities and canals, as in the urinary bladder, the ureters, the intestinal tube, and in the veins. Cirrhosis, scle- rosis, and some other morbid appearances, comprised under the present head by Laennec and Beclard, are evidently foreign CHAP. XVII.] DURATION--ORIGIN. 149 to it, and must therefore be excluded. Any arrangement, however, that may be offered in the present state of the sci- ence must, from the very nature of the subject, be imperfect, and susceptible of further improvement. Indeed, I am not certain that the term heterologous, as applied to these forma- tions, is not altogether ill-chosen and out of place, since most of them are found, when carefully investigated, to have a very close resemblance, in many of their most essential fea- tures, to the normal tissues of the body. Thus encephaloid bears a striking similitude to the substance of the brain ; melanosis, to the coloring matter of the skin; scirrhus, to the dermoid texture ; and tubercle, at least in some of its forms, to fibro-cartilage. But these are topics, concerning which, as we have no positive information, it would be idle to speculate. Although the heterologous formations, properly so called, are not of equal frequency, yet they all have one common tendency, namely, to destroy, sooner or later, the structure in Avhich they are located. Hence the propriety of the term malignant, under which some of them have long been no- ticed by authors, and from which arrangement, from some unaccountable circumstance, tubercle has hitherto been ex- cluded. Not only, indeed, is this disease malignant, but, if we reflect upon the rapidity of its progress, and its extraordi- nary fatality, it must unquestionably be regarded, I think, as the most malignant of all the heteroclite formations of which we have any knoAvledge. The period during which the mor- bid deposits remain, varies from a few months to several years, — a circumstance which, together with the several changes which they themselves undergo, and which they exert upon the structures in which they are located, will be again adverted to in the following sections. These morbid products occur at all periods of life, in both sexes, and in nearly all the organs and tissues of the body. Their origin, although still enveloped in obscurity, is proba- bly of an inflammatory nature, attended with an aberration of the nutritive function, and the deposition of a new sub- stance unlike that, as we have already stated, in part or en- tirely, of any other in the animal organization. 150 TUBERCLE. [CHAP. XVII. SECTION I. Tubercle. Of all the heterologous formations, the most interesting, unquestionably, is the tubercular, Avhether it be viewed in reference to its frequency, the obscurity which still envelopes its nature, or the great attention Avhich it has always elicited from the medical philosopher. Occurring at all periods of life, from the most tender infancy to the most decrepid old age, it is the cause, in all probability, of nearly one third* of all the deaths that annually happen throughout the world. If this be true, as the data Avhich Ave have, though still very imperfect, would lead us to infer, it will be readily granted that a knowledge of the disease before us must be of vast importance to the practitioner, and worthy of his deepest study and investigation. What is a tubercle ? A correct answer to this question, it will at once be perceived, will be a matter of no little mo- ment at the very outset of this branch of our subject. The term tubercle Avas anciently applied, in a very vague manner, to almost every kind of tumor, whatever might be its situa- tion, form, consistence, or chemical composition. The con- fusion concerning the character of this and other morbid products, thus introduced in the infancy of the medical pro- fession, prevailed during more than tAventy centuries, and is still, there is reason to believe, sufficiently common amongst the physicians of our own times, — many of them being ut- terly incapable of pointing out the true distinction betAveen tubercle, scirrhus, melanosis, and encephaloid. The defini- tions which have been given of this term are almost as numer- ous as the authors who have written upon the disease. It is of Latin derivation, and literally implies a little swelling. In the sense in which I shall here use it, it denotes a small, solid tumor, of an irregularly spherical figure, more or less opaque, of a pale yellowish color,'seldom exceeding the vol- ume of a pea, susceptible of organization, and composed of a * The greater part of this mortality is caused directly by pulmonary phthisis; the rest by tubercles of the lymphatic ganglions, the spleen, the serous mem- branes, and the bones. SECT. I.] SITUATION. 151 peculiar scrofulous matter, AA^hich, sooner or later, undergoes a process of softening. Such, then, is the signification in which the term will be employed in the present section; though, as will appear hereafter, the definition does not em- brace more than two of the varieties of form in Avhich the tubercular matter is deposited ; and it is rather in compli- ance Avith the established custom of pathological writers, than in reference to the rules of sound criticism, that I restrict the term Avithin these narroAV limits. Tubercle, as before intimated, is an exceedingly frequent and destructive disease ; and there is no organ in the body in which it has not occasionally been observed. I have seen it in the brain, lungs, thymus gland, pericardium, liver, spleen, kidney, supra-renal capsule, seminal vesicles and prostate gland, ovaries and uterus, the bones, intestinal canal, perito- naeum, pleura, and arachnoid, the bronchial tubes, lymphatic ganglions, on the surface of adventitious membranes, and in the interior of a polypus of the nose. The disease, hoAvever, is much more common in some organs and structures than in others. The lungs, lymphatic ganglions, the liver and spleen, together with the peritonasum, the intestinal canal, and the false membranes of the splanch- nic cavities, are the parts, beyond doubt, in which tubercle is most frequently observed. Of these parts, the summits of the lungs and the lymphatic ganglions, especially those Avhich are clustered around the bronchial tubes, are those in which the heterologous matter is most generally deposited; and it is important to remark, as has been justly observed by Professor Alison, of Edinburgh, that these are textures in which the capillary circulation must necessarily be very tardy. In reference to the primitive tissues, the cellular, it seems to me, is the one in Avhich tubercle is most usually situated. The mucous element is, no doubt, also often the original seat of the morbid product, but by no means so frequently as is supposed by Professor Carswell. It Avould appear, from the researches of some of the Euro- pean pathologists, as Louis, Lombard, Andral, and Papavoine, that the site of tubercular disease is influenced, in a very considerable degree, by the age of the individual. This is a circumstance which, from its practical bearing, is deserving of further attention. The tAvo folloAving tables afford an account of the localization of this heterologous deposit in children and in adults. The first is constructed from the 152 TUBERCLE. [CHAP. XVII. excellent memoir of Dr. Lombard, of Geneva, and is founded on one hundred careful autopsic inspections made with a view of ascertaining the relative frequency of tubercles in different organs. TABLE I. Bronchial ganglions, Lungs, Mesenteric ganglions, Spleen, Kidneys, Intestines, Nervous centres, . Cervical ganglions, Cerebral envelopes, Pancreas, . Gastro-hepatic ganglion, Subperitoneal cellular tissue, Inguinal ganglions, Subpleural cellular substance, Lumbar ganglions, Urinary bladder, Omentum, Gall-bladder, False membranes of tbe pleura, 87 times. 73 31 25 11 9 9 7 6 5 5 5 3 2 1 1 1 1 1 The second table is compiled from the treatise of Dr. Louis, of Paris, and refers to persons that died of consump- tion after the age of fifteen. A comparison of this Avith the materials furnished by Dr. Lombard, will show the occur- rence of tubercles in different organs in the two periods of life. TABLE II. Small intestines, Large bowels, Mesenteric ganglions, Cervical ganglions, Lumbar ganglions, Prostate gland, Spleen, Ovaries, . Kidneys, about x 4 1 TO" 1 T2" 1 T3 TV l 2"tf In the one hundred and twenty-seven examinations made by Louis, the general results of which are exhibited in the SECT. I.] SITUATION. 153 above table, tubercles occurred only once in the uterus, twice in the brain, once in the ureter, twice in the liver, and tAvice in the supra-renal capsules. The inference deducible from these tables is, first, that, in children, tubercles not unfrequently occur in different parts of the body, Avithout existing in the lungs ; secondly, that they are more liable to affect the lymphatic ganglions than in adults; and, thirdly, that they have a tendency to attack a much greater number of organs simultaneously or succes- sively. It is a singular circumstance, that the spleen is seldom tuberculized in adults, whilst it is very often affected in children, in the proportion nearly of one to four. It Avould appear, both from the observations of Louis and of Lombard, but particularly from those of the latter, that the liver is also remarkably exempt from the disease, —a result Avhich is, how- ever, strikingly at variance with the experience of Papavoine, who found these bodies in more than one fourth of his autopsies, namely, in fourteen children out of fifty. The intestines appear to be affected nearly equally in both periods of life. The period of life most liable to tubercle is between tAventy and forty. But no age is exempt from it, and, what is remarkable, it appears occasionally to exist as an intra- uterine malady. The late Professor Chaussier, of Paris, has related several cases of miliary tubercles in the lungs of the foetus; and, more recently, several analogous examples have been published by Billard and Husson. In one of the cases, given by the latter of these Avriters, the infant was still-born at the seventh month; and the tubercles, which were seated in the pulmonary tissue, were in a state of softening. In the three examples mentioned by Billard, the disease oc- curred, in one, in the peritonasum, and, in the other two, in the mesenteric ganglions. My excellent friend and colleague, Professor Rives, a feAV years ago, met Avith tubercles in the lungs of an infant, six weeks old, some of which Avere con- crete, others in a state of suppuration; and in a child of less than three months of age, which I examined last winter, similar phenomena AA^ere Avitnessed. On the whole, however, there is sufficient ground for concluding that tubercles are of comparatively rare occurrence in the foetus, since, in many hundred dissections of new-born infants made in Paris, by Breschet, Guizot, and Velpeau, these bodies were not seen in a single instance. vol. i. 20 154 TUBERCLE. [CHAP. XVII. Of the great prevalence of tubercular disease in early life, little seems to have been knoAvn until a very recent period, and for our information concerning it Ave are mainly indebted to the researches of the Parisian anatomists. The facts which they have furnished upon this point are of a most startling nature, and the practical inferences to be deduced from them are too evident to require any comment in this place. Tubercles are not peculiar to the human race. They have been observed in many species of animals, — in birds, reptiles, and even in insects; though, as respects the latter, facts are still Avanting to illustrate the subject. Amongst quadrupeds they have been noticed in the ape and monkey, the horse, ox, elk, deer, and antelope, the dromedary, sheep, goat, hog, bear, lynx, dog, lion, tiger, cat, squirrel, and rabbit; amongst birds, in several species of macaws and parrots, the turkey, hen, sparrow, and flamingo; amongst reptiles, in the serpent, frog, and turtle.* In all these various classes of beings, the morbid deposit presents the closest analogy to that observed in the human subject, and is likewise more frequently seen in the lungs than in any other organ. Nor is it limited to any particular period of life. It is very frequently witnessed in the youngest animals, and Dupuy has even met with it in the foetus of the sheep and rabbit. In lambs, from two to five months old, I have often seen the liver and lungs crowded with miliary tubercles. It is a singular fact, and one not Avithout its value in a practical point of view, that most of the wild and domes- ticated animals become affected Avith tubercles after a certain period of their confinement. Many of the quadrupeds that are imported into this country, and exhibited in our menage- ries, die from this cause; and the same thing is said to ob- tain in regard to the milch-cows in the larger cities of Europe. Here the disease is no doubt induced in the same manner and by the same agents as in the human subject, — inactivity, want of nutritious diet and of fresh air, being so many pre- disposing circumstances. The composition of tubercular matter has been studied by several chemists, but the most recent and accurate analysis is by Dr. Hecht, a distinguished medical philosopher of Stras- burgh. According to this indefatigable investigator, it con- sists of nearly equal proportions of albumen, fibrin, and * Clark on Consumption and Scrofula, p. 212. London, 1838. SECT. I.] COMPOSITION--VARIETIES. 155 gelatine. With these results the examination of Thenard, previously made, is strikingly at variance. This individual found that one hundred parts of crude tubercular matter con- tained upwards of ninety-eight parts of albumen, the remain- der being made up of muriate of soda, phosphate and carbonate of lime, and a minute quantity of the oxide of iron. These discrepancies in the results of these analyses may be ac- counted for, I think, by supposing that the chemical composi- tion of tubercular matter varies, as no doubt it does, not only in the different stages of its existence, but also in different animals, and probably in different organs. In the ox, in par- ticular, there is ahvays a predominance of earthy salts, and hence the extraordinary bitterness Avhich characterizes the morbid product in the animal in question. In the turtle I have seen the tubercular substance of the color and consistence of calcareous moss, or what, in mineralogical language, is termed tufa. The most interesting fact developed by the researches of Dr. Hecht, and to which I Avould especially direct the attention of the reader, is the existence of fibrin, which intimately as- similates this matter to, if it does not render it identical with, the adventitious membranes of the serous and mucous tex- tures. The morbid matter is deposited under several varieties of form. Of these the most common by far is that called the mil- iary, from its resemblance to a millet-seed, (Plate I, Fig. 1.) The tubercles in this species of the disease are of an irregularly spherical shape, and vary in size between a pin-head and a common pea. In the brain and liver they are sometimes as large as a cherry, a marble, or even a billiard-ball. Most generally they are of a dull yellowish color, occasionally grayish, and in many cases they are speckled, bluish, or of a pale milky aspect. Their consistence is also liable to much diversity. Sometimes they are as hard and dense as fibro- cartilage, whilst, at other times, they are soft, and almost semi- liquid. In the former case, they sensibly creak under the knife, and often exhibit, Avhen cut, a bright vitreous appear- ance, not unlike ground glass. To tubercles possessing these properties Bayle and Laennec have applied the term " granu- lation,"— an expression Avhich is still retained by Louis, and some other writers. In their primitive state, the miliary tubercles are perfectly distinct, but, ultimately, as they augment in volume and number, they coalesce, and thus destroy the separation, re- 15C TUBERCLE. [CHAP. XVII. sembling, in this respect, the pustules of confluent small-pox. In this Avay large masses are frequently formed, varying in density, from the consistence of recent lymph to that of cartilage, and presenting an ovoidal, globular, angular, or stellated configuration. Tumors of this description seldom exceed the dimensions of a walnut, yet sometimes they at- tain the bulk of an orange, the fist, or even of a foetal head. This variety of the tubercular deposition, although most com- mon in the lungs, is often observed in the other organs, and in none more so, according to my own experience, than the spleen, peritonaeum, liver, and kidney, the frequency of its occurrence being in the order here stated. It also occurs very often in the bones, especially in those of the spine, and in the lymphatic ganglions of the mesentery, loins, and bronchial tubes. Cases occasionally occur, in which these bodies are sur- rounded by a distinct capsule, constituting the encysted tubercle of Bayle, (PI. I, Fig. 2.) The envelope is usually of a fibrous nature, and of a pale grayish color; sometimes pink, violet, or mottled. Varying in thickness from the fourth of a line to a line, it adheres closely by its outer surface to the tissues into Avhich it is deposited, and from which it can be separated only by the knife or by forcible detraction. The contents of the cyst are commonly of a grayish-yellow com- plexion, opaque, and speckled with dark points ; and so long as- they remain solid they are firmly attached to its inner sur- face. Both structures have probably a contemporaneous origin. This, hoAvever, is still a mooted question, concerning which it is impossible at present to come to any correct decision. In old tubercles the cyst is sometimes ossified, either in part, or wholly. Laennec mentions an example of this kind, and a similar one is described by the celebrated Bayle. This variety of tubercle is very rare. Louis has seen only a solitary instance ; and Professor Carswell appears altogether to doubt the possibility of its occurrence. The celebrated Laennec also met with it only on a few occasions ; and, thus far, although I have made numerous examinations of persons who have died of this malady, I have never seen more than five or six well-marked examples of it. The situations in which it is most commonly found are the peritonaeum, the lungs, the brain, the bronchial lymphatic ganglions, and the bones. According to Meckel, the encysted variety of tubercle SECT. I.] INFILTRATION--STRATIFORM. 157 is more frequent in the inferior animals, as the monkey, dog, and antelope, than in the human subject.* A third variety of tubercular matter exists in the form of infiltration, (PL I, Fig. 3.) It is often found around tubercu- lar excavations, sometimes in considerable patches, of a gray- ish or yellowish appearance, more or less dense, crisp, and firm, like cartilage. In its texture it is apparently homogene- ous, presenting, Avhen divided with the knife, a smooth, pol- ished surface, in Avhich it is impossible to discern the slight- est trace of the original structure. Occasionally the deposi- tion has the aspect and consistence of jelly, constituting the gelatinoid infiltration of Laennec, —a distinction Avhich is as unscientific as it is unnecessary, since it forms merely a va- riety of what I have just described. The fourth and last variety is the stratiform, in which, as the name imports, the tubercular matter is deposited in the form of a layer, generally upon the free surface of the mucous membranes, (PI. I, Fig. 4.) Next to the miliary va- riety, this seems to be the most common form in which this substance is secreted. It is very frequently met Avith in the bronchial tubes, and occasionally, though much more rarely, in the ureter and pelvis of the kidney, the uterus, and the seminal vesicles. This variety of tubercle is not peculiar to the human subject. It has been repeatedly observed in the cow, sheep, and rabbit; and I have myself recently seen a beautiful specimen of it in the lungs of the green turtle, which I have placed in the museum of the Cincinnati Col- lege. The tubercular matter, in this case, is deposited, in some places, in thin, yelloAvish patches, of an irregular shape, and from the diameter of a five-cent piece to several inches ; in others, in long, cylindrical masses, which are • accurately moulded to the tubes in which they are situated. In some of the bronchia?, the secretion is firm and tenacious, being with difficulty separated from the mucous surface ; in others, it is very brittle, dry, and apparently unconnected. Many of the air-vesicles are entirely closed up Avith this substance, and, what is remarkable, it seems to contain a much greater amount of earthy matter here than where it is spread over the bronchias. When the tubercular matter is poured into the seminal vesicles, the uterus, the ureter, or pelvis of the kidney, the * Pathol. Anatomie, 2 ter Band. S. 370. 158 TUBERCLE. [CHAP. XVII. stratiform arrangement is only Avell-marked so long as the de- posit is scanty; for, as soon as it becomes abundant, it as- sumes an amorphous, nodulated form, composing masses Avhich occasionally entirely distend the interior of these res- ervoirs. The same arrangement is often Avitnessed in the bronchial tubes, and, from the matter sometimes reaching from them into the air-cells, it is not unusual to see it form small caulifloAver-shaped expansions. Such, then, are the four varieties of form in which the tu- bercular matter is deposited in our organs and tissues, name- ly, the miliary, encysted, infiltrated, and lamellated. Of these, the first and last, it will be recollected, are the most common, not only in man, but also, so far at least as Ave now know, in the inferior animals; and they are all, it is obvious, entirely dependent on the structure of the part in which they occur. The consistence of the tubercular matter also varies, it should be remembered, from that of a fluid to the firm- ness of cheese, fibro-cartilage, cartilage, and even bone. Much has been said by Avriters respecting crude and semi- concrete tubercles, some supposing that they are originally de- posited in a solid, others in a liquid state. Without stopping to inquire into the merits or demerits of these questions, which the limits of this paper will not admit, it may be remarked that every known fact in pathological physiology is strongly corroborative of the opinion, that all tubercular matter is primitively soft, semi-liquid, or gelatinous. The chemical, physical, and anatomical characters of this matter, all con- spire to shoAv its similarity with the coagulating lymph, as it is revealed to us upon the free surface of the serous and mu- cous textures, in the various splanchnic cavities, upon the surface of a recent Avound or a granulating ulcer, and finally upon the surface of the crassamentum of blood taken from persons affected with inflammation. From the well-conduct- ed researches of Dowler, Gendrin, and Bretonneau, it clearly appears that the substances found in these different situations are all composed essentially of albumen, fibrin and gelatine, in varying proportions, there being sometimes a predominance of the one, sometimes of the other. The similarity, then, of these morbid products being admitted, as unquestionably it must, who Avill contend that the tubercular matter is ever de- posited in the solid form ? Where is there an instance in which the fibrin of the blood is eliminated in a concrete state ? Do we find it thus poured out in the inflammations SECT. I.] ITS NATURE. 159 of the serous membranes ? Is it thus deposited upon the in- terior of the larynx, the trachea, and bronchial tubes, the in- terior of the uterus, or the alimentary canal, betAveen the edges of a recent wound, or around the fragments of a broken bone ? Experience and common sense alike answer in the negative. But this is not all. In certain parts of the body, as, for example, in the peritonaeum, Ave can detect nature, as it were, in the very act of her work, and distinctly examine this substance as it is about being converted from the fluid into the solid state. In several cases of chronic inflammation of this membrane, I have discovered tubercles in every possible stage of developement, some of them—evidently deposited only a day or two before the individuals expired — being of a soft, viscid consistence, and perfectly transparent appear- ance ; others semi-concrete, yellowish, and consequently more or less opaque; and, lastly, another set perfectly dense and firm, like fibro-cartilage, organized, and covered by an acci- dental serous membrane, of the most delicate texture. Thus, the conclusion is obvious, that all tubercular matter, whatever may be its form, site, extent, is, in the first instance, of a liquid nature, and that it becomes solid only by the removal of the serosity Avhich is always poured out simultaneously with it. The period required for the developement of solid tuber- cles is so exceedingly variable that it is difficult, if not im- possible, to lay down any definite rules on the subject. In acute phthisis, Louis says that they may reach the size of a pea in three or four weeks; and, in the peritonaeum, there is reason to believe that they often attain this bulk in a much shorter time, though this is a point which has not yet been satisfactorily settled. In other eases, they remain small for a considerable period, sometimes for several months, and per- haps even years; all the symptoms of the disease being, in the mean time, fully formed. Various notions have been entertained by pathologists re- specting the precise nature of tubercles, some of which, it must be confessed, are extremely crude and unsatisfactory. Hippocrates and Aretaeus, Fernal and Morgagni, ascribe their formation to the concretion of a thick, viscid fluid, poured out by the vessels into the delicate texture of the lungs, and probably analogous to what has since been termed the coagu- lating lymph. Sylvius de la Boe, whose works were pub- lished towards the close of the seventeenth century, imag- 160 TUBERCLE. [cHAP. XVII. ined that they Avere nothing but lymphatic ganglions, Avhich, scattered every Avhere through the parenchymatous structure of our organs, Avere rendered morbid by the effects of inflam- mation. This opinion Avas aftenvards adopted, and more fully illustrated by Wepfer and Morton, and, strange as it may seem, it has received the sanction of the great Broussais, and several other distinguished authors of our own day. Our illustrious countryman, Dr. Rush, considered tubercles as a collection of inorganic mucus ; and Laennec, it is well known, believed that they are always deposited in a crude state. The reverse of this view has been recently maintained, Avith much zeal and pertinacity, by Dr. Baron, an eminent English phy- sician. In his " Inquiry on the Nature of Tubercular Accre- tions," published in 1819, he attempts to prove that these little bodies are essentially hydatic, and that, instead of pass- ing from an indurated to a softened state, as is asserted by Laennec and some of his disciples, they are originally simple vesicles, filled with thin, albuminous matter, Avhich, in pro- cess of time, undergoes inspissation.* Amidst such contra- rieties of opinion, it is extremely difficult to decide which of the hypotheses here referred to is most entitled to our confidence and regard. After much reflection, however, upon the subject, and from careful and repeated examinations of tubercles in different organs of the body, in different individ- uals, and in different stages of their developement and growth, I am constrained to believe that the heterologous formations are originally nothing but a species of coagulating lymph, thrown out as an effect of inflammatory irritation, and modi- fied in its character according to the tissues in which it is deposited. The doctrine of the hydatic origin of tubercles, although highly ingenious, and ably defended by its author, is, besides * " It is probable that all tubercles, wherever situated, and of whatever sub- stance composed, were, at their commencement, small vesicular bodies with fluid contents. It is impossible to say how minute they may have been at their origin, nor how large they may grow before their transformations begin ; nor are we acquainted with the circumstances which occasion such transformations. But that they do take place has, I conceive, been demonstrated beyond the possi- bility of doubt." (Baron's Inquiry illustrating the Nature of Tubercular Accre- tions of Serous Membranes, p. 214. London: 1819.) Further on, the same au- thor remarks: " It is not known how the change in hydatids are effected; but to these changes, certain tubercles owe their existence, and on the size, relative position and structure of the tubercles which are so formed, depend the characters of many of the most formidable disorganizations to which the human body is exposed." (lb. p: 215.) SECT. I.] ITS NATURE. 161 being opposed by analogy, Avholly unsustained by facts. Dr. Dupuy, a distinguished veterinary surgeon of Paris, has fre- quently witnessed, it is true, the coexistence of tubercles and hydatids in the lungs and other organs of the inferior animals; but such an occurrence, it is Avell knoAvn, is extremely rare in the human subject; nor, were it more common, would it at all prove that the former of these bodies OAved their origin to the latter, any more than that carcinoma and melanosis, because they are sometimes found together, are dependent the one upon the other for its evolution and subsequent groAvth : it merely shoAvs that these morbid products may occur in the same organ; certainly nothing more. On this point tAvo of the best authorities of the present day, Andral and Louis, perfectly agree. Both these writers have had ample opportunities for testing the truth of Dr. Baron's doc- trine ; yet Avhat is their conclusion ? Why, that it is entirely erroneous, from beginning to end. In many thousand dis- sections, they declare that they have never seen hydatids in more than five cases, and in only one of these Avas the disease complicated Avith tubercles. My OAvn experience, although much more limited, is of a similar character; as is also that of Dr. Stokes, of Dublin, decidedly one of the most intelligent observers of the present day. But inde- pendently of the great infrequency of hydatids in our organs and tissues, the fact that the tubercular matter is deposited upon the free surface of the mucous membranes, and infil- trated into the cellular element in various situations, is at once a death-blow to the doctrine, I should rather say hypoth- esis, which we have been considering. Believing, then, that the doctrine of the entozoic origin of tubercles is fundamentally untrue, unsupported, as it is, either by observation or analogy, I will merely remark, in con- cluding this branch of the subject, that we are not singular in ascribing the formation of these bodies to inflammatory irritation. Broussais, as has been already intimated, adopting the vieAvs of Wepfer and Morton, is one of the most strenu- ous advocates of this opinion ; though he undoubtedly erred, in common with these Avriters, in supposing that tubercles are merely diseased lymphatic ganglions. This hypothesis, indeed, is at once overthrown by the Avell-knoAvn fact, that strumous matter is frequently found upon the free surface of the serous and mucous membranes, Avhere there is an entire absence of absorbent glands. Still more conclusive evidence vol. i. 21 162 TUBERCLE. [CHAP. XVII. is afforded by the presence of tubercles in the substance of the adventitious textures, in the thoracic and abdominal cavi- ties. The inflammatory origin of these deposits is also main- tained by Andral, Lombard, Alison, Ravire, Roche, and Sanson. Louis, on the contrary, supposes that irritation, al- though it may occasionally exert an influence of this kind, produces no such results in the great majority of cases. Dr. Stokes, again, refers the tubercular matter to a lesion of nutri- tion, generally brought about by local excitation. The vieAvs of this eminent physician do not therefore differ much, if at all, from those of the above pathologists. In summing up the pathology of this deposit, Andral re- marks that " it must be considered as the result of a modifi- cation or perversion of secretion, Avhich is often attended or preceded by an active sanguineous congestion. This is all we know for certain; beyond this, every thing is mere con- jecture." The doctrine, moreover, of the inflammatory origin of the deposition in question, derives great plausibility from Avhat is observed to occur in the inferior animals from mechanical irritation. In the experiments of Cruveilhier, Kay, and Saunders, well-characterized tubercles were produced in a very short time, simply by dropping mercury into the trachea, and keeping it in contact with the minute vessels of the lungs. When we couple the result of such investigations with what is witnessed in persons who habitually inhale irritating particles of matter, such as weavers, needle-grinders, and miners, who are peculiarly liable to pulmonary phthisis, and Avith the circumstance that incipient tubercles frequently coexist with capillary engorgement, serous effusion, and de- posits of lymph, the conclusion forces itself irresistibly upon the mind, that these bodies are produced by inflammation, either of an acute, or, as is perhaps more frequently the case, of a slow chronic character. Laennec supposes that tubercles grow by intussusception, that is to say, from without inwards. This view, however, has been shown to be erroneous, it being well known now that particle after particle is deposited around the original nucleus of matter, until the foreign body attains its full de- velopement. The process is thus not unlike that of amor- phous crystallization. Are tubercles ever organized ? On this subject, too, much diversity of sentiment prevails amongst pathological anato- SECT. I.] ORGANIZATION. 163 mists. By most of them, indeed, the question is but faintly alluded to, and, so far as my information extends, there is not a single one Avho has furnished us Avith any satisfactory ac- count of it. " The most important fact," says Professor Carswell, " connected with these bodies is, that they are not susceptible of organization, and consequently give rise to a morbid compound, capable of undergoing no change that is not induced in them by the influence of external agents." " Whatever," remarks Dr. Clark, in his Treatise on Pulmonary Consumption, " may be the site, consistence, or form of tubercular matter, it is to be regarded as a morbid inorganiza- ble product, and consequently insusceptible of any change that is not affected by the living tissue in Avhich it is de- posited." In speaking on this subject, Professor Alison, of Edinburgh holds the folloAving language : " Although tuber- cles undergo various changes in the interior of their substance, at various periods after their deposition commences, it does not appear, from injections, that they are themselves provided Avith vessels, and hence they have been called morbid secre- tions, perhaps more properly than adventitious textures." Such are the sentiments of three of the most distinguished pathologists of Great Britain. Hoav far they are correct, we shall endeavor to show, as Ave proceed with the discussion of this question. That tubercles are invariably organized, that is, provided with vessels, nerves, and absorbents, no one, at all acquainted Avith the subject, will, it is presumed, attempt to assert. There are some situations, indeed, in which it would be impossible for the process to be effected ; as, for example, Avhen the strumous matter is spread over the free surface of the mucous membranes, whether in the bronchial tubes, the uterus, seminal vesicles, or the excretory ducts of the kidneys. Here the heterologous nature of the contents of these reser- voirs would be alone an insurmountable barrier to the organi- zation, to say nothing of the peculiar modified character of the morbid secretion itself. I say peculiar modified character, because it is well known that the chemical and physical properties of the tubercular deposits are Avidely different in the localities here specified from what they are in other parts of the body. They are usually of a deeper yellowish color, and much more curdy and friable, from their containing a much greater amount of earthy ingredients. Upon this point, it is impossible, I conceive, that there should be two opinions. 164 TUBERCLE. [chap. XVII. Thus, then, it may be stated, as a general proposition, that, when the tubercular matter is deposited upon the larger mucous surfaces, it is not susceptible of organization ; Avhilst, when it is effused into the cavities of the cellular tissue, into the air-vesicles of the lungs, and into the intermolecular spaces of our organs, it may, and often does, become " part and parcel" of the living frame. Within the last two years, I have examined not less than six specimens of organized tubercles, one occurring in the kidney, two in the spleen, one in the peritonaeum, and tAvo in the lungs. They were taken mostly from children under tAvelve months of age. The tubercles Avere of the miliary kind, and numerous vessels, loaded with florid blood, could be seen shooting into them in every possible direction, many of them penetrating a considerable distance into their substance. Their vascular supply would thus seem to be derived from the tissues in which they are deposited ; and this, in the generality of cases, is no doubt true ; nevertheless, there is reason to suppose that they occasionally possess a self-organizing power, analogous to that of the adventitious membranes in the splanchnic cavities. Placed under favorable circumstances, coagulating lymph can always create vessels of its own, as is shown in the formation of the placenta, and of what are termed the analogous tissues ; and, although the vessels thus constructed are very small and few in number, they are sufficient, it is presumable, in many instances, to preserve the vitality of the tubercle without the aid of the circumjacent textures. Generally, however, such aid is not long withheld ; for as the neAvly-formed vessels extend from the central to the peripheral portion of the heterologous deposit, they speedily communicate with arteries and veins belonging to the affected organ. It is in this manner that the vitalization of tubercles may be supposed to be effected, and in proportion to its perfection will be their power of resisting such agents as have a tendency to destroy them. In making these remarks, I would not wish to be under- stood as asserting that I have seen the vessels Avhich have been supposed here as forming the proper circulation of tuber- cle : their existence is altogether assumed from the analogy afforded by encephaloid growths, and the adventitious mem- branes. Actual observation will, perhaps, never avail us greatly in determining the question, inasmuch as the subject is beset Avith difficulties scarcely to be found in any other morbid deposit. But I do assert, unhesitatingly, that I have repeat- SECT. I.] ORGANIZATION. 165 edly traced vessels into such tumors from the tissues around them, and, that upon dividing them, the section thus made has frequently exhibited small florid dots of blood. Several of these examinations were made in the presence of highly in- telligent pupils, and one was Avitnessed by Professor Harrison, my distinguished colleague in the chair of materia medica. But it may be objected that these vessels have never been injected. Granting this to be true, and what, it may be asked, does it prove ? Are we reduced to the necessity of denying the vitality of a structure, because we cannot succeed in throAving foreign substances into its vessels ? If this be a fair criterion, then we must conclude that the cornea, the crystalline lens, the membrane of Jacob, the inner coat of the arteries and veins, the endocardium, and the arachnoid tunic of the brain, together with the chorion and amnion, are not organized. But Avho would be so silly as to suppose that this was the case, when daily observation demonstrates that these textures are abundantly supplied with vessels, nerves, and absorbents, though none of these tissues can be detected by inspection, no matter to what methods we resort to for that purpose. At what period the organization of tubercles commences, is a point concerning which we are still perfectly in the dark, and which must remain for the present undetermined. It is reasonable, however, to suppose that nature observes no uni- form law in regard to this matter, and that she begins her efforts at vitalization at a period varying from two to three days to as many months, from the moment of the morbid deposition. I have never been able to trace any nerves or absorbent vessels into these bodies, nor am I aware that this has been done by others ; nevertheless, as these structures are every where necessary to organization, it is allowable at least to infer their existence. Another proof, but of a more indirect character, of the organic nature of tubercle, is furnished by the fact, witnessed by numerous and highly respectable ob- servers, that these bodies are often of a yellowish tint in jaundice, — oAving obviously to the admixture of the coloring matter of the bile Avith the blood, both being simultaneously circulated through the heteroclite mass. But, Avhatever notions may be entertained concerning the origin and nature of these bodies, — whether Ave consider them with Wepfer, Broussais, and others, merely as diseased 166 TUBERCLE. [CHAP. XVII. lymphatic ganglions, or Avith myself, as depositions of coagu- lating lymph, produced by inflammatory action, and suscep- tible, under certain circumstances and conditions of the sys- tem, of organization, they sooner or later become soft and fluid, the necessary consequence, it may be presumed, of their crude state. This process is supposed, by Louis and Laennec, always to begin in the centre of each mass ; but Andral and Carswell maintain that it may commence at any part, indif- ferently, at the centre or at the circumference ; and such, pre- cisely, is the result of my OAvn observations. As it pro- gresses, the tubercular matter becomes daily more and more soft, moist, and unctuous, until at length it acquires the ropi- ness and fluidity of pus. When the degeneration involves the Avhole mass, it is usual to find two different kinds of mat- ter in it; one thick, straw-colored, and inodorous, like lauda- ble pus ; the other thin, commonly tinged with blood, and mixed Avith small, opaque, cheesy flakes. This is more par- ticularly the case in scrofulous subjects, in whom the fluid in question often strongly resembles Avhey, with minute portions of curd floating in it. Conformably Avith the doctrine Avhich it has been attempted here to enforce, — that tubercles are organized structures, — the process of softening may be supposed to be analogous to sIoav suppuration, by Avhich the heterologous tissue is gradual- ly broken up and destroyed. Let me be understood. After tu- bercles have existed for some time in an organ, as, for exam- ple, the lungs, they begin to act as extraneous bodies, pro- ducing irritation in the immediately circumjacent textures. This irritation, it may be presumed, is speedily propagated to the tubercles themselves; and, as their vital endoAvments are comparatively feeble, and consequently incapable of much resistance, they soon yield to the invasion, the rapidity of their softening being always in direct proportion to the vio- lence of the exciting cause and the density of the morbid groAvth. Those, on the other hand, Avho believe that tuber- cles are inorganic, maintain that their softening is brought about by the agency of the surrounding tissues, alleging that they are incapable of undergoing such a change by any powers of their own. If this explanation were correct, the process should always begin at the periphery of these bodies, which, hoAvever, as Avas before stated, is not the case. The softening takes place much more rapidly in some or- gans than in others, in Avhich it does either not occur at all, SECT. I.] SOFTENING. 167 or only after a long period. In the lungs, where the process has hitherto been chiefly studied, it may take place as early as the end of the first month from the time of the deposition, though generally not until much later. Upon this subject, however, it is obviously impossible to lay doAvn any definite rule, as the production of the phenomenon in question must necessarily be influenced by a great variety of causes, such as the extent of the disease, the state of the patient's health, the density of the heterologous deposit, together with numer- ous other circumstances which will readily suggest them- selves to the mind of the reader. Occasionally the softening goes on simultaneously over a large extent of surface, so as to break doAvn one third, a half, or two thirds of an organ ; but this occurrence is extremely rare, and is confined exclu- sively to acute cases. In the lungs, the degeneration usually begins at the summit of these organs, and gradually extends toAvards the base, as is shown by the fact, that if these viscera be examined in this direction, Ave successively find, at va- rious heights, excavations and tubercles in different stages of softening, — the more solid being almost always lowest in the scale. Before the changes, of which we have now spok- en, take place, the morbid deposit appears to create little dis- turbance in the general economy, and may exist, sometimes to a very considerable extent, Avithout giving rise to symp- toms indicative of its presence. After having become perfectly soft, the tubercular matter is either absorbed, or, if it be favorably situated, it works its way out. In the lungs, it usually breaks into the bronchial tubes, leaving thus, not unfrequently, a considerable number of excavations, ox fistulous apertures. In the examinations of Dr. Louis, these caverns were never found entirely empty before the end of the third or the beginning of the fourth month, counting from the time of the invasion of the disease. In recent cases of this kind, the Avails of the chamber are soft, and lined by a thin coating of lymph : in more ancient ones, the false membrane is dense, grayish, sometimes semi- cartilaginous, and from one fourth to one third of a line thick. These excavations are most common in the lungs : they are sometimes found in the brain, the liver, spleen, kidney, and bones ; but so seldom, that our knowledge concerning them is still very imperfect. In the kidney I have met with this lesion but once, in a young man, whose case will be 168 MELANOSIS. [CHAP. XVI I. more particularly described in its proper place. In the long bones, these caverns, as they may be termed, occasionally com- municate with the medullary canals, or some contiguous joint, establishing thus an analogy with tubercles of the lungs opening into the bronchial tubes ; and in the short bones, as those of the spine, it is not uncommon for them to work their way out to the surface, in many instances by long, tor- tuous passages, Avhich it is ahvays difficult, nay, frequently impossible, to heal. The size of these caverns is sometimes very considerable. I have frequently found them as large as a lien's egg, and, in one or two instances, even of the volume of the fist: gen- erally, hoAvever, they are much smaller, not exceeding the size of a hazelnut, an almond, or a walnut. The lesions Avhich have been observed in the pulmonary tissue around these cavities, together with the changes experienced by the vessels, will be more fully described in the chapter on tuber- cles of the lungs, to which Ave must also refer for an account of the process of cicatrization, as it takes place much oftener in those organs than in any other parts of the body. SECTION II. Melanosis. One of the most singular, and, at the same time, one of the rarest of the heterologous formations, is fhe melanotic, — for a correct knoAvledge of Avhich, we are indebted to Laen- nec. The first account of this disease was given by this dis- tinguished pathologist in 1806, in the Bulletins de la Faculte de Medicine de Paris; and the same description was after- wards imbodied in his learned work on thoracic maladies. The term employed to designate this morbid product is a Greek compound, literally signifying the black disease, and is synonymous with what Dupuytren and Alibert, with some others, have since called black cancer. The account which Laennec has left of this accidental product, and which may be considered as one of the most ac- curate and graphic that has ever been furnished, describes it as SECT. II.] COMPOSITION. 169 a homogeneous substance, very similar in its structure and consistence to a bronchial gland, of a deep black color, opaque, humid, and slightly unctuous to the touch. This substance, after a while, has a tendency to become soft, — the process by Avhich this is effected generally commencing in the centre, and gradually proceeding towards the circumference, until it is en- tirely broken up and dissolved. When this is accomplished, nature sets up an eliminating effort, the surrounding parts take on inflammation, and the heterologous matter is finally expelled, thus leaving a corresponding cavity, Avhich either continues open, is lined with lymph, or else completely ob- literated. No age nor sex seems to be exempt from this disease, though it is, without doubt, much more frequent in the old than in the young. Nor is it confined exclusively to the hu- man subject. Dupuy and Rodet have frequently seen it in the horse; Breschet and others, in the dog, cat, rabbit, rat, and mouse ; and I myself often in the ox. What is remark- able, this substance is much more common in Avhite than in colored horses ; and the same is true, I have reason to believe, in regard to cattle. To what this circumstance is to be at- tributed, it is not very easy to determine, unless we admit the conjecture of Andral, that the black pigment of the skin, instead of being deposited in its usual place, is transferred to other organs and textures in which it is not naturally found. In the horse, melanosis most frequently occurs under the shoulder-blade, in the pelvis, around the anus and vulva, and along the under surface of the tail. It is also frequently ob- served beneath the skin, Avhere it forms numerous chaplets, composed of granular bodies, from the size of a filbert to that of a small egg. The melanotic substance has been examined by different chemists, both in England and on the continent of Europe ; and, although the results are someAvhat varied, yet they all agree in one important particular, Avhich is, that it bears a very strong analogy in its composition to that of blood. My limits Avill not allow me to enter into any minute details con- cerning this subject, and I shall therefore merely observe, that the most complete investigation which has been made, is that of Dr. Barruel, of Paris. According to this distin- guished chemist, melanosis of the human subject is essentially composed of the coloring matter of the blood, united with fibrin, and of three distinct fatty substances. Of these, the vol. i. 22 170 MELANOSIS. [CHAP. XVII. first is soluble in alcohol at a moderate heat, and susceptible of crystallizing in small brilliant scales; the second, is solu- ble only in boiling alcohol,— soft, and amorphous ; the third is fluid at the ordinary temperature of the atmosphere, of a red- dish broAvn color, and contains a considerable quantity of the phosphate of lime and iron. The result of this analysis is fully confirmed by that subsequently obtained by Dr. Hecht, of Strasburgh, from a specimen of melanosis of the lungs; and it corroborates, likeAvise, its identity with the coloring matter of the blood.* Dr. Henry, of Manchester, found that a stream of chlorine, passed through a solution of this substance, destroys its black color, and throws down light yellowish flakes. Boiling pro- duces no change, not even Avhen a small quantity of caustic potash is added. Acids do not alter it, except the nitric, which turns it yellow. Corrosive sublimate, the nitrate of mercury, and the muriate of tin, precipitate it, the supernatant fluid being left quite clear. To these analyses it may not be improper to add the re- sults recently obtained by Dr. Foy, of Paris, from a melanotic tumor of the horse. They are as follows: Albumen, ......... 15.00 Fibrin,........ 6.25 A highly carbonized principle, probably altered cruor, 31.40 Water,........18.75 Oxide of iron, ....... 1.75 Sub-phosphate of lime, ..... 8.75 Muriate of potash, ...... 5.00 " " soda,......3.75 Carbonate of soda,......2.50 " " lime, .....3.75 " " magnesia, ..... 1.75 Tartrate of soda,...... 1.75 100.40 The melanotic matter is miscible with water and alcohol, opaque, and without any marked taste or smell. When placed in contact with white linen, it readily communicates to it its peculiar tint; but the stain that is thus produced is easily re- moved by ablution. Exposed to the atmosphere, it becomes * Lobstein, vol. i. p. 463. SECT. II.] COLOR--FORMS. 171 dry, brittle, and pulverizable, and a long period elapses before it undergoes decomposition. By burning, it is converted into a dark carbonaceous substance, and emits a strong empyreu- matic odor. The color of melanosis, as might be expected, is consider- ably influenced by accidental circumstances, as the quantity of cruor and cellular tissue entering into its composition. It may be said ahvays to incline to black; but not unfrequently it presents various shades of brown and yellow, which are usually most conspicuous when this substance is stirred in a small quantity of Avater. In its consistence, melanosis varies from the fluidity of ink to the density of fibro-cartilage. With respect to form, there are three varieties under which this matter is deposited, the tuberoid, lamellated, and dot-like. The first of these, as the name indicates, occurs in distinct masses, Ararying in diameter betAveen a currant and a walnut, of a dull sooty color, and of a spherical, ovoidal, or conical shape, (PI. II, Fig. 1.) By the agglomeration of a number of such bodies, large tumors are sometimes formed, with a rough, lobulated surface, Avhich always attain their greatest developement in the cellular and adipous tissues. In the hu- man subject, their size seldom exceeds that of the fist; in the horse, on the contrary, they have been found to weigh from twenty to forty pounds. A thin, transparent covering, evidently formed out of the natural tissues, invests these tumors, and gives them the ap- pearance as if they were encysted. Vessels and nerves can occasionally be seen ramifying over their surface, or penetrat- ing into their substance, and in many cases they are in- tersected by fibrous filaments, which are either derived from the general envelope, or they are the remains of the lacerated cellular substance into which the heterologous matter is origin- ally deposited. These circumstances have led to the opinion — at first sight plausible enough, yet Avholly erroneous — that these tumors are organized. Of the vessels which are distrib- uted to the melanotic mass, the veins greatly predominate: they are often very large and tortuous, and Noack says that they terminate by open mouths on the interior of the cysts. Both arteries and veins are incapable of being injected, the matter that is used for this purpose being ahvays extravasated in the substance of the morbid deposit. When the tumor is developed on the serous surfaces, it fre- quently presents a pedunculated appearance, like certain polypi 172 MELANOSIS. [chap. XVII. of the uterus and the vagina, (PI. II, Fig. 2.) In such cases it is ahvays surrounded by a distinct cyst, of Avhich it is difficult to say Avhether it be a neAV formation, or simply an extension of the natural membrane. There is another variety of melanotic tumor in Avhich the covering seems to be formed by condensed fibrin, effused, in all probability, in consequence of the irritation excited by the presence of the foreign matter. Sometimes the cyst is of considerable thickness, firmly con- nected with the circumjacent tissues, and furnished with mi- nute vessels; generally, however, it is remarkably thin, soft, flocculent, and without the least visible trace of organization. This variety of melanosis occurs most commonly in the liver and the brain. It is extremely rare. Carswell states that he has never seen an instance of it, and Laennec appears to have met with it only twice. I have noticed it several times in the liver of the ox. The lamellated variety has hitherto been observed chiefly in the inferior animals, being extremely rare in the human subject, (PL II, Fig. 3.) It is confined exclusively to the serous membranes, Avhere it is usually deposited into the con- necting cellular tissue, forming small, irregular patches, of a black brownish color. More rarely the matter is poured out upon the free surface of these textures. When this happens, the layer is seldom more than half a line in thickness, of a soft, pulpy consistence, and covered over with a thin transpar- ent pellicle of new formation. The peritonasum is the most usual seat of the lamellated variety of melanosis ; and here it is often extremely difficult to distinguish it from the spurious form of the disease, caused by the deposition of blood, and the subsequent changes which this fluid undergoes from con- tact with the acid contents of the alimentary tube. In some instances the serous membranes present a stained appearance, as if the heterologous matter had been effused into their in- termolecular spaces. Such spots are very frequent in the peritonaeum of those who die of ascetes. In the dot-like variety, (PI. II, Fig. 4,) the melanotic mat- ter appears in small points, thousands of Avhich are sometimes scattered over the surface of the affected organ, giving it a singularly speckled aspect. This form of the disease, which may be easily imitated by dusting a piece of white paper with soot or powdered charcoal, is most common in the lungs, the liver, and the subserous cellular tissue of the alimentary tube. I have also repeatedly seen it in the skin of white SECT. II.] COMBINED WITH SCIRRHUS AND TUBERCLE. 173 horses. When the points are very close, the affected part may present the appearance of being infiltrated, as in Plate II, Fig. 5. The tissues most prone to the melanotic deposition are, beyond all comparison, the cellular and adipous. Amongst the different organs, the liver, lungs, and ovaries may be enu- merated as being most frequently affected. The cartilages, synovial membranes, and fibrous textures, are rarely if ever implicated. Occasionally the system seems to be really la- boring under a sort of melanotic diathesis, the disease occur- ring either simultaneously, or in rapid succession, in a great number of organs and tissues. Of this, a remarkable case has been recently published by Dr. Norris, an English physician.* Not only was the external surface extensively studded with black tumors, but immense numbers were seen scattered over the stomach, intestines, mesentery, and omentum; the lym- phatic ganglions, kidneys, pancreas, and liver, were also more or less affected ; the lungs were thickly mottled throughout the greater part of their texture; and the heart was literally en- crusted with them, both externally and internally. The brain was healthy, but the dura mater was deeply involved. In the interesting case recorded by Professor Alison, of Edin- burgh, the integuments, mammae, ovaries, membranes of the brain, heart, lungs, pleura and peritonaeum, the sternum and ribs, together with a large portion of the parietal and occipital bones, Avere all affected with this disease; some of them in a very high degree. Like tubercles, then, this heterologous de- posit seldom occurs in a single organ, but generally in a con- siderable number of them, which corroborates our assertion, that the system occasionally labors under a melanotic dia- thesis. Melanosis may exist alone, or be combined with other heterologous formations. Of these, the most common is the scirrhus; the rarest, the tubercular. Dr. Rouzet met with a case of carcinoma of the breast, in Avhich a black fluid, evidently of the nature of that in question, constantly exuded from the ulcerated surface. The tissues immediately around the melanotic deposit are often very much contaminated. Sometimes they are only hardened, or perhaps softened ; at other times they are extensively infiltrated with the morbid matter, and of a deep black color. When the tumors are * Medico-Chirurgical Review, October, 1836. 174 MELANOSIS. [CHAP. XVII. developed in the muscular substance, the fibres are merely pushed aside by them, Avithout being contaminated by the disease. The nerves and bones likeAvise remain intact. Melanotic tumors, after having acquired a certain size, generally remain stationary, giving rise to little or no incon- venience, save what results from their bulk and consequent pressure. At times, hoAvever, they manifest a disposition to ulcerate, and, when this happens, a most intractable sore is left, with hard, ragged edges, from the surface of Avhich there is a constant discharge of black, inky matter, mixed with blood, pus, or a thin, fetid, ichorous fluid, formed by the surrounding structures. When removed, the most re- markable feature of these tumors is their tendency to re- appear in the neighborhood of the cicatrix, or in some remote organ. Notwithstanding that Laennec has asserted the contrary, the melanotic matter is probably always poured out in the liquid form. Indeed, we can scarcely conceive of the possi- bility of its being secreted in any other Avay. In the course of a short time after the deposition has taken place, the mat- ter becomes inspissated, by the gradual absorption of its more attenuated particles; and it is in this manner that it finally acquires the hardness and density of a solid substance. What corroborates this view, is the fact, that thin, liquid melanotic matter is sometimes found in the splanchnic cavi- ties Avithout any breach of the serous membranes, and that it frequently exudes in this form from the surface of carcinom- atous and other tumors, in a state of ulceration. Of the causes of this disease, and of the states of the system which predispose to it, nothing can be said to be knoAvn Avith any degree of certainty. That the melanotic matter is de- rived immediately from the blood, both anatomical examina- tion and chemical analysis abundantly show ; but how far, or in what respect, this fluid is altered before the deposition in question is effected, are points in the history of this disease concerning which pathology and physiology are equally silent and undetermined. If we remember that melanosis is essen- tially composed of the same elements as the coloring matter of the skin and of the choroid coat of the eye, it may be allowed us to suppose that this substance, existing in an unnatural quantity in the blood, is deposited into organs and tissues in which it does not exist in the normal state, by an aberration of the nutritive functions of the vessels. Noack, a recent SECT. III.] SCIRRHUS. 175 German Avriter, regards the black matter as a secretion from the veins, — an opinion in Avhich he is joined by Dr. Hodg- kin, of England. This vieAV, I need scarcely remark, is altogether gratuitous, and is, moreover, entirely inadmissible on physiological grounds, there being no instance, so far as Ave know, except in the liver, in Avhich the veins perform such an office. This disease, I presume, is extremely rare in the inhabitants of this country. It is said to be most com- mon in individuals who are of a melancholic temperament, and occasionally betrays a hereditary tendency. SECTION III. Scirrhus. Concerning no one of the heterologous formations have anatomists expressed such a diversity of sentiment as of that, the nature of which Ave are about to investigate. Notwith- standing the numerous treatises that have been published within the last thirty years, it is a singular fact that we are scarcely in possession, even at the present moment, of an accurate and unexceptionable definition of the term scirrhus. The reason of this may be discovered, if I mistake not, in the circumstance that all malignant diseases, whatever be their origin, seat, or structure, were described, until very recently, under the vague name of "cancer." Nor was this the only difficulty. Scirrhus, as will be shoAvn hereafter, often co- exists with encephaloid, which, independently of the varieties to Avhich it is itself subject, must have been a source of much confusion and embarrassment. No wonder, then, that writers should have failed in presenting clear and definite notions on the subject. Indeed, with all the light that has been thrown upon the heterologous formations by morbid anatomy, it must be confessed that the most experienced find it sometimes extremely difficult, even at the present day, to draw a correct line of demarcation between scirrhus and encephaloid. How far the definition which we are about to give is free from objection, must be left to others to determine. Those who are acquainted with the difficulty of the subject will 176 SCIRRHUS. [CHAP. XVII. agree Avith me at least, that any effort of the kind, although it may only be approximately correct, is much better than none. No lesion can be studied Avith advantage, unless the student have a proper notion of its nature at the very outset of his examination; and noAvhere is this more true than in the disease before us. With these remarks, I proceed to define scirrhus to be a hard, crisp, opaque substance, of a light grayish color, Avith dull yellowish fibrous intersections, organized, liable to lancinating pain, occurring for the most part after the middle period of life, and passing sooner or later into ulceration. This definition, it Avill be perceived, is not so concise as could be desired, yet, on the Avhole, perhaps as correct an one as can be given, consistently with the present stage of pathological science. Like tubercle, schirrus has its regular period of groAVth, maturation, and decay; and, in order to comprehend, in the fullest manner, the circumstances which modify its physical characters, it will be necessary to study it in its various stages as it affects different textures of the body. The principal form in Avhich the scirrhus matter is depos- ited is the tuberoid, (PI. Ill, Fig. 5.) True it is, we some- times find it diffused through the interstitial cellular tissue of various organs, as the uterus, lungs, liver, kidneys, and bones, which it converts into a solid substance, resembling a slice of raw pork. This rare disease constitutes Avhat some of the French anatomists have termed the lardaceous tissue. In this variety of scirrhus, the primitive texture, whatever it may be, gradually loses its normal color and consistence, but the volume of the affected part is seldom much augmented or diminished. This substance may also appear under the form of a layer, beneath or upon the surface of the serous and mucous mem- branes, (PL III, Fig. 2.) This variety, indeed, is more com- mon than the one just described, and is observed chiefly in the submucous cellular tissue of the oesophagus, the stomach, and bowels. In these situations it is not unusual to find large patches of this description, of a pale bluish tint, crisp, from one to six lines in thickness, and of a dense, fibro-cartila- ginous consistence. The lining membrane, together Avith the muscular tunic, sooner or later participates in the disease; and the part of the tube corresponding with the seat of the lesion becomes hard, rigid, and contracted. SECT. III.] FORMS. 177 In the tuberoid variety, the most common, as we have al- ready said, of all the heterologous substances, forms small circumscribed nodules, the number of Avhich, as in the liver, is sometimes very great, and the consistence of Avhich varies between fresh pork and fibro-cartilage. Their size and shape are much influenced by the nature of the tissues in which they are developed, and by the resistance Avhich is offered to their progress. Single tumors of this kind are rounded, oA'oidal, or conical ; when, on the contrary, several are agglomerated together, they are generally very irregular, angular, and more or less lobulated. In their size they vary from a mustard- seed to an adult head, — their average Arolume being that of a billiard-ball, a lemon, or an orange. A scirrhous tumor creaks under the knife, is opaque, firm, inelastic, and of a white bluish color, Avith various shades of gray, red, and drab. These tints are most conspicuous Avhen there is an admixture of bile, blood, or pus, as some- times happens when the heterologous matter is very old. To examine the interior of such a tumor it is neces- sary to divide it into thin slices. These will be found semi- transparent, flexible, and elastic, and, on being dried, they assume all the properties nearly of the horny tissue. Fibrous intersections, generally of a slight yellowish color, will also be seen to pervade the diseased mass, starting from the centre as their common nucleus, and radiating out towards the circum- ference. These lines are merely the remains, in most cases, of the cellular substance of the affected part, and are often so arranged as to resemble very closely the fibrous structure of an unripe pear or turnip. A creamy-looking fluid is occa- sionally incorporated with the heteroclite mass, and consti- tutes the most decided evidence of its carcinomatous nature. Scirrhous growths, especially such as occur in the female breast, occasionally contain hydatids. A more common ap- pearance is the developement of cysts, filled Avith a thin, grayish, gummy substance, meliceric matter, or eA>en pus, though the latter, I believe, is very rare. Clotted blood is likeAvise present in some instances. By some writers, scirrhous tumors are said to be furnished always with a distinct cyst ; as a general rule, however, this is not the case, and this forms one of their characteristic features. When they are very large and old, the cellular tissue around them is generally a good deal condensed, but seldom to such an extent as to entitle it to the appellation of a capsule. Distinct vessels are very vol. i. 23 178 SCIRRHUS. [CHAP. XVII. rarely perceived in them; nor is it possible to discern any nerves. Scirrhus occasionally exhibits a regularly lobulated arrange- ment, resembling the section of the healthy female breast. When this appearance is present, it constitutes what Mr. Aber- nethy has called the mammary sarcoma, (PI. Ill, Fig. 3.) In other cases, it is of the color and consistence of the pan- creas, and is there termed, by the same distinguished writer, pancreatic sarcoma, (PI. Ill, Fig. 4.) In a third class, the morbid structure has a lardaceous aspect, (PI. Ill, Fig. 5 ;) in a fourth, it is gelatinoid, (PI. Ill, Fig. 6 ;) and, in a fifth, it may be essentially fibrous, (PI. Ill, Fig. 7,) being composed of dense, grayish filaments, Avhich are inextricably interwoven Avith each other. These are varieties Avhich depend upon the peculiar arrangement, color, and consistence which the scirrhous substance exhibits in different regions of the body, or at the different stages of its groAvth. That the chemical composition of scirrhous matter should vary in different parts of the body, and in different stages of its developement, as well as in different animals, is a circum- stance which readily suggests itself from Avhat we know of some of the other heterologous formations. Upon this point, hoAvever, there is very little positive information. The best analysis of this substance, as occurring in the human subject, is by Dr. Hecht. He found seventy-two grains of scirrhous breast to consist of twenty of fibrin, tAvo of albu- men, tAventy of gelatine, ten of a fluid fatty matter, and tAventy of water. Seventy grains of scirrhous uterus con- tained ten of fibrin, fifteen of gelatine, ten of fatty matter, and thirty-five of water.* It Avill be perceived that, in the latter of these analyses, there is an entire absence of albu- men, with a considerable diminution both of fibrin and gel- atine ; thus showing, as was before stated, that the nature of this substance varies in different organs of the body. The researches of Dr. Hecht have not, I believe, been repeated by other chemists, which is so much the more to be regretted, as they would probably lead to most important results concerning the true character of this singular disease. One thing, how- ever, I think, has been fully established by the experiments of the German philosopher, namely, the close analogy between scirrhous and tubercular matter. Scirrhus rarely appears before the age of thirty, in Avhich * Lobstein, Traite d'Anatomie Pathologique, t. I. p. 403. SECT. III.] DEVELOPEMENT-- AGE--SEX. 179 respect it strikingly differs from encephaloid. It is much more common in women than in men, and its favorite period of attack is from the fortieth to the fiftieth year. Rarely, perhaps never, does it occur before the period of puberty. The lymphatic temperament is said to predispose to it, and in some instances it seems to be connected with a hereditary taint, being transmitted from parent to offspring. In the uterus, mammary gland, and testicle, it has been repeatedly observed in three or four members of the same family. Very often it supervenes upon external violence, such as a blow, kick, or bruise, syphilitic disease, suppression of the menses, and the repulsion of herpetic eruptions. In other cases, again — and these are very common—it arises without any assignable cause. Corroding cares, by impairing the general health, sometimes induce this disease ; and, in the female, it is often dependent upon sympathetic action between the uterus and the breast. Scirrhus sometimes attacks a considerable number of organs in the same individual, either simultaneously, or in gradual succession. In females, for example, it is not uncommon to find both the breast and the uterus involved at the same time. It not unfrequently coexists Avith encephaloid, tubercles, me- lanosis, and hydatids. What I mean by this remark is, that the heterologous formations here specified may affect different organs, or even different portions of the same viscus, or they may all, or at least several of them, occur in the same morbid mass, constituting different sections. The parts of the body most liable to scirrhus are such as have a glandular structure. In females, it is most common in the breast and uterus ; in males, in the testicle, penis, stomach, and rectum. In both sexes the lips, nose, and liver may be mentioned as frequent seats of it. The spleen, lungs, and kidneys are seldom affected. It is also extremely rare in the bones, and it is doubtful whether it ever occurs in the carti- lages ; in the serous, synovial, and fibrous textures, and in the muscles of voluntary life. After Avhat has been stated, under the head of the tuberoid variety of scirrhus, it Avill scarcely be expected that we should enter into a formal discussion respecting the mode of organi- zation of this disease. There is one theory, hoAvever, which demands brief notice, as well from its extrinsic singularity, as from the high source from Avhich it emanates. I need scarcely say that I allude to the well-known doctrine of Professor CarsAvell, Avhich inculcates the strange notion, that, Avhilst 180 SCIRRHUS. [CHAP. XVII. encephaloid is capable of generating its own vessels, scirrhus is dependent for its vascular supply upon the surrounding tex- tures. Noav, if Ave look upon scirrhus merely as a modifica- tion of the coagulating lymph, as Ave certainly must if Ave duly contemplate its physical and chemical properties, together with its origin and mode of termination, we must ascribe to it, I think, a self-organizing poAver, and consequently a proper as Avell as a collateral circulation. It is not necessary to re- iterate here Avhat Avas said in reference to this subject under the head of tubercle, and what Ave shall have occasion again to advert to in the next section; and I shall therefore only add one other remark, which is, that the vessels of the hete- rologous formation in question, Avhether Ave regard them Avith Carswell as being derived from the circumjacent tissues, or as created, in fact, by its own inherent poAvers, are ahvays much smaller and less numerous than they are in encephaloid, being so extremely fine and delicate as to escape, in most cases, the naked eye. Concerning the proximate cause of scirrhus, nothing is knoAvn Avith any certainty, notAvithstanding the numerous at- tempts that have been made to investigate it. By some of the older authors, the disease was ascribed to the presence of Avorms, Avhich, destroying the natural tissues of the part, pro- duced, as they conceived, all the local mischief. Singular as this theory may appear, one very similar to it Avas broached about thirty years ago, by Dr. Adams, of England. He contends that scirrhus uniformly depends upon the presence of a parasitic animal, to Avhich he has given the name of the carcinomatous hydatid. Of this he has pointed out three varieties,— the serous, the gelatinous, and the sanguinolent, each of Avhich is capable of exciting, as he supposes, a specific irritation in the part Avhere it occurs, resulting in a deposition of the hetero- logous substance in question. This doctrine, if such it de- serves to be called, has been adopted, Avith certain restrictions, by Dr. Richard Carmichael, of Dublin, Avho is still one of its most zealous advocates, as would appear from an essay which he published, a few years ago, on the " Origin and Nature of Tuberculous and Cancerous Diseases." That such is the source of scirrhus in some cases, very feAV, it is to be pre- sumed, will attempt to deny; for it may be easily imagined that hydatids would excite irritations, to some extent at least, in Avhatever organ they might occur, folloAved occasionally by a deposition of foreign matter. The circumstance, then, I SECT. III.] CAUSES : HYDATIDS. 181 would suppose to be Avithin the range of possibility : that it is constant, however, as is alleged by the abettors of this theory, is an assumption, Avhich is not less opposed by analogy, than it is unfounded in fact. If the doctrine were true, hydatids should always be met with wherever there is scirrhus, which, it need scarcely be remarked, is not the case. Instead, there- fore, of considering these bodies as the immediate cause of this disease, we are justified in the belief that, in the great majority of instances, they are nothing but accidental growths supperadded to the original disorder. Equally applicable are these remarks to the theory recently proclaimed by Dr. Hodgkin, also an English physician, in his excellent work on the morbid anatomy of the serous mem- branes. Disbelieving the doctrine which we have just been examining, he maintains that all scirrhous and malignant dis- eases are produced by the presence of serous cysts. These, which are the result of a new formation, he supposes always exist prior to the heterologous substance, forming so many nests for its reception. The number of cysts is sometimes very considerable: they are generally small, of a globular shape, occasionally pear-like, or pediculated ; and their contents vary from a fluid that is perfectly clear and limpid to a sub- stance that is more or less opaque and solid. This theory, which is certainly highly ingenious, has been ably refuted by Professor Carswell, who, however, admits that it holds good in some cases. The late Mr. Abernethy advanced the idea that all scir- rhous tumors are formed from the coagulating lymph, deposited in consequence of inflammation. He fixed their seat in dif- ferent parts of the body, as the cellular, serous, and paren- chymatous textures, and supposed that they became organized, not by any vessels of their own creation, but by the assist- ance which they receive from the surrounding structures. This theory, on the whole, seems more plausible than any other, and is the one which will be adopted, to a certain ex- tent, in the present work. It has been already seen that the matter of scirrhus is close- ly allied to that of tubercle, both in its color, its consistence, and, above all, in its chemical composition. Indeed, no one who studies the subject can help being struck with the re- markable analogy existing between these tAvo heterologous formations. What the precise difference is, or where the con- nection begins and terminates, we cannot of course say. A 182 SCIRRHUS. [chap. XVII. profound study of pathological anatomy, not in books, but in the dead-room, is alone competent to decide the question. Chemistry, too, must lend her aid, and lay the results of her analyses upon the altar of science. In the mean Avhile, it is enough for us to knoAv that there is such an analogy. Tubercle, as Ave attempted to shoAV in a preceding section, is always the result of inflammation; and that this is the case likewise with scirrhus, seems sufficiently evident from Avhat has been stated in regard to its exciting causes. Very fre- quently, it is true, the disease arises imperceptibly, Avithout local injury or obvious constitutional derangement. But this certainly does not prove that inflammation is not concerned in its production. How often do Ave not find traces of inflam- mation after death, Avithout having had the slightest indica- tion of it during life. The fact, then, that it is not mani- fested ahvays by the usual phenomena, does not invalidate the idea of its presence. The opinion that scirrhous and other malignant disease^ are caused by inflammatory irritation, is not neAV. It has been zealously inculcated by Broussais, Breschet, Sanson, and other pathologists of the French school, and has likewise received the sanction of several of the most distinguished Avriters in Great Britain, Germany, and Italy. The precise nature of this inflammation we cannot of course define : all that can be said about it is, that it is of a specific kind, and that it gives rise to the effusion of a fluid analogous to the fibrin of the blood, and not very dissimilar, conse- quently, from the matter of tubercle. The effusion that is thus produced takes place in the cell- ular element of our organs, the proper structure of which it gradually transforms, effaces, or destroys. That this is the case, is sufficiently evinced by Avhat happens in the liver, the kidney, and the pancreas. Cases occasionally occur, in which the heterologous substance can be discovered in differ- ent stages of its developement, so as to enable us to deter- mine the manner in which it is deposited. Thus, in the liver, the scirrhous matter generally appears in very minute, circumscribed points, corresponding with the granulations which are so abundantly found here in the natural state. At first, there is merely a change of color, the granulations exhibiting a pale grayish aspect, without the slightest de- formity or augmentation of volume. Examined at a some- what later period, the little tumors are observed to be of a white milky hue, hard, dense, crisp, opaque, irregularly SECT. III.] SOFTENING. 183 spherical, and perfectly devoid of the original structure. Now these alterations, it is quite plain, can only be accounted for on the assumption, that, in proportion as the heterologous matter is deposited into the cellular texture of the acini of the liver, their proper parenchymatous substance, whatever it may be, together Avith their vessels, is obliterated by absorp- tion, the pressure Avhich the accidental secretion produces being fully adequate to bring about this result. Similar phenomena are to be Avitnessed, as scirrhus is being developed in other organs. From the foregoing remarks, then, it may be concluded, first, that scirrhus is invariably produced by inflammation ; secondly, that it has a great predilection for the glandular viscera; thirdly, that it rarely occurs under the age of thirty ; fourthly, that the matter of Avhich it consists strongly resem- bles that of tubercle; and, in the fifth and last place, that this matter is deposited always into the cellular tissue of our organs, in such a manner as to transform, to a greater or less extent, their proper parenchymatous structure. After having existed for some time, varying from a feAV months to several years, the scirrhous matter manifests a disposition to become soft, the process by which this is effected, like that of tubercle, commencing at different parts of the diseased mass, from which it extends in various direc- tions, until the Avhole or the greater portion of it is broken up and dissolved. Some authors have contended that the lique- faction invariably begins in the centre; but that this is not true, the Avritings of pathologists abundantly attest. The process, then, may commence at any point, at the centre or at the periphery, or simultaneously in both these situations; and, as it advances, the superincumbent integuments crack at one or more places, through Avhich the softened matter, noAV of the aspect of encephaloid, jelly, sirup, gum, or honey, is ultimately discharged. Ulceration, however, it should be observed, often occurs in scirrhous tumors long before the internal disorganization in question is accomplished. A scirrhous ulcer possesses certain features Avhich may be considered as characteristic. Generally, it is remarkably irregular in its shape, Avith a surface that is either cracked, fissured, or fungous, of a dark reddish color, and of a peculiar glossy oedematous aspect. Soft cauliflower excrescences sometimes sprout from it, so sensitive as to bleed on the slightest touch, or even of their OAvn accord. The edges of 184 SCIRRHUS. [CHAP. XVII. the sore are of a reddish-gray color, elevated, everted, irregu- larly serrated, and harder in some places than in others, emitting more or less sanies on pressure. A deep excavation is occasionally formed, presenting the appearance as if a portion of the diseased mass had been lifted out of its bed. In cases which run their course very rapidly, the surface of the ulcer is frequently covered with a soft, grayish putrilage, of the most intolerable odor. This fluid, which bathes the surface of the ulcer, is gener- ally of a thin, bloody, ill-conditioned nature, with an odor approaching that of ammonia. It is always highly irritating, and the quantity discharged is sometimes surprisingly great. Dr. CraAvford, an English physician, who has particularly examined this fluid, states that it blackens silver, and imparts a green color to sirup of violets. Potash produces no change; but, on the addition of sulphuric acid, a peculiar gas is evolved, having many of the properties of sulphuretted hydrogen. This gas appears to exist in union with ammonia, and gives the fluid its peculiar fetid odor. In this advanced stage of the disease, the skin around the ulcer is of a purple color — from the overloaded state of its capillaries — hard, puckered, somewhat tender on pressure, and easily corroded by the irritating discharges. By degrees, the ulcer spreads, both in depth and in diameter, until at length the whole mass is involved in the disorganizing process, and the patient sinks under the exhausting hectic, caused by the pro- fuse local discharges, and by the violent constitutional irrita- tion. The lymphatic ganglions, it should be further stated, in the neighborhood, are almost constantly enlarged and indurated, and the tumor, instead of being movable and cir- cumscribed, as it was in the early stage of its growth, forms a hard, solid, undefined mass, which firmly adheres to the surrounding structures. Scirrhus is recognized by its circumscribed character, its hardness and incompressibility, and by the peculiar nature of the accompanying pain. The hardness is greater than that of any normal texture, save the cartilaginous and osseous. The pain is usually of a gnaAving, lancinating kind, darting through the swelling in different directions, and coming on in irregular paroxysms, Avhich, as the disease progresses, increase both in frequency and violence, as well as in dura- tion. Sometimes it is prurient, hot, burning, or scalding, and is then commonly more permanent. At first, the tumor, SECT. IV.] ENCEPHALOID. 185 as Avas before stated, is movable, distinctly circumscribed, and the skin over it perfectly natural; by and by, however, it contracts adhesions, and soon becomes fixed and less defined, at the same time that its cutaneous covering experiences various alterations, both as respects its smoothness, its color, and its consistence. These remarks are intended, of course, to apply solely to external scirrhous groAvth : when they are seated internally, the diagnosis is always difficult, nay, often impossible to be made out. SECTION IV. Encephaloid. Intimately allied to scirrhus, in its mode of origin, yet dif- fering from it Avidely in many of its essential features, is en- cephaloid, one of the most formidable and destructive of the heterologous formations. As the term indicates, this morbid growth bears a great resemblance to the cerebral tissue, not only in appearance, but also in chemical composition. For the first accurate account of it, we are indebted mainly to Mr. John Burns, of Glasgow, who described it under the name of spongoid inflammation. The observations of this eminent surgeon soon attracted the attention of other pathologists, both in Great Britain and on the continent of Europe, and, as might have been expected, led to further and more thorough investigation. Amongst those Avho have particularly distin- guished themselves in this respect, may be mentioned the names of Hey, Abernethy, Wardrop, Laennec, Roux, Mau- noir, and CarsAvell. Most of these writers have designated the disease by a different appellation, according to the pecu- liar notion Avhich they entertained of its composition and struc- ture. Thus Abernethy has called it medullary sarcoma; Hey, fungus haematodes; Roux, soft cancer; Maunoir, medullary fungus; and Mr. Burns, as already stated, spongoid inflam- mation. The term encephaloid, devised by Laennec, seems, on the Avhole, less objectionable than any other, and I shall therefore retain it on the present occasion. vol. i. - 24 186 ENCEPHALOID. [ciIAP. XVII. The most common seats of this morbid groAvth are the bones, eyes, testicles, liver, lungs, kidneys, uterus, lymphatic ganglions, and subcutaneous cellular tissue. In infants it often occupies the shoulder, the region of the clavicle, the side of the chest, and the fore-arm. In adults I have seen a number of cases where it attacked the hand and fingers. Never have I observed it in the inferior extremities; but that it sometimes occurs here, the writings of pathologists abundantly testify. Encephaloid has likewise been noticed in the veins, especially in those of the liver, of the kidney, and the uterus. The varieties of form under Avhich the encephaloid matter is deposited are three, — the tuberoid, the stratiform, and the infiltrated, to each of Avhich it will be proper to devote a few remarks. In the tuberoid variety, (PI. IV, Fig. 1,) the heterologous matter appears in the form of a circumscribed tumor, from the size of a pea to that of a muskmelon. In its shape it is generally irregularly rounded, ovoidal, or even quite flat, ac- cording to the amount of pressure that is exerted upon it by the surrounding parts ; and, if it be examined by dissection, it will be found to be composed of different lobules, envel- oped by a thin covering, and separated from each other by delicate membranous partitions. The outer covering, which is evidently formed out of the neighboring cellular tissue, is usually not more than half a line in thickness, easily torn, semi-transparent, and of a light rose color. From its inner surface are detached numerous processes, Avhich, dipping into the morbid growth in various directions, form so many cavities for the reception of the new deposit. These septa, which are sometimes remarkably rough and shreddy, ahvays become more obvious after the pulpy mass is squeezed out. The cells which they form by their intersections, are subject to much variety, and hence the peculiar lobulated shape Avhich characterizes the morbid growth when occurring in parts that offer little or no obstacle to its extension. Although the covering of encephaloid tumors is ordinarily derived from the preexisting structures in their immediate vicinity, yet cases occasionally occur in which it is evidently of new formation. That this is true, my own dissections fully convince me. In such cases, the external envelope is generally very thin; sometimes, indeed, almost like a film, SECT. IV.] EXTERNAL ENVELOPE. 187 easily lacerated, and of a grayish color, with rough, shreddy surfaces. The interior septa are likeAvise less perfect, and the whole mass is commonly so soft as to yield to the slight- est force. The external envelope, together Avith the internal processes here described, is abundantly supplied with vessels which pervade the diseased mass in different directions, assist in its groAvth, and maintain its vitality. These vessels, which al- Avays consist of a much greater number of veins than of arteries, are often remarkably large and convoluted, and can be easily traced to the neighboring vascular trunks : their walls are exceedingly brittle, and the most trifling accident is therefore liable to be attended Avith an effusion of blood. Hence the dark clots which are so frequently met Avith in encephaloid tumors. The cerebriform substance itself, it should be stated, is easily squeezed out of its cavities, oAving to its imperfect adhesion ; and, interspersed through different parts of it, we frequently observe, besides the sanguineous deposits just adverted to, small cells filled Avith purulent mat- ter, serum, or thin, sanious, and offensive fluid. In one case, 1 saw as much as half a pint of reddish serosity Aoav from a single cavity, the inner surface of Avhich had a peculiar hon- eycomb-like appearance. When developed beneath the pleura and peritonaeum, these tumors generally assume a pear-shaped appearance, the foot- stalk, by Avhich they are attached, being often quite slender, (PI. IV, Fig. 2.) In their volume they vary between that of a pea and a walnut: they are of a dirty straw-color, and of a semi-concrete consistence. Although commonly isolated, they sometimes occur in groups, and are always distinctly en- cysted, — the capsule Avhich covers them being either of new formation, or, as more frequently happens, derived from the serous membrane beneath Avhich they are developed. This species of encephaloid is rare. The stratiform variety, (PI. IV, Fig. 3,) is exceedingly rare, and hitherto I have not met with it except in a few in- stances. It is found only in the subserous cellular tissue, prin- cipally in that of the pleura and arachnoid, in circular patches, from the diameter of a pin-head to that of an American dol- lar. The deposit is generally of a whitish, cream-like color, tolerably hard and dense, and from the fourth of a line to the twelfth of an inch in thickness. Several such patches occa- 188 ENCEPHALOID. [CHAP. XVII. sionally run together, and thus form an irregular layer of con- siderable extent, over which the serous membrane is consid- erably indurated and puckered. The encephaloid matter is sometimes infiltrated into the substance of our organs, (PI. IV, Fig. 4.) This variety, Avhich is likewise very uncommon, is seen principally in the uterus, liver, and lungs, Avhere it forms small, irregular masses, of a semi-concrete consistence. In the situations here referred to, the heterologous substance usually partakes more or less of the color of the parts into Avhich it is depos- ited, and is often distinguished Avith difficulty from the tuber- cular infiltration described in a previous section. The color of the heterologous substance, although general- ly inclining to cineritious, runs through various shades of Avhite and red, having either the yellowish aspect of cream, the complexion of jelly, or the black appearance of the cras- samentum. In the tuberoid species, it is not unusual to see different sections of the morbid mass present different shades of color, one part being pale, another cineritious, and a third of a deep brown, from the intermixture of clotted blood. It is seldom that the tumor has the pure white aspect of the medullary substance of the brain. The consistence of this heterologous growth is also sub- ject to much variety. Though in general pretty nearly that of the foetal brain, it is sometimes as soft as cream, and at other times almost as hard as fibro-cartilage. Like the tuber- cular matter, it is supposed by Laennec, Lobstein, and oth- ers, to be originally deposited in a concrete state. But for this opinion there seems to be no just ground; and I feel, therefore, disposed to reject it, — the more so as it cannot be supported even by a single argument drawn from analogy. The error into which these, together with some other anato- mists, have fallen, may be readily explained, it seems to me, by the fact that the heterologous matter varies in its physical and chemical properties, not only in the different organs of the body, but often in different sections of the same mass. Thus, we frequently find encephaloid tumors hard and larda- ceous in one part, semi-concrete and medullary-looking in a second, pulpy and cineritious in a third. That these differ- ences of consistence, as well as of color, are the result, in some degree at least, of changes affected in the morbid sub- stance after the deposition has taken place, will, I presume, SECT. IV.] ORGANIZATION. 189 scarcely be denied. We Avould therefore say of this matter what Avas previously said of the tubercular, — that it is never poured out in any other than a fluid state, whatever may be its consistence at the time it is examined, whether con- crete, pulpy, or semi-liquid. No very accurate analysis has yet been furnished of the substance under consideration, which is so much the more to be regretted as it might throw considerable light upon its nature and origin. From an examination made by my col- league, Professor James B. Rogers, of a specimen of enceph- aloid tumor of the elbow, it would appear to be essentially composed of the same ingredients as the cerebral texture, containing, like it, a considerable quantity of albumen and fatty matter, together with certain earthy salts. It is of a viscid, jelly-like consistence, emits a peculiar spermatic odor on being heated, and readily coagulates when steeped in alcohol. Concerning the mode of organization of this substance, especially the tuberoid variety of it, we have already made some remarks; and it will only be necessary, therefore, in connection with this subject, to advert briefly to the inge- nious doctrine that has been recently advanced by Professor Carswell, of London. This distinguished anatomist supposes that encephaloid matter, like coagulating lymph, is always endowed with a high degree of vitality, in virtue of which it is qualified to create its OAvn vessels. These, it is con- tended, often arise in the midst of the morbid deposit, from whence they gradually extend towards its circumference, where they finally anastomose with arteries and veins in their immediate vicinity. If this view be adopted — and I cannot myself see any particular objection to it — encephaloid will be found to have two circulations, one of them proper to the diseased mass, the other common to it and the surrounding structures. Owing to this peculiarity of its vascular system, it often grows Avith great rapidity, so as to attain a frightful magnitude in the course of a few months. For the same reason it is very prone to bleed, the new vessels, which are usually very imperfectly organized, being exceedingly liable to be ruptured on the slightest injury. Nerves probably exist in considerable abundance in encephaloid, though it is a singular fact that this disease is generally much less painful than scirrhus. Whether they are of new formation, 190 ENCEPHALOID. [CHAP. XVII. or derived from the tissues in Avhich the morbid growth is developed, is a point for the determination of which we have no data. How does this substance originate ? Desirable as it cer- tainly Avould be to give a satisfactory solution of this problem, it must be confessed that any attempt of the kind would be likely, in the present state of the science, to prove abortive. The opinion of Dr. Maunoir, of Geneva — that the encephaloid matter is effused by the nerves when under the influence of some peculiar morbid state — although highly ingenious, is entirely unsupported by facts, and cannot, therefore, receive the sanction of the pathologist. The circumstance that this substance has been found in the blood, is of no small moment in the discussion of this question. It Avould lead to the in- ference that, Avhen the sanguine fluid is surcharged Avith it, the cerebral matter, instead of being deposited in the brain, spinal cord, and nerves, is poured out into the meshes of the cellular element of one or more of the organs of the body. This conjecture is so much the more plausible, as the en- cephaloid disease often arises without any assignable cause, is sometimes decidedly hereditary in its tendency, and almost always existing in se\reral situations at the same time. Chem- ical analysis, also, comes to our aid here, bringing to light the important fact that the cerebral tissue and the heterologous deposit are essentially alike in their character. Nor is analogy without its utility in a discussion of this kind. Cholesterine, the crystalline matter which constitutes the basis of biliary concretions, is frequently formed in parts of the body which have no connection whatever with the hepatic circulation, in consequence merely of deranged vascular action. Christison found it in the fluid of hydrocele ; Breschet, in a tumor under the tongue ; Caventon, in an abscess of the jaw ; and Barruel, in an ovarian cyst. Thus we see that a substance which is naturally confined to one organ may, by a perversion of the secretory function, be deposited in another, totally unlike it in structure and office. Similar illustrations, it is obvious, might be adduced from other parts of the body. Encephaloid is emphatically a disease of early life, being most generally observed in children under the age of ten years. Occasionally, indeed, it makes its appearance soon after birth. In a few rare cases, I have seen it in adults and in persons far advanced in life ; and I have also thought that SECT. IV.] A DISEASE OF EARLY LIFE. 191 it Avas more common in females than in males. However this may be, it is certain that I have seen five instances in the former to one in the latter. Upon this point, however, I Avould speak with caution, as my experience has been too limited to enable me to make any positive assertion. The disease is of very frequent occurrence in Europe, as well as in certain districts of America, and is often observed in the inferior animals, especially in the equine genus. Although encephaloid is sometimes grafted on scirrhus, it generally exists as a primitive affection, which in its progress becomes associated often with tubercles, melanosis, hydatids, and other lesions. One of its most constant features, as already hinted, is, that it manifests itself simultaneously in different organs, and not less extraordinary is its disposition to re- appear after extirpation, either in the original seat, in the structures immediately around, or in remote parts. An in- teresting case of encephaloid, Avell calculated to illustrate this renovative tendency, is detailed by Mr. Allan, of Edinburgh.* The patient suffered during thirteen years from a very large tumor which occupied the left hip, and was operated upon not less than five times by different surgeons. Within several months after each extirpation, the disease usually reappeared, and soon attained the volume of a child's head. This case, certainly one of the most extraordinary and instructive of the kind on record, plainly shows the futility of any attempt at removing this disease, save by amputation ; and even this, unfortunately, is often only of temporary benefit. Nor will this seem so singular, when we consider, as unquestionably we must, that this disease is of a constitutional origin, and that the deposits to Avhich it gives rise are only so many local manifestations. Encephaloid disease, after having attained a certain devel- opement, may remain stationary for years, unaccompanied by the slightest uneasiness, until the part receives some injury, Avhen it often grows with frightful rapidity. When seated in the subcutaneous cellular tissue, the tumor that is thus formed is at first quite movable, smooth on the surface, and devoid of sensation; but gradually, as the enlargement pro- gresses, it becomes stationary, irregularly lobulated, elastic to the touch, and more or less painful. If allowed to pro- * Surgery, vol. i. p. 264. 192 ENCEPHALOID. [CHAP. XVII. ceed, the diseased mass has a tendency to open and protrude, generally by ulceration, sometimes by sloughing, and occa- sionally by the bursting of an abscess situated in its interior. In either case, the exposed surface presents a dark reddish fungous appearance, is highly sensitive, extremely vascular, very prone to hemorrhage, and constantly bathed Avith a thin, fetid, irritating, sanious fluid, the quantity of which is some- times quite profuse. In many instances, pure blood is effused, caused by a rupture of some of the vessels of the morbid groAvth; and this may be so obstinate and copious as gradu- ally to destroy the patient. Occasionally there is a discharge of thin, glairy fluid, resembling the white of egg. Such sores, besides being always highly disagreeable, never heal, from the inability of the parts to form healthy granula- tions. Sometimes the ulcerated mass sloughs as completely away as if it were dissected out; but these cases are un- common, and are soon followed by a reproduction of the heterologous substance. Obstinate hemorrhage is most apt to occur in such tumors as are of the class to Avhich Mr. Key applied the term fungus haematodes. In the eye, for example, much more frequently than elsewhere, the morbid growth, if it be permitted to go on unrestrained, is extremely prone to bleed. The reason of this is obvious. The diseased mass is almost always com- posed, in part, of a vascular, erectile tissue, interspersed with encephaloid matter, and, as soon as ulceration sets in, hemor- rhage, occasionally to an alarming and even fatal extent, is the consequence. The eroded surface, in these cases, is pale, livid, or mahogany color, and studded with large fungous excrescences, so grouped together as to resemble a cauli- floAver. In this advanced stage of the disease, there is a rapid failure of the strength, the flesh wastes, the appetite declines, the patient is harassed Avith hectic fever, and the counte- nance assumes a peculiar yellowish, cadaverous hue. The lymphatic ganglions in the neighborhood meanAvhile become enlarged, and converted into a substance resembling that of the original tumor. Two modes of explanation may be offered to account for this phenomenon. The one supposes that these bodies are affected merely sympathetically, in con- sequence of which their vessels pour out encephaloid matter; the other, that this substance is carried to them by absorbent SECT. IV.] TERMINATION. 193 vessels coming from the affected part. Although this en- largement of the lymphatic ganglions seldom occurs before ulceration sets in, yet, in a few instances, I have known it to exist at an early period after the developement of the hete- roclite mass, a good while before the skin covering it mani- fested a disposition to give Avay. The diagnosis of an encephaloid tumor can, in general, be easily determined by its history, consistence, and situation. In most instances, as has been already stated, the morbid mass is soft, elastic, and slightly fluctuating, with an irregu- larly lobulated surface. The skin exhibits a peculiar glossy aspect, and the subcutaneous veins are enlarged, tortuous, and of a beautiful bluish color. The pain that attends it is extremely uncertain, being sometimes scarcely perceptible, at other times very severe, sharp, and lancinating. Add to these symptoms the fact that encephaloid is essentially a disease of early life, and that it often occurs in situations Avhere scirrhus is never found, and no difficulty can arise in coming to a correct decision in regard to the diagnosis. VOL. I. 25 PART II. SPECIAL PATHOLOGICAL ANATOMY. PATHOLOGICAL ANATOMY. CHAPTER I. Of the Blood. Physical Properties. — Chemical Analysis. — Division into Serum, Fibrin, and Hematosine. — Lesions of the Blood. — Nature and Formation of the buffy Coat. — Cupped appearance of the Blood. — Want of Coagulability. — Relative quantity of Fibrin an healthy and diseased Blood. — Alterations of the Hema- tosine.— Lesions of the Serum, in Inflammation, Dropsy, and other Mala- dies.— Changes of the Blood, from acceleration of the Circulation and Division of the Pneumo-gastric Nerves.—Appearances in Cholera, Fever, Chlorosis, and Scurvy. The blood, derived from the chyle and lymph, is a thick, opaque fluid, contained in the heart and arteries, the capil- laries and veins, by which it is distributed, as by so many canals, to every part of the animal fabric. Examined as it flows from the arm, it is of a dark reddish color, slightly saline to the taste, somewhat viscid to the touch, of the average temperature of 96° of Fahrenheit's thermometer, and apparently homogeneous in its nature. On remaining at rest, however, for about three minutes and a half, it begins to concrete, and, finally, in about three minutes and a half more, it separates into two parts, one of them, thin and watery, termed the serum of the blood, the other, red and solid, named the crassamentum, cruor, or clot. The process by Avhich this disunion is effected is denominated coagulation, and generally requires from five to twenty hours for its com- pletion. Respecting the actual quantity of blood contained in the entire body, our means of appreciation are altogether too inaccurate to enable us ever to arrive at any satisfactory con- clusions. Fixing the ordinary standard of the adult human body at one hundred and fifty pounds, it may be supposed that the average amount of blood is about eighteen pounds, of which eleven are contained in the veins, seven in the 198 BLOOD. [CHAP. I. arteries. This estimate nearly coin&ides with that of Sir Astley Cooper, Avho, from an experiment performed on a small dog, was led to infer that the proportion of the blood, as compared Avith the solids, is as one to sixteen. Fortunately, it is not of much practical importance Avhether our data on this point are correct or not, since in the abstraction of blood from the system, the merest tyro in the profession is gov- erned, not by the amount or quantity, but by the effects it produces on the individual. From the great discrepancy still existing among authors concerning the specific gravity of the blood, it may reasona- bly be presumed that it varies, not only in different persons, but even in the same individual, at different periods. Com- pared Avith Avater, its mean specific gravity is generally stated to be as 1052 to 1000; or, in other words, as about one tAventieth part heavier than that fluid. In ten observations, I found it range from 1002, the minimum, to 1031, the maximum. According to some, however, it has been found as high as 1126; but this, if true, must be regarded as an exception. Various attempts have been made to ascertain the different constituents of the blood of the human subject. The latest and most complete analysis that we possess, is that published by Dr. Lecanu, a distinguished chemist of Paris. A careful examination of the blood of two robust, healthy men afforded the following results: * Water,....... Fibrin, ...... Albumen, ...... Coloring matter, .... Fatty crystallizable substance, Oily matter, ..... Extractive substances soluble in alcohol and in water, ..... Albumen combined with soda, . Chloruret of potassium and sodium, to- gether with alkaline subcarbonates, phosphates, and alkaline sulphates, . 8.370 7.304 Subcarbonate of lime and magnesia, with the phosphates of these salts and of iron, 2.100 1.414 Loss,...... 2.400 2.586 Total,.....1000.000 1000.000 780.145 785.590 2.100 3.565 65.090 69.415 133.000 119.626 2.430 4.300 1.310 2.270 1.709 1.920 1.265 2.010 * Ann. de Chemie, 2de serie, t. xxiii. CHAP. I.] chemical composition. 199 Since this analysis was made, Dr. Boudet, another French chemist, has shown that the fatty crystallizable substance above mentioned is identical with cerebrine, discovered by Vanquelin in the brain, and that the oily matter is a mixture of cholesterine and an alkaline soap, similar to that which is met with in the bile.* From these results it follows, that the blood, instead of being a homogeneous fluid, as it would seem to be before it has undergone coagulation, consists of a great number of ingredients, existing in various proportions, and differing from each other essentially in their character. To these, chemis- try, which has of late years been making such rapid progress, will no doubt add others, until the list will be swelled far beyond what it is at present. So much respecting the nature and composition of the blood, considered as a mass. Let us iioav make a few re- marks concerning its three grand constituents, — the serum, fibrin, and hematosine. Serum, Avhen pure, is of a yellowish straAV-color, slightly tinged Avith green, of a saltish taste, unctuous to the touch, and perceptibly alkaline. Its medium specific gravity is about 1029, or a little greater than that of the cruor, though this is by no means constant, as the latter not unfrequently sinks in it. From the analysis of Berzelius, it Avould appear that one hundred parts of serum are composed of about ninety parts of water, eight of albumen, and the remainder of earthy salts. Besides these ingredients, Dr. Lecanu has recently detected in this fluid both an oily and a fatty matter, in the proportion of one part of each to one hundred of serum. Serum is readily coagulated by heat j and the same result is produced, though less perfectly, by alcohol, a solution of corrosive sublimate, and the dilute mineral acids. On being cut into thin slices, and subjected to pressure, the hardened albumen yields a transparent watery fluid, holding in solution about one fiftieth part of its Aveight of animal matter, the precise nature of which is unknoAvn, together with a little muriate of soda. This fluid, it may now be observed, is technically called the serosity ; and for the first account of it we are indebted to Dr. Butt, of Edinburgh, who directed the attention of the profession to the subject in 1760. * Op. cit. t. Hi. 200 BLOOD. [CHAP. I. Very recently, M. Boudet, a French physician, has detected another substance in the serum, to Avhich he has given the name of serosine. It is a Avhite, slightly opalescent matter, fusible at about 94° of Fahrenheit, insoluble in water, but soluble in alcohol, and containing, apparently, a minute quan- tity of azote. Thus serum Avould seem to be a very com- pound substance. The crassamentum is a thick, opaque, spongy mass, of a dark reddish color, someAvhat lighter, as a general rule, than the serum in Avhich it floats. If it be Avashed for some time under a gentle stream of water, it may be separated into tAvo portions, one of which is solid, and constitutes Avhat is denom- inated the fibrin of the blood, Avhile the other, dark and soft, essentially consists of hematosine : these tAvo substances exist in varying proportions. The weight of the fibrin usu- ally exceeds that of the serum, but is less than that of the hematosine. In twenty experiments by Lecanu, the medium amount of fibrin in one hundred parts of blood Avas four, from which it ranged from one, the minimum, to seven, the maxi- mum. Hematosine is invariably heavier than fibrin, on which ac- count it generally subsides to the bottom of the crassamen- tum during the coagulating process. Its relative proportion to the other constituent principles varies remarkably in dif- ferent individuals, so that no very accurate information has yet been obtained respecting it. Berzelius calculated that it formed about sixty-four parts of the cruor in the one hun- dred ; but, according to the more recent researches of some of the French chemists, the amount is considerably less. This substance, it need scarcely be said, is intimately connected Avith the globules of the blood, and is always of a deeper hue, in proportion to the health and vigor of the animal. The globules themselves are of a spherical figure, and about the three thousand and five hundredth part of an inch in diameter. Concerning the nature of hematosine, chemists are still at variance. According to the analysis of Michaelis, it appears to consist essentially of the same ingredients as fibrin and al- bumen, Avith the addition of a small amount of iron, which the other elements want. Berzelius was the first, I believe, to announce this substance, the existence of which was ques- tioned until about fourteen years ago, when it was fully estab- lished by Dr. Engelhart, of Germany. From the fact that iron resides exclusively in the hematosine, it was natural to CHAP. I.] ITS IMPORTANCE. 201 suppose that it imparted to that matter its peculiar color,— an idea, Avhich, as has been suggested by the late Dr. Turner, of London, receives additional support from the well-known ten- dency of the peroxide of that metal to form red salts. It is, nevertheless, highly probable that its presence is merely acci- dental, and that the coloring substance is a peculiar animal principle, capable, like madder, of acting as a dye, and of com- bining Avith metallic oxides, the most effectual of which are those of tin and mercury. Such is a rapid sketch of the appearances Avhich this fluid presents in the healthy state. Let us now turn our attention to some of the principal alterations which it undergoes in disease. Although I do not feel disposed to attach that great impor- tance to the blood which the advocates of the old humoral pa- thology did, yet it cannot be denied that it is decidedly the most essential fluid in the animal economy, inasmuch as it furnishes the various materials which dispense vitality and nourishment to the different tissues, as well as vigor to its several organs, serving thus, in the expressive language of our medical ancestors, as the pabulum of life. From it all the solids are formed, and all the other liquids secreted ; and hence it may justly be considered as the basis of every part of the complicated fabric, as, Avithout it, it would be utterly impossi- ble for any growth, Avhether healthy or morbid, to take place- Pervading every portion of the body, and penetrating every fibre, however minute, or hoAvever constituted,—acquiring con- stantly new properties as it passes through the lungs, and losing them again as it meanders through the rest of the sys- tem,— it is in the highest degree probable, that, whilst it thus fertilizes the various structures, it may convey to them alike the elements of general health and of general disease. So long as it preserves its integrity, the impression Avhich it makes upon the solids must be of the most salutary kind, cal- culated to stimulate the Avhole machine, and rouse it to the proper performance of its functions. Any departure from this state, although so slight as to escape our notice, Avould be fol- loAved, it is reasonable to presume, by a corresponding de- rangement in the hard parts. In inflammatory affections, it undergoes most important changes, exhibiting frequently, as will be presently seen, a peculiar buff-colored aspect: in drop- sy, it is thin and pale, like weak claret; in plethora, on the contrary, it is thick, remarkably tenacious, firm, and of a deep vol. i. 26 202 BLOOD. [CHAP. I. red complexion. If it be imperfectly elaborated, a morbid dia- thesis is established, Avhich often lays the foundation of mor- tal maladies, and which is transmitted, in many instances, from the parent to the offspring. In this Avay " God visits the in- iquity of the fathers on their children, down to the third and fourth generation," as is exemplified in the hereditary predis- position to arthritic and tubercular diseases, mental imbecility, and a host of other disorders, as afflicting to the patient as they are generally perplexing to the practitioner. In the further discussion of this subject, I shall describe, in the first place, the lesions of each of the three grand constit- uents of the blood ; and, secondly, its alterations in reference to the entire mass. The most remarkable change Avhich the fibrin of the blood experiences, and one Avhich Ave have more frequent opportu- nities of observing in this country than any other, is that in- flammatory condition which gives rise to what has been termed the buffy coat, or, from its frequent occurrence in acute disease of the serous lining of the thoracic cavity, the pleu- ritic a^ust. In general, it presents itself in the form of a thin lamella, of a pale straAV-color, which is spread over and closely adherent to the upper surface of the crassamentum, looking a good deal like a sheet of tallow. In some instances, it is of the color of a lemon-rind, nearly Avhite, or greenish. The latter appearance is especially conspicuous in the blood of pregnant females, and has been considered by some, though erroneously, to be an indication of that particular state. The formation of the buffy coat is always consentaneous Avith the process of coagulation, appearing at first like an opaque, viscid crust, of a reddish opaline tint, and of a con- sistence equal to that of mucus, Avhich is either diffused over the whole surface of the fluid, or occurs in small insulated spots, looking like so many little islands in the midst of a body of water. Whilst warm, this substance is remarkably tenacious, and may be drawn out in the form of little fila- ments, which, on cooling, assume a white or reddish aspect. When fully formed, which, however, it is not under some hours, the buffy coat is dense, elastic, slightly diaphanous, strongly adherent to the cruor, which it covers, smooth on its free surface, and rough on the other. Now and then it is re- markably soft, and reticulated, or like the interior of a honey- comb, from the developement and rupture of little air-vesicles. If the buffy coat be carefully separated from the crassa- CHAP. I.] BUFFY COAT : HOAV MODIFIED. 203 mentum, Avashed in cold Avater, and then immersed in strong alcohol, its elastic properties will be greatly augmented, and the membrane will present the appearance precisely of a half- tanned hide, or of the proper uterine tissue during pregnancy. In this Avay I have prepared several beautiful specimens, Avhich have now been in my museum of pathological anatomy for several years. Various accounts have been published respecting the chem- ical constitution of the buffy coat, but it is to the researches of Dowler and Gendrin that we are indebted for the most pre- cise information. From the observations of these physicians, it clearly appears that this substance is essentially composed of fibrin, containing a considerable but variable amount of albumen and serum, or what Dr. Babington has termed the sanguineous liquor, which may be squeezed out by pressure. The greatest analogy thus exists, both as regards appearance and chemical composition, between the buffy coat of the blood, as exhibited in certain diseased states of the system, and the substance that constitutes the adventitious membranes of the serous cavities. Considerable diversity prevails in respect to the thickness of the buffy coat, this depending on the intensity of the disease, and the nature of the affected part. Most commonly, it does not exceed the eighth of an inch ; but, in some rare instances, I have known it to be from three to six lines. As a general rule, it may be stated to be greater in plethoric subjects than in such as are weak, and in inflammations of the joints, se- rous membranes, and parenchymatous organs, than in similar diseases occurring in other structures. The consistence of the buffy coat is also liable to vary. In typhus, scurvy, and chlorosis,—in short, in all cachectic states of the body, it is generally soft and brittle, thin, iri- descent, and of a dirty yellowish color. On the contrary, in simple inflammatory affections, it is usually highly tenacious, thick, and of a uniform opaline tint. This peculiar appearance of the blood, it may now be ob- served, occurs in all inflammatory disorders, and, in fact, in almost every condition of the system in which there is a pre- dominance of vascular action. It is usually found in the acute stages of pneumonitis, hepatitis, scarlet fever, small-pox, gout, rheumatism, and invariably, perhaps, in pleurisy; at least, I do not remember ever having bled a patient laboring under this affection in Avhom the blood was not more or less buffed. 204 BLOOD. [CHAP. I. It is also very generally met Avith in pregnant Avomen, in dropsy, in chronic diseases of the chest and abdomen, in scurvy, in chronic gout and rheumatism, and in those who resort to frequent venesection. In chronic inflammation, in whatever tissue or organ seated, the buffy coat usually con- tinues for a long time, especially if it be attended with much constitutional disturbance, reappearing at almost every repe- tition of the bleeding until the malady wholly subsides. The same phenomenon is wintessed in those affections in Avhich the primary morbific impression seems to make on the circu- lating current, as small-pox, for example, the virus of which is evidently absorbed by the vascular system. At the com- mencement of this disease, the blood is usually covered with a tolerably thick crust, but this crust seldom exists, or, at most, only in a very slight degree, prior to the establishment of the eruptive fever. When the exanthem is moderate, the quantity of buffy matter is commonly very small : in nearly all cases it continues until the scabs are perfectly dried, and occasionally even a few days later. Baglivi, one of the most celebrated physicians of the seventeenth century, has justly remarked, that the presence of a thick inflammatory crust, at the beginning of small-pox, is a sure indication of a plentiful crop of pustules, — a fact Avhich has been amply verified by more recent observation. Persons sometimes labor under intense inflammation, and yet the blood does not exhibit the buffed appearance until af- ter they have been bled several times. The reason of this is not very obvious ; but we may suppose that the system in these cases is so surcharged with blood, or that the heart and vessels are so exhausted that the usual nervous energy upon which the slow coagulation of this fluid depends is not im- parted. At other times, the reverse of this obtains, — the blood Avhich flows first exhibiting the buffy coat, whilst that which is drawn towards the close of the operation will have little or none of it. This phenomenon is particularly apt to take place when the blood is allowed to issue slowly from a small orifice. Occasionally, again, the buffy coat can be obtained at pleasure, as Avhen, after having abstracted a small amount of blood, Ave close the vein for eight or ten minutes, and then finish the operation. The last portion of fluid thus ob- tained Avill have little or no buff, unless this appearance is very conspicuous on the surface of the portion first drawn. CHAP. I.] BUFFY COAT : CAUSE. 205 From this it may be concluded the first effect of every small bleeding, when the system labors under an inflammatory dia- thesis, is the disappearance of the immediate elements of the fibrinous crust; and that, if this state continues, these ele- ments are speedily reproduced. Hence, as Avas previously intimated, it may frequently happen, in bleeding a sick per- son, that the blood which is taken away at the outset of the disease shall have no buffy coat, whilst that drawn subse- quently, shall exhibit it in a very high degree. Under such circumstances, too, if the patient be bled to syncope, and then, waiting until he has recovered, abstract more blood, it will be found that it does not present the pleuritic crust. The manner in which the formation of the buffy coat may be modified by the state of the nervous system, is well illus- trated by a case related by the late Dr. Hewson, of England. A young, robust man was bled during an attack of inflamma- tory fever. On opening the vein, the blood merely trickled down the arm, owing, apparently, to the fright of the patient; but, in a few seconds, it began to run quite freely. Three ounces were then received into a second cup, and a like quantity was immediately caught in a third. The indi- vidual now became faint, and Avas laid on the floor, when a few drachms more blood were taken in a fourth cup. Of these four measures of fluid, that which Avas removed last coagulated in three minutes, the first in twelve minutes, and the second in about twenty-two minutes. Neither of these had any inflammatory buff; but the blood received into the third cup began, in five minutes, to appear transparent on the surface ; and, although it did not fully coagulate for upwards of half an hour, it had a remarkably thick, tough crust.* The immediate cause of this appearance is sufficiently ob- vious : the globules, with their coloring matter, begin to sub- side before the coagulation is completed, and thus the upper surface of the crassamentum is left without them. With re- gard to the remote cause, it can scarcely be said to be fully ascertained, notwithstanding the numerous attempts that have been made to discover it. Hewson thought that the fibrin was rendered specifically lighter than the red globules, by which the latter would be disposed to sink to the lower part of the cruor; he also supposed —which, however, is not true — that the blood always coagulated more slowly. Dr. * Hewson on the Blood, vol. i. p. 82, et seq. 206 BLOOD. [CHAP. I. Dowler, an English physician, Avho published an account of this theory in 1822, endeavored to explain the phenomenon on the assumption that inflamed blood contains an unusually large proportion of serum, which, by diminishing its viscidity, readily alloAvs of the subsidence of the hematosine. Neither of these opinions, it seems to me, affords a satisfactory solu- tion of the difficulty. That the red particles are specifically heavier than the fibrin, is a circumstance with which every one is familiar; but as this is the case even in the sound state, very little use can be made of it as a proof of the position assumed by Hewson. Nor is it, as I before intimated, a fact that in- flamed blood retains its fluidity a much longer time than healthy, as is asserted by the same ingenious author. In the great majority of instances, indeed, the very reverse of this obtains, — the concretion taking place with extraordi- nary rapidity. If this be true — and multiplied observations induce me to think it is — it is obvious that another explan- ation must be sought for. Shall we adopt the idea of Dow- ler, — that the phenomenon depends upon a redundancy of thin serum ? This also is inadequate, for the fact, if it be one, remains to be established. The explanation Avhich I would propose is this : in the healthy state, the fibrin is ex- ceedingly tenacious, and the red particles are so intimate- ly connected Avith it as to render it impossible for them to subside during the coagulation, however sloAvly this may be effected. In inflammatory affections, on the contrary, this cohesive property is either greatly diminished, or, Avhat is more probable, the fibrin loses its affinity for these little bodies, which consequently gravitate to a greater or less depth before before the blood separates into its two grand stituents. In this manner the top of the crassamentum is covered with a buff-colored layer, the thickness and density of which vary according to the repulsive power existing be- tween the two elementary principles referred to, the intensity of the disease, the general state of the system, and the ex- tent of the contraction of the inspissated mass. The reason why this separation is not effected whilst the blood is circu- lating within its vessels, is the constant motion to which it is subjected, which is incompatible with the process. How far the explanation here offered is correct, I cannot pretend to determine: I throw it out merely as a hint, in the hope that others may be induced to test its truth, or point out its fallacy. CHAP. I.] BUFFY COAT : MODIFIED BY CIRCUMSTANCES. 207 Every physician knows how much the formation of the buffy coat is influenced by extraneous circumstances. Of these, the most important are the shape and capacity of the receiving vessel, the degree of motion to which the blood is subjected, and the size of the orifice in the vein. Dr. Belhomme, of Paris, Avho has minutely investigated this sub- ject, in a series of one hundred and fifty experiments, has come to the conclusion, that a narrow basin, a large orifice, and a full, rapid stream, in the form of an arch, are the external circumstances most favorable for producing the buffy coat. The results of these researches have since been veri- fied by those of Gendrin* and other physiologists; and they are Avell Avorthy of being remembered, as they have a direct bearing on the practice of our profession. If blood be draAvn simultaneously from both arms, it will generally be perfectly uniform, both as respects the quantity of the serum, and the density of the cruor. Should the blood, however, run disproportionably sIoav on one side, there Avill be no appearance of inflammatory crust, Avhilst it will readily form on the blood Avhich issues from the other, for the obvious reason, that in the former case the liquid will concrete before the red globules have time to disengage themselves from the fibrin; Avhereas, in the latter, the fluidity will be sufficiently protracted to admit of this occurrence. This circumstance is alluded to by the sagacious Rush, in his " Defence of Blood-letting," published soon after the beginning of the present century. In a case of pleuritis, the blood which Avas taken from one arm, he observes, was sizy, whilst that which flowed from the other Avas of a scarlet hue; and similar appearances Avere noticed by him in the blood of a pregnant female. It Avill be seen, from the foregoing remarks, that we cannot, as a general rule, consider the inflammatory crust as depending uniformly upon the shape of the receiver, the size of the orifice, or the volume of the stream, since all these circumstances merely modify, but can never produce the buffy coat, unless the fluid is susceptible of it, or has undergone those changes Avhich are necessary for its devel- opement. Nevertheless, it should be constantly borne in mind, when we wish to draw any legitimate conclusions in relation to the inflammatory crust, that it is all-important * Historie Anatomique des Inflammations, t. ii. 208 BLOOD. [CHAP. I. that the blood should not be exposed to too Ioav a tempera- ture, that the receiver should be rather narroAv and deep, and, lastly, that the orifice in the vein should be large enough to furnish at least tAvo ounces of fluid in a minute. To effect this, the incision should be about a line and a half in length, and the blood should run in a full and continuous jet. When the middle of the buffy coat is depressed, or scooped out, as it Avere, it is said to be cupped, —an appearance Avhich is very common in nearly all diseases of a highly inflamma- tory character, such as pleurisy, peritonitis, rheumatism, and gout. Venous blood is not alone susceptible of being buffed and cupped: the same phenomena are observed in arterial blood, and the only reason, perhaps. Avhy they are not so familiar to us is owing to the less frequent performance of arteriotomy than of venesection. The manner in which this cupped condition of the blood disappears, is Avell exemplified in a case Avhich came under the notice of my friend, Dr. Charles Woodward, of this city, a few years ago. He attended a married lady under a violent attack of pleuritis, for which she was several times bled: the blood which was taken on the first day of the treatment, was deeply buffed and cupped. Twenty-four hours after, the same appearances Avere exhibited, except that the clot Avas not quite so much depressed in the centre ; in tAvelve hours more, the fluid was still buffed, but no longer cupped; and, at the fourth opera- tion, performed three days after the first, it was neither buffed nor cupped. This cupped state of the blood, as has been just hinted, is generally indicative of the highest degree of inflammatory action, yet, strange as it may seem, it is not unfrequently found in very opposite conditions of the system, as in^persons who are greatly exhausted by hemorrhagic and other pro- fuse discharges, and Avho do not evince the slightest symp- toms of phlegmasial excitement. Most commonly, it occurs in connection with inflammation of the serous membranes and the parenchymatous organs; being seldom present in the mucous and dermoid textures. Although it is not consistent with the plan of this Avork to enter upon any therapeutic considerations, yet I cannot dis- miss this branch of our subject without briefly inquiring hoAV far the buffy coat should be regarded as an index to the abstraction of blood. We have already seen that this phe- nomenon occurs under very opposite states of the system, CHAP. I.] WANT OF COAGULABILITY. 209 in the most debilitated as Avell as in the most robust, in the highest degrees of disease as well as in the lowest, and in individuals Avho are in the enjoyment, apparently, of the most perfect health. The blood, in the advanced stages of pregnancy, is almost ahvays covered Avith a layer of fibrin; and the same thing is generally observed in persons that have suffered from profuse hemorrhages of the stomach, lungs, or other organs. In individuals subjected to a course of mer- cury, the blood draAvn from the arm is frequently as much buffed as in the most violent attacks of gout or pleurisy, notwithstanding the great reduction of the vital powers. The same effect may be produced' simply by taking severe exercise. Thus, if a horse be bled immediately after a smart gallop, Avhile the circulation is carried on with great vigor, the blood Avill exhibit the buffy coat, Avhereas that previously abstracted will be perfectly free from it.* Similar appear- ances have been repeatedly Avitnessed in the human subject. If these circumstances be coupled Avith the fact, that the buffy coat may be entirely absent, even in the most intense inflammation, the conclusion is obvious, that the phenomenon in question can neither be regarded as a certain test of morbid action either in the solids or in the vital fluid, nor a safe index of the propriety of blood-letting. The fibrin is sometimes remarkably destitute of coagu- lating poAver. This is strikingly evinced in persons who are suddenly destroyed by lightning and electricity; a violent bloAv on the stomach, or severe injury of the brain ; by the bite of venomous serpents ; by acid vegetable poisons, such as prussic acid; excessive fatigue, as in hunting doAvn wild animals ; and even violent agitation of the mind. It is also frequently witnessed in Asiatic cholera, in scurvy, and in malignant fevers. Occasionally, too, it is present, and yet the individual is apparently in the enjoyment of good health. Under such circumstances, the most trifling injury may prove fatal, since the only means by which hemorrhage can be successfully combated is taken away, the blood refusing, in spite of all our efforts, to coagulate. Mr. Wardrop, of Eng- land, in a short but valuable treatise on blood-letting, pub- lished a few years ago, has cited a number of cases of this kind, several of which came under his own immediate ob- * Cyclopedia of Anatomy and Physiology, part v. p. 420. The article on the morbid conditions of the blood in this work is from the able pen of Dr. Babing- ton, of London. vol. i. 27 210 BLOOD. [CHAP. I. servation. In one of the instances alluded to, the patient died from hemorrhage, induced by the introduction of a seton in the side ; in another, from a slight Avound of one of the fingers; in a third, from the extraction of a tooth ; in the fourth, from a superficial wound in the palm of the hand; and, in the fifth, from a bite of the tongue. An instructive case in Avhich this deficiency in the coagu- lating poAver of the blood existed, and became a source of fatal hemorrhage, Avas recently communicated to me by Dr. Charles Barnes, of this city. It occurred in a servant girl, fifteen years old, of a delicate constitution, Avho had never menstruated, and had been in bad health for about four months previously to her death. During the last six Aveeks, she had been taking a variety of the most poAverful emena- gogues, Avithout any apparent benefit. In this state of things, Dr. Barnes Avas requested to extract the second molar tooth on each side of the loAver jaAV. Five days after the opera- tion, the patient was attacked Avith profuse hemorrhage from the wounded sockets and surrounding structures, Avhich per- sisted, notAvithstanding the employment of the most energetic measures, until in a short time she died perfectly exhausted. In compressing the parts Avith a piece of cork, the bleeding could be temporarily arrested, but the blood would soon ooze out from the mucous membrane of the cheek. Mr. Wardrop gives a curious case in which this peculiarity Avas hereditary. The patient was a boy, and the hemorrhagic tendency displayed itself Avhen he Avas scarcely tAvo months old. On several occasions, he nearly lost his life from the most insignificant Avounds. His brother, tAventy-two years old, Avas frequently afflicted in the same Avay. Of his five uncles, not one Avas free from this predisposition : three died after a division of the frsenum of the tongue, one from the extraction of a tooth, and the other, although he suffered from the same disease, finally died from some other cause. His two aunts exhibited no signs of this diathesis ; but, Avhat is singular, all the male branches of their families, excepting one, were thus affected. A still more remarkable case has been recently reported by Dr. Hughes, of the state of Kentucky. The predisposi- tion here was associated Avith a rheumatic diathesis, and was satisfactorily traced as far back as five generations. It Avas confined exclusively to the male branches of the different families; but the females, nevertheless, invariably transmitted CHAP. I.] HEMORRHAGIC DIATHESIS. 211 it to their offspring. Many of the individuals died in infancy and childhood, — death resulting in some from the cut of the lancet; in some from accidental Avounds ; in some from in- ternal hemorrhage ; and two simply from the application of blisters, the vesicles being filled with blood instead of Avater.* To what is this Avant of coagulating property of the blood to be ascribed ? That it is owing, at least in part, to the insufficient supply of nervous influence, upon the presence of which the vitality of the fluid in question essentially depends, cannot, I think, be denied. The matter, indeed, may be considered as reducible to a syllogism that contains its own proof. The direct influence of the nervous system on the blood was long ago contended for by Barthez and other physi- ologists, and has been happily elucidated in our OAvn time, by the researches of Dupuytren, Brodie, Dupuy, Thackrah, Cooper, and Meyer, with a host of others of minor character. The latter experimentalist ascertained that, whenever both pneumo-gastric nerves are tied in animals, the blood soon coagulates in the Avhole pulmonary circle, the coloring matter at the same time separating from the fibrin. Sir Astley Cooper, on repeating this operation, observed similar results ; that is to say, the sanguineous fluid was of a semi-concrete consistence, of a dark modena color, even in the arteries, and the lungs were so much loaded Avith it as to be tAvice as heavy as in the normal state. Simple division of these cords does not appear to give rise to any such effects, for the reason, probably, that it does not produce any serious obstacle to the transmission of the nervous current. Dupuy, it is true, de- clares, that he has seen the blood entirely dissolved under these circumstances, and that, upon being infused into the jugular vein of a sound animal, it produced mortification ; but I am not able to say, being obliged to quote from Andral, whose statement is very unsatisfactory, Avhether all this was the result merely of the simple division of the pneumo- gastric nerves, or, as seems most likely, of the removal of a small section of them. The influence of the nervous system, however, is nowhere more strikingly evinced than in the effects produced by a severe blow on the coeliac ganglion. Here death is caused by the same rapidity as by lightning and the most subtle poisons; * Transylvania Journal of Medicine, vol. v. For a similar case, related by the same gentleman, see Op. cit. vol. iv. p. 518. 212 BLOOD. [chap. I. and the blood, as was before stated, exhibits precisely similar appearances, being unusually black, dissolved, and incapable of separating into serum and crassamentum. I shall only further illustrate this interesting branch of our inquiry by a passing notice of the relative quantity of fibrin contained in healthy and diseased blood. Upon this subject, the late Mr. Thackrah, of England, made numerous experi- ments, from which he deduced the conclusion that there is ahvays a great redundancy of this substance in inflammatory disorders, even Avhen there is an entire absence of the buffy coat. Sir Charles Scudamore has more recently con- firmed these facts, and Mr. Jennings has verified his results,* so that the question must be considered as finally settled. The increase, in most of the experiments performed by these physicians, was about two thirds above the normal standard ; and it Avould appear that it is proportionably greater in gouty and rheumatic affections than in any other maladies. It has been supposed that the tying of the pneumo-gastric nerves in the neck has the effect of diminishing the quan- tity of fibrin in a very notable manner. Professor Dupuy, of the Veterinary School at Alfort, in France, having performed this operation, dreAV a certain amount of blood from the carotid artery, and ascertained that it contained twenty-one grains of fibrin. In a few hours after, the same amount con- tained only nineteen grains; at the end of sixteen hours, eighteen grains; and, at the end forty hours, twelve grains. In a little more than two days from the operation, the horse died in a state of asphyxia, Avhen the same quantity of fluid, still taken from the carotid, had only seven grains of fibrin.f The question naturally presents itself, — was the progressive diminution, here spoken of, directly produced by the division of the pneumo-gastric nerves, or indirectly by disturbing the process of sanguification ? In all probability the section of the nerve had nothing to do Avith it; for it is not at all un- likely, though this is not stated, that the animal at each bleeding lost more blood than was necessary for the purposes of the experiment; and, if this be admitted, the facts observed by Dupuy, though he accounted for them in a very different way, will be found to tally with the results of the experi- ments of Dr. Andrews, alluded to in another part of this chapter. * Transactions of the Provincial Medical Association for 1834. t Andral. Anat. Path. t. i. p. 204. CHAP. I.] HEMATOSINE. 213 The hematosine, the second constituent of the crassamen- tum, is no doubt often altered in disease ; but Avhat these changes are, or with what states of the fluids or solids they are connected, has not yet been determined. In many mala- dies, it seems to disentangle itself from the globules in which it naturally resides, and to percolate through the vessels into the different cavities of the body, or into the interstices of some of the organs. This disengagement frequently occurs in sea-scurvy, in malignant dysentery, and in typhous fever, and is the cause, in all likelihood, of the passive hemorrhage, and petechial spots Avhich are so commonly met Avith in these affections. To the same circumstance is to be attributed the stained condition of the endocardium and the inner mem- brane of the vessels, which usually takes place Avithin a short time after death, especially in Avarm weather, and which has sometimes been mistaken for the effects of inflammation. The hematosine often exists very sparingly. This dimi- nution, as might be anticipated from its apparent cause, is usually connected Avith those conditions of the system which are characterized by great debility, Avhether occasioned by impoverished living, protracted indisposition, or profuse hem- orrhagic discharges. It is very constantly met with in chlorosis, in ascites, in organic affections of the stomach, and duodenum, in persons who are frequently bled, and in females who suffer habitually from menorrhagia. As having a direct bearing on this subject, it may be stated that Avomen have always, comparatively speaking, less hematosine in their blood than men, — a fact which Avas first ascertained, I believe, by Lecanu, and which, he thinks, is attributable to their monthly evacuations. The folloAving comparative view is the mean of his analysis made with blood drawn from ten adults of both sexes: Female. Male. Water,.....804.37 789.32 Albumen,.....69.72 67.50 Saline and extractive matter, . 9.95 10.69 Red globules, .... 115.96 132.49 1000.00 1000.00 In the above diseases, the countenance is remarkably blanch- ed from the want of hematosine, the different tissues are literally exsanguineous, the nutritive function is badly exe- cuted, and there is great failure of the strength, Avith a dis- 211 BLOOD. [CHAP. I. position, in many cases, to cellular infiltration of the extremi- ties. This state of things often persists for months, and, occasionally, as in chlorosis, even for years, —a fact strongly illustrative of the tardy reproduction of the hematosine on which it depends. The blood, under such circumstances, is absolutely impoverished, being scarcely fit for the purposes which nature has assigned to it, from the absence of fibrin and red particles. Acute maladies produce, in effect, the same re- sults, with this difference, that these two important elements of the vital fluid are usually much more quickly regenerated, especially when the individual has the benefit of free exercise, and animal food. There are some maladies, such as cholera, typhus, and plague, in which the hematosine is unusually black. The reason of this has not yet been determined. By some it has been attributed to a diseased state of the blood, by which it is rendered unfit for being duly arterialized by exposure to the atmosphere. Such, amongst others, is the opinion of Dr. Thomson, of Europe, which, however, is directly at variance with that of Dr. O'Shaughnessy, Avho maintains, and I believe correctly, that cholera blood is not only capable of absorbing oxygen, but also that it emits carbonic acid gas. Dr. Stevens, on the other hand, supposes that the black color is directly ascribable to the contaminating influence of the contagious virus of this disease, whereby the circulating fluids are chang- ed in their character, at the same time that they suffer a great loss of saline matter. These views are neither of them, it seems to me, entitled to much respect, as not one of them, with the exception, perhaps, of the latter, is supported by positive fact. In the production of the appearance under con- sideration, Ave may suppose that the combined agency of several causes is necessary. Amongst these, the most impor- tant, without doubt, is the partial abstraction of the vital prop- erties of the blood, producing thereby a general impairment of the various functions of the system. In no organ is this disordered action carried to so great a degree as in the lungs, where, although the atmosphere still comes in contact Avith the delicate air-cells, the sanguineous fluid, from its exhaust- ed condition, and destitution of saline principles, is no longer susceptible of being properly arterialized. That this is true, is abundantly established by pathological anatomy, physio- logical experiments, and chemical analysis j for, as will be seen hereafter, the blood, in the diseases referred to, is generally CHAP. I.] HEMATOSINE. 215 extremely black, dissolved, highly carbonized, and some- times almost entirely drained of its salts. In cholera especi- ally, these states of the blood are amongst the most uniform occurrences ; and it is to them that are to be mainly attributed the livid color of the skin, the embarrassed breathing, and the rapid exhaustion which those Avho are the subjects of the mal- ady generally exhibit. To this general statement several other facts, strongly cor- roborative of what Ave have said, may hoav be added. In the first place, Ave may notice the effects that result from a divis- ion of the pneumo-gastric nerves, which are the governors, if I may use the expression, of the respiratory organs. This experiment is invariably followed by a suspension of the ar- terializing process, in consequence of which the blood is always found of a black color after death, both in the veins and in the arteries. The same effect has been observed by Sir Astley Cooper to be produced by merely tying these nerves. The blood also, he states, flows of a dark color when the carotid artery is opened after the phrenic nerves have been secured: the lungs, in this case, are not found heavy and en- gorged, as in the former. These researches, together with many others of a similar character, that might be cited, clearly demonstrate the dependency of the arterializing process upon the nervous influence. Take this agent away, and the vital fluid becomes darker and darker, until at length the lungs are utterly incompetent to make any salutary impression upon it. These changes, secondly, are generally produced more rap- idly in proportion to the abstraction of the salts of the blood. The truth of this remark is strikingly corroborated by Avhat occurs when Ave inject saline fluids into the veins of cholera patients,—an operation Avhich Avas performed successfully in several instances, both in this country and in Europe, during the prevalence of this disease. In the collapsed stage of this disease, Avhen the individual is actually in a state of asphyxia, the skin cold and livid, the respiration labored, and the pulse imperceptible at the Avrist, no sooner are the watery and saline materials restored than the Avhole aspect of things is changed ; the heart begins to act Avith increased vigor, Avarmth is dif- fused throughout the body, the breathing becomes easier, the strength returns, and the surface recovers its accustomed hue. Blood drawn from the arm, under these circumstances, will exhibit, if not its usual appearance, a very close approxima- tion to it. Thus, then, there are at least two elements con- 216 BLOOD. [CHAP. I. cerned in the production of the black color of the hematosine, — a partial abstraction of the vital principle, and a diminished amount of saline matter. Whether these are the only ones, I cannot pretend to decide ; nor can we expect to be able to re- move the veil Avhich still enshrouds the subject, until animal chemistry shall make the discoveries, and reveal to us the true nature of hematosine, its mode or origin, and the manner in which it is combined Avith the other principles of the blood. Until this be effected, no speculation on the part of the mor- bid anatomist, however refined or ingenious, can be entitled to any sort of confidence, or throAV any real and substantial light upon his profession. The serum, like the cruor Avith Avhich it is so intimately combined, is liable to various alterations, carried to such a de- gree, frequently, as to entitle them to be termed morbid. Thus it has been found to have the aspect and consistence of milk ; to have streaks upon its surface like cream ; to have oil in it; and, finally, to be remarkably destitute of saline and animal principles. These changes may occur exclusively in the se- rum ; but, in the great majority of instances, there is reason to believe that the fibrin and hematosine participate in them. The occurrence of milky serum is not so uncommon, I am disposed to think, as the silence of the profession, in regard to it Avould lead us to infer. Morgagni relates two cases of ma- lignant fever, in which he noticed this appearance : Mr. Hew- son also mentions several examples of it; and, since his time, numerous instances have been recorded by other writers. This state of the serum is usually met Avith in inflammatory disorders, and seems to be connected, in some way or other, with deficient assimilating power of the digestive organs. In a case of milky serum, which fell under my observation in 1832, the patient, a young man, thirty years of age, had long been addicted to the intemperate use of ardent spirits, and at the time here specified, he labored under symptoms of pleuri- tis, accompanied with headache, want of appetite, and con- siderable constitutional disturbance. The blood, as it issued from the vein in the arm, had a singularly dirty, turbid ap- pearance, not unlike a mixture of chocolate and milk. It had scarcely been drawn ten minutes before it began to assume a white creamy aspect; and it finally formed a layer on the sur- face of the clot about the eighth of an inch in thickness. In the course of an hour, some of this fluid was skimmed off, and put in another vessel, in which it Avas allowed to remain dur- CHAP. I.] „ MILKY SERUM. 217 ing a period of half a day. On examining it, at the expira- tion of this time, I found it to be slightly concrete, of the spe- cific gravity of 1.026, remarkably unctuous, and of a strong saline taste. It readily coagulated, on the addition of alcohol, corrosive sublimate, and the mineral acids, as well as on ex- posure to heat; and, on being viewed with the microscope, exhibited no appearance whatever of globules,— circumstances Avhich justify the conclusion that it Avas essentially composed of albumen. The cruor in this case Avas someAvhat more abundant than usual, and the quantity of serum of course less. It is Avorthy of remark, that, upon a repetition of the bleed- ing, twenty-four hours afterwards, the blood presented precise- ly the same characters as before. Milky serum, as might be expected, always contains an in- ordinate amount of adipous matter. In a specimen examined by Laennec, 1000 parts were found to consist of 794 of Avater; 65 of albumen; 108 of fatty matter, cholesterine, and acid soap ; 17 of elaine, margarine, and stearine ; and 25 of saline and extractive substances. The fibrin and hematosine had nearly entirely disappeared ; and, in place of the globules, there was a large quantity of fatty matter, which Avas suspended in the serum, and gave the fluid its characteristic milky aspect. Similar results have been obtained by Christison, Babington, and other writers. To the same class of cases ought to be referred, I appre- hend, those in which the serum is said to have contained oil, of which several well-marked examples have been recorded by Dr. Traill, of Liverpool, in the twenty-fourth volume of the Edinburgh Medical and Surgical Journal. In the last specimen which he has described, the serum was of a light straw-color, cream-like in its consistence, and at first appa- rently homogeneous. On being kept, however, for a short time it coagulated, and was poured with difficulty from the bottle in Avhich it was contained. On analysis, it yielded a large proportion of albumen and oil, the latter of which was so pure as almost to burn when exposed to the flame of a lamp. It has been made a matter of inquiry to ascertain, if possi- ble, the cause of this milky state of the serum. On this sub- ject, hoAvever, there is no positive testimony. By some it has been attributed to the admixture of fatty matter; by others, among whom may be mentioned Haller, to the presence of crude chyle. That it is connected Avith deficient assimilat- vol. i. 28 21S BLOOD. [CHAP. I. ing poAver appears altogether probable, both from the nature of the diseases in which this peculiar state of the serum is found, and from the resemblance Avhich this substance bears to the fluid just referred to. Chyle, it is well known, varies in appearance as the food has or has not contained fatty mat- ter : in the former case, its color is milk-white ; in the latter, it is nearly transparent. Soon after being drawn, it coagu- lates, and subsequently separates into three parts, —one solid, which rests at the bottom of the vessel, and looks like fibrin ; another liquid, which is analogous to serum; and a third, Avhich forms a thin layer on the surface of the others, and is of an oily nature. If to this remarkable similarity betAveen these two fluids we add the fact, that nearly all the cases in Avhich milky serum has been observed were characterized by derangement of the chylopoietic viscera, it renders it more than probable, I think, that the appearance under considera- tion is owing to deficient assimilation, by Avhich a larger amount of fatty substance is retained in the circulation than in the normal state. Where the fault actually resides, whether in the mesenteric glands, in the thoracic duct, or in the lungs, or in all these organs, is a question which, in the present state of the science, it is impossible to determine. Future obser- vations, cautiously and patiently conducted, will alone be adequate to solve the problem. It is seldom that Ave find this state of the blood associated with the buffy coat. I knoAV of but one case of the kind, Avhich is reported in a late number of the London Medico- Chirurgical RevieAV.* It occurred in an intemperate man, forty-seven years old, Avho was bled for pneumonitis, attended with high febrile excitement; the crassamentum was coated with a thick layer of fibrin, and the serum exhibited not only a milky aspect, but likewise a milky odor. The urine, too, had a similar appearance, and was sparingly secreted. It has been long a matter of observation, that, in high de- grees of inflammations, the watery part of the blood is more, viscid, and of a deeper yellowish color than usual, presenting frequently, the aspect and consistence of synovial liquor. This appearance is less evident when the clot does not float in, or occupy the centre of the fluid. Gendrin has shown that the serum, in these disordered states of the system, contains at least twice as much albumen as in the healthy state,— a cir- *No. 63, p. 229. CHAP. I.] SERUM IN DISEASE. 219 cumstance which readily accounts for its remarkable viscidity, its astonishing coagulable properties, its' increased specific gravity, and its deep yellowish color. In dropsical and cachetic persons, on the contrary, the se- rum is generally much thinner, and of a paler hue, than in such as are favored with an opposite state of the system. Its specific gravity is also much less, and there is a sensible dimi- nution of albumen. Similar alterations take place in persons Avho are in the habit of being frequently bled. The effects thus produced, though long known, have been placed in a very striking light by the recent researches of Dr. Andrews, of England.* The animal selected for the experiments Avas the calf, Avhich Avas bled from a large orifice in the jugular vein, till symptoms of syncope were induced. The operation Avas repeated at intervals of twenty-four hours, during which the calf was generally once fed upon a mixture of meal and water. The appearance of the blood thus drawn Avas greatly altered at each successive abstraction. At the first operation, the cruor Avas very large, and a considerable portion of hema- tosine was collected from it; but, as the venesection Avas re- peated, it gradually diminished in bulk, Avhilst its consistency augmented till the fourth bleeding, Avhen it presented the ap- pearance of a small contracted ball immersed in a great quan- tity of serum. This experiment was frequently repeated on different ani- mals, and uniformly with the same results; whence it may be fairly inferred that an increase of serum, with a correspond- ing diminution of crassamentum, is a very constant if not an invariable effect of the repeated abstraction of this fluid from the system. Dr. Andrews further ascertained that there is a perceptible decrease of albumen and salts at each bleeding; he states, however, that the diminution is very variable, and that it seldom exceeds one and a half per cent, even after the fourth operation. In the globules a still greater diminution occurs, being not unfrequently reduced to less than one half their original number. These experiments are unquestionably of a highly interesting nature, and their results are well calculated to lead to useful precepts in practice. Organic disease of the kidney is another of those condi- tions in which there is a deficiency of albumen with a con- sequent diminution of specific gravity. The reason of this * London Medical Gazette, vol. xv. p. 592. 22U BLOOD: [chap. I. is obvious, in nearly all cases of this disorder, the serum is deprived of its animal principles, and the urine, Avhich is loaded Avith them, is readily coagulable by heat, alcohol, and acids. Dr. BarloAv, of London, Avho has devoted much atten- tion to the examination of the blood and urine in organic disease of the kidney, ascertained that the specific gravity of the serum is sometimes as low as 1.013, and seldom higher than 1.020. These results coincide with those of Dr. Bab- ington, who states that, in Avhat the French have called " Bright's disease," he has invariably found this fluid much beloAv the healthy standard. In a case of this kind, there Avas nearly one eighth as much albumen in the urine as in the serum, and the patient lost as much of this constituent daily as if he had been bled to the extent of four ounces.* In cholera, on the other hand, the Avatery portion of the blood being drained off, the serum Avhich remains is of high spe- cific gravity, and contains nearly double the ordinary propor- tion of albumen. Jaundice, as was long ago observed by John Hunter, is another disease in Avhich this fluid is morbid- ly affected. In this condition of the system, it is not un- usual, indeed, to find the serum, as well as the urine, of a deep orange color. How far, or in Avhat respects, the saline ingredients of the serum are liable to be altered, are points concerning which Ave have no accurate information. That they frequently ex- ist, in excess as Avell as in defect, does not admit of a reason- able doubt. The ill effects resulting from the long-continued use of salt provisions are familiar to every army and navy surgeon. Inflammatory fever, irritable ulcers, itch, and tetter, Avith other highly distressing and troublesome disorders, are often directly chargeable to such a mode of life. On the other hand, in scurvy, Asiatic cholera, and in the malignant fever of tropical climates, it is extremely probable, as has been observed by Dr. Stevens, O'Shaughnessy, and others, that there is generally a great deficiency of saline ingredients. In these disorders, the hematosine remains dark even in an atmosphere of pure oxygen; but, on the addition of a solu- tion of muriate of soda, instantly assumes a florid hue ; and this is said to take place even when the solution is very weak. Frequent bleeding, as we have already seen, has also the effect of sensibly diminishing the saline matter of the blood. * Cyclopedia of Anatomy and Physiology, part v. p. 426. CHAP. I.] GENERAL DISEASES OF. 221 On the whole, it must be confessed that our knowledge con- cerning this subject is extremely meagre and imperfect, and numerous researches and chemical experiments will have to be made before we can hope to arrive at any satisfactory or useful results. That the blood, considered as a mass, may be variously affected, is equally true as of its several constituents. All such changes, whatever they may be, should be carefully studied, as they correspond with so many particular morbid states of the system. Professor Andral has cited numerous cases in which the blood not only contained the different ele- ments of the secreted fluids, but likeAvise a variety of other accidental products, such as pus, entozoa, and encephaloid matter. In Avhatever way these substances may gain admis- sion into the vessels, or in Avhatever mode they may be there developed — and concerning Avhich I do not feel disposed here to speculate — certain it is, that, by combining with the blood, they not only vitiate it, but sometimes completely alter its physical, chemical, and vital properties. From the recent observations of some of the English and French anatomists, little doubt can be entertained that the elements of what are termed the heterologous formations, have their origin in the circulation, and that they are deposited subsequently in the various organs and textures, like other substances, by a sort of perverted action, induced by their presence. The ill effects of contaminated blood on the solids are well illustrated in the operation of transfusion. This operation, which was invented by Lower, in 1665, consists in transfer- ring the blood of one animal into the veins of another, and has recently been performed, with complete success, by several European practitioners. That no detriment, however, may accrue from this source, it is absolutely necessary that the fluid thus used should be of a healthy character, otherwise it will invariably act as a poison. Of the truth of this asser- tion there can be no reasonable doubt, as it has been fully established by experiments on the inferior animals, to say nothing of the innumerable instances in which this effect has been witnessed in the human subject. The first case I shall refer to is one recorded by Dr. Gendrin, of Paris, a gentle- man of acknowledged veracity, great talents, extraordinary professional attainments, and Avell known as the author of several admirable treatises in medicine and morbid anatomy. A man, a player, by occupation, was affected with putrid fe- 222 BLOOD. [CHAP. I. ver, attended with excessive prostration of strength, gangren- ous pustules, and hemorrhagic exudations from the mouth and nostrils. His breath, fcecal discharges, and, in fact, his Avhole body, exhaled a most offensive odor ; and the blood Avhich was taken from the arm Avas unusually black, scarcely coag- ulated, and displayed a remarkable tendency to decomposi- tion, being already quite fetid at the end of three hours and a half. Under these circumstances the vein was reopened, and an ounce of blood being drawn, it was introduced into the cellular tissue of the groin of a cat. The animal was soon seized Avith copious vomiting, followed by dyspnoea, thirst, and extreme prostration, and, in less than seven hours, it ex- pired in convulsions. On inspection, the different viscera were found in a state of congestion and ecchymosis ; the heart was soft and flabby ; the blood was every Avhere black and uncoagulated : the left pleuritic sac contained several ounces of sero-sanguinolent fluid; and the whole body emitted a nasty, fetid odor, and speedily began to putrefy. A small quantity of blood, taken from the same patient, was next injected into the femoral vein of a dog. Similar phenomena ensued as in the preceding case ; the animal soon died from the effects of the morbid fluid. The same distinguished writer details some experiments which he performed with the blood of persons affected with confluent small-pox. In a very short time the most violent effects arose, and the dogs, the subjects of the investigations, usually died in from twenty to thirty hours, in consequence, apparently, of inflammation of the principal internal viscera. On repeating this experiment, some years ago, upon a cat, no unpleasant effects followed; from Avhich it may be inferred that this sort of blood does not ahvays possess noxious properties. To these experiments may be annexed the extraordinary case related by Du Hamel, of a butcher, who died of malig- nant pustule, four days after having held in his mouth the knife with which he had slaughtered an over-driven ox. Another person lost his life by accidentally pricking his hand with a bone of the same animal; and two women suffered severely merely from some drops of blood falling on them. Not less conclusive are the results of the experiments of Du- puy and Luret. These physiologists assure us that, on intro- ducing blood, taken from a horse affected with malignant car- buncle, into the veins and cellular tissue of another, they have frequently succeeded in inducing the disease. In like manner, CHAP. I.] MORBID CHANGES : CAUSES. 223 glanders have been communicated by Professor Coleman, of London; and we are informed, by Dr. Hertrizch,,of Berlin, that hydrophobia can be readily produced by inoculating a sound animal Avith the blood of one that is rabid. A pecu- liar disease of the dog, called mange, has been transferred in the same way. These facts are highly interesting, inasmuch as they throw light on another subject, namely, the propaga- tion of exanthematous affections by artificial means. As the blood, in the examples above quoted, Avas capable of transmitting similar affections, no doubt can be entertained that it Avas really contaminated ; and there is, moreover, the strongest ground for believing that fatal disturbance is often induced in this Avay, Avhere Ave are little prepared to expect it, for aught Ave can discover in this fluid. The experiments, indeed, of Dr. Christison, Dr. Coindet, and others, of inject- ing poisonous substances into the veins of animals, conclu- sively show that, although the smallest quantity will fre- quently destroy life, yet the most delicate chemical tests will be insufficient to detect their presence in the vital current. Inordinate acceleration of the circulation appears to be often folloAved by serious alterations of the blood. It was long ago remarked by Haller — and the observation has been repeatedly made by others — that violent muscular exertion will vitiate this fluid, render the perspiration strong and offensive, change the qualities of the urine, and termi- nate, if long continued, in intense fever, and even death. Dupuy, of France, has ascertained by experiments that the fibrin is either very sensibly diminished or otherwise altered, in animals that are subjected to excessive exercise ; and the celebrated Chaussier assures us, that the transfusion of the blood, under such circumstances, will be speedily followed by the developement of gangrenous pustules and malignant fever. The deleterious effect on the blood produced by over-driving animals is well illustrated by the case narrated by Du Hamel, detailed in a preceding paragraph, and is still further ex- hibited in an instance which occurred in our own country. The case to Avhich I refer is this: A feAV years ago, a number of fattened cattle were driven into one of the New England cities, and, having been pressed too hard in a sultry day, Avere so overheated, that some of them became quite exhausted. In this condition they Avere slaughtered, and the consequence was, as is stated by the reporter of the case, Dr. 224 BLOOD. [chap. I. Fountain,* that nearly all Avho partook of their flesh Avere seized with typhous fever. In Asiatic cholera, again, in feA^ers, and other maladies, the blood, contemplated as a mass, is very materially altered; but whether primarily or consecutively, is a question by no means decided. In the first of these singular disorders, the fluid is drained of its water, and consequently contains a disproportionate amount of albumen, fibrin, and hematosine; its color is excessively black, both in the veins and in the arteries; it coagulates very imperfectly; is greatly augmented in specific gravity; and the saline matter occasionally Avholly disappears. One of the most extraordinary circumstances connected with the blood of cholera subjects, is the presence of urea; this substance, however, is not always found, and, according to Dr. O'Shaughnessy, it is usually most abundant where there is marked and long-continued suppression of urine. The great diminution of the serum of cholera blood is easily accounted for by the rice-fluid discharges, which are often so excessively copious in this disease, and which are essentially composed of the same elementary principles, namely, water, animal matter, and neutral salts. According to the analysis of Lecanu, the most elaborate that has yet been furnished, it contains neither caseum, nor bile, nor albumen, except in the form of flakes suspended in the ejected liquor. The blood of fever patients has recently begun to attract a considerable share of attention among practical writers; but as yet our knowledge in relation to this subject is both limited and imperfect. In those who died of typhus at Brest, in 1757, the blood is said to. have been grumous, black, and decomposed, particularly in the portal vessels; and Dr. Tweedie, in his "Clinical Illustrations of FeArer," states that the crassamentum of the blood in this class of diseases, instead of forming a firm coagulum, is unusually soft, scarcely of the consistence of half-boiled currant jelly, preternaturally small, and so destitute of cohesive power as to break on the slightest touch. Similar phenomena have been noticed by Dr. Gerhard, in the blood of typhous fever patients in the Philadelphia Alms-house Infirmary, to which he is a physician. * Transactions of the Medical Society of the State of New York, vol. ii! p. 219. Albany, 1837. chap, i.] in chlorosis: jaundice. 225 In the yellow fever of Philadelphia, in 1797, Dr. Rush found the blood frequently quite dissolved, dark, grumous, and occasionally like the washings of flesh. In some of the cases, the serum had a yellow color ; and, towards the close of the disease, it was very common to see the cruor more or less sizy. This appearance, it would seem, generally por- tended a favorable issue.* Similar states of the blood have been noticed by Ariquila, Bally, Palloni, and others, in the epidemic yelloAV fever of Spain; and, more recently, by Dr. Copland and Dr. Stevens, in the same disease, as it occurred in the West Indies. These authors describe the blood of yellow fever patients as semi-concrete, of a dark color, very poor in regard to its fibrous and saline constituents, and extremely prone to decomposition. A state very analogous to this is observed in the plague, in epidemic peritonitis, and in the worst forms of erysipelas. The blood frequently experiences great changes in chlorosis, both as it regards its color, its consistence, and the relative proportion of its ingredients. It is almost always remarkably impoverished, and it is to this circumstance that is to be ascribed the blanched appearance of the skin, Avith the diminished temperature which form such prominent features in its history. In the violent degrees of this malady, the cras- samentum is soft and small, the serum thin and copious, and the hematosine so pale as scarcely to leave a stain Avhen dropped on white linen. From an examination of two speci- mens of chlorotic blood, by Mr. Jenkins, of England, it Avould appear that the albumen and salts exist in the usual propor- tions, that there is a considerable increase of water, and a very great diminution of coloring matter, to the amount nearly of tAvo fifths. Jaundice is another disease, in which, as was formerly stated, the blood is more or less altered in its properties. Not only the coloring principle of the bile, but even the resin of this substance has been detected in the circulation; and, as a necessary consequence, especially when the disease is of long continuance, every tissue of the body assumes a yellowish tinge, as Avell as, in many cases, the different secretions. In four subjects that I have had occasion to dissect within the last five years, all the soft parts, together with the whole of * Medical Inquiries, vol. ii. p. 13. vol. i. 29 226 BLOOD. [CHAP. 1. the osseous and cartilaginous systems, Avere of a deep orange complexion, from this cause. Even the brain participated in the change ; for its substance Avas by no means of so clear a Avhite as in the healthy state. When the bile is thus intro- duced into the general circulation, it appears to act as a sort of narcotic, inducing drowsiness and irritability. In other cases it generates fever, with headache, nausea, and loss of appetite. It should be observed, that the presence of this fluid may be easily detected in the serum of the blood by adding to it an equal quantity of sulphuric acid, diluted Avith tAvice its bulk of water. The serum, as has been stated by Dr. Babington, will thus change its yellow straw-color for the characteristic green tint of bile. But in no deranged condition of the body is the blood more remarkably altered than in scurvy. This fact, although long ago noticed by physicians, appears to have been first placed in its true light by Dr. Mead, of Dublin. In his medical Avorks, published in 1767, it is distinctly announced that the blood of persons laboring under this disorder is ahvays un- naturally black, greatly deficient in cohesive poAver, and manifesting no disposition Avhatever to separate into serum and crassamentum. In the latter stages of the malady, the fluid had the aspect and consistence frequently of thin tar, treacle, or even of ink, the fibrin looking like wool floating in a dark, muddy substance, sometimes of a greenish tint. The blood that oozed from the mucous surfaces, in the form of spontaneous hemorrhage, exhibited similar appearances, thus showing, most conclusively, that it had undergone essential changes, both in its chemical properties and in its vital affinities. To the instances now cited, numerous others might be added, equally striking and satisfactory, in Avhich the vital fluid is most seriously altered, and transformed into a substance very different in its character from that observable in the healthy state of the economy. But to do this would far transcend the limits of the present work, and would be liter- ally Avriting a treatise on individual maladies, — a task Avhich I do not feel disposed, even if this were the proper place, to undertake. From the facts that have been presented on this interestiug subject, it cannot be doubted, I think, by any one Avho duly and impartially contemplates it, that the blood is a fruitful source of disease, or, in other Avords, that it is suscep- CHAP. I.] CONCLUSION. 227 tible of various morbid impressions, of which, in many in- stances, it is the primary and original seat. Considering the vast surface from which the chyliferous vessels imbibe the nutritious matter, and the heterogeneous nature of our food and drink, it is highly probable that the elements of disease may thus readily find their way into the current of the circu- lation, and establish a prejudicial action in the solids, by which they in turn are disordered, and throAvn into com- motions incompatible Avith the harmony and well-being of the general system or of some of its numerous members, tied together as they all are, figuratively speaking, by the closest consanguinity. CHAPTER II. Of the Cellular Texture. Distribution. — Physical Characters. — Organization. — Physiological Proper- ties. — Lesions. — Acute Inflammation. — Suppuration. — Gangrene. — Chron- ic Inflammation. — Induration. — Serous Infiltration. — Emphysema. — De- generations. — Foreign Substances. — Guinea Worm. There is no tissue which is so extensively and universally diffused as the cellular. Occurring in every organ of the body, it not only contributes materially to its composition, but serves the more important purpose of cementing together its several anatomical elements, binding them up into one united whole. In quantity it varies very much in different situa- tions, being extremely abundant in some, and almost entirely Avanting in others. There is a great deal of it immediately beneath the skin, especially in the axilla and the groin, in the mediastinal cavities, in the abdomen, and in the pelvis. The vessels have likewise a considerable share of it; the lungs are well supplied Avith it; and a large quantity of it is ahvays found amongst the voluntary muscles. On the other hand, there is very little cellular tissue in the heart, brain, liver, spleen, and kidney ; in the uterus, ovary, testicle, and penis; * in the tendons, ligaments, and fibrous membranes. None exists, except in a combined state, in the bones, the cartilages, and the substance of the cerebro-spinal axis. In regard to its density, this substance likewise presents considerable variation in different regions of the body. Gen- erally speaking, this property may be said to be in direct ratio to the quantity of the tissue, being very slight in those situations Avhich abound in it, and very great Avherever there is a scarcity of it. It is very lax beneath the skin, except at the mesial line, and around most of the internal viscera. The same arrangement obtains in the muscles; but, as this sub- * These remarks are applicable, of course, only to the proper structure of these organs. CHAP. II.] ORGANIZATION. 229 stance penetrates into their interior, it becomes gradually more dense, short, and delicate, until it finally escapes obser- vation. Under the skin, the cellular tissue is spread out in the form of a lamella, Avhich can be traced as a continuous whole from one region of the body to the other, and which constitutes what, in surgical language, is denominated a fascia. It may also be stated here that this substance receives differ- ent names, according to the organ with which it is associated, as subcutaneous, retro-peritonaeal, submucous, inter-muscular, and subserous. The peculiarities Avhich it exhibits in these localities will be pointed out in their proper places. The cellular texture is highly extensible and elastic, and is thus Avell qualified to discharge the various functions that have been assigned to it in the animal economy. Another property possessed by it is the hygrometric, by virtue of Avhich it expands and regains its primitive softness and pliancy, when immersed in water after having been dried. It is composed principally of albumen, in union with a little gelatine, the quantity of which is always less in the old than in the young. It resists putrifaction for a long period, and is not easily broken down by boiling. Exposed to destructive analysis, it yields oxygen, hydrogen, carbon, and azote. The cellular substance is every Avhere lubricated by a thin watery fluid, the presence of which is essential to the due exercise of its healthy functions. It is of an albuminous nature, and iden- tical with the serum of the blood, whence it is derived. Examined in reference to its structure, (Fig. 7,) this tissue is found to be Fig. 7. composed of whitish fila- ments, homo- geneous, soft, and transpar- ent, which in- tersect each other in all di- rections, form- ing thereby an infinity of cells Avhich freely communicate together over the entire body. Of the many proofs that might be adduced in illustration of the truths of this position, it will suffice to mention that, fluids introduced 230 CELLULAR TEXTURE. [CHAP. II. at one point can be readily forced to another, however re- motely situated. In anasarca, the effused Avater ahvays gravi- tates toAvards the most depending part of the limb, Avhere it may be readily discharged by slightly puncturing the skin. On the same principle, the air in emphysema frequently ex- tends over the Avhole body, elevating the integuments into a soft, irregular sAvelling, which emits a peculiar crackling noise on pressure. All these are so many circumstances demon- strating the direct continuity of the cells of the substance in question. In their shape, the meshes of the cellular substance are too variable to enable us to express any definite opinion respect- ing it. In some situations, they appear to be of an oval form; in others, they are rounded ; in others, cylindrical; in others, angular. In most parts, these figures occur in a state of combination. Equally variable are the dimensions of these cavities. In the normal state, they are quite small, so much so, indeed, that some writers have been induced to deny their existence ; but, in certain pathological states, they often ac- quire a considerable magnitude. The cells can be easily demonstrated by injections of melted glue, or still better by distending them with water, and afterwards exposing the part to a freezing mixture. In this way, numerous icicles will be formed, having the form and volume of the cavities which they occupy. The filaments of which ^this tissue consists are variously aggregated in different parts of the body. In the glands, they are arranged into a species of frame-Avork, into the meshes of which is deposited the substance Avhich imparts to them their characteristic attributes, Avhilst upon their walls are ramified the vessels and nerves Avhich are required for their support and animation. In the bones, they form a nidus for the re- ception of earthy matter ; in the serous membranes, they pre- sent a lamellated disposition, and in the vascular tubes, they are arranged spirally. Thus, these filaments do not merely enter largely into the construction of the various organs, but they actually form the basis of every one of them, no matter Avhat are its essential anatomical elements. The sensibility of the cellular texture is very obscure in the normal state; but, Avhen inflamed, it is often the seat of severe pain. Nervous filaments penetrate it on every side, but they do not appear to be lost in it, for in general they can be traced to some contiguous organ. The same remark CHAP. II.] MODIFIED BY AGE--ITS LESIONS. 231 is applicable to its blood-vessels and absorbents, the former of Avhich are excessively delicate, and do not convey red fluid in the healthy state. It is also said to receive exhalants, but this is a mere conjecture, unsupported by facts. The absorbing poAvers of this texture are very great. Fluids of various kinds, so often effused into its meshes, are rapidly taken up, and eliminated by the kidneys, skin, and other outlets. Some articles of the materia medica, placed in contact Avith it, exhibit their specific action in distant or- gans in as short a period nearly as when introduced into the stomach. A solution of emetic injected into the subcuta- neous cellular substance of a dog, speedily induces vomiting, morphia, sleep, and strychnine tetanic spasms. The cellular substance presents certain peculiarities de- pending upon age. In infancy, it is extremely delicate, soft, spongy, aud transparent; in the adult, it is firm, dense, and somewhat opaque ; and, in advanced life, it is remarkably hard, dry, and resisting, not unlike aponeurotic membrane. It likewise loses a considerable share of its elasticity, and hence that withered appearance of the skin which forms so characteristic a trait of old age and decrepitude. Notwithstanding its apparently unorganized character, the cellular substance possesses the formative power in a very eminent degree. When destroyed, it is speedily regenerated ; and, in many instances, it supplies the loss of these textures that cannot be perfectly reproduced, as the muscular and ten- dinous. Every growth, in fact, whether normal or acci- dental, begins, there is reason to believe, in the cellular substance. It has been already stated that the cellular texture is ev- ery Avhere continuous, and it may be added, in conclusion, that that of the exterior of the body freely communicates with that of the splanchnic cavities, by certain openings existing at different parts of the body. The cellular tissue, diffused, as we have just seen, through every part of the body, and cementing together its various anatomical elements, is prone to numerous diseases, both of a primary and consecutive nature. Many of these lesions are of a highly interesting character, as affording an admirable insight into some of the most striking processes employed by the animal economy, in repairing injuries, and in throwing off from the system such materials as have a tendency to impede the exercise of its normal functions. The principal 232 CELLULAR TEXTURE. [CHAP. II. morbid affections of the cellular tissue, those Avhich demand the special attention of the morbid anatomist, may be com- prised under the following heads : 1. acute inflammation, suppuration, and gangrene ; 2. chronic inflammation ; 3. in- duration ; 4. serous infiltration; 5. emphysema; 6. trans- formations into other substances; 7. and lastly, the devel- opement of insects. I. In acute inflammation, the cellular tissue is of a light reddish color, soft, spongy, and inelastic ; its cavities are filled with an opaque, gelatinous fluid ; and all the vessels ramify- ing through it are enlarged, and distended with blood. The nerves, too, are increased in their dimensions; and, Avhen the irritation has been violent, it is not unusual to find small ex- travasations, produced by a real rupture of some of the capil- laries. If the part affected contains much adipous matter, it will be variously modified, according to the degree of the in- flammation ; Avhen moderate, the fat is commonly absorbed; but, if intense, it is broken doAvn, mixed Avith the effused blood, and converted into a yelloAvish, pap-like substance, nearly destitute of its original features. These appearances, Avhich denote a high degree of morbid action, ahvays decrease towards the periphery of the inflammation : the redness also gradually declines in intensity ; the vessels are less minutely injected; and the tissue, although someAvhat edematous, preserves its accustomed elasticity and expansibility. After some time, varying from three to eight days, soften- ing takes place toAvards the centre of the inflamed mass, and the cells of the tissue become loaded with globules of pus. Subsequently the Avails of these interstices are broken down, and the purulent matter is collected into one or more cavities. The swelling, in the mean time, becomes more circumscribed, the surrounding oedema diminishes, and the neighboring cells being agglutinated together by lymph, an effectual barrier is thus presented to the extension of the pus. The cellular substance immediately around the matter is of a dense com- pact texture, forming a firm, resisting sac, the inner surface of which, at first red and rough, gradually assumes a smooth, velvety aspect, not unlike mucous membrane. Such are the ordinary characters, and such the usual ter- mination of circumscribed phlegmonous inflammation of the cellular tissue. Another variety, much more formidable than the preceding, because much more destructive in its results, is the diffuse, so termed from its spreading tendency. In CHAP. II.] CHRONIC INFLAMMATION. 233 Avhatever manner this disease arises, whether from external violence, phlebitis, poisoned wounds, phlegmonous erysipelas, or any other cause, it ahvays attacks a large extent of sur- face, often invading a whole limb, or even a considerable por- tion of the trunk. In most cases it terminates in suppuration, and sometimes even in sloughing. The matter, which is generally of an unhealthy, sanious character, is not contained in a sac, nor is it restrained by an effusion of fibrin, as in the phlegmonous form, but is extensively diffused, and often causes great havoc in the adjacent structures. When diffuse inflammation occurs in debauched, worn-out individuals, as it is apt to do Avhen it presents itself in the form of a carbuncle, it not unfrequently terminates in gan- grene. This disease, which is usually located in parts remote from the centre of the circulation, is characterized by a soft, doughy, undefined swelling, with deep-seated, burning pain, an oppressive sense of Aveight, and vesication of the cuticle. In a short period, the swelling assumes a dark brownish, vio- let or purple color, and imparts a peculiar, boggy feeling, as if the subjacent textures were floating in a fluid. Numerous apertures iioav appear in different parts of the skin, giving vent to a thin, acrid sanies. If the cellular substance thus affected be examined after death, it will be found to have the appearance very much of wet tow, being of a deep ash-color, soft, inelastic, extensively detached, and bathed in a bloody and highly offensive fluid. These changes are not always confined to the subcutaneous cellular tissue, in which they more commonly commence. Not unfrequently, long, sinuous tracts are formed between the muscles, and gangrenous shreds are seen hanging from aponeurotic sheaths, tendons, liga- ments, and blood-vessels. Sometimes, though rarely, the dis- organizing process extends to the periosteum, involving it and the subjacent bone in the destruction. Excessive pain and great constitutional disturbance — at first of an inflammatory, and afterwards of a typhoid character — are the usual at- tendants of this formidable malady. II. In chronic inflammation, the cellular tissue no longer tears Avith the same facility as in health : it is dense and hard, so as to crisp when cut; and, although it admits of slight extension, it is nearly destitute of elasticity. When the disease is protracted, the tissue gradually assumes an opaque, milky color, and its cavities are distended with sero- fibrinous matter, so as to be no longer permeable to blood, vol. i. 30 234 CELLULAR TEXTURE. [cHAP. II. air, pus, or Avater. These alterations, Avhich give the seat of the disease a tumid and constricted feature, are Avell charac- terized in the callous edges of old ulcers, in chronic erysipelas, in the hard swellings so often witnessed in gouty and rheu- matic affections, in pelagra, elephantiasis, and in the indura- tion of the cellular substance of neAV-born infants. This disease seldom produces healthy pus; on the contrary, the matter is commonly of a sanious, sero-purulent, or san- guinolent nature. Occasionally small abscesses are scattered through the affected tissue, containing a yellowish, turbid se- rum, or thick curdy matter, not unlike that of a strumous lymphatic ganglion. In the subcutaneous cellular substance, these deposits are often enclosed by a thick layer of lymph, by Avhich their contents are kept within their proper sphere. During the developement of this sac, the circumjacent tissue is red and indurated ; but, as soon as the membrane is organ- ized, as often happens Avhen the irritation is protracted, these phenomena generally disappear, the parts gradually resuming their normal properties. The sac often acquires great thick- ness and density, layer after layer being deposited upon its internal surface, as is the case with the adventitious mem- branes in other situations, Avhen they participate in the in- flammation of the surrounding structures. This affection is rarely attended Avith much pain ; indeed, Avere it not for the hardened and inflexible state of the affected part, the patient Avould experience but little inconvenience. III. Induration of the cellular tissue constitutes a peculiar disease in children, which has been described by writers under the several appellations of cedematous hardening, scle- roma, and skin-bound. It was first noticed as a distinct mal- ady in 1718, by a German author, of the name of Uzembezi- us. Since that period it has been described, with great ac- curacy, by Denman and Underwood, of England, and by Doublet, Billard, and others, of France. The disease is com- paratively rare in this country and Great Britain; but, on the continent of Europe, especially in the foundling hospitals of Paris, it is extremely prevalent and fatal, hundreds of infants annually dying with it. Many children, it would seem, come into the Avorld with this affection, or are attacked within the first twenty-four hours after birth. Its progress as usually very rapid, most of the little patients being cut "off in the course of three or four days. The disorder sometimes affects the whole body; more com- CHAP. II.] INDURATION. 235 monly, howeArer, it is restricted to particular regions, as the ab- domen and inferior extremities. The skin in this affection is of a brownish color, interspersed Avith yelloAvish looking patches, and its texture is remarkably hard and firm, almost like leather. The subcutaneous cellular tissue is very dense and granular, communicating, Avhen cut, the sensation of fibro- cartilage, calf's-foot jelly, or half-dissolved glue. Frequently it is of a bright lemon-color, and contains a large number of dark yelloAV granules, Avhich are nothing but diseased adi- pous vesicles. The infiltrated matter is sometimes firm and concrete ; but, in the early stages of the disorder it is common- ly thin, and straAV-colored, like serum, and readily coagulates by heat, alcohol, or dilute acid. The greatest induration is usually met with on the outer surface of the leg, and on the dorsal aspect of the hand and foot. Associated Avith these morbid appearances, are various le- sions of the internal organs. The lungs are hard, increpitous, marbled, and congested; the oval foramen and arterial duct often remain patulous, or are but partially closed; the liver is extremely vascular, and the gall-bladder is distended Avith vitiated bile ; the mesenteric glands are enlarged and injected ; the gastro-enteric mucous lining more or less inflamed ; and the Avhole venous system remarkably engorged Avith blood. Various opinions have been suggested respecting the precise nature of this affection; but the most plausible, decidedly, is that which ascribes it to inflammatory irritation, either of an acute or chronic character, which determines an effusion of sero-fibrinous matter into the imeshes of the cellular tissue, closing up its cavities and hardening its texture. The cellular tissue is liable to various morbid growths, de- posits, and transformations. Amongst these the most common are cysts, melanosis, and fungus haematodes, neither of which will require particular notice in this place. Fibrous, cartila- ginous, and bony formations are most prone to occur in the sub- serous cellular tissue of the chest, abdomen, and scrotum; in small grains, patches, or irregular incrustations. Such degen- erations are extremely rare in the cellular tissue under the skin, and still more, if possible, in that of the mucous mem- branes. As occurring in the former situation, a highly inter- esting case has been given by Andral, of a patient who died of elephantiasis ; on dissection, the subcutaneous cellular tex- ture of the lower extremities was found to be excessively dense and indurated, possessing, in many places, all the physi- cal properties of real cartilage. 236 CELLULAR TEXTURE. [CHAP. II. IV. Serous infiltrations of the cellular tissue are very com- mon in persons of deteriorated constitutions, and in those who have become exhausted by protracted diseases, profuse hemorrhages, and other affections impairing the vital powers. In cases of poisoned Avounds,the effusion is generally very rapid, large in quantity, and highly acrid in quality. Various terms have been employed to designate this condition of the cellu- lar tissue. Thus, when it is restricted to a particular region, as, for instance, the eyelid, leg, or scrotum, it is named asdema; whilst, Avhen it is more extensive, or diffused over the greater part of the body, it is called anasarca. Neither of these ap- pellations, it is obvious, is Avell chosen, as the one literally signifies merely a swelling, the other dropsy of the flesh. The interstices of the cellular tissue in this disorder are very much enlarged, and the skin over the part, which has generally a singularly glossy and tumid appearance, readily pits upon pres- sure. The effused fluid is of a sero-albuminous nature, as is evinced by its coagulability by heat, alcohol, and acids; and, according to the testimony of Dr. Blackall, an eminent writer on dropsy, it occasionally undergoes spontaneous concretion. These serous infiltrations, in whatever part of the body they may occur, ought to be regarded as the result of congestion of the capillary vessels, depending either upon inflammation, de- bility, or mechanical obstruction. Hemorrhage always arises from a rupture of the blood-ves- sels, produced by external violence, or by some internal cause, the precise nature of which is not so well understood. In the former case, the fluid, although sometimes Avidely diffused, generally forms an elastic, circumscribed tumor, technically denominated an ecchymosis ; in the latter, it is more common- ly seen in small patches of a dark purple color, which have received the name of suggillations, death-marks, or cadaveric lividities. These spots, which are always most conspicuous on the posterior parts of the body, are very distinct in persons who die from petechial fevers, the plague, and the scurvy, and can be readily distinguished from ecchymoses by the entire absence of all signs of violence. Suggillations, hoAvever, do not always arise exclusively in the manner here indicated. In many instances, if not in most, they result merely from an accumulation of blood in the capillary vessels of the skin and cellular tissue, without any extravasation Avhatever. These facts should be borne in mind, as they have a most impor- tant bearing upon legal medicine. For the want of correct in- CHAP. II.] FOREIGN SUBSTANCES--PARASITES. 237 formation upon this subject, errors the most serious have some- times been committed by physicians. F- g * V. Emphysema may be produced by a great **^^ variety of causes, but the most common are |i penetrating Avounds of the chest, rupture of the JJ air-cells, of the lungs, from violent coughing, or ^^^ ulceration, and lesions of the lining membrane /^^ of the windpipe. Dr. Baillie supposes that it M sometimes arises spontaneously, as the result of Yj, a process of secretion from the blood-vessels; 1/ and, in a considerable number of cases, it has £/ been met with as an attendant on gangrene. if The infiltration is sometimes very great, the air ^^^^^^ occupying nearly the whole of the cellular tis- ^ sue. The distended parts have a bloated aspect, 1] pit under the finger, and emit a peculiar crepitat- jfi/ ing sound, when pressed, not unlike the lungs. £r V. Foreign substances are sometimes found If in the cellular tissue. In most cases, they excite fv inflammation in the contiguous parts, and are 1 finally discharged by suppuration. Not unfre- ^ quently, however, especially when they get \j, admission through the alimentary tube, they |\ become encysted ; that is, the cellular tissue is IJ condensed around, them, and converted into a JjJ sac. At other times, again, after traversing /^^^^ the body in different directions, they are ar- if rested, and work their way out through the |f skin, generally at the back of the hand and ¥, foot, though in this respect there is no inVaria- ^^^ ble rule. It is thus that bullets and needles ^^^, often pervade the subcutaneous cellular tissue, ^\ starting, perhaps, at the trunk, and gradually I) reaching the most distant parts of the extremi- 1/ ties, and this, too, frequently without produ- f/ cing any serious mischief. Not long ago, a Jy^ case occurred in one of the Parisian hospitals, if where the cellular substance was literally ^L^^ loaded with needles, and yet the patient lived ^^^Sx several years, in tolerable comfort, after she . y^ swallowed them. ^i) JJ VI. The cellular tissue is occasionally the ^^s * a, the head j b, the caudal extremity. 238 CELLULAR TEXTURE. [dlAP. II. residence of parisitic animals, developed either in its sub- stance, or introduced from Avithout. Of these, the only one requiring notice is the filaria medinensis, (Fig. 8,) the little dragon, or Guinea-worm. This animal, Avhich is extremely simple in its structure, generally occurs immediately beneath the skin. The legs and feet are the parts which it more commonly infests, but it has also been observed in the scrotum, the anus, and in different parts of the head and trunk. It is of a white color, about the thickness of a violin-string, and, when full groAvn, from five to ten inches in length; its diameter being nearly equal from one end to the other, ex- cept towards the tail, which is somewhat tapering and curled. The countries in which these worms most frequently occur, are Egypt, Arabia, Guinea, Persia, and Abyssinia. Several of them have been known to coexist in the same patient; and occasionally they have been found from three to four feet in length. * CHAPTER III. Of the Adipous Texture. Organization. — Exists only in particular regions of the Body. — Office of the Adipous Vesicles. — Nature and Uses of the Fat.— Lesions of the Adipous Tissue. — Wounds. — Liability to Inflammation.— Hypertrophy, general and local. — Adipous Diathesis. — Atrophy. The adipous texture consists of an infinite number of vesicles, Avhich are variously arranged in different regions of the body, and the diameter of which scarcely exceeds the eight hundredth part of an inch. In their natural state, these little reservoirs are of a spherical shape, and are so closely agglomerated as to resemble clusters of fish-spawn; but, when their contents are partially absorbed, they assume a flattened appearance ; and, in great emaciation it is often impossible to distinguish them from the cellular substance in which they are immersed. The parietes of the adipous vesicles, are formed out of the cellular element: they are excessively delicate, and so trans- parent as to render it difficult to distinguish them, even with the aid of a magnifying instrument, from their own contents. Each reservoir receives an arterial and venous branch, to- gether with a nervous filament and a lymphatic vessel, by which it is attached, as by a sort of foot-stalk, to those imme- diately around it. The precise arrangement of these struc- tures is not ascertained, but is probably not different from Avhat it is in other parts of the body. Modern researches have disclosed that these little vesicles (Fig. 9) do not communicate together, as Avas formerly sup- posed by anatomists and physiologists. They are, indeed, perfectly distinct the one from the other, and hence the fat which they contain never escapes until they are ruptured. If it Avere not for this arrangement, the contents of these reser- voirs would be constantly liable to extravasation, and, like the water of anasarca, gravitate towards the most depending 240 ADIPOUS TEXTURE. [CHAP. III. parts of the body, interfering thereby not only with the free- dom of its move- Pi„ 9 * ments, but leading to the most hideous deformity. The texture be- fore us does not, like the cellular, exist in all parts of the body. There is none in the pa- renchymatous and glandular organs, in the cartilages, tendons, fibrous membranes, and lymphatic ganglions. The lids and the eye, the scrotum and penis, the uterus, clitoris, and nymphae, are also deprived of it. The brain has no adipous substance, at least not in a free state ; and the same is true of the spinal cord, together with most of the nerves. On the other hand, it generally exists in great abundance in the subcutaneous cellular tissue, in the orbits about the kidneys, in the folds of the peritonaeum, and in the interior of the long bones, where it constitutes what is vulgarly called the marrow. There is frequently a considerable quantity around the heart and great vessels, particularly in old, corpulent subjects, and the larger intervals betAveen the muscles are usually filled with it. In its mode of arrangement, the adipous tissue exhibits considerable diversity, according to the locality in which it is examined. Under the skin, it is spread out in the form of a lamella, the thickness and density of which vary in different parts of the body, as well as in different individuals. In the orbit of the eye, and on the cheek, it occurs in rounded packets, Avhilst in other situations, as in the great omentum, it presents itself in narrow band-like strips, or in the form of pedunculated masses, as in the epiploic appendages. The office of the adipous vesicles is to deposit the fatty matter which they contain. How this elaboration is effected, it is needless to inquire ; for, beyond the mere circumstance of * 1, a portion of adipous tissue; 2, minute bags containing fat; 3, a cluster of bags separated and suspended. CHAP. III.] STRUCTURE AND COMPOSITION. 241 the elements of this substance being found in the blood, nothing Avhatever is knoAvn. The process by Avhich these elements are combined, so as to form the adeps, is still com- pletely enveloped in mystery, if, indeed, it is suceptible of explanation. Oil and fat have been detected in the general circulating mass by Traill, Thackrah, Chevreul, Lecanu, and other experimentalists; and it is not improbable, therefore, that the office of the arterial capillaries of the adipous vesi- cles simply consists in evolving the principles of these sub- stances from the fluid Avith which they are incorporated. The fatty matter, considered apart from its containing vesicles, is of a light yellowish tint, OAving to the presence of a peculiar coloring principle, which is easily removed by Avashing. During life, it varies in its consistence, from the condition of a liquid to that of a semi-concrete substance, being naturally softer in some parts of the body than in others. After death, it is ahvays more solid. Possessing all the characters of the fixed oils, it is specifically lighter than Avater, has a mild, insipid taste, and is completely inodorous when fresh, but soon becomes rancid and offensive by expo- sure to air and heat. Fat is one of the few animal sub- stances which do not contain azote. We learn from the experiments of M. Chevreul, a French chemist, that it is formed of two proximate principles, elaine and stearine, the former of which is of a fluid consistence, and an oily nature, the latter, solid, Avhite, rather shining, and easily fused Avhen heated. The relative proportions of these materials vary in different parts of the body. The marrow of the bones appears to be almost entirely composed of elaine. Besides serving as a sort of aliment in reserve, the fat moderates in certain regions — the effects of pressure — fills up the voids betAveen the muscles and the skin, and probably assists in preserving the temperature of the body. That it contributes to the production of this latter result, may be inferred both from the circumstance of the fat being a bad conductor of caloric, and from the fact that almost all arctic quadrupeds are abundantly supplied with it,—Providence thus enabling them to defy the most dreadful extremities of cold, and to sustain a high temperature even under the eter- nal ice of the poles. But the most important use of the adeps is the part which it performs in the nourishment of the system, Avhen the stomach is temporarily disqualified from carrying on the digestive function, in consequence of local or VOL. I. 31 242 ADIPOUS TEXTURE. [CHAP. III. general disease. The adipous vesicles in such cases are robbed of their contents, which, being taken up by the absorbents, are conveyed into the circulating current, to be reconverted into blood. It is owing to this removal of the fat that per- sons recovering from painful and protracted indisposition have such a constant desire for food, being tormented, if I may so express myself, Avith an omnipresent appetite. The demands of the system, under such circumstances, are of the most urgent nature, every adipous vesicle, every fibre, and every organ calling aloud, as it were, for nourishment, and for a share of the fatty matter which it contributed to the support of the body, at a time when the digestive apparatus, languid and oppressed with disease, was incapable of per- forming its accustomed functions. The same thing is beau- tifully exemplified in hibernating animals which are very fat, on retiring to their Avinter quarters, but are always lean on the return of spring, Avhen they awaken from their torpid state. Wounds of the adipous tissue present nothing unusual in their mode of healing: they generally unite without difficul- ty, in fact, not unfrequently by union of the first intention. When the divided parts are kept asunder, the fatty matter is gradually absorbed, and the restoration is finally effected by the granulating process, as in similar injuries of other textures. It has been questioned by some, whether the adipous tissue is susceptible of inflammation, the opinion having arisen, probably, from the belief, at one time very current amongst physiologists, that this substance is not endoAved with a suf- ficient degree of vitality for this process to take place. In en- deavoring to solve this problem, the reader should bear in mind the distinction between the adipous tissue, properly so called, and the fat. The one, as has been already seen, is an organized substance, provided with blood-vessels, nerves, and absorbents, and is, therefore, liable to the different kinds of in- flammation ; the other, on the contrary, being inorganic, must, of course, be insusceptible of morbid action. In acute inflam- mation, the adipous tissue assumes a dark reddish aspect, and always manifests a peculiar tendency to slough, in conse- quence, it would seem, of its vascular and nervous endow- ments being too feeble to offer the necessary resistance. In peritonitis, I have several times seen the fatty omentum in- flamed in one part, and gangrenous in another, though there was little effusion of lymph or serum. CHAP. III.] ADIPOUS DIATHESIS. 243 The adipous tissue is liable to hypertrophy. This may be either general or partial. Various attempts have been made to estimate the standard amount of fat; but, as the quantity varies in different individuals, and even in the same person, under different circumstances of health and disease, it is ob- vious that there must be great difficulty in arriving at a satis- factory conclusion. The majority of anatomists, however, agree in the opinion that in an adult of ordinary size, it forms about one tAventieth part of the entire body. Thus, a man weighing one hundred and sixty pounds, Avould have about eight pounds of fat. But, in cases of obesity, it often greatly exceeds this quantity ; and, on the other hand, in emaciation it often falls far beloAv it. In general hypertrophy, the quantity of fat is sometimes enormous, amounting to five or six times the Aveight of the entire body. The celebrated Pritchard, of Kentucky, who exhibited himself in Litton's museum, in this city, in 1834, weighed five hundred and fifty pounds. The Canadian giant, as he was called, Avhom I saw in Philadelphia, in 1829, Aveighed six hundred and eighteen pounds. He was six feet four inches in height, and the circumference of each leg, around the calf, Avas nearly three feet. The most re- markable feature in this case was, that this enormous deposit of fat, making him so much larger than ordinary men of the same stature, Avas confined chiefly to the abdomen and lower extremities, the thorax, shoulders and arms being little stouter than in other persons. Daniel Lambert, of England, who died at the age of forty, Aveighed seven hundred and thirty- nine pounds ; and the German journals give the case of a man Avho- weighed eight hundred pounds. The individual was carried off by fright, and, on inspection, the fat of the abdo- men Avas found to be nearly fourteen inches thick. An ac- count of a somewhat similar case has been published by the late Professor Dupuytren, of Paris. The individual, who was a poor beggar-woman, measured five feet one inch in height, and five feet two in circumference. The thoracic and ab- dominal cavities were enormously loaded with adeps, and, on the mammas, the subcutaneous layer Avas seven inches in thick- ness. But the most extraordinary example of this affection, of which I have any knowledge, has recently occurred in the State of NeAv York, in a girl that weighed three hundred and sixty-four pounds, though only ten years and a half old. There would thus seem to be, from the above detail of cases, sometimes a real adipous diathesis, nearly all the ma- terials entering the circulating mass being converted into fat. 244 ADIPOUS TEXTURE. [CHAP. III. Various articles of food and drink have a tendency to bring about this state of the system. Malt liquors, taken to excess, and the moderate use of Avine and ardent spirits, are, perhaps, the most poAverful means for producing general hypertrophy of the adipous tissue. But, Avhatever may be the exciting causes of these depositions, certain it is, that indolence and freedom from care are necessary, if not essential, to the pro- cess. Castration is generally followed by considerable obesity ; and the same thing has long since been observed in women that have been deprived of the ovaries, or in Avhom these or- gans are diseased or imperfectly developed. Similar phenom- ena have been noticed in animals, after the removal of the spleen*; though the obesity, in these cases, is generally only temporary, the body gradually returning to its former Aveight and spareness. Whether the same changes have ever been witnessed in the human subject, as the result of the extirpa- tion of this organ, I am not prepared to say, as there are no data from which to judge. In birds, considerable accumula- tions of fat sometimes occur in a very short time. Thus, when the ground is loaded Avith insects and other nutritious substances, robins and thrushes will occasionally fatten to such an extent, in the course of twenty-four hours, as to be almost unable to get out of the way of the sportsman. Partial hypertrophy of this texture is well exemplified in adipous tumors. Generally developed under the skin, these tumors not unfrequently occur Avithin the abdominal cavity, in connection with the peritoiiEeum. Their size, though com- monly small, is sometimes enormous. Sir Astley Cooper gives an account of one that weighed nearly thirty-eight pounds ; and in a recent French journal are recorded the par- ticulars of another that weighed still more. In their shape, these tumors are usually somewhat globular, but as their bulk augments they are apt to become elongated, and to assume a pyriform, gourd-like, or pediculated configuration. Often- times their surface is tabulated, irregular; and Avhen cut into they are found to be composed of large rounded masses of fat, which differs in no respect from the adipous texture in other situations. They are surrounded by a thin but firm capsule of cellular substance; and their supply of blood is by no means so liberal as might be supposed from their size, and the rapidity of their growth. These tumors sometimes exist in considerable numbers. Dagorn, a French physician, men- tions an instance Avhere there Avere as many as eight, several of them of prodigious size, in different parts of the body. CHAP. III.] ABDOMINAL OBESITY. 245 In abdominal obesity, the encumbered organs are often literally buried in beds of fat. The tumors are generally more pediculated than those which are developed under the skin, and they may grow either on the omentum, from the epiploic appendages, or beneath the peritonaeum, giving that projecting rotundity to the abdomen which is vulgarly dis- tinguished by the name of " pot-belly," and which is so well described by Prince Henry, in his address to Falstaff, as " a huge hill of flesh," " a globe of sinful continents." Large quantities of fat occasionally envelope the kidney. In a specimen which I took from an old man a few years ago, the mass amounted to three pounds; and Dr. Horner refers to one, removed from a bullock, Avhich filled a common-sized wash-tub. In the chest large masses of fat sometimes surround the pericardium, and, by compressing the heart and great vessels, induce palpitation, and even fatal syncope. Of this, an in- teresting case is to be found in the admirable treatise of Senac. Atrophy of the adipous tissue, which is far more common than its preternatural accumulation, may arise from one or other of the following causes : defective or unwholesome diet; organic lesions of the lungs, heart, stomach, or bowels; pro- tracted abstinence, as in fasting, sickness, and the periodical sleep of hibernating animals; excessive loss of blood; im- moderate indulgence in ardent spirits ; long Avatching ; ex- posure to intense heat; severe study, and great bodily fatigue. This is well exemplified in the case of grooms, and in per- sons who make long journeys on horseback. Captain Riley, of Ohio, who was shipwrecked on the coast of Africa, and captured by the natives, was reduced from two hundred and forty to ninety-two pounds, from excessive exercise, partly on an old camel, partly on foot, across the sandy desert. There seems to be a great diminution of this substance sometimes, without our being able to assign any satisfactory cause; as, for example, in the case of the celebrated Calvin Edson, who, although apparently in good health, was literally nothing but skin and bone, his entire weight not exceeding fifty-eight pounds. The removal of the fat, by whatever cause induced, is effected probably by the conjoined agency of the veins and lymphatics ; but upon this subject physiologists are by no means agreed, some ascribing it exclusively to the former, others to the latter, of these vessels. It would be interesting 246 ADIPOUS TEXTURE. [CHAP. III. to knoAV in what form this substance is absorbed, whether as oily matter, or after undergoing decomposition. Facts are not wanting in support of both these vieAvs ; but it must be confessed, that, whilst the one is plausible, the other, namely, the last, is infinitely most in accordance Avith the laws and operations of the living system. The adipous vesicles, in this affection, diminish in size; and, as their Avails are brought in apposition, an erroneous opinion has hence arisen, that they are sometimes entirely obliterated. The adipous tissue is occasionally the seat of melanosis, which is either disseminated in minute inky spots, or deposit- ed in small, spherical tubercles, of a concrete or semi-fluid con- sistence. Most commonly it occurs in the fat of the orbit, the anus and rectum, in the mesentery and omentum, and around the kidneys. It has also been noticed in the subcutaneous adeps, but much less frequently than in the situations here indicated. Fatty transformations are not unfrequently met with. Hoav they are produced, the present state of our knoAvledge does not enable us to explain. It is not improbable, hoAvever, I think, that they are partly, if not entirely, the result of a tar- dy inflammatory action, causing a perversion of the nutritive function. These changes, Avhich have hitherto been noticed chiefly in the heart, liver, mammae, and voluntary muscles, will be described in their appropriate places. Men of anxious mind and fretful temper seldom get fat. With Avhat justice does Shakspeare, in one of his most mag- nificent plays, make Caesar say, — " Let me have men about me that are fat; Sleek-headed men, and such as sleep o' nights. Yond' Cassius has a lean and hungry look: He thinks too much: such men are dangerous." * * Julius Cassar, act i. scene 2. CHAPTER IV. Of the Muscular System. SECTION I. Of the Muscles. I. The Muscles. — Different Classes. —Structure.— Color and Consistence.— Chemical Analysis. — Sensibility. — Reunite when divided. — Inflammation, — Suppuration. — Mortification. — Chronic Irritation. — Softening.— Indura- tion.— Ossification.— Fibrous and Fatty Transformations. — Heterologous Deposits. — Hypertrophy. — Atrophy. — Parasitic Animals. — Sanguineous Effusions. — II. The Tendons. — Appearance and Organization. — Reunite when divided. — Inflammation. — Ossification. — Atrophy. — Diseases of the Sheaths of the Tendons. — III. The Aponeuroses.— Structure. — Acute and Chronic Inflammation. — IV. The Synovial Burses. — Situation and Struc- ture. — Are liable to Disease. — Fibrocartilaginous Concretions. — Hyper- trophy.— Hydatoid Bodies. Although it is my design, in the present chapter, to speak only of the lesions of the voluntary muscles, yet this appears to be the proper place for making some remarks on the minute structure of the system generally of Avhich they are a part. The muscles, constituting what is familiarly called the flesh, may be divided, in reference to their functions, into three great classes, — the voluntary, involuntary, and mixed. These differ considerably from each other, not only as regards the special impressions Avhich they require to call them into action, but likewise in respect to their physical properties, and the arrangement of their fibres, together with several minor points which it is unnecessary to dAvell upon in a treatise of this kind. The muscles of volition embrace those of the trunk, head, and limbs, of the tongue, the soft palate, the larynx and pharynx; and, as their name implies, they are strictly under the control of the will. They are supplied by the spinal nerves, on the division of which their action is paralyzed, and they consist each of a body and two extremities, which. 248 MUSCLES. [chap. IV. in most instances, are tendinous or aponeurotic. The number of voluntary muscles has been variously estimated, but may be stated at about four hundred and fifty. They are of a florid red color, and their size, as Avell as shape, varies in dif- ferent regions of the body, the principal bulk of which they form. The involuntary muscles comprehend the fleshy layers of the alimentary tube, from the cardiac extremity of the stom- ach to the anus, together Avith those of the heart and the urinary bladder. They are in general of a much paler color than the preceding class, and their fibres are spread out so as to form tunics to the hollow viscera; the cavities of Avhich they diminish by their action, and thus serve to propel their contents. No tendons are appended to these muscles, ex- cepting in the case of the heart. They are supplied by the branches of the great sympathetic ; and they are consequently enabled to carry on their operations Avithout a conscious ef- fort of the will. Like the preceding class, they have their alternate periods of action and repose, and they are the agents of important vital functions which it Avould have been dan- gerous to leave under our control. The third class consists of the diaphragm of the oesopha- gus, together Avith the trapezoid, sterno-mastoid, intercostal, scalenous, and serrated muscles. The office of these bodies is to preside over the function of respiration. In their color and consistence they do not differ from the voluntary, mus- cles ; but they are supplied by a distinct system of nerves, namely, the respiratory of Sir Charles Bell; and they are therefore, as far as their action is concerned, of a mixed char- acter, being partly involuntary, yet not wholly withdraAvn from the influence of the Avill. It may be observed, en pas- sant, that, in certain diseased states of the body, the volun- tary muscles become involuntary, and the involuntary volun- tary, though the latter circumstance is much less frequent than the former. All muscles are composed of fibres, (Fig. 10,) which are themselves resolvable into minute filaments, held together by cellular substance. In many of the larger muscles, bundles, fasciculi, or lacerti, are observable, which vary very much in magnitude and distinctness : thus they are very large in the gluteal and deltoid, in the fleshy columns of the heart, and in the longitudinal bands of the colon. In general they run parallel to each other, being separated merely by a thin SECT. I.] STRUCTURE. 249 Fis layer of cellular matter ; and, in some situations, they far apart as to appear like so many mus- cles. By dissection, these bundles can be divided into fibres, Avhich are ren- dered still more conspicuous by boiling, or immersion in alcohol. The form of these fibres, Avhich is nearly the same in all parts, is prismatic, pentagonal, or hex- agonal, but never cylindrical; and they appear to extend in a continuous manner from one extremity of the muscles to the other. This arrangement, Ave are in- formed by Prochasca and Bichat, actu- ally obtains, eA'en in the longest muscles, as the gracilis and sartorius. The ultimate filament (Fig. 11) has been carefully examined by a great many distinguished physiologists, but thus far, OAving to its excessive tenuity, no very satisfactory information has been elicited. It is thought by some to consist of a se- ries of rounded corpuscles, about the two thousandth part of an inch in diam- eter, which are connected by cellular substance so as to look like a string of pearls or a row of beads. It is pretty gen- erally agreed, hoAvever, since the publica- tion of the researches of Hodgkin, Lister, Grainger, and others, that this view is in- correct, the observations of these gentle- men having led them to conclude that the ultimate filament is a peculiar pulpy struc- ture, arranged into threads of extreme mi- nuteness, Avhich are placed close and par- allel to each other, and intersected by a great number of the most delicate trans- verse lines. Similar results were obtained, long ago, by Fontana.J Thus formed, the muscles are enclosed, in general, by an aponeurotic sheath, the lie so * A portion of muscle enclosed in a fibrous sheath. t Ultimate fibres of a muscle highly magnified, showing the string of globules of which they are supposed to exist. t Traite sur le Venin de la Vipcre, t. ii. p. 228. vol. i. 32 250 MUSCLES. [chap. IV. degree of condensation of Avhich varies in different situations being very close in some, but slight in others. The connec- tion between this structure and the organ it invests is effected by cellular substance, Avhich is at the same time prolonged inwards, furnishing thus a distinct covering for each fascicu- lus, for each fibre, and for each ultimate filament, its delicacy becoming greater and greater as it passes from the one to the other, until at length it escapes the naked eye. No aponeu- rotic sheaths envelope the muscles of organic life: they are interposed, for the most part, between the mucous and serous membranes, and their interstitial cellular texture is not less abundant, but so short and condensed as to render it dif- ficult to separate the fibres from each other. With the exception of the mucous membranes, the skin, and some of the internal viscera, the muscular tissue is more abundantly provided Avith vessels, absorbents, and nerves, than any other substance of the body. The arteries, derived from the neighboring trunks, penetrate the muscles at differ- ent points of their periphery, creeping, in the first place, be- tween the larger bundles, then betAveen the smaller, and, finally, betAveen the fibres, their ultimate branches being spent upon the ultimate filament. By means of the micro- scope, they may be seen ramifying upon the surface of the delicate web of membrane that encloses the muscular pulp, but cannot be traced into it. The arteries are generally pro- portioned to the size of the muscles Avhich they are destined to supply, though, in this respect, there is some diversity. The accompanying veins are arranged into two sets; some folloAv the arteries, and the others run superficially on the surface of the muscles. They are large, someAvhat flexuous, and may be easily injected from the adjacent trunks, not- withstanding the presence of numerous valves. The ab- sorbents are quite abundant: they pursue pretty much the same course as the sanguiferous vessels, but of their mode of origin nothing Avhatever is knoAvn. The muscles are furnished Avith nerves in proportion, not simply to their volume, but to the variety, frequency, and vivacity of their movements. Hence the reason why some of these bodies that are comparatively small, but which are destined to perform many combinations of actions, are much better provided in this respect than others double their size, but with more simple functions. As a general observation, it may be stated that the muscles of volition receive large and numerous cords ; whereas the involuntary, in proportion SECT. I.] COLOR. 251 to their magnitude, are sparingly supplied. The filaments of the nerves usually accompany the sanguiferous A'essels, par- ticularly the arteries, to Avhich they are united by cellular substance. They enter the muscles at different points, and at length, after many divisions, they become so minute as to elude all observation. There is, consequently, some uncer- tainty concerning their ultimate termination, notwithstand- ing the numerous attempts that have been made to detect it. Before they disappear, they part with their cellular envelope, by which circumstance they are rendered soft and transparent, and brought in more immediate contact Avith the substance in Avhich they end. Sir A. Carlisle states that the ultimate termination is in the cellular web that encloses the muscular pulp. On the other hand, Provost and Dumas, who have more recently investigated the subject, maintain that the nervous filaments are not actually spent upon the mus- cles, but that they return on themselves, and pass either to the trunk Avhich furnishes them, or anastomose with some neighboring ones, either of the same or of a different class. But this is a topic which is interesting rather in a physiologi- cal than in a pathological point of view, and we shall there- fore dismiss the further consideration of it. It has been already stated that the muscles are of a red complexion, and, it may noAV be added, that the intensity of their color varies not only in different persons, but likeAvise in the same individual in different regions of the body. Thus the voluntary muscles are of a florid color, whilst the fleshy fibres of the intestinal tube and the urinary bladder are always several shades lighter, being in some places, indeed, of a rosaceous gray. Generally, too, these bodies are of a deeper hue in adults than in children and old people, and in those who are constantly engaged in laborious exer- cise than in such as are indolent, or make but little use of their limbs. Hence it may be assumed as an axiom, that the florid complexion of the muscles is in direct ratio to the frequency and energy with which they are employed. The truth of this remark is strikingly exemplified in the muscles of the arm of the blacksmith, as compared with those of the arm of the student; the latter of whom seldom uses his upper extremities except for the purpose of turning over the leaves of his book, or gratifying the appetites of hunger and thirst. Hence, his muscles are, throughout, soft, pale, and flabby; whereas those of the laborer are hard, firm, and of a deep red color. 252 Ml'SCLES. [chap. IV. The red color of the muscular tissue is altogether acci- dental, or does not, so to speak, form an essential attribute of this substance. Depending entirely upon the amount of blood Avhich it contains, it can be readily removed by repeated Avash- ing, or by maceration in alcohol or alkaline fluid, the fibres remaining in other respects unchanged. Hence the color of the muscular tissue, observes an eminent writer, varies with that of the blood, — is dark Avhen it is dark, pale Avhen it is pale, and white when it is Avhite. As the color of the muscular texture varies, so also does its consistence. It ahvays contains a much larger amount of moisture in the young than in the old, and is therefore much softer, as Avell as more pliant and lacerable. Exercise, as Ave have just seen, exerts a great influence over the consistence of the muscular tissue ; and it has long been a matter of observation that there are some subjects in Avhom it is natu- rally more soft and juicy than in others. Its cohesive poAvers are very feeble, and it is Avholly devoid of elasticity. On the other hand, it is highly flexible and extensible. The analysis of the muscular texture shows it to be com- posed of fibrin, albumen, gelatine, osmazome, leucine, free lactic acid, and various kinds of salts. The most remarkable circumstance, perhaps, Avhich chemistry has brought to light in this investigation is, that nitrogen exists in a larger pro- portion in the flesh of old than that of young subjects, and in Avarm blooded animals than in reptiles and fishes. The quantity of gelatine and albumen is in an inverse ratio in the different periods of life, the former predominating in infancy, but entirely disappearing as Ave advance in years. It is difficult to say Avhether the gelatine is to be regarded as proper to the muscles, or as being derived from the cellular substance Avhich enters into their composition. The latter supposition, on the Avhole, is perhaps the most correct. The distinctive attribute of the muscular tissue is con- tractility, or that property by virtue of which it alternately shortens and elongates its fibres. The chief purpose of this function is to enable us to carry into effect our various reso- lutions and designs, or, in other words, the mandates of the will. Three conditions are necessary to the successful exe- cution of this function : 1. a sound state of the muscle ; 2. a free and uninterrupted nervous communication ; 3. a healthy state of the cerebro-spinal axis. For the production of the involuntary movements, only tAvo conditions are re- SECT. I.] SENSIBILITY--MODE OF UNION. 253 quired, namely, a sound state of the fleshy fibres, and the action of an appropriate stimulant. Thus, the blood is the proper and accustomed stimulant of the heart, the urine of the bladder, the food of the stomach, the bile and foecal mat- ter of the intestinal tube. Finally, the sensibility of the muscles, notwithstanding their great nervous endoAvments, is rather obscure, and, like that of all other organs, is of a peculiar character. When these structures are subjected to severe exercise, a feeling of lassitude is experienced, often amounting to considerable uneasiness. The distressing sensations in the back and limbs of patients laboring under bilious and intermittent fevers, as Avell as in some other diseases, are doubtless seated in the muscular texture, instead of the bones, to which they are usually referred by the vulgar. In amputations, the division of the muscles is never attended Avith the same degree of pain that is felt in cutting through the skin. Yet, although the organs in question enjoy little sensibility in the healthy state, the suffering from them, when inflamed, is sometimes truly exquisite, and almost intolerable. The voluntary muscles, Avhen divided, unite by adhe- sive inflammation, with nearly the same facility as the cuta- neous and cellular textures, the period required for the repa- ration varying according to the extent of the injury and the nature of the constitution. If the edges of the Avound be alloAved to remain apart, the restoration is effected through the medium of granulations, the growth of which is often rapid and luxuriant. As the healing advances, these bodies contract in volume, and are ultimately converted, by a mod- elling process, into real muscular tissue, or, at all events, into a substance so closely resembling it as to render it difficult to distinguish them from each other. I cannot understand upon what grounds the partial regeneration of the muscular tissue has been denied by some anatomists. That the bond of union is occasionally of a fibrous, ligamentous, or even cartilaginous character, as is contended by these Avriters, can- not be doubted; but that such is not the course Avhich nature generally pursues, even in old persons, the observations of every one must fully convince him. Is it more difficult to conceive of the partial reproduction of a muscle than of a bone ? Certainly not, especially when it is remembered how much more delicately the one is organized than the other; or, Avhat is the same thing, how much more liberally it is 254 MUSCLES. [CHAP. IV. supplied both Avith vessels and nerves. Yet. notAvithstanding, how often does it. not happen that some of the largest pieces of the skeleton are almost wholly regenerated Avhen destroyed by necrosis. I do not contend that a muscle, similarly affected, is ever completely reproduced ; for, upon this subject, I have no personal experience: I should imagine the circum- stance, hoAvever, to be Avithin the range of possibility : but that it is extremely rare is sufficiently evident from the feAV cases of it Avhich are on record. The principal lesions of the voluntary muscles are inflam- mation, change of consistence, ossification, atrophy, and their conversion into a substance resembling fat. Inflammation of the muscles is by no means so common as in some of the other textures. It is not improbable, I think, that it sometimes commences in their oavii substance ; but much more frequently it is communicated to them from the contiguous parts, as the inteiwening cellular structure, and the aponeurotic expansions, by Avhich they are connected and enclosed. The disease here, as elsewhere, may be acute, as Avhen it is caused by Avounds or external injury, or chronic, as when it is associated with gout and rheumatism. In either case, it is generally limited to particular muscles ; though, in a feAV rare instances, it affects a whole group of them, either simultaneously or successively. As comparatively feAV op- portunities have occurred for studying this lesion, it is not surprising that a good account of its anatomical characters should still be a desideratum. The initial step in the acute form of the disease, as well, perhaps, as in the chronic, consists iii an engorged state of the vessels of the connecting cellular texture, Avhich, in con- sequence, loses its natural Avhiteness, and assumes a faint red complexion. The fleshy fibres are at the same time increased in density, though as yet they have experienced no change of color. Gradually, hoAvever, their vascularity is augmented, the affected part becomes rigid, and their contractile poAver is so much impaired that motion is not only difficult but painful, the muscle, the subject of the disease, being the seat of constant spasmodic actions. At a more advanced period, Avhen the disease has reached a higher grade of intensity, the connecting cellular tissue is SAVollen, and infiltrated Avith serosity, intermixed Avith globules and shreds of lymph. The muscular fibres are of a deep mahogany hue, soft, flaccid, easily torn, and scarcely distin- SECT. I.] INFLAMMATION--SUPPURATION--GANGRENE. 255 guishable from the surrounding parts. The discoloration, al- though sometimes uniform, and diffused over a large extent of surface, more commonly occurs in irregular patches, with intervals of sound substance. In violent cases, it is not un- usual to find small ecchymoses, caused by the rupture of some of the capillary vessels. The muscle, at this advanced stage, is totally changed in its character, and there is gener- ally more or less effusion of serum, lymph, and blood, betAveen it and the circumjacent structures, Avith inflammatory appear- ances of its aponeurotic sheath. The ordinary stimulants, as might be supposed, no longer exercise their accustomed in- fluence. The fleshy fibres remain rigidly fixed, in spite even of the division of the main nerve. Galvanism also fails in producing the usual phenomena. It is seldom tha$ inflammation, whether acute or chronic, passes into suppuration. This rare occurrence is most fre- quently Avitnessed in neglected erysipelas of the extremities ; but the most perfect example of it is that which is seen in Avhat is called psoas abscess ; Avhence the psoas and iliac mus- cles sometimes entirely disappear, being converted into a large purulent sac, extending from the first lumbar vertebra to the groin. The pus, which is of the same nature as in other parts of the body, is deposited originally in small disseminated globules, which give the affected part a singularly speckled appearance. Not less rare is mortification of the external muscles. This termination has hitherto been observed chiefly, if not Avholly, in erysipelatous and carbuncular inflammation, occurring in old Avorn-out subjects. The lesion is easily recognized by the altered color of the fleshy fibres, which are usually of a dark, cineritious aspect, by their softness and lacerability, and by their gangrenous odor. The sloughs are detached in ragged shreds, bathed by a thin, dirty, sanious, and offensive fluid. The injured muscle is never entirely regenerated, and, if the sphacelus be extensive, it generally proves fatal. In chronic inflammation, the muscular tissue loses its florid complexion, and assumes a pale yellowish appearance, not unlike that of an autumnal leaf. Its consistence is also in- creased ; and the fleshy fibres, which are often very much thickened, are so firmly glued to each other as to render it difficult to separate them. This form of myositis, as before intimated, occasionally terminates in suppuration. Another effect, which is still more rare, is ulceration. This is some- 256 MUSCLES. [chap. IV. times observed in phagedenic sores of the leg, extending in succession through the skin, cellular substance, aponeurosis, and, finally, the muscular texture. The most remarkable circumstance about these erosions is the disappearance of the fleshy fibres, or their conversion into fibrous substance. When the constitution is good, the restorative process generally goes on kindly, and the ulcer is soon filled Avith healthy granula- tions. The muscles are occasionally deprived of their natural consistence. The diminution of cohesion to Avhich this alteration gives rise is generally limited to particular muscles, or even to particular portions of them. The exciting causes of this affection are still involved in considerable obscurity; but that it frequently depends upon irritation and loss of nervous power, does not admit, it seems to me, of any rea- sonable doubt. In proof of the justice of this view, it may be added, that the lesion we are iioav contemplating is unusu- ally connected Avith inflammatory appearances of the col- lateral tissues, or Avith general or partial paralysis. De Haen relates a remarkable example of softening of the muscles of an individual Avho Avas seized Avith palsy of the superior extremities, after an attack of painter's colic; and similar instances are recorded by Barthez and other Avriters. In both the cases mentioned by these authors, the affected structures Avere of a soft, pulpy consistence, but gradually regained their normal character as the enteric disease subsided. A flaccid condition of the muscular system often coexists Avith what is termed the tubercular cachexy, and with a watery and impoverished state of the blood. By whatever cause the lesion is induced, the fleshy fibres are unusually pale, bordering on light fawn, flabby, and easily lacerable, the slightest pressure being sufficient to convert them into a soft, pulpy mass. The reverse of the condition now described is sometimes observed, namely, a considerable degree of induration of the muscular tissue. This lesion, which appears to arise from the effusion of plastic lymph into the interstitial cellular substance, is frequently seen in the neighborhood of frac- tured bones, around scirrhous tumors, and in the legs of persons affected with elephantiasis, gout, and rheumatism. Under the influence of these causes, the muscular fibres are rendered hard and firm, and, in some instances, almost car- tilaginous. The color, in the early stage, is simply brown : SECT. I.] OSSIFICATION. 257 subsequently it acquires a pale reddish tint, and at a still later period the part exhibits a grayish leaden aspect, with here and there a spot retaining a portion of its natural complexion. It has been doubted by high authority, whether the mus- cular texture is ever the seat of ossification. I am myself inclined to think, Avith Andral and others, that the primitive locality of the deposition is the interstitial cellular substance, from Avhence it gradually extends to the fleshy fibres, blanch- ing and extenuating them, or even Avholly destroying them by absorption. This degeneration, though commonly con- fined to individual muscles, occasionally affects a great num- ber of them. A striking example, in Avhich the whole muscular system exhibited the ossific diathesis, is recorded by Dr. Henry, an English practitioner.* The patient was a laborer, nineteen years of age, and the disease, as is usual in such cases, was connected with exostotic enlargements of the bones. \ painful swelling was first perceived at the right Avrist, Avhich, as it increased, gradually involved all the muscles of the fore-arm, and converted them into one solid mass as high as the elbow. The left limb Avas attacked in a similar manner; then the right leg, from the ankle to the knee, and finally the shoulders and hands, rendering the superior extremities completely stiff and useless. Of the individual muscles, those of the loins, shoulder, and calf, are more particularly liable to suffer from this transformation. In gouty and rickety subjects, Avhitish stone-like concre- tions are occasionally found in the muscles: they are usually of a spherical shape, Avith a volume seldom exceeding that of a pea, and consist principally of phosphate and carbonate of lime, cemented together by a minute quantity of animal matter. I have never seen the true conversion of the muscular into the fibrous texture ; but a number of examples of this kind have been recorded by others. The degeneration sometimes involves whole muscles, which, Avhen the change is com- pleted, scarcely retain a single vestige of their original fea- tures, save their shape, and even this is often materially altered. The deltoid and sterno-mastoid appear to be more frequently affected in this way, than any other parts of the muscular system, — for Avhat reason is not knoAvn. The cause of the present transformation admits of easy explanation. * London Philosophical Transactions, vol. xxi. p. 89. vol. i. 33 258 MUSCLES. [chap. IV. Whenever a muscle is placed in a state of total inactivity, it experiences a modification of nutrition, by Avhich, without any appreciable irritation, it gradually loses its fleshy charac- ter, and is converted into a fibrous substance, the economy making an effort, so to speak, to get rid of it, as a structure that is of no further use. This view of the case derives confirmation from what occurs in the inferior animals. In some species of quadrupeds, parts that are distinctly muscular in early life, are subsequently, by some change in the func- tion of nutrition, transformed into another texture, better adapted to the Avants of the system than one which is simply contractile. Another lesion to which the muscles, in common with several other organs, are liable, is the fatty degeneration. In this affection they generally retain their original form and volume, though in some instances they are partially shrivelled and disfigured. They are of a pale straAv-color, or even entirely white, unctuous to the touch, and rather diminished than increased in consistence. Notwithstanding all this, however, the linear arrangement of their fibres is not only recognizable by the eye, but can be easily traced Avith the scalpel. On pressure, a clear oily fluid oozes out, Avhich greases the finger, or Avhatever else is brought in contact with it, and is of an unusually inflammable nature. According to the analysis of Cruveilhier,* muscular tissue, Avhich has undergone the adi- pous degeneration, consists of an oily liquid, probably elaine, gelatine, adipocire, solid fat, and a substance resembling boiled flesh. These materials, the quantity of which is valuable, are not deposited between the muscular filaments, as has been conjectured by some, but form actually a part of their component principles. It is worthy of remark, however, that the interstitial cellular element is always considerably altered, being of a Avhitish color, very soft, and lacerable. The fatty transformation is most marked in the muscles of the loins, hip, thigh, and leg of old persons affected with paralysis. It is likewise observed, in some rare instances, in the muscles around unreduced luxations, large exostoses, and old deep-seated ulcers. When the change is complete and extensive, it occasionally involves the corresponding tendons and aponeuroses, which, in consequence, lose their polished, satin-like lustre. * Essai sur l'Anatomie Pathologique, t. i. p. 189. SECT. I.] HETEROLOGOUS FORMATIONS. 259 It rarely happens that we have an opportunity of observ- ing tubercles in the muscular tissue. When present, they are generally connected with a strumous diathesis, and coexist in other parts of the body. Otto states that he has several times seen tubercles in the muscles of the neck and thigh of scrofulous monkeys; and Andral has noticed similar bodies in the muscles of the hog. In the case to which the latter writer refers, they occurred in association Avith small trans- parent hydatids, evidently of the cysticercic kind. Not less rare is melanosis. The first of these deposits is sometimes seen in the form of an infiltration, Avhich imparts its peculiar stain to the muscular fibres, and converting them into a soft, pulpy substance, in Avhich it is impossible to recognize the slightest trace of the primitive structure. Occa- sionally, again, the black matter is encysted, presenting an irregularly spherical mass, of pretty firm consistence, the volume of which varies from that of a pea to that of a foetal head. This morbid formation is sometimes directly charge- able to external injury ; at other times, it takes place without any assignable cause. It usually betrays a malignant char- acter, proceeding, if allowed to remain, to ulceration, and returning, sooner or later, Avhen extirpated. Scirrhus and encephaloid are also extremely infrequent. Indeed, so seldom do these heteroclite formations occur in the muscular system, that it has hitherto fallen to the lot of few pathological anatomists to observe them. The diagnosis of their tumors is often obscure, and difficult of determination. Scirrhus, it should be remembered, generally makes its ap- pearance in old persons, whereas encephaloid is rarely seen after the age of thirty. Much assistance may also be derived from the form and consistence of the morbid deposits. A scirrhous tumor is pretty regularly circumscribed, hard, and almost incompressible ; an encephaloid one, on the contrary, is generally lobulated, firmer in some parts than at others, doughy, and somewhat inelastic : the growth of the one, moreover, is usually very sIoav, and attended with darting, lancinating pain; that of the other is almost always rapid, unaccompanied Avith much local uneasiness, and remarkable for its great bulk. When the ulceration takes place, the scir- rhous tumor gives vent to a thin, ichorous, irritating discharge; the sore is deep, and the edge hard and inverted : the en- cephaloid swelling, on the other hand, throws out a soft, fungous excrescence, and is the seat of frequent hemorrhages. On the whole, it appears extremely doubtful, whether any 260 MUSCLES. [CHAP. IV. of the heterologous formations are ever seated, in reality, in the muscular substance. In all probability they are originally developed in the interstitial cellular tissue, from Avhence, as they augment in \rolume, they gradually encroach upon the fleshy fibres, displacing them, altering their texture, or even producing their entire absorption. On this point, how- ever, I am not prepared to deliver a positive opinion ; nor do I know any person that is. Professor Warren, of Boston, Avho has written one of the most excellent treatises on tumors extant, has given us no information which enables us to solve this question; and I am fully persuaded, from all that can be gathered on this subject, that further observation is necessary before we can arrive at any definite and satisfactory conclu- sion concerning it. Hypertrophy of the voluntary muscles is extremely infre- quent, and has hitherto been noticed chiefly in the tongue, where, as Avill be shoAvn hereafter, it is occasionally con- genital. As occurring from the influence of inordinate exer- cise, and the unusual influx of blood, the best example is that which takes place in the muscles of the arm of the blacksmith, and in the leg of the rope dancer. Muscles that have experienced this change, whether it be the result of accident, or purely physiological, are of a deep red color, firm, tough, and comparatively little compressible, with a bulk greatly exceeding what is observed in the normal state. A more common affection is atrophy, or unnatural diminu- tion of volume. It may arise either from general disease, such as phthisis, carcinoma, or dropsy, or from local difficul- ty, as inflammation, ordinary palsy, or defective nutrition. Indeed, whatever has a tendency to impair the function of innervation, retard the circulation of the blood, or produce permanent inactivity, may be considered as so many causes which are followed, sooner or later, by atrophy of the volun- tary muscles. Hence this lesion is generally associated with palsy, whether proceeding indirectly from disease of the cere- bro-spinal axis, or directly from the injury of the nerves sup- plying the affected part. The muscles around luxated joints, especially those of the hip and shoulder, are often atrophied, simply, it would appear, from want of exercise. The extent to which the wasting of the muscles proceeds is various. Frequently they are reduced to mere membran- ous bands, pale, flaccid, and almost devoid of irritability ; and, in some rare instances, their fibres are entirely absorbed, a dense cellular substance being all that is left in their place. SECT. I.] PARASITES. 261 In persons dying of protracted diseases, I have repeatedly ob- served a dark bluish color in particular muscles, especially those of the abdomen, accompanied Avith remarkable flaccid- ity and facility of laceration. These changes are more com- mon in negroes ; and, from having often noticed them within a few hours after death, I am disposed to think that they are not altogether cadaveric. Dropsical and consumptive subjects, more frequently than any other, present these appearances. The voluntary muscles are occasionally infested by para- sitic animals, the principal of which are the cysticercic hyda- tid, and the spiral trichina. The former are seldom seen in the human subject, but are very common in the sAvine, sheep, and other quadrupeds, in which, particularly in the first, they often exist in immense numbers, rendering the flesh com- pletely unfit for use. The spiral trichina, (Figs. 12, 13, 14,) which has been recently discovered by Mr. Richard Owen, a distinguished English natural- Fio. 12 * „. 13 + ist, is a very delicate, minute, coiled-up entozoon, about the twenty-fourth of a line in length, and the seven hundredth part of an inch in diameter. It is of a cylindrical shape, and termi- nates obtusely at both extremi- ties, which are of unequal size, the larger being furnished with a transverse linear orifice, Avhich evidently answers the purpose of a mouth. It is a singular fact that this worm is always en- closed by a distinct cyst, which is the reason, probably, why it so long escaped the observation of anatomists ; since it appears, from the researches of Owen, Knox, Hodgkin, and others, that its occurrence is rather frequent than otherwise. This cyst, which is supposed by some to be merely con- densed cellular tissue, is formed out of the plastic lymph of the blood, and is scarcely one fortieth by one hundredth of an inch in diameter. It is of a whitish appearance, and Fig. 14.t * Cysts of the spiral trichina in situ, natural size. t Separate cyst, containing the trichina magnified. t The animal magnified: a, the head; b, the tail; c, the body. 262 MUSCLES. [chap. IV. of an oblong shape, Avith one extremity so contracted as to form a short, imperfect neck. Amongst a collection of trichinas, it is by no means un- common to find some which have lost their vitality or been entirely removed by absorption. In such cases, the enclosing cyst is usually collapsed, more or less opaque, or even ossi- fied, like that of a dead hydatid. It is probable that these parasitic animals enjoy^but a very brief existence, though, upon this point, we have no satisfactory information. Gen- erally there is only one in each cyst, but, in some instances, there are tAvo, or even three. They are developed in the in- terfibrillar cellular tissue, and appear to be wholly confined to the muscles of A'oluntary motion, together with the tendin- ous structures immediately connected with them. Their number is sometimes immense, the flesh being every where studded with them. The presence of these Avorms in the system appears to be unconnected with age, sex, or any par- ticular form of disease.* Under the name of muscular apoplexy, M. Cruveilhier, of Paris, has recently described a very singular disease, which, notwithstanding its great infrequency, is deserving of brief notice in this place. The lesion appears to be most common in scorbutic subjects, or in persons of a weak and lax fibre, with a thin and Avatery state of the blood. It has likewise been noticed in people affected with intermittent fever, de- lirium tremens, and phlegmonous erysipela. No muscles, not even the heart, are exempt from this effusion ; but, ac- cording to the author above quoted, the straight muscles of the abdomen are more frequently and extensively affected than any other. The number of apoplectic depots is extreme- ly variable. In some instances there are only a few, whilst in others there are several dozens. They are at first of a dark color, and soft consistence, but, by degrees, they become lighter, and acquire greater lividity, resembling, in these respects, the apoplectic depots of the cerebral tissue. In volume, they range between that of a pea and a hen's egg. The muscular texture immediately around these collections is more or less lacerated, and infiltrated Avith blood. M. Cruveilhier thinks f he has conclusively proved that these sanguineous effusions are dependent upon phlebitis. By injecting ink, diluted with water, into the femoral veins of * London Cyclopaedia of Anatomy and Physiology, p. 115. t Diet, de Medicine et de Chirurgie Pratique, t. iii. p. 288. SECT. II.] TENDONS. 263 dogs, he found, in a few days, all the muscles of the corres- ponding limb studded Avith clots of blood, which had evident- ly been deposited in the midst of the lacerated fibres. In such of the animals as survived from four to eight weeks, cica- trices were discovered, entirely similar to those that are some- times seen in the brain. These experiments require to be re- peated and modified before we can venture to deduce any positive conclusions from them. As being next in order, we may speak of the lesions of the tendons, the aponeuroses, and synovial burses, inasmuch as these organs are all more or less intimately connected with the muscles, as Avell as closely allied to each other in structure and function. A rapid outline, embracing the more impor- tant facts relative to the general and pathological anatomy of these textures, is all that Avill be attempted in the present chapter. They will be considered in the order in Avhich they have been enumerated. SECTION II. Of the Tendons. The appearance of the tendons must be familiar to every one. They are a set of Avhite, elongated bodies, Avhich serve, on the one hand, to receive the muscular fibres, and, on the other, to connect them Avith the bones, ligaments, and car- tilages. In regard to their shape, some are rope-like, others membranous; and, in most situations, they are enclosed by strong sheaths, the inner surface of which is lined by a syno- vial structure, to facilitate their gliding movements. The connection between the tendons and muscles is so intimate that it is impossible to sever it, except by protracted boiling and maceration. It Avas owing to this circumstance that some of the older anatomists Avere induced to assert the real identi- ty of these organs ; the only difference depending, as they al- leged, upon the greater density of the one over that of the other. The tendons consist of Avhite, glistening fibres, the tena- city of which exceeds that of almost every other animal tis- sue : they lie close and parallel to each other, and they are tied together by condensed cellular substance. No nerves 264 TENDONS. [CHAP. IV. have been traced into the tendons, and in the normal state they are perfectly insensible. Their vessels, although small, are perfectly injectable, notwithstanding the reverse is usu- ally asserted by anatomists. A feAV years ago I was shown a beautiful specimen of the tendo-achillis of a child, in the cabinet of Dr. Mott, of NeAV York, the arteries of which Avere so completely filled with size, colored Avith vermilion, that the whole exhibited quite a florid appearance. A similar prepara- tion is contained in my OAvn collection. Immersion in spirits of turpentine, by rendering the tendinous structure more transparent, shows the distribution of the vessels to great ad- vantage. The basis of the tendinous texture is gelatine, which is readily extracted by boiling. It is destitute of elasticity, as well as of extensibility, and is therefore well calculated to transmit to the bones the action of the muscles; in the accom- plishment of which purpose — the principal one it has to ful- fil — its operation appears to be wholly mechanical. The tendons, as before stated, are embraced and fixed in their place by fibrous sheaths, the internal surface of which is lined by a synovial membrane, and constantly lubricated by a sort of oily halitus. Externally they are rough, and united to the surrounding parts by lax, cellular substance. These envelopes are very strong, thick, especially on the dor- sal surface of the leg and fore-arm : some of them contain several tendons, and they are composed of aponeurotic fibres, closely interwoven with each other. Their organization is similar to that of the tendons. Professor Mayo * has made a number of experiments, which show that the extremities of tendons Avhich have been divid- ed readily reunite, through the intervention of a firm, tough substance, Avhich gradually assumes all the properties of the original texture. During the first few days, this matter is very soft, and of a red color, from the admixture of the blood that is poured out in the operation. By and by, it augments in density, becomes slightly elastic, and adheres more or less tenaciously not to the cut ends only of the tendon, but like- wise to its fibrous sheath, Avhich is discolored for some dis- tance from the Avound. Towards the end of the third week, the extravasated blood is entirely absorbed, and the new sub- stance, which is now of a pale grayish complexion, is found diminished in thickness, but increased in firmness, and to be * Outlines of Human Physiology, p. 477, fourth edition. SECT. II.] REGENERATION-- INFLAMMATION. 265 inseparably coherent with the original structure, to the prop- erties of Avhich it ultimately assimilates itself. When these bodies are destroyed by gangrene, it is proba- ble that they are never entirely regenerated. I am not igno- rant of the remarkable example related by Dr. Baronio, an Italian physician, of the reproduction of the Avhole tendo- achillis ; but such instances are extremely rare, and, at best, of a very doubtful character. From Avhat is known concerning the organization of the tendons, it might be inferred that they are not very prone to inflammation ; and such, indeed, experience has shown to be the fact. The disease, in most cases, arises spontaneously from the influence of the syphilitic poison, the operation of mercury, or from the effect of atmospheric vicissitudes. Its march, under these circumstances, is generally of a chronic nature, the most important alterations which it induces being hypertrophy and induration of the affected part. Conjoined Avith these changes are usually certain morbid appearances of the fibrous sheaths, such as infiltration of its external cellular texture with a greenish jelly-like fluid, thickening and opaci- ty of the lining membrane, and effusion of yelloAv turbid synovia. Purulent matter is sometimes poured out; and the tendinous structure may be so much altered as to become un- fit for its functions. The process of acute inflammation is most distinctly seen in Avounds, sprains, and whitloe. The tendon loses its natu- ral polish, assumes a faint reddish color, from the engorged state of its capillaries. At a more advanced stage, lymph is poured out, either alone, or mixed with serum and blood ; and, in violent cases, suppuration occasionally sets in; but this, I presume, is very rare. When the inflammation has attained its height, the tendon is of a pale ash-color, soft, pulpy, and considerably thickened. Inflammation readily deprives the tendons of their vitality, — a circumstance Avhich is not surprising when we consider their feeble and imperfect organization. Whole cords are sometimes destroyed by this disease, which nature always attempts to eject from the system by setting up the process of ulcerative absorption around the dead substance : the work of separation is usually very tedious, and resembles a good deal the exfoli- ation of a necrosed bone. In this state, the tendons lose their glistening lustre, assume a dull grayish aspect, and become thick and doughy ; the individual fibres, hoAvever, retaining, vol. i. 34 266 TENDONS. [CHAP. IV. in some degree, their original consistence. This occurrence most frequently happens in the fingers and palms of the hand in Avhat is called whitloe, — one of the most painful and dis- tressing affections to Avhich these textures, in common with some others, are liable. Ossification of the tendons is much less common in man than in the inferior animals. Birds are very liable to it; and it is also frequently observed in the horse, sheep, goat, and ox. The change is most common in the tendons of the foot in old subjects, where they slide over, and rub upon the bones. Atrophy is likewise very rare, and is only observed in con- nection with great Avasting of the muscular texture. Inordi- nate enlargement occurs principally as an effect of chronic in- flammation. I am not aAvare that any of the heterologous deposits ever take place either in the tendons, or in either of the other structures included in the present chapter. The sheaths of the tendons, like other serous structures, are subject to dropsical accumulations. The bags thus form- ed are generally of an ovoidal shape, and vary in size, from that of a pea to that of an apricot. Their contents are usu- ally of a glairy viscid character, like the white of eggs, though, in this respect, there is considerable diversity in dif- ferent cases. Sometimes, along with the fluid, the sac con- tains a number of loose bodies, similar, in all respects, to the concretions found in the movable joints and the synovial burses. They are of a pale yelloAvish color, tough consist- ence, frequently shaped like gourd-seeds, and of variable size, from that of a grain of wheat to that of a bean. This disease constitutes Avhat, in surgical language, is call- ed a ganglion. A difference of opinion has existed in regard to the nature of this affection, the question being, whether it is of neAv formation, or merely a succulated expansion of the serous lining of the tubular structure in question. For my own part, I have no hesitation in saying, from Avhat I know respecting this lesion, that the former opinion is entirely gra- tuitous, not having the slightest foundation in truth. The disease occurs most frequently at the wrist, along the extensor tendons. Females are more subject to it than males, espe- cially such as are much engaged in hard manual exercise. It is likewise very common in horses, in which it is known by the name of wind-galls. SECT. III.] APONEUROSES-- INFLAMMATION. 267 SECTION III. Of the Aponeuroses. The aponeuroses are fibrous membranes, which bind down and enclose the muscles, at the same time insulating them from each other. Their arrangement is that of sheaths, which encase the extremities, and thus serve to prevent any dis- placement of the organs they envelope. Externally they are rough, flocculent, and in contact with cellulo-adipous matter : internally they correspond to the muscles, to which they are loosely united in some places, but very firmly in others. Gen- erally speaking, these structures consist of a single layer, the thickness of which is proportionate to the volume and strength of the bodies which they enclose. They are very sparingly supplied with vessels, nerves, and absorbents ; and, iu the normal state, they appear quite insensible. The aponeuroses, possessing the same organization as the periosteum, dura mater, and pericardium, are liable to the same diseases. Acute inflammation is very rare, and observed principally as the result of external violence, Avhitloe, and anthrax. Gout and rheumatism are supposed to have their seat exclusively in the fibrous envelopes of the extremities, but of the truth of this opinion many physicians still enter- tain serious doubts. My own idea, which coincides with that of Scudamore, is, that the aponeurotic, ligamentous, tendinous, and bursal textures are all implicated in nearly the same de- gree, the diseases here referred to sometimes beginning in the one, sometimes in the other, but sooner or later attacking the whole of them. But upon these subjects we stand in need of further and more substantial information. In chronic inflammation, which, by the way, is much more common than the acute form of the disorder, the aponeuroses become thickened, preternaturally hard, and of a pale yel- lowish color, interspersed with grayish, leaden, or brownish patches. Spicules of bone sometimes sprout from them, which occasionally acquire quite a large size, and exhibit the appear- ance of so many stalactites. Another effect of chronic irrita- tion, likewise very rare, is extreme attenuation of these mem- branes, constituting a sort of real atrophy. This result is 268 SYNOVIAL BURSES. [CHAP. IV. generally produced by the pressure of a tumor, Avhich, exert- ing its detrimental influence for some time, by degrees causes the absorption of the aponeurotic fibres. Inflammation of these structures manifests little disposition to pass into suppuration, gangrene, or ulceration; and the heterologous deposits are, I believe, entirely unknoAvn in them. SECTION IV. Of the Synovial Burses. The synovial burses are small semi-transparent sacs, filled with a thin unctuous fluid, which are situated about the joints, especially those of the extremities. For the most part, they lie between the bones and tendons, or between tendon and tendon, or finally between the bones and skin. Nearly one hundred and fifty of these pouches are to be found in different situations of the body. Their structure is perfectly identical with that of the synovial membranes of the joints, being, like them, resolvable by maceration into cellular substance : they are sparingly supplied with vessels and nerves, possess little sensibility in the sound state, and are constantly lubricated by a thin oily fluid, Avhich thus enables them to facilitate the motions of the parts between Avhich they are situated, and which seems to be their princi- pal office. Thus constituted, the synovial burses are liable to inflammation, suppuration, thickening, and cartilaginous degeneration. One of the earliest effects of acute inflammation is an in- crease of vascularity, — the redness here, as in the other serous structures, appearing at first in separate lines, which at length coalesce and thus assume an arborescent arrangement. In some instances, the redness has a dotted form, or there are small ecchymoses, caused by the rupture of one or more capillaries. The synovial membrane loses its transparency, and presents an opaque, milky aspect, being as yet little or not at all thickened. When the disease is at its height, the natural secretion is partially suspended, which, hoAvever, lasts only for SECT. IV.] INFLAMMATION. 269 a short time, when it not only augments in quantity, but is likewise changed in quality. Instead of being thin, oily, and transparent, it takes on the appearance of a brownish turbid serum, mixed with flakes of lymph, pus, or even small clots of blood. The tumor which is thus formed is some- times as large as a cocoanut, but generally it does not exceed the size of a walnut, an orange, or a goose's egg : in most cases, it is somewhat rounded, elastic, and painful on pres- sure, the skin covering it being red and hot. The abscess may open externally, or the sac may burst, and the matter be effused into the surrounding cellular tissue. I have, in a few instances, found these tumors filled with a fluid of the color and consistence of currant jelly. When the disease is chronic, the effused fluid is sometimes loaded with loose concretions, of a dense semi-cartilaginous consistence. They are of a light brownish color, and of a flat oval form, not unlike melon-seeds. Their numbers are occasionally quite great, upAvards of fifty having been ex- tracted from a single burse. How are these bodies produced ? Sir Benjamin Brodie supposes that they are merely masses of plastic lymph originally poured out in soft, amorphous flakes, Avhich by degrees become firm, and assume a deter- mined shape by the pressure of the surrounding parts. This is one way of accounting for them ; another is to suppose that they originally grow from the inner surface of the sac, from which they are at length detached by friction, like the little tumors which are sometimes met with in the movable joints. Bodies closely resembling hydatids are sometimes found in the synovial burses. In a case, the particulars of which were detailed a few years ago by Professor Cloquet, of Paris, there were upAvards of one hundred and forty of these substances, varying from one to three lines in diameter, nearly transpa- rent, and of a lenticular shape, in a large pouch between the great trachanter and the tendon of the great gluteal muscle. More recently he .has met Avith them in an acci- dental cyst, near the insertion of the tricipital muscle of the arm, and also in the sheath of the tendon of the long palmar muscle. In protracted cases of this disease, the sac is very apt to become hypertrophied and indurated. Sir Benjamin Brodie has seen it more than half an inch in thickness, with a small 270 SYNOVIAL BURSES. [CHAP. IV. central cavity filled with synovial fluid. In the horse I have repeatedly seen it converted into a hard gristly substance; and the same phenomenon has often been witnessed in the human subject. Cases are even recorded, where it is said to have partaken of an osseous character. Not unfrequently the inner surface of the sac exhibits a honey-comb appearance, the shreds of lymph intersecting each other in various direc- tions. In other instances, however, though the inflammation has persisted for a long time, the membrane retains nearly its primitive structure. CHAPTER V. Qf the Arteries. Their Tunics. — Nutrient Vessels. —Nerves.—Cellular Sheath.—Lesions.— Wounds. — Inflammation. — Suppuration.— Ulceration. — Aneurism. — Con- traction . — Hypertrophy. — Morbid Deposits. The arteries distributed through the various organs and textures of the animal fabric (Fig. 15) are composed each of three cylindrical coats, differing from each other materially in their structure and functions. The external one, decidedly the most important of the three, is of a Avhite grayish color, and made up of dense cellular sub- stance, the filaments of which, although closely matted togeth- er, follow no assignable course. It is highly tenaceous, extensi- ble, and elastic, and therefore well qualified to resist violence, and slide out of the way of injury. Its firmness is so great, that it is not easily divided by the ligature; and, in cases of disease, it often preserves its integrity long after the other tunics are destroyed, or, at all events, very much altered. In old, corpulent subjects, this membrane is sometimes the seat of a small quantity of adipous matter; but it does not appear Pis. 15.* * Mode in which an artery separates into its ultimate branches: 1, trunk of the vessel; 2, large branches into which it subdivides; 3, small branches dimin- ishing gradually in volume until they become capillary, — 4. 272 ARTERIES. [chap. V. to be liable, like the same structure in other regions of the body, to serous infiltration, owing, doubtless, to the peculiar mode of aggrega- tion of its component fila- ments. (Fig. 16.) The middle tunic, sup- posed at one time, though erroneously, to be muscu- lar, contains the peculiar tissue which imparts to these tubes their characteristic attributes. It is composed of dense, yelloAvish, buff-colored fibres, arranged spirally around the caliber of the vessel, none of ..them forming complete circles, but rather segments, which are joined so as to produce rings. United together by short cellular substance, these fibres are proportionally stronger in the smaller than in the larger trunks, in the latter of Avhich they can be separated into a number of lamellee, varying in thickness and density, according to the artery in which they are examined. Thus constituted, the middle coat is firm, solid, and elastic, yet withal so brittle that it is readily divided by the ligature. Its thickness exceeds that of the other membranes, and its extensibility is much greater in the longitudinal than in the transverse direction. VieAved in reference to its structure, it may be considered as forming a sort of connecting link between the cellular and yelloAV fibro-elastic tissues, combin- ing the strength of the former Avith the astonishing elasticity of the latter. No fibrin, the proximate element of muscle, has yet been detected in its substance. The internal tunic, by far the most delicate of the three, is remarkably thin, smooth, and transparent, being designed, apparently, not so much to give strength to the arteries as to furnish their interior with a polished and unctuous surface, to facilitate the movement of the blood. Lining the Avhole aortic portion of the vascular system, it passes through the left chambers of the heart into the four pulmonary veins, which it supplies in their entire extent, but is not continued into the pulmonary arteries. This membrane, from its great fragility, readily yields under the ligature, and is not sus- * Coats of an artery separated from each other: 1, the internal membrane ; 2, the middle tunic; 3, the external membrane. CHAP. V.] STRUCTURE-- VALVES. 273 ceptible, moreover, of much extension. Its inner surface is smooth, polished, and constantly bedewed by a thin, Avatery fluid,, on which account it is customary to associate it Avith the serous textures. Although it presents many characters in common Avith these organs, it nevertheless differs from them in several important particulars, and may therefore be very properly regarded, I think, as a peculiar structure, unlike any other in the body. In some of the arteries, the inner tunic is disposed in longitudinal, in others, as in the popliteal, in transverse plaits. The latter are ahvays very conspicuous in lacerated Avounds, and they are supposed, by Mr. Guthrie, to perform a very important part in the suppression of hemorrhage. No valves are formed by this membrane, except at the mouth of the aorta, Avhere it is arranged into three duplicatures, at the free margin of Avhich is a peculiar fibro-cartilaginous body, styled the corpuscle of Aurantius. These valves will be described more particularly in another page. These different tunics are cemented together by cellular matter, and they are not only liberally supplied with proper nutrient vessels, but likewise with nerves and lymphatics. None of these structures can be traced beyond the subserous cellular tissue; but, that they extend into the internal mem- brane, is abundantly proved by its capability of undergoing the various processes dependent upon inflammation, to say nothing of the fact of its free surface being the seat of a constant secretion in the normal state. The nutrient vessels can be easily demonstrated by artificial injection, and they are generally very conspicuous in the larger trunks after death, especially in asphyxiated subjects. From their physi- ological importance, it is obvious that they should be as little disturbed as possible in surgical operations, as any violence done to them must necessarily eventuate in corresponding mischief to the parts which they supply. The nerves of the arteries are extremely numerous, and, in many of the larger trunks, they may be seen forming a sort of plexus around them, not unlike those which encircle the oesophagus. In the splanchnic cavities they are furnished principally by the great sympathetic, but in the extremities they are entirely derived from the cerebro-spinal axis. The pulmonary arteries, besides receiving some filaments from the sympathetic, are supplied by the par vagum. Finally, the arteries, in most regions, are enclosed by a vol. i. 35 274 ARTERIES. [chap. V. loose sheath of cellular substance, which has been described by some as a distinct and separate coat. By this sheath, Avhich performs a most important character in the suppression of hemorrhage, the vessels are connected to the surrounding organs, and enabled to maintain their proper position. Thus constructed, the arteries are liable to wounds, inflam- mation, suppuration, ulceration, dilatation, and contraction, hypertrophy, and different morbid deposits. That wounded arteries possess the poAver of self-reparation is a fact which was long since proclaimed by Haller, Petit, and other Avriters of the last century ; but the process by which this is effected, or the various steps Avhich precede and accompany it, were first clearly pointed out by Dr. Jones, of England, about thirty years ago. Convinced that a question of so momentous a character could only be determined by carefully interrogating nature, he instituted a series of the most laborious experiments upon the inferior animals, such as the horse and the dog, from Avhich he deduced the conclu- sion, since so abundantly confirmed by the researches of other physiologists, that the immediate effect of the division of an artery is an impetuous flow of blood, attended by a forcible retraction of the vessel within its sheath, and a slight annular contraction of its extremity. The canal of the sheath is now closed by the formation of a coagulum, blood being at the same time effused into the surrounding cellular sub- stance. The next step in the process is the concretion of the fluid within the divided vessel, generally as high up as the nearest collateral branch. The stopper thus formed is com- monly of a slender conical shape, Avith the apex directed to- wards the heart. It is seldom sufficiently large to constitute a perfect plug for the vessel, nor does it at first adhere very firmly to its internal surface, excepting at its base, where it is also closely united with the outer coagulum. The con- nection between the two clots, and the relation which they sustain to the orifice of the divided artery, have been felici- tously compared by Beclard to the mouth of a bottle, closed by its stopper, and spread over Avith sealing-wax. Soon after these coagula have formed beneath, around, and within the divided artery, the different tunics, taking on in- flammation, pour out plastic lymph, which serves still further to seal up the orifice of the vessel, and to strengthen the con- nection betAveen it and the clotted blood. The absorbent vessels of the parts are also actively engaged carrying away, CHAP. V.] WOUNDS. 275 at first, the more attenuated, and aftenvards the more solid elements of the coagula, until the Avhole mass is finally trans- formed into a dense grayish cord, in which it is difficult to discern any trace of the original textures. The period re- quired for the perfection of these changes varies in different cases, depending upon the volume of the vessel, the nature of the Avound, and the constitution of the patient. Such, in feAV Avords, is the process employed by nature in arresting hemorrhage from a divided artery. Similar phe- nomena, very nearly, take place when a vessel of this kind is tied Avith a ligature, except that there is no external coagulum. The internal clot is also generally more complete ; and, as the serous and fibrous membranes are usually cut through, the inflammation is apt to run much higher, the different coats being often rendered extremely vascular and pulpy. The ligature is either removed by absorption, or, as is more frequently the case, it remains until the outer tunic is de- stroyed by ulcerative action ; which, Avhen the artery is small, usually happens in eight or ten days, but, Avhen large, not under several Aveeks. In whatever Avay an artery be oblit- erated, the collateral vessels, as they are termed, are always permanently enlarged, compensating thereby for the lost power on the part of the main trunk. Thus, by the anastomoses of the vascular system, and by the happy contrivance here al- luded to, the Creator has provided the means of carrying on the circulation, even after the stoutest branches are completely closed up. When an artery is Avounded longitudinally, or to a small extent obliquely, either an aneurism is formed, or the breach is repaired by adhesive inflammation. The same consequences folloAV when an artery is punctured with a sharp-pointed in- strument, or if it be divided transversely through one fourth of its circumference. If the vessel be cut across one half or two thirds, cicatrization will be impossible ; the injured tunics will either yield to their native power of retraction, or they will be destroyed by ulceration. In either case, the final restoration is effected in the same manner nearly as Avhen the vessel is cut across in the first instance. When an artery is forcibly lacerated, it is much less apt to bleed profusely than one that is divided by a transverse cut. Cases occur where whole limbs, involving of course the largest arteries, are torn from the body, and yet scarcely any blood is lost. The retraction and annular constriction are 27G ARTERIES. [CHAP. V. ahvays much greater here, and the coagula also much larger, as Avell as more rapidly formed, than under opposite circum- stances ; and these occurrences, added to the ragged state of the inner and middle coats, and the exhausted condition of the patient, as must ahvays happen in such severe accidents, afford a speedy and effectual barrier to the emission of blood. Acute arteritis is generally induced by external injury, or by an extension of disease from the adjoining structures. Nevertheless, it Avould seem occasionally to exist as an idio- pathic affection, or to come on Avithout any assignable cause. Restricted in the majority of instances to one or more of the larger trunks, it not unfrequently involves the smaller branches, and sometimes even the capillaries. Occasionally the disease appears to be almost universal, pervading nearly the Avhole arterial system. In a man forty years of age, Dr. Bade, a French author, observed the inner membrane of all the larger arteries thickened, and of a red color, the traces of the inflammation gradually diminishing towards the smaller branches ; and examples of a similar kind are to be found in the works of Bertin, Hodgson, and other writers. When arising spontaneously, the disease usually begins in the internal membrane and subserous cellular tissue, from which it gradually spreads to the other tunics; the reverse happen- ing when it is induced by external violence. The anatomical characters of acute arteritis are redness, opacity, rugosity, and softening of the lining membrane, Avith an engorged, lacera- ble, and thickened state of the outer and middle tunics. When the inflammation is severe, the parietes of the affected artery are generally remarkably pulpy, and so much dimin- ished in consistence as to be easily torn or divided by the ligature. The nutrient vessels are loaded Avith blood, and often exhibit a real varicose aspect, their ultimate tAvigs end- ing apparently in the subserous cellular substance. With regard to the redness of the internal membrane, it is liable to considerable diversity; but, generally speaking, it occurs in small patches, which are diffused over a considerable ex- tent of surface, and which vary in diameter between that of a split pea and a five cent piece. In intensity it ranges from a light pink to a deep scarlet, through numerous intermediate shades of lilac and purple. In some instances the redness is uniform. With this change of color are always associated important alterations of texture. The inner membrane, as was before intimated, losing its smoothness and polish, as- CHAP. V.] CHRONIC INFLAMMATION. 277 sumes a rough fleecy aspect, and, owing to the softened state of the subserous cellular tissue, is easily detached from its natural connections. Globules of lymph, either alone or blended with pus, occasionally adhere to its inner surface ; and, in the larger arteries, it is not uncommon to meet Avith well- developed pseudo-membranes, similar in all respects to those of the serous textures of the splanchnic cavities. The other tunics are also seriously affected. They become moist, tumid, friable, and transformed frequently into a redish homogeneous mass, almost void of cohesive power. Their elasticity, natu- rally so great, is partially lost, and in many instances they are freely infiltrated with serosity, sanguinolent fluid, or even pure pus. Patches of a scarlet, purple, or broAvnish color, caused by the imbibition of the blood, are sometimes observable on the inner coats of the arteries after death, which Corvisart and some others have supposed to be the result of inflammatory irritation. They are most conspicuous on the under surface of the vessels, or Avhere there is the greatest amount of blood accumulated, and they are frequently Avitnessed in persons who die of pulmonary phthisis, putrid fever, apoplexy, and malignant cholera. The redness thus produced exhibits the appearance as if it were dyed into the very substance of the lining membrane, and it commonly exists in stripes, small specks, or geometrical figures, having an abrupt termination : that, on the other hand, which results from irritation general- ly loses itself by insensible degrees, nor is it diffused over so large an extent of surface. But, be this as it may, no diffi- culty can possibly arise upon this subject, when it is remem- bered that the inflammatory discoloration is constantly as- sociated with important lesions of the arterial tissues. The cadaveric redness always appears much sooner in warm than in cold weather, and may be produced at pleasure by steeping a vessel for twenty or thirty hours in fluid blood, at a moderate degree of heat. Chronic arteritis is probably a much more common affec- tion than the great silence of the profession respecting it would lead us to infer. Like the acute form of the disorder, it is much more frequently observed in the large than in the small arteries, and hitherto has been noticed chiefly in per- sons who have died of lesion of the heart, or Avho have been constitutionally affected by mercury, syphilis, or scurvy. The most prominent feature of chronic inflammation is 27S ARTERIES. [CHAP. V. thickening of the several-coats of the artery, Avhich, in pro- tracted cases, may amount to such a degree as to encroach materially upon its caliber. The nutrient vessels are not much injected, and the redness, so conspicuous in the acute variety of the disease, is rarely present in this. The lining membrane, on the contrary, is of a yellowish, dusky, broAvnish, or grayish tint, interspersed frequently with bluish spots, which thus give it a mottled appearance. All the tunics are abnormally thickened, dense, and brittle, possessing little elasticity or cohesive power. Patches of fibrin are often ob- served upon the inner surface of the vessel; and, in many instances, the lining membrane is considerably puckered, cracked, or even forced out of its natural situation. The various deposits, presently to be noticed, are all caused, probably, by chronic inflammation. Although suppuration is seldom spoken of by pathologists as an attendant on arteritis, yet I am inclined to believe that it is much more frequent than is commonly imagined. The matter being generally poured out upon the inner surface of the vessel, is swept away by the circulating current as fast as it is secreted, Avhich is the reason, doubtless, Avhy it is not oftener noticed after death. Sometimes, however, it is entangled in the substance of the false membranes, infiltrated into the arterial tunics, or collected into small points betAveen the inner and middle membranes. In a case observed by Andral, the serous lining of the aorta was elevated into half a dozen abscesses, each as big as a small nut, and filled Avith phlegmonous pus. Arteritis is, on the Avhole, much less liable to terminate in suppuration than phlebitis, in Avhich respect the one resembles inflammation of the serous mem- branes, the other of the mucous. Ulceration, although a frequent consequence of chronic irritation, is seldom witnessed in the acute form of the disease. Manifesting a peculiar predilection for the larger trunks, it commonly commences in the serous membrane, from which it gradually extends to the middle and outer tunics until it leads to complete perforation. Such a termination, however, must be regarded as extremely rare. The ulcers, which are extremely irregular in respect to their form, vary very much in their size, number, and general characters. At times they are very small, scarcely exceeding the diameter of a mustard- seed ; but, in the plurality of cases, they are as big as a split pea, a five cent piece, or even a guinea. Their margins are CHAP. V.] ULCERATION--TUBERCLES. 279 usually ragged and irregular, considerably elevated, but seldom injected ; and their bottom, Avhich is rough and un- even, is commonly formed by the middle tunic, the fibres of which frequently present a shreddy, lacerated appearance. In many instances, the erosions look like so many fissures, cracks, or chops, Avith sharp prominent, and irregular borders. This form of the disease is by no means uncommon, and is ordinarily associated with, or rather, dependent upon, the calcareous deposit. The number of ulcers is seldom consid- erable, though in a few rare cases the inner surface of the larger trunk has been found completely checkered with them. When confined to the internal tunic, M. Bouillaud thinks that they sometimes admit of cicatrization, — an opinion in Avhich I am disposed to coincide, from having seen several examples of ulcers of the aorta which had obviously been partially repaired. The arteries may be said to be insusceptible of gangrene. Their conservative energies, as stated on a former occasion, are surprisingly great, and thence they often escape destruc- tion in the midst of parts that are perfectly deprived of vitality. In such cases, their outer surface becomes incrusted, at an early period of the disease, with a thin layer of fibrin ; and, long before the deadened textures begin to separate, the blood coagulates in their interior, and thus opposes an effectual barrier to the occurrence of hemorrhage. Another deposit, which I have occasionally observed, is the tubercular. This affection, I have reason to believe, is ex- tremely rare in this country, but appears to be very common in Europe. It usually begins in the cellular substance Avhich connects the inner and middle tunics, in small isolated points, of a pale yellowish color, greasy to the touch, and of a semi- concrete consistence. As these points augment in size, the inner membrane of the tube is forced beyond its natural level; and, if many of them chance to be seated together, they often become confluent, forming thus irregular patches, which in some instances pervade the Avhole surface of the vessel. After having remained stationary for a while, the heterologous deposit manifests a disposition to soften, and, in process of time, is converted into a pliable, curdy substance, having all the properties, both physical and chemical, of scrofulous pus. Resulting, probably, always from slow chronic irritation, this lesion is usually accompanied by the calcareous formation, and is most frequently witnessed in strumous subjects. 280 ARTERIES. [CHAP. V. Though the quantity of tubercular matter is seldom great, its tendency is uniformly to impair the elasticity of the vascular tunics, and to dispose them to ulcerative action. The most common seats of this disease are the bifurcations of the arteries, though it is .by no means confined to these localities. The disease of which I have thus given a rapid outline has generally been described by European Avriters under the vague name of the atheromatous deposit. The term Avhich I have here substituted is, I think, altogether preferable, as it designates at once the true nature of the lesion in question. But it may be objected, perhaps, that the deposit is not in reality of a tubercular nature, and that, therefore, the name is equally unphilosophical as the other. To this I reply that there is nothing to justify such a conclusion, inasmuch as the physical properties of this substance, its mode of secretion, and its final conversion into purulent fluid, all conspire to show its identity Avith tubercular formations in other textures of the body. Much less frequent than the deposits noAV described are the melanotic and encephaloid. These, in fact, are among the rarest affections of the arterial tissue, and, Avith the exception of several cases reported by Cruveilhier, CarsAvell, Velpeau, and Otto, no authentic information Avhatever is to be found concerning them. I have never met Avith an example of either. When occurring in this situation, the melanotic matter is usually deposited into the subserous cellular sub- stance, in the form of minute dots, or in that of small irregular patches. The encephaloid matter, on the contrary, although it is occasionally seated in the same locality, more frequently occupies the interior of the artery, assuming an arborescent arrangement, and filling up its caliber. Occasionally we find deposits of cartilage, either alone, or, as is more generally the case, in association Avith calcareous or tubercular matter, being either of them the result, proba- bly, of chronic irritation. Most commonly they are limited to the inner membrane of the arteries in the connecting cellular substance of Avhich they appear to be developed, in the form of irregular isolated patches, of a Avhitish, yellowish, or gray- ish aspect. Not unfrequently, hoAvever, they implicate all the tunics, occupying the vessel to such an extent as to con- vert it into a firm, inelastic tube. Writers are by no means agreed in regard to the question, Avhether this matter is origi- CHAP. V.] CALCAREOUS MATTER. 281 nally deposited in the form of cartilage, or simply in that of fibrin. The result of my own researches Avould lead me to adopt the former opinion. The most common morbid affection of the arteries, by far, is the deposition of calcareous matter. It is particularly frequent in old people, after the sixtieth year ; but no period of life,except early infancy, is exempt from it. Young found it at fifteen months; Wilson at three years, and Andral at eight. The arteries most commonly implicated are, according to my OAvn observations, the thoracic aorta, the femoral, tibial and fibu- lar, splenic, spermatic, iliac, cardiac, and radial. The deposit is very frequent in the cerebral arteries of old persons, and there is much reason to believe that it often lays the founda- tion of the apoplectic effusions so common at this period of life. The carotid, subclavian, brachial, hypogastric, hepatic, mesenteric, and stomachic arteries are seldom ossified. In the pulmonary artery, this degeneration is so rare that Bichat Avas induced to affirm the impossibility of its occurrence. The observations, hoAvever, of Morgagni, Stoll, Lobstein, Otto, and others, abundantly show that this assertion is too sweeping. Instances occur Avhere there seems to be a peculiar ossific di- athesis, almost all the arteries in the body being rendered bony. Of this I witnessed an extraordinary example in 1834, in a man sixty-five years old, in Avhom not only the larger trunks, but all the muscular tAvigs, were transformed into rigid, in- elastic cylinders, blunting the knife at every incision. Simi- lar cases have been seen by Riolan, Harvey, Loder, and other authors. The calcareous matter exists in various forms; sometimes in small grains and nodules; sometimes in scales, plates, and patches ; and sometimes in complete rings, which encircle the vessel, and convert it into a firm, inflexible tube, totally de- void of its normal attributes. In the incipient stage of their developement, these depositions often consist in minute iso- lated specks, of a light straw-color ; and not unfrequently they are associated with other secretions, especially the atheromatous and cartilaginous. In whatever form the matter be deposited, the coats of the arteries always experience important modifi- cations, becoming preternaturally hard and brittle, and either thickened or attenuated. These changes are generally most conspicuous in the two inner membranes, which assume a dense, wrinkled appearance, and are extremely liable to break and ulcerate, obliging thus, the outer tunic frequently to re- vol. i. 36 282 ARTERIES. [chap. V. ceive the whole brunt of the circulating torrent. The serous lining is often remarkably thick, dense, opaque, and trans- versely wrinkled. Destitute of the usual fibrous structure of bone, the calca- reous deposit differs still further from this texture in not hav- ing, in the greater number of cases, a cartilaginous matrix, in possessing no vitality, and in being always secreted in the form of a homogeneous mass, without any definite arrange- ment. The component elements of this substance vary in different specimens, even from the same individual; but, in most case, the proportion of animal matter is small. In the experiments of Brande, one hundred parts were found to con- sist of sixty-five of phosphate of lime, and thirty-five of al- bumen, with some traces of gelatine ; whereas, in those of Vauquelin, the animal matter formed only about one fourth, the remainder being made up of the phosphate and carbonate of lime and soluble salts. Various opinions have been en- tertained by pathological anatomists respecting the precise seat of this deposit; some placing it in the substance of the lining membrane, others in the middle coat, others in the cel- lular texture, by which these two layers are connected to- gether. The latter of these views is borne out by the anal- ogy Avhich is observed in the subserous cellular tissue in other parts of the body; but, independently of this, I am disposed to adopt the opinion from personal observation, too carefully conducted, and too often repeated, to permit me to entertain the slightest doubt upon the subject. At the same time, it must be admitted that this matter may occasionally be poured out in the substance of the different tunics, other- wise Ave could not account for the deposition being entirely limited to the exterior of the arteries. In regard to the ex- citing causes of these formations, it will scarcely be going too far, to ascribe them wholly to chronic inflammation, seat- ed in the cellular element of the arterial structure. Dilatation of the arteries, constituting what, in surgical language, is termed an aneurism, is decidedly one of the most frequent lesions to which these interesting structures are lia- ble. Varying in size and shape, under different circumstances, the enlargement exists sometimes at one point, sometimes at several, and sometimes is more extensively diffused, occu- pying the whole circumference of the tube. In the ma- jority of instances, the disease is seated in the larger trunks; but occasionally it attacks the smaller branches, and not unfre- CHAP. V.] SACCULATED ANEURISM. 283 quently even the capillaries. Aneurismal enlargements may be divided into four principal species,— the sacculated,"cylindroid, varicose, and anastomotic. To these may very properly be added another, namely, the arterio-venous, or that form of the disease which has been described by Avriters, since the time of Dr. William Hunter, under the name of aneurismal varix. When a tumor of this kind is composed of all the arterial tunics, it is called a true aneurism; if, on the other hand, it consists only of the external coat, the inner and middle being ruptured, ulcerated, or destroyed, it is denominated a false aneurism. Of these tAvo varieties, the latter is by far the most common. Cases occasionally occur, though rarely, where, in consequence of the laceration of the fibrous mem- brane, the internal coat is protruded across the crevice, in the form of a hernia, which gradually encroaches upon the cellu- lar membrane, and thus dilates it into a distinct pouch. In the sacculated aneurism, (Fig. 17,) the coats of the artery are dilated into one or more pouches, occupying only a limited portion Fig. 17.* of its circumfer- ence. It occurs most frequently in the great trunks, particu- larly the thoracic aorta, and occa- sionally affects all the principal branches of the body. M. Pel- letan, a French surgeon, examin- ed an individual, in Avhom he dis- covered upAvards of sixty of these dilatations; and a still more extraordinary example has re- cently been reported by Professor Cloquet, of Paris. In this case, the number of tumors was upwards of tAvo hun- dred the largest of Avhich did not exceed the volume of a * Sacculated aneurism: a, the artery; b, the aneurismal pouch. 284 ARTERIES. [chap. V. common pea.* There would thus seem to be occasionally a real aneurismal diathesis. Much diversity obtains in rela- tion to the dimensions of these sac-like projections: in some instances, as we have just seen, they are remarkably small, Avhilst, in others, they acquire the magnitude of a large egg, the fist, or even of a mature foetal head. The manner in which they are attached is also subject to considerable varia- tion. Very frequently they arise by a narrow foot-stalk ; at other times they repose upon a broad base,— the opening be- tween them and the artery being ahvays much larger in the latter than in the former case. The cylindroid aneurism (Fig. 18) is of an elongated spherical shape : the dilatation, which is pret- Fig. I8.t ty nearly uniform, embraces the entire cir- cumference of the vessel, varying in length from a feAV lines to several inches. The coats are generally somewhat thickened, and the inner surface of the tube is rough, uneven, and covered with thin, irregular layers or patches of fibrin. In some instan- ces, the dilatation is truly enormous. In a specimen of cylindroid aneurism of the arch of the aorta, presented to me by my friend Dr. W. M. Charters, of Lebanon, in the State of Ohio, the tumor measures upwards of ten inches in circumference, by five and a half in length. It formed an immense ovoidal SAvelling in front of the neck, which extend- ed nearly as high up on the left side as the angle of the jaAV ; whilst, below, it pressed upon and destroyed the inner half of the clavicle, part of the first rib, and a small portion of the breast bone. Almost all the arteries in the body are sometimes affected with this species of enlargement. In a man, fifty years of age, Dr. Geddings, the distinguished professor of pathological anatomy in the medical college of South Carolina, found not only the * The subject in whom these dilatations were found was about fifty years of age. They affected every artery, almost, in the body, even the aorta and its principal divisions, but they were most numerous in the extremities. The axillary, hu- meral, radial, and ulnar arteries, the femoral, popliteal, tibial, and peroneal, were closely studded with them. In volume they varied between that of a millet seed and a large pea. In other respects, the coats of the vessels were perfectly healthy. (Pathologie Chirurgicale, par Jules Coloquet, p. 86.) t Cylindroid aneurism : a a, the vessel above and below the tumor. CHAP. V.] ANASTOMOTIC ANEURISM. 285 l^^i larger trunks, but nearly all the principal branches, dilated to at least double the normal size. The superficial temporal ar- teries were nearly as capacious as the main vessel of the arm, and the same circumstance was observed in the bigger branches of the brain.* The varicose aneurism (Fig. 19) consists, as its name im- ports, in an enlarged and nodulated state of the artery, similar to that of a varicose vein. The dilatation or- dinarily embraces a considerable por- tion of the length of the vessel, the coats of which are at the same time very thin and brittle, preternaturally light, and readily collapse when di- vided. In this variety of the disease, the artery is remarkably elongated, tortuous, and convoluted: the lesion seldom occurs in the larger trunks, but is most frequently observed in the secondary and ternary divisions, as the splenic, carotid, humeral, and femoral, tibial and radial, temporal and occipital. The anastomotic aneurism (Fig. 20) usually described by the Ger- man pathologists under the name of telangiectasy, is composed of a congeries of convoluted capil- lary arteries and veins, dilated into a soft pulsating tumor, generally of a bright florid tint, but oc- casionally of a bluish, mulberry, or pur- ple color. In some instances, it appears as a congenital disease, constituting what is called a ncevus maternus. When of long standing, the vessels are often di- lated into small sacs, and so form a truly erectile tissue, analogous to that of the penis, nipple, or wattles of the turkey- cock. Although every part of the capilla- ry system is probably susceptible of this singular dilatation, yet the most frequent situations of anastomotic aneurism are the head, hands, and feet. In a few rare instances, it has Fig. 20. "American Cyclopaedia of practical Medicine and Surgery, vol. ii. p. 413. 286 ARTERIES. [chap. V. been observed on the gums and inside of the cheeks. There is a form of hemorrhoidal tumor, which, as will be subse- quently shoAvn, is probably merely a variety of anastomotic aneurism. A tumor of this kind throbs synchronously with the heart, has a soft, spongy feel, and becomes smaller when compressed, but immediately regains its former volume when the pressure is Avithdrawn. Violent excitement of the heart renders it preternaturally turgid, and the same circumstance follows Avhen there is an impediment in the venous circula- tion. This species of aneurism, often acquires a considerable magnitude. Its progress is not ahvays rapid, and occasion- ally, indeed, it remains stationary for years. Finally, how- ever, ulceration sets in, and, in this way, the tumor becomes the seat of frequent hemorrhages. The fifth and last species of dilatation which I shall notice, is the arterio-venous, (Fig. 21,) or, as it has generally been denominated since the time of Dr. William Hunter, who first described it, aneurismal varix. Although this lesion is most apt to happen at the bend of the arm, where the median basilic vein lies over the hu- meral artery, yet it may occur in any part of the vascular sys- tem in Avhich two considerable sized trunks of this kind are contiguous. In most instances, it folloAvs upon the operation of venesection, but occasionally it arises spontaneously, or, more properly speaking, as the effect of ulceration. When produced by a sharp-pointed instrument, as, for in- stance, the lancet, the superficial wound generally heals by the first intention; but that between the two vessels remains permanently patent, and thus allows the blood to flow readily * Arterio-venous variety of aneurism: a, the artery; b, the vein ; c, the open- ing between them. chap, v.] ARTERIO-VENOUS ANEURISM. 287 from one to the other. By degrees the channel here estab- lished augments in diameter, and the tAvo vessels are either effectually agglutinated together, or their connecting cellular substance is injected Avith blood, so as to form a sort of glob- ular pouch. The artery and vein, in the mean time, become sensibly altered, both as respects the size of their caliber and the texture of their parietes. The former, Avhich now re- ceives black blood, is gradually dilated into a soft, thin, flexuous tube, which ultimately acquires all the properties of a vein. These changes, Avhich are always more distinctly marked in the immediate neighborhood of the preternatural aperture, frequently extend as low down as the first large collateral branch, and their invariable effect is to obscure the pulsation in the corresponding part of the limb. The vein also loses, in some measure, its normal characters. It be- comes large and tortuous, both above and below the seat of the injury, acquires an extraordinary degree of density, and is no longer either so extensible or elastic. The cause of these textural changes, is chronic inflammation, leading, in the one case, to partial atrophy, in the other, to partial hyper- trophy ; or, in other words, Avhat one vessel loses, the other gains. This species of aneurism, which is generally of slow for- mation, seldom acquires any great bulk. Occasionally, it is as big as an egg, but ordinarily it does not exceed the volume of a common plum. It communicates to the hand which examines it a sort of jarring sensation, and to the ear a pecu- liar hissing sound, not unlike what would result from the prolonged articulation of the letter R, which are the pathog- nomonic signs of its existence. Most of the species of aneurism here enumerated, are dependent, directly or otherwise, upon an altered or modified state of the arterial tissues. The internal and middle tunics are commonly most affected ; indeed, it is rare to find them perfectly free from disease. The calcareous, cartilaginous, or tubercular deposits, noticed in a previous page, are usually present; and oftentimes the aneurismal pouch is exclusively formed of the outer coat, the other two being entirely destroyed. In the sacculated variety of the disease, as well as in some of the rest, one of the earliest effects consequent on the developement of the tumor, is the deposition of the plastic lymph of the blood, as this fluid sweeps over its inner surface. This deposition, which generally occurs in concen- 288 ARTERIES. [chap. V. trie layers, (Fig. 22,) is sometimes remarkably abundant. Its thickness commonly varies from six to eight lines, according to the age and size of the sac, but occasionally it has been known to exceed two inches. The oldest lamellae, or those lying directly in contact Avith the inner surface of the tumor, are generally of a Avhitish, gray- ish, or yelloAvish color, remarkably hard, dry, and brittle ; whereas, those which are of recent formation, are always of a darker hue, soft, and elastic. The occurrence of aneurism is much more frequent in men than in women, and in the old than in the young. Of sixty-three cases, recorded by Mr. Hodg- son, of England, in his admirable Trea- tise on the Diseases of the Arteries, fifty- six were noticed in the male, and seven only in the female. Similar observations have been made by Scarpa, Guthrie, Langenbeck, and other pathologists. Aneurismal dilatation of the pulmonary artery is extremely rare, and, thus far, I do not remember having met with a well-marked example of it. We have already stated that aneurism is much more fre- quent in old than in young persons. In confirmation of the truth of this remark, I may mention that of one hundred and eight cases, collected by Dr. Bizot of Geneva,* from the Avrit- ings of Morgagni, Corvisart, Laennec, Scarpa, Boyer, Hodg- son, Richerand, and S. Cooper, only a single one occurred before the twentieth year. Fifteen were noticed from the age of tAventy to twenty-nine ; thirty-five from thirty to thirty-nine; thirty-one from forty to forty-nine ; fourteen from fifty to fifty-nine ; eight from sixty to sixty-nine; two from seventy to seventy-nine ; and tAvo from eighty to eighty- nine. Thus it would appear that more persons suffer under this malady from the age of thirty to fifty, than during all the other periods of life put together. The bad effects of aneurism are ulceration and gangrene, followed by fatal hemorrhage. Occasionally, nature institutes * Recherches sur le Cceur et le Systeme Arteriel chez l'Homme, dans " Me- mories de la Societe d'Observation Medicale de Paris." t. i. p. 400. CHAP. V.] DIAGNOSIS--HYPERTROPHY--CONTRACTION. 289 a process of reparation, the contents of the tumor becoming coagulated, and the communication between it and the artery shut up. The diagnosis of aneurism of the extremities, neck, groin, or axilla, is usually not difficult. There is a pulsating tumor, either of a globular, ovoidal, or cylindrical figure, which subsides under pressure, but immediately refills with a pecu- liar Avhizzing noise as soon as the finger is removed. The progress of the disease is generally rapid, and there is feeble- ness of pulse, with numbness and oedematous swelling in the parts beyond the disease. Internal aneurism, on the other hand, is always difficult of detection, especially in the early stage of its developement. When seated at the arch of the aorta, it simulates lesions of the heart, and is not easily identified. The physical signs, upon Avhich our reliance is mainly to be placed, are limited to a preternatural loudness in the pulsations at the upper part of the sternum, often accompanied by a belloAVS-sound, and dulness on percussion over the same region. In the abdominal portion of the aorta and the common iliacs, the tumor can frequently be recog- nized by its great bulk, and by its violent beatings. Of aneurism of the pulmonary artery, no diagnostic symptom has yet been pointed out. Hypertrophy is well exemplified in the arteries of the uterus during gestation, and in the growth of various tumors, especially such as attain a great bulk. In these states of the system, they often become extremely capacious, elongated, and tortuous, being coiled up like varicose veins. The object of this augmentation of volume is to alloAv a larger quantity of blood to flow into the groAving part; and hence, in the instance of the uterus, we find that, as soon as the child is expelled, the dilated and thickened arteries gradually revert to their former dimensions. Hypertrophy of these vessels is generally associated with hypertrophy of the veins, and is, in most cases, purely physiological, there being no discernible lesion whatever of their tunics. Contraction of the arteries, either alone or associated with dilatation, occasionally exists as a congenital defect; but, in the great majority of instances, it is the result of inflammation, most commonly of the chronic kind, giving rise to fibrinous concretions, tubercular deposits, or calcareous degeneration. In this Avay, the caliber of the vessel is sometimes completely obliterated, and its texture transformed into a dense ligament- vol. i. 37 290 ARTERIES. [chap. V. ous cord, the circulation being carried on by enlarged collateral channels in the same manner as Avhen an artery is secured by ligature. Hitherto, this lesion has been observed more par- ticularly in the larger trunks, especially in the aorta, but no part of the arterial system is exempt from it. Indeed, there Avould occasionally seem to be a peculiar predisposition to this contraction, the capacity of almost every vessel in the body being sensibly affected by it. The pulmonary artery, although seldom implicated, is sometimes remarkably con- tracted. In a case observed by Dr. Knox, of Edinburgh, it Avas reduced to the size of a small goose-quill. Examples of contracted aorta have been reported by numerous patholo- gists. One of the most extraordinary and instructive cases that has yet been published is narrated by Meckel. It oc- curred in a SAviss peasant. The aorta, near the arterial duct, was diminished to the volume of a common straw. All the collateral vessels were enormously dilated, and many of them resembled varicose veins.* * North American Archives of Medical and Surgical Science, vol. i. p. 155. CHAPTER VI. Of the Veins. More numerous and capacious than the Arteries. — Tunics and Valves; proper Vessels and Nerves. — Lesions. — Acute Inflammation.— Suppuration. — Ul- ceration. — Chronic Inflammation. — Dilatation. — Obliteration. — Calcareous Deposits. — Phlebolites. — Admission of Air. The veins are much more numerous than the arteries, and their uni- ted capacity is nearly three times as great. In their general arrange- ment, structure, and mode of distribution, the closest resemblance exists between the two species of vessels ; but it may be observed that the former are more tor- tuous, that their parietes are thinner, that their anastomoses are more frequent, and, finally, that they are not so regularly cylindrical. (Fig. 23.) Their elas- ticity, although well marked, is not so great as in the arteries ; and their extensibility is likewise less in the longitudinal direction, but more conspicuous in the lateral. In most parts of the body there Fig. 23.« * The manner in which the minute branches of a vein unite to form the larger branches and trunks: 1, venous capillaries; 2, small branches formed by union 292 VEINS. [CHAP. VI. are two veins to one artery : in some organs, however, as in the stomach, spleen, and testicle, the tAvo species of vessels exist in equal number; and, in a fe.Av rare instances, as in the penis, clitoris, and umbilical cord, there is only a single vein to two arteries. The general arrangement of the veins is arborescent, but in a manner the reverse of what obtains in the arterial system ; that is to say, they begin in the remote parts of the body by minute rootlets, Avhich increase in size as they diminish in number, forming thus a series of branches, which finally resolve themselves into several large trunks, which terminate in the auricles of the heart, — those of the general system conveying black blood, those of the lungs, blood that has been exposed to the influence of the atmos- phere. Although the tunics of the veins bear a general resemblance to those of the arteries, yet they differ from them in several important particulars, which require brief comment in this place. The outer tunic is composed of the same substance as that of the arteries, but is much less stong and dense: it is liberally sup- plied with vessels, and is connected to the surrounding organs by a sheath of loose, cellular texture. The middle coat is also comparatively thin, and is formed of soft, reddish, ex- tensible fibres, disposed for the most part longitudinally. In the large veins, a few appear to run obliquely, transversely, or spirally; but this arrangement cannot always be satisfactorily made out. This lamella is supposed by some anatomists to be of a muscular nature,— an opinion for which, so far as my observation enables me to judge, there is no just foundation. It is, doubtless, merely a modification of the yellow fibro- elastic texture Avhich forms so abundant an ingredient of the corresponding coat of the arteries. The middle tunic is pro- portionally thicker in the small than in the large veins: it is also more distinctly developed in the superficial vessels than in the deep-seated, and in the veins of the inferior half of the body than in those of the superior. In certain situations, as in the sinuses of the bones and of the dura mater, it is entirely deficient, as is also the external, the serous membrane being alone discoverable. The internal coat, besides being much more delicate and extensible than the corresponding one in the arterial system, of capillaries; 3, larger branches uniting to form a great trunk,—4, a portion of which is laid open to show the valves; 5, formed by the inner coat of veins. CHAP. VI.] STRUCTURE -- INFLAMMATION. 293 is likewise less brittle, and less liable to ossification. It forms, moreover, by its duplications an immense number of valves, the presence of Avhich is of essential importance to the venous circulation. Each fold is of a semi-lunar shape, the convex edge being attached to the circumference of the vessel, whilst the other, Avhich is straight, slightly concave, or reticulated, is loose, and directed towards the heart. The lamellae of which it is composed are someAvhat thicker at the borders than at the middle ; and they are connected together by cellular substance, which is so short and firm as to render it extremely difficult to separate them by means of the knife. In most of the vessels, the valves occur in pairs; but in some, as in the iliac and femoral veins, they are triple, and in a few even quadruple. In the smaller branches the folds are single; and a similar arrangement exists at the mouth of several of the larger trunks, such as the coronary vein of the heart and the inferior hollow vein of the trunk. In regard to the number of valves, much variation exists in different regions of the body. They are remarkably abun- dant in the superficial veins, less so in the deep-seated, and in the splanchnic cavities there are scarcely any ; they are also more numerous in the inferior than in the superior extremity, and in the subcutaneous vessels of the abdomen than in those of the chest. In certain situations, these structures are ab- sent. There are no valves in the liver, spleen, kidney, uterus, brain or spinal cord; and they are likewise wanting in the portal vein, the great hollow veins, and in the median vein of the arm. There are but very feAV in the azygos and pulmonary veins. Like the arteries, the veins have their appropriate vessels, nerves, and lymphatics : they are surrounded by loose cellular substance; and, during life, they are always of a bluish tint, owing to the remarkable tenuity of their parietes, which al- Ioavs the color of the blood to appear through them. After death, they are whitish, semi-transparent, and collapsed. Acute inflammation of the veins is much more frequent than in the arteries ; the reverse being the case in respect to the chronic form of the disease. It usually implicates a large extent of surface, often affecting a number of veins simulta- neously, and, what is remarkable, ahvays tends to spread in the direction of the heart. The anatomical characters of this disorder are swelling, opacity, and pulpiness of the in- ternal membrane, with uniform redness, varying from light 294 VEINS. [CHAP. VI. pink to deep florid. The middle and outer coats soon become deeply injected, and their proper substance, although at first preternaturally soft and humid, is at length rendered so dense and firm, that the vein feels like a hard, contracted cord. The cavity of the inflamed vessel is filled with clotted blood, sometimes blended with pus or coagulating lymph, and in many cases it is lined by a false membrane, susceptible, under certain circumstances, of organization. Instances occur in which the pus is infiltrated into the substance of the vein, or collected into small abscesses beneath the lining mem- brane. Suppuration is very liable to occur in the veins of the uterus and inferior extremities of lying-in females. This fact seems to have been first noticed in 1793, by Dr. John Clarke, of England. It soon afterwards attracted the atten- tion of Meckel and Reil, of Germany ; and, very recently, the subject has been developed in all its bearings, by Dr. Robert Lee and Mr. Arnott, of London, and by Dauce and Tonnelle, of Paris. The pus generally resembles that of a phlegmonous abscess, and sometimes completely fills one or more of the larger veins of the womb and surrounding parts. In a case mentioned by Wilson, the uterine and iliac veins were greatly thickened, and the abdominal cava contained upwards of four ounces of purulent matter, which was prevented from reach- ing the heart, partly by the contraction of the vessel near its entrance at the diaphragm, and partly by a mass of pseudo- membrane,* Suppuration is also liable to occur after vene- section, amputation, compound fractures, and the application of the ligature. In the umbilical vein it often follows the tying of the cord, causing erysipelatous inflammation, which in a few days destroys life. Ulceration of the veins occurs much less frequently than in the arteries. Commencing most commonly at one or more points of the inner membrane, it gradually extends to the other tunics, which it sometimes completely erodes. The immediate effect of this accident is an effusion of blood, which may be so great as to produce fatal results. The ulcers, which affect various forms, are occasionally quite numerous, occupying a large extent of surface. Dr. Ribes, of Paris, has related a case in Avhich nearly the whole of the * Transactions of a Society for the Improvement of Medical Knowledge,1 vol. iii. p. 65. CHAP. VI.] HYPERTROPHY--DILATATION. 295 lining membrane of the cephalic, median basilic, and radial veins, was studded with them, the other coats being at the same time much inflamed, thickened, and indurated. The characters of chronic inflammation of the veins dif- fer considerably from the acute. The coats are usually much thickened, hypertrophied, and so dense that the vessel, when cut across, preserves its cylindrical figure, like an artery. The redness is of a brownish tint, interspersed with numerous shades of gray, violet, or purple; and the inner membrane, which is rough and shriveled, can be easily raised in large opaque shreds. In some instances, the vein is dilated, or con- tracted, obstructed with clotted blood, lined by coagulating lymph, or filled with pus. There are certain states of the system in which the veins seem to attain a very great size, carrying an inordinate amount of blood. This hypertrophy, for so it may be termed, is very conspicuous in chronic affections of the joints, in vascular and malignant tumors, and in the veins of the uterus during the latter months of pregnancy. It is always conjoined with hy- pertrophy of the arteries, and forms one of the most serious obstacles to the cure of various diseases. Dilatation (Fig. 24) is most frequently observed in the veins of the testicles and lower extremities, in persons whose employments compel them to stand for a long time in one position. It has also been observed in the superior ex- tremities, and, in a few in- stances, I have witnessed it in the superficial veins of the abdomen. Of the deep-seated veins, those frequently affect- ed are the subclavian, jugu- lar, azygos, and hemorrhoidal. The vessels, in this disease, become larger, elongated, knotty, irregular, and tortu- ous, Avinding in a serpentine manner underneath the skin. Their coats are either of the natural structure, or they are thick and rigid, or thin and expanded, or, finally, they are Aveak in some places, and hypertrophied in others. When 296 VEINS. [CHAP. VI. laid open, they are found to be rough and irregularly saccu- lated, strong bands being sometimes stretched across their in- terior, Avhich divide the vessel into little cells, filled with co- agulated blood. The valves, although they generally retain their normal texture, are sometimes thickened, indurated, dis- placed, or ruptured. This varicose state of the veins is usu- ally attended by chronic inflammation, and often leads to great and irreparable mischief. In many cases, the vessels are con- verted into hard, rigid cylinders, or their tunics are invaded by ulceration, followed by perforation and profuse hemorrhage. Obliteration of the veins is by no means uncommon, and is almost always the result of inflammation. Sometimes it is caused by the pressure of a tumor, by forcing the sides of the vessel closely in contact, and so converting them into a dense, ligamentous cord. The largest veins are sometimes thus obliterated. Albinus, Baillie, Knape, Ponchelt, and numer- ous other writers, have related cases Avhere the great hollow veins themselves were either transformed into hard, fibrous cords, or obstructed by coagulating lymph, pus, clotted blood, polypous growths, or morbid deposits. A feAV years ago, along Avith Professor Drake and Professor Rives, I examined the body of a man, aged forty, in whom the ascending cava was closed by a plug of plastic lymph, from the second lumbar vertebra as high up as the liver. The A^essel retained its normal size, and the morbid substance, which was of a pale straw-color, and of the consistence of semi-concrete albumen, adhered firmly to its inner surface, having evidently been de- posited a long time previous to death. A similar substance was found in the portal, and right renal veins, and in sev- eral of the smaller veins of the left lung. All the abdom- inal viscera showed signs of chronic disease, and, during the last two years of his life, the individual suffered at intervals from ascites. In another case, which I saw eighteen months ago, a similar substance was found in the external iliac and femoral veins, together with some of the smaller vessels of the pelvis. The most prominent symptom here, as far as the veins were concerned, was oedema of the corresponding ex- tremity. Calcareous deposits within the coats of the veins are much more rare than in those of the arteries, this circumstance de- pending upon their difference of organization. Instances of this, however, are recorded by various authors. Thus Mor- gagni and Baillie found patches of earthy matter in the Avails of the great hollow vein of the abdomen; Beclard in the fern- CHAP. VI.] PHLEBOLITES. 297 oral vein; Macartney and Andral in the external saphen- ous vein. Whether the venous tissues are liable to the athero- matous degeneration, so common in the arterial, I am not pre- pared to say; probably they are not: at all events, I am not acquainted Avith a single instance of it on record, nor have I met Avith it in my own dissections. A sort of fatty substance is occasionally found. Andral once saAv a tumor of this de- scription, about the size of a walnut, which exhibited all the anatomical characters of the adipous texture. It Avas devel- oped in the substance of the great portal vein, the cavity of which it almost filled. Loose concretions, phlebolites, (Fig. 25,) or vein-stones, varying in size from a currant to a pea, are occasionally found in the interior of these tubes. Common- ly of a yelloAvish, broAvnish, or bluish color, they are of a hard and brittle consistence, and of an oblong, oval, or spherical form, with a smooth, even surface. When divided by the saw, they are found to be made up of several thin but distinct lamellae, dispos- ed concentrically around a small delicate nucleus, frequently con- sisting of fibrin. The number of these calculi is extremely variable ; rarely are there more than two or three, though occasionally as many as eight or ten, have been observed. In a case examined by Tiedemann, there were thirty-six. They are generally met with in the smaller veins ; more frequently, perhaps, in the spermatic, uterine, vaginal, vesical, hemorrhoidal, and splenic, than in any other. Ac- cording to the analysis of Gmelin, which has been recently confirmed by that of Dr. Prout, vein-stones are composed principally of phosphate and carbonate of lime, Avith a small amount of animal matter, probably albumen, and a trace of the oxide of iron. A difference of opinion still prevails re- specting their mode of origin. Some suppose that they are *#,:broad ligament of uterus; b b, uterine veins containing phlebolites; c, phle- bolite sawed open, exhibiting its concentric arrangement. vol. i. 38 298 VEINS. [CHAP. VI. developed in the substance of the veins, from Avhence they make their Avay into their interior by destroying the lining membrane; others, on the contrary, believe that they are formed directly from the fibrous matter of the blood itself. The rounded shape and polished surface of these bodies, Avith the fact that the inner coat is often perfectly sound, strongly corroborate the latter conjecture. Cruveilhier has given a draAving of a number of phlebolites, Avhich appear to have been deA'eloped in the very centre of fibrinous concretions; and every pathologist must have seen specimens in Avhich he could clearly trace the progress, so to speak, of these new formations, — some portions being of an earthy nature, and others presenting all the characters of the plastic substance of the blood blended with more or less hematosine. There is another topic upon which, in concluding this section, it Avill be necessary to make a few remarks, although it is one rather of a physiological than of a pathological nature. I allude to the fact that air thrown suddenly and in large quantity into the venous system is followed by fatal effects. This circumstance, although long ago known to Wepfer, Chabert, and other writers of the eighteenth century, appears to have been almost entirely forgotten, until it Avas again -brought before the profession by the researches of Bichat, Nysten, Magendie, and Piedagnel. The experiments of these distinguished individuals clearly prove that the insufflation of air into the veins produces instantaneous death, and that, on dissection, traces of this fluid can be detected in different parts of the body, particularly in the right cavities of the heart. As an accidental occurrence, this effect is some- times witnessed in surgical operations, involving the jugular, subclavian, or axillary veins, and as such it was first noticed by M. Beauchene, of Paris, in 1818, in cutting out a tumor from the neck of a young man. The dissection was nearly finished, when the patient suddenly became faint, and ex- pired in forty-five minutes from the commencement of the operation. On examining the body, an aperture was found in the internal jugular vein, from which the air had evidently passed into the superior cava and to the right chambers of the heart, thereby causing death. Since that period, similar results have been observed by Dupuytren, Mott, Cooper, Warren, and other surgeons. It is a singular fact, that the effects from this cause are CHAP. VI.] ADMISSION OF AIR INTO THE VEINS. 299 much less violent, if the air be introduced gradually and in small quantity into the veins. The only difficulty, indeed, that is produced in this case is a momentary excitement of the action of the heart. If the insufflation, however, be re- peated for several days, at intervals of six or eight hours, the powers of this organ will become very much weakened, and the pulmonary tissues so far deranged as to give rise to severe cough, frothy expectoration, and considerable embarrassment of the respiratory function. When the air is suddenly in- jected, the animal is instantly seized with partial syncope, utters cries expressive of suffering, and quickly expires. In the human subject, the accidental introduction of this fluid is sometimes attended with a peculiar hissing noise, like that which is heard when the air rushes into an exhausted re- ceiver. In other cases, symptoms of apoplexy ensue: the countenance is of a livid complexion; the respiration deep and stertorous; the pulse slow, labored, and almost imper- ceptible ; the surface is bathed with cold perspiration, and the patient is perfectly insensible. The question may be asked, in conclusion,— in Avhat manner does air, when introduced into the venous system, operate so as to produce these deleterious effects ? This question, as might be anticipated, has been variously answered by different writers. By some it is maintained that the fluid acts princi- pally, if not entirely, upon the brain, causing symptoms of violent congestion, loss of sensibility, and spasmodic rigidity of the muscles, — an explanation Avhich is favored, in some degree, by the experiments of Nysten and Magendie, in which they induced apoplectic phenomena, by injecting air into the carotid arteries of animals. Others, on the contrary, believe that the primary difficulty is in the lungs, since these organs have been found in a condition similar to Avhat is observed in asphyxia. Piedagnel and Leroy, from having seen these structures in a lacerated and emphysematous state, suppose that death is caused solely by this lesion. But the grounds of these opinions are by no means conclusive ; and we are at last compelled to resort to the explanation, long ago suggested by the French physiologists, that the fatal effects in question are the result of the sudden distension of the right cavities of the heart, whereby the powers of that viscus are partially paralysed, and the circulation materially impeded. This view is strongly corroborated, in the first 300 VEINS. [chap. VI. place, by the fact, already adverted to, that, if the air be in- troduced into the veins in a slow and gradual manner, little or no functional derangement will manifest itself, in either of the above organs ; secondly, by the almost total failure of the pulse in cases of an opposite description ; thirdly, by the remarkable insensibility of the patient; and, fourthly, by the circumstance that the foreign fluid is usually found in greatest abundance in the right chambers of the heart. CHAPTER VII. Of the Lymphatics. Organization. — Liability to Inflammation and Suppuration.— Tubercular De- posits.— Dilatation. — Aneurism of the Thoracic Duct. —Situation and Struc- ture of the Lymphatic Ganglions.— Lesions.— Inflammation and its ordinary consequences. — Hypertrophy. — Encephaloid Disease. — Tubercle. — Ossifi- cation. — Melanosis. The lymphatic vessels, closely connected to the surround- ing parts by cellular tissue, are composed each of two tunics, an external and an internal. The first, which may be likened to the middle membrane of the arteries and veins, is highly elastic, firm and resisting, of a Avhite-grayish color, and that upon which the tubes depend mainly for their strength and. support. Muscular fibres have been supposed to exist in this coat, but this idea is solely conjectural. The internal tunic, which is continuous with that of the veins, but more soft and extensible, is extremely Fi 26 Fi 27 thin, diaphanous, of a serous character, and yields readily in all directions. It presents a large number of short, semi-lunar folds (Figs. 26 and 27,) technically called valves, which give rise to the knotted appearance of these vessels, and which usually occur in pairs, being attached, as in the venous system, by their convex edges. These two membranes are bound together by delicate cellular tissue, and furnished with appropriate arteries and veins. No nerves have yet been, detected in them, though we may reasonably infer their presence, inasmuch as both the right and left thoracic ducts, the common centres of the lymphatics, are surrounded each by a venous plexus.. It has been just intimated that all the ab- 302 LYMPHATICS. [chap. vii. sorbents converge towards tAvo principal trunks, called the right and left thoracic ducts. The first of these, situated on the right side of the upper dorsal vertebrae, is formed by the confluence of the lymphatics of the right side of the head, neck, right upper extremity, and some of those of the chest: the other, which is about three lines in diameter, and conse- quently the largest vessel of this kind in the body, is stretched along the left side of the spinal column, and re- ceives not only the absorbents of the loAver extremities, the abdomen, and the chest, but likewise those of the left side of the head, neck, and left upper extremity. Both these trunks, it is well known, open respectively into the right and left subclavian veins, near their junction with the internal jugulars, thus pouring their contents in the current of blood flowing towards the right auricle of the heart. The lymphatics being so extremely delicate, it is by no means easy to detect in them those various alterations of structure to which they are liable. The following remarks, therefore, embracing a rapid outline of the principal lesions of this system of vessels, will have special reference to the left thoracic duct, in which it is alone possible, in the generality of cases, to detect any deviation from the normal standard. Bichat long ago affirmed that the lymphatics are much more frequently affected Avith inflammation than the veins, — an opinion which has been amply corroborated by the obser- vations of more recent writers. In the early stage of the disease, the lining membrane is of a light reddish tint, opaque, slightly thickened, and preternaturally dense, yet so friable as to allow itself to be peeled off readily in small pellicles. As in the veins, the discoloration occurs at-first in minute, cir- cumscribed patches ; but, after some time, it becomes uniform, deeper, and gradually invades the other tunic, the vessels of which, very much injected, may be seen ramifying in every direction, forming a net-work so delicate as to render it difficult to distinguish it with the naked eye. Flakes of lymph are sometimes found adhering to the inner surface; and, in violent cases, it may even be bathed with pus. Under these circumstances, both tunics are of a deep red, violet or purplish color, soft, and spongy, and the surrounding cellular tissue is swollen and infiltrated with serous and other fluids. The proper nutrient vessels, also, being exces- sively engorged with blood, are no longer permeable to injecting matter. CHAP. VII.] INFLAMMATION-- SUPPURATION. 303 When the superficial lymphatics are affected, they can be easily traced underneath the skin, like small red cords, tense, nodulated, and painful to the touch, accompanying the prin- cipal veins, and going as far as the first conglobate glands, — rarely beyond them. This appearance is Avell seen in dis- secting wounds, in punctures, and in poisonous wounds, and is often attended with considerable swelling and oedema of the connecting cellular texture. Such is a succinct outline of the anatomical characters of acute inflammation of the lymphatics. Of those which mark the chronic form of the disease, nothing need be said in this place, as the subject does not seem to have yet been properly investigated. That they are very analogous to those characterizing chronic inflammation of the veins, is highly probable; at least, such must be our conclusion, when we reflect upon the similarity of structure and function of these two systems of vessels. It has been already stated, that suppuration sometimes takes place in these vessels, and it may now be added, that they occasionally contain pus, the result obviously of absorp- tion. Mascagni tells us, that it is by no means uncommon to find purulent matter in the pulmonary lymphatics in phthisical subjects; and Velpeau and others have repeatedly seen the same thing in those of the womb and inferior extremities in women who died of phlegmasia dolens. It is still undecided, Avhether acute inflammation ever terminates in gangrene; but there is reason to believe that such an event is not only extremely rare, but that it never occurs as an idiopathic affection. Andral has often seen tubercular matter in the lymphatics. In a woman Avho died of cancer of the uterus, in the Charity Hospital at Paris, he found the thoracic duct literally filled with this substance ; and, in another case, besides being present in this reservoir, he noticed it in the absorbents of the lungs, the groin, and pelvis. Similar appearances have been witnessed by others. Walther had seen these vessels ossified, and of stony hardness; but this morbid change is much less common than in the arteries, and has only been observed in a few instances. More frequently they contain calcareous, chalky or bony matter; of this latter, examples are narrated by Scherl, Assalini, Lauth, and Poncy. A remarkable dilatation of the lymphatics is sometimes 304 LYMPHATICS. [CHAP. VII. observed, giving them a tortuous, varicose arrangement. (Fig. 28.) This lesion is well illustrated by a case mentioned by Pro- fessor CarsAvell. The sub- ject of it Avas a young man, twenty-six years of age, who died with two sAvell- ings, — one in each groin, nearly as large as an orange, for Avhich he had worn a double truss from his boy- hood, under the supposition that they were of a hernial character. On examining the patient after death, the tumors Ave re found to con- sist of an enormous dilata- tion of the lymphatics of the inguinal glands. When cut into, instead of present- ing a solid, compact struc- ture, they had the appear- ance of a coarse sponge, — the size of all these vessels being augmented, most of them from one to three lines in diameter. The same phe- nomenon was seen, only more strikingly, in the absorb- ents of the pelvic and lumbar regions. None of them were less than tAvo, and many of them from three to four lines in diameter, whilst the thoracic duct itself was fully three times the natural dimensions. Soemmering has seen the lymphatics of the intestines varicose in hernia; and the same condition was witnessed by Bichat, in those of the serous membranes in dropsy. Dr. Albers, of Bonn, has recently reported a case of Avhat he Jerms aneurism of the thoracic duct. The patient, a man fifty-one years old, died of abscess of the liver. On exam- ining the body after death, a knotty, elastic tumor Avas found, about the size and shape of a fig, and resembling very much a hydatid. Its walls were preternaturally thick and firm, and, on cutting through them, a director could be easily passed up and down the canal, thus showing that it Avas connected with the duct in question. The swelling was filled Avith thin, flaky lymph, and its inner surface Avas perfectly smooth and uniform. Baillie states that he has seen the thoracic duct varicose, and as large nearly as the subclavian vein. CHAP. VII.] OBLITERATION OF THE THORACIC DUCT. 305 The thoracic duct is sometimes obliterated. This may depend either upon a thickening of its tunics, upon the pres- ence of a foreign body, or upon the reciprocal adhesion of its valves, as in the interesting case narrated by Sir Astley Cooper.* In whatever way produced, this occurrence almost ahvays impairs the nutritive function, though, owing to the numerous anastomoses of these vessels, and to their continua- tion with the veins, this process is perhaps never entirely interrupted, the chyle finding its Avay along collateral chan- nels, just as the blood does after the tying of an artery. The other portion of this system consists of small, flat- tened bodies, of an oval or rounded shape, Fig. 29.+ Avhich have been described by authors under the several names of absorbent glands, lym- phatic ganglions, or kernels. (Fig. 29.) Va- rying in size from two to ten lines, they are of the average diameter of the third of an inch, of a light pink color, and situated always in such places as abound in cellular tissue, particu- larly at the bends of the joints. At the groin, they occur in great numbers, as Avell as at the arm-pit, the side of the neck, the posterior mediastinal cavity, and in the cellular tissue of the pelvis and mesentery. In several of these places, they are connected in chains, or clusters. Each absorbent gland consists of a peculiar parenchymatous substance, surrounded by a thin capsule, made up essentially of condensed cellular tissue, as can be shoAvn by maceration. This envel- ope, which sends numerous processes into the structure of the gland, is abundantly supplied with blood, the vessels forming upon it a beautiful net-Avork, which is always deeply injected in persons dying from asphyxia. On making a sec- tion of one of these bodies, it is found to consist of a homo- geneous, porous substance, soft and fleshy to the touch, the central portion of which is whiter and somewhat firmer than the exterior. This substance is composed mainly of absorb- ent vessels, remarkably convoluted, dilated into irregular cells, bound together by very delicate cellular tissue, and * London Medical Records and Researches, vol. i. p. 28, 1798. t A lymphatic ganglion, with lymphatics running to and from it. vol. 1. 39 306 LYMPHATICS. [dlAP. VII. accompanied by a great number of the finest arterial and venous capillaries. Thus constituted, these glands are liable to inflammation, suppuration, gangrene, hypertrophy, carcinoma, tubercles, melanosis, and ossification. In acute inflammation, the lymphatic glands are, at first, of a pale flesh-color, hard and dense to the touch, considera- bly swollen, and cannot be torn Avith the same facility as in the normal state. When cut into, numerous minute points, of a broAvnish tint, and evidently the orifices of divided ab- sorbents, may be observed; and, in many instances, blood is extravasated into the connecting cellular tissue, in circum- scribed specks, not larger, frequently, than the head of a small pin. The covering of the glands, of a light reddish hue, is every where croAvded with injected vessels, radiating in beautiful, dendritic lines. At a more advanced period, these bodies acquire a dark violet color, become soft and spongy, from the infiltration of their bloody matter; and, on being torn, their substance looks very much like that of the spleen. In this affection, ganglions, that are naturally not larger than the kernel of an almond, sometimes acquire the magni- tude of an orange, or even of the fist; as is exemplified in cases of buboes, and in lymphatic swellings in the axilla, or about the neck. The tumefaction arises, apparently, from the internal connecting cellular tissue, or from thickening of the external coat of the absorbents, as these tubes are still pervious to a mercurial injection. This disease may affect a single gland, extend to several, or involve a Avhole chain or group. Maceration in water, for a few days in hot weather, de- prives the inflamed ganglion completely of its red color, and converts it into a soft, grayish mass, which easily yields to the pressure of the finger. Boiling has the effect, at first, of rendering it dense and slightly elastic, — afterwards, friable and granular. This disease occasionally terminates by suppuration, the period at which this event happens varying from a few days to a fortnight. The pus may be either diffused through the proper parenchymatous structure, converting it into a dirty, grayish mass, or it may be disseminated in distinct globules, or, finally, be collected into an abscess, Avhich may be so large as to occupy the Avhole gland, the only thing that re- CHAP. VII.] GANGRENE--HYPERTROPHY. 307 mains being its external envelope. The quantity of matter is sometimes very great: and, in the majority of cases, it is of a thin, greenish character, intermixed Avith hard, cheesy flakes. The glands most liable to suppuration are those of the groin, axilla, neck, and jaAV. Acute inflammation sometimes ends in gangrene. When this takes place, the substance of the gland is found to be of a dirty, grayish color, soft and pulpy, and bathed in a foul, fetid sanies, occasionally so acrid as to prove highly irritating to the surrounding parts. This termination of acute inflam- mation is Avell exemplified in cases of syphilitic buboes, occur- ring in debauched and Avorn-out habits. In such patients, immense sloughs are sometimes formed, the gangrene gradu- ally spreading from the affected glands of the groin to the adjacent textures. In chronic inflammation, the lymphatic ganglions are hard, firm, not easily lacerated, and of a light broAvnish color, inter- spersed with streaks and specks of gray, Avhich have the effect of giving them a mottled aspect: their substance is infiltrated with lymph; and, on being cut, they slightly creak under the knife, the section presenting a homogeneous aspect. The fibrous envelope is very dense and thick ; and both its own vessels and those which are distributed to the proper paren- chymatous tissue are tortuous, knotty, and dilated. The absorbents entering into the composition of these bodies are also more or less enlarged, though, occasionally, their cavity is so much diminished as to render it impossible to inject them. The disease sometimes passes into suppuration, the parenchymatous structure being entirely destroyed, the thick- ened and indurated capsule being the only part that is left. The pus in such cases is semi-concrete, and often remarkably offensive, apparently from its long sojourn in the parts. Chronic inflammation leaves these glands sometimes in a state of hypertrophy. In this condition, they may be either perfectly Avhite or grayish, or else they may acquire a light brownish or yelloAvish tint; their consistence, also, is fre- quently much augmented, and cases occasionally occur in which they are of a dense, gristly hardness, like scirrhus. The glands most liable to be thus affected are the mesenteric, bronchial, internal iliac, inguinal, and cervical. I have a preparation, taken from a child three years of age, in which the mesenteric ganglions, all melted into one general mass much larger than a foetal head, are of a bluish gray color, 308 LYMPHATICS. [CHAP. VII. homogeneous, and of the consistence of cartilage, each one grating sensibly under the knife. Many of them are as large as an orange, and they all have a very thick, indurated cap- sule, of the same tint very much as the altered parenchyma- tous substance. Hypertrophy of the lymphatic glands may arise from irrita- tion, seated originally in their oavii tissue, or it may proceed from irritation propagated to them from the surrounding parts. In the glands of the mesentery, it is commonly caused by irritation of the boAvels, especially of the ileum ; in the groin, by that of the penis; in the axilla, by that of the breast; in the neck, by exposure to cold; and at the jaw, by disease of the gums, teeth, or tonsils. Great mischief is sometimes occasioned by this morbid developement. Cruickshank gives an instance in which the bronchial glands Avere affected to such an extent as to induce fatal suffocation ; and Dr. Wil- liam Hunter mentions that he has seen the internal iliac glands so much augmented as to cause death by preventing the descent of the child's head during parturition. When those of the mesentery are enlarged they may obstruct nutri- tion, and produce excessive emaciation, followed at length by loss of life. At the jaw, they sometimes produce permanent anchylosis ; and at the transverse fissure of the liver, an enlarged lymphatic ganglion has been known, more than once, to cause jaundice, by compressing the hepatic or the ductus choledochus. Such are a few of the effects Avhich may result from hypertrophy of these bodies, in Avhatever manner induced. We have already mentioned that the lymphatic ganglions sometimes acquire the hardness and density of scirrhus, and it may now ue added that they occasionally contain encepha- loid. This disease, hoAvever, is extremely rare, and as yet I have met only with a feAV instances. When thus affected, these bodies are metamorphosed into a soft, brain-like sub- stance, contained in a strong membranous cyst, with irregular fibrous filaments intersecting it in different directions. Gru- mous matter is sometimes found in such tumors, and now and then one part is medullary, another fibrous, another scirrhous. Serous cysts are also occasionally seen. In a case of encephaloid of the axillary ganglions, which I observed in a man fifty-six years of age, there Avas a single cavity of this kind which fluctuated under the finger, and contained upwards of eight ounces of sero-sanguinolent fluid. CHAP. VII.] TUBERCLES. 309 Cattle are sometimes affected Avith scirrhus of the absor- bent glands, especially such as live in Ioav and damp situa- tions. Cows are more particularly liable to it, and hitherto the disease has been observed chiefly in the glands of the mesentery. Mr. BroAvn, an English veterinary surgeon, has recorded a singular case, where a body of this kind weighed one hundred and sixty pounds. It was of a very irregular form, and, on making a section of it, it was found to exhibit a bluish, scirrhous appearance.* Tubercles are frequently observed in the lymphatic glands, occurring either in small isolated granules, or in considerable clusters. They are generally associated Avith tubercles of the lungs, and are most common in children betAveen the ages of three and ten. A late Avriter, Dr. Louis, considers this morbid change as peculiar to phthisis ; and he even goes so far as to affirm that it never exists, after the fifteenth year, without pulmonary consumption. This sweeping assertion has been contradicted by M. Broussais. It is certainly at variance with my own, and the experience of our best writers. It is but recently that I examined the body of a man, aged thirty, who died of psoas abscess, in whom, although the lungs were perfectly sound, the lumbar, pelvic, and mesen- teric glands Avere most extensively tuberculized. Nor is this the only instance which I have seen of this disease uncon- nected with pulmonary phthisis. This deposition of tubercular matter is much more com- mon in the bronchial glands than in any other. In one hundred children, in which these organs were carefully in- spected, Dr. Lombard found them affected in eighty-seven. Age seems to exert a considerable influence in respect to the frequency of this deposition in different parts of the system. In adults, the mesenteric glands are more commonly affected. In one hundred phthisical subjects, Louis found these bodies tuberculized in twenty-three, or in the proportion nearly of one to four. When suffering under this disease, the glands exhibit different appearances, according to the progress it may have made. Generally speaking, they are enlarged in their size, of a dense gristly texture, white externally, and of a light rosy tint internally, either uniformly in streaks or in patches. The tubercular matter itself is of a singularly yel- lowish color, especially if it has existed for some length of time, and often contains particles of curdy pus. * Youatt's British Cattle, p. 472. 310 LYMPHATICS. [CHAP. VII. The lymphatic glands are occasionally ossified, and still more frequently, they are transformed into a soft, Avhitish sub- stance, like chalk. These changes most commonly occur in persons who are cut off by pulmonary phthisis, in the con- globate glands at the root of the lungs ; but sometimes they are witnessed in other situations, as in the groin, the mesen- tery, and pelvis. Not long ago, I met Avith a case in which a considerable number of the absorbent glands of the neck were ossified. They Avere perfectly hard, like bone, of a light brownish color, irregularly rounded, and varied in size, from that of a pea to that of a hazelnut. Occasionally the lesion seems to be confined entirely to the cellulo-fibrous envelope of these bodies, their parenchymatous structure either remaining sound, or else containing tubercular or calcareous matter. In the bronchial glands, it is not unusual to find hard sabulous concretions, matted together by cellular tissue; and similar substances, only of a more regular shape, I have several times seen in the lumbar and pelvic glands. In most of the cases which have come under my notice, they Avere perfectly spherical, smooth, uniformly hard, and very few of them bigger than a currant; they occurred in the midst of the parenchymatous texture, to which they adhered by dense, cellular tissue, and Avhich was, in other respects, entirely natural. These morbid changes may be considered as resulting from a sIoav chronic inflammation, similar to that which accom- panies ossific deposition in the arteries. Ordinarily, the meta- morphosis begins at one or more points, from whence it gradually spreads in different directions, until it embraces the whole gland. When purely ossific, it is supposed by some to be preceded by cartilage, but this, I think, admits of much doubt. Another morbid deposition Avhich is sometimes noticed in these glands is melanosis. Both Andral and Craigie state that this disease is very frequent in Europe, but that it is not so in this country is abundantly proved by the concurrent testi- mony of our most experienced writers. Excepting in the bronchial glands, this deposition, indeed, is seldom Avitnessed in any other portion of the absorbent system. Such, at least, is the result of my own observation. CHAPTER VIII. Of the Joints. SECTION I. Of the Articular Cartilages. I. The Articular Cartilages.— Structure and Chemical Composition. —Vascu- larity. —jLesions. — Reparation. — Inflammation. — Softening. — Suppuration. __Tjlceration. — Ossification. — II. The Si/novial Membranes. — Organization, Appearance, and Office. — Diseases: Inflammation — Effusion of Lymph and pus_ Tjlceration— Chronic Irritation — Loose Cartilages— Chalky Concre- tions. — III. The Ligaments.— Structure and Sensibility. — Adhesive Inflam- mation. — Atrophy. — Calcareous Concretions. The articular extremities of the bones are incrusted with a thin, delicate lamella of cartilage, which adheres to them Avith so much firmness that it is impossible to separate it without the aid of protracted maceration in Avarm Aveather. Of the tAvo surfaces which it presents, one is free, perfectly smooth, and covered throughout by synovial membrane ; the other, on the contrary, is rough and mammillated, being studded with numerous little processes, which are received into corresponding osseous pits. In regard to its thickness, the lamella is subject to considerable variation; but it may be stated, as a general observation, that it is greater in the large than in the small joints : it is also greater in the convex articular surfaces at the centre than at the periphery ; the reverse of which is the case in the concave. Of a pearly white color, it exhibits, when cut into layers, a semi-transpa- rent, horny appearance, Avith a light cast of blue. Although seemingly homogeneous, this substance is found to be com- posed of small, delicate fibres, which are implanted perpen- dicularly to the surface of the bone, like the villi upon a piece of velvet, only infinitely more close and dense. During embryotic existence, the articular cartilages exhibit the aspect and consistence of mucilage ; but they gradually 312 ARTICULAR CARTILAGES. [chap. V11I. augment in density, until at length they acquire the hardness and solidity almost of the osseous tissue. In adult life, they are highly flexible and elastic; in decrepitude, on the con- trary, they are dry, brittle, opaque, and sensibly thinner. These structures are easily cut Avith the knife. By boil- ing, they become brittle, indented, and are finally converted into a pulpy, tremulous mass. Exposed to the rays of the sun, or the dry heat of a fire, they assume a transparent, yel- lowish color; but, by immersing them in Avater for a feAV days, they gradually regain their former aspect. They resist, for a long time, the putrefactive process, and months elapse before they yield to maceration. According to the analysis of Dr. John Davy, of Edinburgh, the diarthroidal cartilages are composed of the folloAving ingredients: Albumen,........44.5 Water,........55.O Phosphate of lime,...... . .5 100.0 The results of this experimentalist are somewhat different from those obtained by Allen and Gendrin, Avho, in addition to the substances already enumerated, detected a small pro- portion of carbonate of lime, and of gelatine. It is altogether probable that the chemical composition of cartilage, like that of bone, varies very much in the different periods of life. In children, there is generally a preponderance of animal matter, the quantity of Avhich gradually diminishes in old age, being replaced partly by earthy substances. In the immovable joints, the cartilages are arranged some- what differently: they form very thin crusts, Avhich are uu- provided Avith synovial membrane, and which, in some of the articulations, are of a fibro-cartilaginous texture. Are cartilages supplied Avith vessels and nerves ? This is an interesting, and, in reference to the pathology of these textures, a highly important question. That cartilages are as highly endoAved with vitality as some of the other parts of the body, is what no anatomist who has investigated the subject will assert; but that they are furnished with all the necessary ingredients of organization, has been abundantly demonstrated by observation and experiment. To deny that they are vascular, as has been done by some, is no less absurd than it is unphilosophical. Does it follow, because the naked eye is incapable of discerning the presence of vessels, that SECT. I.] ORGANIZATION. 313 there must needs exist none ? Who has ever demonstrated the vascular structure of the healthy cornea, the arachnoid tunic, or the synovial membranes ? No one ; and yet that these organs are highly organized, every pathologist must admit, from his own observation. But analogy, in this case, I conceive to be, if not misapplied, at all events unnecessary. Repeated inspection of the cartilages of young animals, as well as of the human subject, has convinced me that these organs are infinitely more vascular than has been generally supposed. The vessels at this period are always large and Avell developed, carrying red fluid in every direction. In old age, they become less distinct, and many of them, no doubt, are obliterated. In inflammation of the joints, especially in the young, the vascularity of the cartilages, as will presently be shown, is not unfrequently quite conspicuous. In jaun- dice, I have repeatedly seen them of a light yelloAvish color, from the deposition of bile. No nerves have hitherto been traced into these bodies; but their existence is indicated, both by analogy, by the presence of vessels, and by the pain Avhich they experience when laboring under disease. Cartilages, both articular and non-articular, are susceptible of reparation, inflammation, suppuration, softening, ulceration, and ossification. When divided by a sharp instrument, or torn asunder, as in fractures of the bones, cartilages readily unite, the edges of the wound being at first rounded off, and afterwards joined by a dense fibro-ligamentous substance, whiter and more opaque than the original structure. In some instances, the reparation is effected through the medium of osseous matter; but this is rather a rare occurrence. In this respect, the articular cartilages differ remarkably from the costal, which, when cut or broken, ahvays unite by bony matter, the re- paratory process being exactly analogous to that which nature employs in the cicatrization of a fracture. The difference in these two cases depends, no doubt, upon some difference of structure, though it is by no means easy to determine why it is that an organ, which naturally contains less earthy matter than another, should, Avhen injured, be more easily united by bone. The reverse, one Avould suppose, would be the more natural method. Is cartilage ever regenerated? Laennec and Beclard think it is; and careful observations, made since the time of those celebrated pathologists, fully authorize us in answering this question affirmatively. The reproduction, vol. i. 40 314 ARTICULAR CARTILAGES. [CHAP. VIII. however, is generally very imperfect, and serves, therefore, as a very indifferent substitute for the original structure. Inflammation of the cartilages may occur as a primary affection; but it more generally succeeds to disease of the osseous, synovial, or ligamentous texture. Its progress is usually slow, and its characters are, for the most part, very slightly marked. In young persons, there is sometimes a considerable degree of redness, the vessels of the joint being enlarged, and continuous Avith those of the subjacent bone ; but in old subjects this phenomenon is rarely present, the only evidence of the disease being a softened, spongy, and tumid condition of the cartilages. The inflammation is ac- companied by severe pain, deep-seated, and of a dull, aching nature ; and in a short time, if its course be not arrested, it is folloAved by ulceration or destructive mollescence. Softening of the cartilages seems to be the result commonly of severe inflammatory action, by which their structure is converted into a semi-transparent, pulpy substance, not unlike thick starch. The change, which is sometimes effected with great rapidity, is generally connected with caries of the artic- ular surfaces of the bones, and seems to be somewhat analo- gous in its character to gangrene of the soft parts. Genuine suppuration of the movable cartilages is seldom if eArer met Avith, the purulent matter Avhich is found in the diarthroidal joints being generally poured out by the sonovial or bony texture. In the pubic and sacro-iliac symphyses, pus has been seen by Ludovici, Hunter, and other writers ; but the occurrence, I presume, is extremely rare. Even in ulcera- tion of this tissue, the formation of purulent fluid is by no means a constant accompaniment. In gouty affections, the articular cartilages of the fingers and toes are often softened and either partially or entirely removed ; and similar effects are occasionally Avitnessed in scrofulous disorders of the spinal column, and of the joints of the hip and knee. During the latter stages of utero- gestation, the fibro-cartilaginous substance of the pubic sym- physis is sometimes remarkably softened and relaxed, allowing the tAvo contiguous bones to ride upon each other. A case of this kind came under my notice not long since. The lady Avas in her fifth pregnancy, and the separation Avhich commenced about a month before her lying-in, Avas so great that she could scarcely Avalk, or turn in bed without the greatest suffering. The parts Avere almost as tender as a boil, SECT. I.] ULCERATION. 315 and more than five weeks elapsed after her confinement, before they regained their healthy character. This affection, Avhich on the Avhole is rather uncommon in the human sub- ject, seems to be natural to some of the inferior animals, as the rabbit and Guinea pig,— its object, in them, being evident- ly to facilitate the parturient efforts. An analogous lesion is sometimes observed in the sacro-iliac junction ; but then the softening and concomitant separation are always much less. Ulceration of the cartilages occasionally exists as a primary lesion; but in most cases it depends upon disease of the ad- joining tissues, as caries of the extremities of the bones, or in- flammation of the synovial membranes. It may take place at any period of life, or in any articulation; but it is in the hip and knee that it is most generally met Avith, and in per- sons betAveen twenty and thirty years of age. In general, the disease is confined to a single joint ; but occasionally tAvo or three are affected in the same individual, either simulta- neously, or in succession. Its causes are referable to local injury, atmospheric vicissitudes, or to a strumous, gouty, or syphilitic taint of the constitution. Ulcers of the cartilaginous tissue vary much in their size and form. Sometimes they are small and deep, like excava- tions; more commonly, hoAvever, they are superficial, and occupy a pretty large extent of surface. In the primary va- riety of the disease, in which the erosion ahvays begins to- Avards the centre of the free surface of the cartilage, the ul- cer is sometimes smooth, narroAV, and of a light grayish color, as if a portion had been scooped out with a knife ; but more generally it is broad, irregular, and of a dull yelloAvish cast, involving a large amount of structure, and extending into the adjacent bone. The edges are often irregular, never elevated or undermined ; there are no vessels to be observed, no granulations, frequently no pus ; and the synovial mem- brane either retains its normal characters, or is vascular, opaque, and slightly thickened. The primary ulcer often spreads with great rapidity, producing complete denudation of the bones in the course of a few weeks. This is es- pecially apt to occur in wounds of the large joints, attended with loss of substance, or the ingress of the atmosphere. When the ulcers begin in the synovial membrane, or in the articular extremities of the bones, they are called secondary, and ahvays possess certain traits by which they may be dis- tinguished from the preceding. These differences, however, 316 ARTICULAR CARTILAGES. [CHAP. VIII. do not consist so much in any thing that relates to the shape, size, or depth of these ulcers, as in the changes Avhich are wrought in the adjoining structures. When the disease de- pends upon inflammation of the synovial texture, it commonly commences at the circumference of the cartilage, from which it slowly extends towards the centre of the articulation, destroying, as it proceeds, the lining membrane. Should the ulceration, on the other hand, have its origin in the bone, the cartilage will be gradually detached from its connection, par- tially absorbed, or broken down into a soft, pulpy, gelatinous, or lardaceous mass. This form of the disease is commonly associated with a strumous diathesis, and is most apt to occur in young children in the ilio-femoral articulation. There is a singular condition of the diarthrodial cartilages, which is considered by Sir Benjamin Brodie as being pretty constantly produced by incipient ulceration. I allude to the peculiar fibrous condition in which the free surface of these bodies is sometimes found. The cartilage seems to be de- nuded of synovial membrane, and is every where studded with villosities, spicules, or bristles. The affection is most common in old people, and is probably caused by inflammation, at- tended Avith slow ulcerative action, or partial absorption. Ulceration of the cartilages is always accompanied with severe pain, more or less tumefaction, and tenderness on pressure. Every motion of the joint causes uneasiness ; the patient limps in walking, and is unable to exert himself with his accustomed freedom. After some time, the pain becomes more constant and annoying; there is great constitutional irritation, with loss of appetite and sleep ; and the joint is permanently flexed, or completely disqualified from perform- ing its proper functions. By degrees, matter collects in the articulation, the skin around it ulcerates, and the patient final- ly falls a victim to hectic fever. Writers have endeavored to lay down certain characters by which this disease might be distinguished when affecting particular joints ; but as an ac- count of them Avould lead us into unnecessary details, we beg leave to refer such as take a special interest in the sub- ject to the general treatises on surgery. The cartilages sometimes ossify, especially in persons far advanced in life. In the diarthrodial joints, this event is rather uncommon, and is witnessed chiefly in disease of the spine, the hip, and knee. In these situations, the cartilages become not only bony, but are sometimes converted into a substance SECT. II.] SYNOVIAL MEMBRANE. 317 similar to ivory. The most frequent seat of ossification is the sacro-iliac junction, which is so often affected in adults that it is regarded by many as a natural occurrence. Several specimens of this kind are preserved in the college museum. In two of these, cartilages of both apophyses are entirely re- placed by osseous matter, Avhich has connected the contiguous bones into one common mass. SECTION II. Of the Synovial Membrane. Besides the structures already enumerated as entering into the composition of the diarthrodial joints, there is another class which are knoAvn, from the fluid which they secrete, under the name of the synovial membranes. These textures, like the serous membranes of the splanchnic cavities, to Avhich they bear the closest resemblance, are every Avhere arranged in the form of shut sacs, which are reflected on the one hand, over the articular cartilages, and, on the other, over the artic- ular ligaments, to both of which they adhere Avith extreme tenacity.* Their connection Avith the central portions of the diarthrodial cartilages, indeed, is so firm and obscure, that several able anatomists have been induced to deny altogether their existence in this situation. This opinion, however, is by no means correct, as I am convinced, from a number of ex- periments that I have performed, with a view of satisfying myself respecting this much-disputed and interesting point. By macerating the cartilages of the hip, knee, or shoulder- joint, for several weeks, or by subjecting them, for a short time, to boiling water, or the action of a dilute acid, I have almost invariably been able to detect these membranes, and to raise portions of them with the forceps. But, independent- ly of their easy demonstrability, the existence of the struc- tures is often rendered evident in certain pathological states of * In some of the larger articulations, as in that of the hip and knee, loose folds are to be seen, analogous to those of the serous sac of the abdomen. They are formed by the duplicatures of the synovial '• membranes, and usually contain small masses of fat, which were formerly supposed, but erroneously, to be true secretory glands. 318 SYNOVIAL MEMBRANE. [CHAP. VIII. the joints, not only, indeed, merely at the circumference, but at the Arery centre of their cartilaginous facings. She synovial membranes have a Avhitish, semi-transparent aspect, are extremely soft and delicate, and appear to be mere- ly a modification of the cellular clement of our organs. Their external surface is closely attached, as Ave have already seen, to the surrounding textures ; the internal, on the con- trary, is free, smooth, and constantly lubricated, resembling, in this respect, the free surface of the pleura and peritonaeum. No nerves can be traced into their substance ; and their ves- sels, which do not naturally convey red blood, can only be seen when they are in a state of inflammation. Their vital properties are also very obscure. The free surface of these membranes, as was previously in- timated, is constantly bedewed Avith a yelloAvish, transparent fluid, of a saline taste, and of a thick, viscid consistence. It is remarkably soft and unctuous to the touch, and is there- fore admirably calculated for the office Avhich nature has in- tended it to perforin : heat partially coagulates it. and it readi- ly mixes with water. From the analysis of Dr. John Davy, of Edinburgh, it appears that one hundred parts of synovia consists of Water,........98'03 Gelatine,........'93 Albumen,.......'53 Muriate of soda,.......'23 99'81 In addition to these ingredients, Dr. Davy also detected a small proportion of fixed alkali, and traces of phosphate of lime. As there are no glands connected with these membranes, it is obvious that the fluid, the physical and physiological prop- erties of which we have just described, must be immediate- ly derived from the vessels Avhich are distributed through their substance. Its quantity varies in the different joints; for, Avhilst in some it can scarcely be said to exist in an ap- preciable manner, in others, as in the hip and knee, there is always, comparatively speaking, quite an abundance of it. Synovial membrane readily unites when torn or divided, and is highly susceptible of inflammation. All the joints are liable to inflammation of their lining membrane, but that of the knee is perhaps more frequently affected than some of the others. The disease is most apt to SECT. II.] INFLAMMATION--SUPPURATION. 319 occur when the body has attained its full vigor, and may be produced by a great variety of causes, such as external vio- lence, cold, the long-continued use of mercury, gout, rheuma- tism, or syphilis. The anatomical characters of the acute variety of the malady are, redness, opacity, thickening, and diminished density of the affected membrane, with alteration of secretion, and infiltration of the surrounding cellular sub- stance. In the early stage of the disease, the redness is commonly very ✓slight, the capillaries being disposed in delicate lines, separated by large intervals. After some time, hoAvever, the vessels assume an arborescent form, and the color becomes more intense, occurring either in a uniform manner, or in mi- nute patches, resembling so many ecchymoses. As these changes proceed, the membrane loses its smoothness and trans- parency, augments slightly in thickness, and becomes so soft that it may be easily scraped off Avith the finger-nail, or the edge of the scalpel. The natural secretion, Avhich is at first increased in quantity, thin and limpid, is soon rendered thick and turbid, and often contains flakes of lymph. At a more advanced degree, the secretion is entirely changed in its character, being puriform, sero-sanguinolent, or even purulent. Occasionally clots of pure blood are contained in the joint; and, in many instances, the free surface of the membrane is covered Avith minute shreds and globules of lymph, Avhich have the effect of giving it a rough, tomentous aspect. The surround- ing cellular tissue is distended with serum, and the vessels penetrating it are engorged Avith blood, which is so firmly im- pacted into them that it cannot be easily forced out. The quantity of lymph throAvn out in this disease is some- times very great, filling up nearly the Avhole of the affected joint. It is generally of a pale straAV-color, grayish, or lilac, and often adheres very intimately to the inner surface of the articulation, being spread out in the form of an adventitious membrane. 1 do not know that vessels have ever been traced into this substance, but that it is susceptible of organization there can be no doubt. Suppuration of the synovial membranes is very apt to take place in scrofulous persons, and in such the matter is general- ly of a thick, flaky character, like that of a psoas abscess. In most cases, the pus is remarkably viscid and ropy, OAving to the admixture of synovial fluid, and not unfrequently it is of a dark grumous appearance, and more or less offensive. 320 SYNOVIAL MEMBRANE. [CHAP. VIII. When the accumulation is small, it is sometimes absorbed, but more commonly it Avorks its Avay out through the joint by the ulcerative process, and destroys the patient by consti- tutional irritation. The synovial membranes are liable to ulceration. This occurs especially where they are reflected over the peripheral portions of the joints. The edges of the erosions are generally very thin, and their size seldom exceeds that of a ten cent piece. It is difficult to say, in these cases, Avhether this ulceration begins in the membrane itself, in the subjacent cellular tissue, or in the substance of the cartilage. But, be this as it may, the latter of these textures are always sooner or later involved in the process, and in this way small superficial abrasions are often converted into deep cavities. In the chronic form of the disease, in which the vascularity is much less than in the acute, the membrane often presents a remarkably dull, mottled appearance. Its substance is some- times very much thickened, either by an effusion of sero- albuminous matter into its molecular texture, or by the for- mation of adventitious membranes; and not infrequently, especially in cases of long standing, it is converted into a soft pulpy mass, of a light brownish color, intersected by numerous Avhitish shreds. Cases occur, in which the synovial membrane is covered with multitudes of small pendulous ex- crescences, something like melon-seeds, warts, or the epiploic appendages of the large intestine. Occasionally, fibro-cartila- ginous tumors grow beneath it, of considerable magnitude, adhering by one or more foot-stalks. These productions are usually very irregular in their shape ; and as they are gener- ally invested by a duplicature of the synovial membrane, it is not unreasonable to infer that they are originally developed in the subjacent cellular tissue. Loose cartilages are sometimes found in the joints, espe- cially in the knee, Avhere they are often a source of great trouble and anxiety to the patient. They vary in size, from a mustard seed to that of a small bean ; occasionally, how- ever, they are much larger; and, in one instance, a body of this kind was found of the magnitude nearly of the patella. Their numbers also vary. In most cases, there are not more than three or four ; but Haller saAV a case in which there were twenty ; and Morgagni another, in which there Avere twenty-five. These concretions are generally concave on one side, convex on the other, and of an irregularly oval SECT. II.] INFLAMMATION. 321 form. Sometimes they are lenticular, rough in one part, and smooth in another, or are marked round their circumference by a red striated zone. Consisting ordinarily of a single mass, they are occasionally divided into several lobules, which are connected together by fibrous matter. In some instances, they are tough and tenacious, or soft, like ligamentous tex- ture ; but, mostly, they are partly cartilaginous, and partly osseous, the bony structure being in the centre, the cartila- ginous on the surface. These substances, like the fibro- cartilaginous tumors before mentioned, are probably developed in the subserous cellular tissue: they are covered by synovial membrane, and they finally become detached through the accidental rupture of the slender pellicle Avhich joined them to the part on which they greAV. The diarthrodial joints are occasionally the seat of gouty concretions, which, from their color and softness, have re- ceived the name of chalk-stones. The true nature of these bodies Avas first discovered by Dr. Wollaston, in 1797, Avho proved that they are composed of urate of soda. More recently, John Davy has detected, besides this substance, a peculiar fatty matter, phosphate and carbonate of lime, and a minute quantity of carbonate of magnesia. In an old man, whom I examined some years ago, I found these concretions in nearly all the principal joints of the body, in small amor- phous masses, of a whitish color, and of a soft unctuous con- sistence. Sometimes they are perfectly smooth and round ; more commonly, hoAvever, they are rough and irregular, grooved or nodulated. In most cases they are small, though they have been observed of the size of an egg. These bodies are almost always connected with a gouty diathesis, and are, no doubt, caused by chronic inflammation of the synovial texture. In chronic inflammation, the fluid which is thrown out is either thin and glairy, sero-oleaginous, or puriform, — rarely purulent. The quantity varies from one to five ounces, and in some rare cases it has been known to amount to more than a quart. This affection, Avhich is distinguished by the term " dropsy," is rarely attended with much pain or inconve- nience. VOL. I. 41 322 LIGAMENTS. [chap. VIII. SECTION III. Of the Ligaments. Two varieties of ligaments enter into the composition of the movable joints, the capsular and funicular; the former of Avhich seem to partake a good deal of the character of the fibrous membranes, Avhile the latter are always extremely dense, firm, resisting, and of a dull white argentine color. They possess only a very slender share of elasticity, and yield scarcely any Avhen an effort is made to stretch them. Their supply of blood, Avhich is furnished by the small arte- ries in their immediate vicinity, is extremely scanty ; and, as yet, few anatomists have succeeded in tracing any nerves into them. By protracted maceration, these structures may be reduced into a soft, pultaceous, grayish mass, which can be almost entirely resolved into gelatine by boiling. The sensibility of the ligaments is extremely obscure in the normal state, so that they may be cut Avith a pair of scissors without the individual being conscious of it. In this respect, they resemble the other fibrous tissues ; but differ from them in the excruciating pain which ensues Avhen they are forcibly stretched or contorted. Their sensibility is also remarkably heightened under inflammatory irritation. They are entirely destitute of contractility of texture ; and, when injured, they are seldom if ever repaired. The diseases of the ligaments are few in number and in- frequent in their occurrence, OAving, no doubt, to their very imperfect vascular and nervous endowments. The most important morbid changes are inflammation, atrophy, gouty concretions, and lardaceous degeneration. When a ligament is cut or lacerated, it readily unites by adhesive inflammation, the process being exactly analogous to that Avhich occurs in the restoration of a fractured bone. The vessels of the part, becoming enlarged, throw out lymph, which forms a capsule round the di\Tided extremities, and thus keeps them in contact. The same kind of matter is after- Avards effused between the ends of the ligament; and, in pro- portion as this becomes organized, and assumes the proper- ties of the original texture, the outer capsule, to which we have just referred, is diminished, until at length it is Avholly absorbed, leaving behind it merely a slight cicatrix. SECT. III.] INFLAMMATION--ATROPHY. 323 Doubts have been expressed by some writers whether ligaments are susceptible of inflammation. That they are occasionally the primary seat of this disease, cannot be denied ; and that they become often affected secondarily, is equally certain. The dissections of Sir Benjamin Brodie and other distinguished Avriters have fully established the latter point; and, as respects the former, its existence is daily witnessed in gouty and syphilitic disorders of the joints. When laboring under inflammation, the ligaments generally give rise to the most severe suffering, aggravated during the night, and leading to great constitutional irritation. This is well exemplified in sprains, Avhich are always among the most painful accidents. The physical properties of these textures do not seem to be much altered in the early stages of the inflammation : they retain their Avhite argentine as- pect, and here and there may be discovered a straggling capillary. Subsequently, they become more vascular, and their substance is infiltrated Avith serous, albuminous, or sero- sanguinolent fluid. If the disease continues its ravages, the ligament breaks down into a soft, lardaceous mass, containing white, silvery shreds, but no trace of vessels. No pus is secreted during these changes ; indeed, it is doubtful whether this fluid is ever deposited by this species of tissue, however much it may be inflamed. Atrophy of the ligaments is sometimes produced by the pressure of an aneurismal tumor, or other morbid growth ; but it more commonly arises through disease of the surround- ing textures. When the muscles of the shoulder or hip are paralysed, the capsular ligaments of those joints are not in- frequently so much attenuated and relaxed as to allow the bones to slip out of their sockets, and this occasionally in a very short period. Similar phenomena are sometimes wit- nessed in the temporo-maxillary articulation, and in the joints of the fingers and thumb. In these situations, indeed, spon- taneous dislocations, from atrophy of the ligaments, are by no means uncommon. Calcareous concretions, of the same character as those which are deposited within the synovial sacs, are sometimes found in the ligaments. When this matter is very abundant, as it is apt to be in persons of a gouty diathesis, it has a ten- dency to fret and irritate the ligaments, and to render them highly sensitive, and liable to hypertrophy. CHAPTER IX. Of the Osseous System. SECTION I. Of the Bones. I. The Bones. — Notions of the older Writers respecting their Organization. — Vessels and Nerves. — Chemical Constitution. — Effects of Heaf and Acids.— Classification. — Compact, Areolar, and Canaliculated Textures. — Discnses of the Bones. — Reparation. — Inflammation. — Suppuration. — Ulceration. — Gangrene. — Softening. — Fragility. — Hypertrophy. — Atrophy. — Hydatids. — Aneurism. — Carcinoma. —Melanosis. — Tubercle. — II. The Periosteum. — Its fibrous structure liable to the same kinds of Diseases as the fibrous Mem- branes generally. — Hypertrophy. — Ossification. — Is seldom, if ever, affected by the Heterologous Formations. — III. The Medullary Membrane. — Situa- tion and Character. — Diseases few, but important. The notions of the older anatomists respecting the organi- zation of the bones, were exceedingly vague and unphilosophi- cal. Many classed them among what they called the blood- less structures; and not a feAV imagined that they were entirely destitute of vitality. More correct observation, however, whilst it has long since exposed the fallacy of this opinion, has fully demonstrated that the bones, like the other organs of the body, possess a great abundance of vessels, so that they grow, waste, and are repaired ; and that their dis- eases differ in no respect, save in the tardiness of their pro- gress, from those of the soft parts. Nerves and absorbents do exist in the osseous tissue, probably in vast numbers, though it is difficult, if not impossible, to demonstrate them by the usual processes. The bones owe their importance in the economy to their mechanical properties: they are entirely passive in their character, forming so many solid pieces for the action of the muscles and their tendons; and hence, although they are furnished with vessels and nerves, they are destitute of that SECT. I.] ORGANIZATION. 325 sensibility which forms so striking an attribute of the soft parts. It is owing to this circumstance, that, in the normal state, the osseous tissue may be sawed, rasped, cut, or even cauterized, without the slightest indication of pain. When this substance is laboring under disease, it ahvays becomes highly sensitive, and often gives rise to the most excruciating suffering. Nothing, therefore, can afford a better proof of the vitality of the bones than this fact; for, although this property, as just mentioned, is quite obscure in their sound state, yet, when morbidly affected, they are subject not only to inflammation, but likewise to suppuration, ulceration, and even gangrene, — thus showing, in the most conclusive manner, that they possess the same organization, only in a less degree, as the other parts of the body, of which they have too fre- quently been considered, if I may so express myself, as semi- dead appendages. The vessels of the bones, which enter their surfaces at every point, may be demonstrated by injection, and a variety of other means, as sawing, cutting, and rasping. When they are filled with fine red matter, and steeped in dilute muriatic acid until the earthy matter is removed, they will become quite distinct, especially if the part so treated be afterwards immersed in oil of turpentine. The vessels of the bones un- dergo remarkable changes in consequence of age. In infancy and youth, they are not only comparatively larger, but they are also much more numerous than in the old and the de- crepid. These differences give rise to differences of color. In the young subject, the bones are of a bluish tint ; in the adult, on the contrary, they are pale and almost white. In death from droAvning, they are naturally well injected and highly vascular; and, in dropsical persons, they are generally remarkably blanched. I have never succeeded in tracing any nerves into the bones, nor have others been more fortunate. Some of the French anatomists, it is true, pretend that they have occasion- ally followed branches of the fifth pair through the nutrient foramina; but their dissections have not, I believe, been verified by subsequent investigations. As to myself, I have long been of the opinion that the nerves of the osseous tissue are conveyed to it through the medium of the arteries; that they enter the same apertures, and that they are so complete- ly concealed in their coats as to baffle all attempts at dis- covery. Whether this view is correct, future observation 326 BONES. [CHAP. IX. Fig. 30. can alone determine : it is certainly plausible, and strongly supported by analogy. Although the osseous tissue has been submitted to analysis by a great number of distinguished chemists, yet the results which have been obtained are by no rn^a^s so satisfactory as could be desired. According to Berzelius, one hundred parts of human bone consists of nearly thirty-three of gelatine, fifty-one of phosphate of lime, two of fluate of lime, and eleven of carbonate of lime, together Avith a small quantity of phosphate of magnesia, soda, and chloride of sodium. Fourcroy and Vauquelin met with no fluate of lime in their examinations, but detected some oxide of iron and manganese, silex, alumine, and phosphate of ammonia. The chemical composition of the osseous tissues varies considerably in the different stages of life under different circumstances of health and disease, in different pieces of the skeleton, and even in different parts of the same bone. In infancy and childhood, the relative proportion of animal matter is at its maximum, the earthy at its minimum. In advanced age, from the great predominance of phos- phate and carbonate of lime, the osse- ous tissue is remarkably brittle, and prone to fracture. If a portion of bone (Fig. 30) be sub- jected to a charcoal fire, and the heat be gradually raised, it will be found to burn first Avith a considerable flame and to emit a disagreeable animal odor, and at length to become almost perfectly red. If it be now carefully removed, and permitted to cool in a sIoav and gradual manner, it will exhibit a white chalk-like appearance, and be so light and brittle as to crumble on the slightest touch. In this operation, the animal sub- stance is extracted by destructive decom- position, whilst the earthy matter remains almost entirely unchanged; at the same time that the bone retains its mechanical figure, having merely lost a small portion of its weight. These results may also be ob- tained in a more or less perfect manner by long-continued boiling. A large part of the animal substance will thus be extracted, SECT. 1.] FORMS. 327 and furnish a solution, which, on cooling, gradually concretes into a tremulous jelly-like mass. If, on the other hand, a bone be exposed for some days to the action of a solution of nitric, muriatic or sulphuric acid, the saline ingredi- ents Avill be gradually withdrawn, whilst the organic part remains and becomes gradually soft, flexi- ble, and elastic, (Fig. 31.) When dried, it will be found to have lost a portion of its Aveight, which is in direct proportion to the quantity of earthy matter taken up by the acid ; yet it will be impossible to perceive that the least atom of its substance has been mechanically removed, or that its form and aspect have been in any Avise altered. In regard to their varieties of form, the bones may be divided in- to four classes, — the long, the broad, the short, and the mixed. The first, which are situated in the extremities, form a series of broken columns, which increase in number, but diminish in size, as they recede from the trunk. Each piece consists of a body, Avhich is cylindrical in some, triangular in others, and in nearly all a little curved, and of two heads, which are thick and expanded. But what particularly distinguishes the long bones is the fact of their having an internal canal, Avhich is usually of the same configuration with their shafts, and which is occupied, in the recent state, by the marrow and medullary membrane. The broad bones assist in enclosing the cranial and pelvic cavities: they are, for the most part, exceedingly irregular in their form ; and of the two surfaces which they present, one is generally convex, the other concave. The short bones are arranged in groups, forming masses Avhich combine mobility with solidity : they are characterized by an equality cf length, breadth, and thickness, by which they may be readily distinguished from the other pieces of the skeleton. * Animal substance of the radius, the earthy part being removed by the action of acid, leaving the remainder perfectly flexible. 328 BONES. [CHAP. IX. In the fourth division are included those parts of the skele- . ton which combine the form and character of the other classes. They are situated chiefly in the cranium and the chest, and consist of the occipital and temporal bones, the sphe- noid and ethermoid, the ribs, the clavicle, and the sternum. The form of these pieces is too irregular to admit of any general description. Although these different classes of bones all consist essen- tially of the same anatomical and chemical constituents, yet their texture is varied, not only in each division, but in different parts, frequently, of the same piece. The princi- pal modifications of form of the osseous tis- sue are three,— the compact, the areolar, and the canaliculated, (Fig. 32.) The compact substance occurs, in a greater or less degree, in every bone in the skeleton ; but it is in the long that it is more particularly conspic- uous, especially in their bodies, where it forms a layer of great thickness, Avhich gradually diminishes as it approaches the extremities. In its texture, this substance is so remarkably close as to render it impos- sible to detect any interstices in it with the naked eye. With the aid, hoAvever, of the microscope, we are enabled to discover nu- merous minute canals, Avhich freely commu- nicate with the canaliculated and spongy structures, which are designed for the trans- mission of the capillary vessels of the peri- osteum. These apertures, the existence of which was first clearly demonstrated by the celebrated Havers, an English anatomist, are found in great abundance throughout the whole skeleton, and their diameter va- ries, according to the recent measurements of Dr. Miescher, from the three to the eight hundredth part of an inch. In the long bones, the canals are directed obliquely ; in the broad, on the contrary, they run parallel with the external surface. In many places, they pursue a transverse course. * A section of the femur, showing its structure and medullary cavity. SECT. I.] MINUTE STRUCTURE. 329 When carefully examined, the compact texture appears to be made up of numerous concentric lamellae, Avhich are bound together by horizontal and oblique processes, and the thickness of Avhich varies in different parts of the skeleton, from the fiftieth to the five hundredth part of an inch. This arrangement, Avhich is best seen with the microscope, can be satisfactorily displayed by exposing a bone for a long time to the weather, and by protracted maceration in Avater after it has been deprived of its earthy salts. It is also rendered perceptible occasionally, on a rough scale, in mortification of the osseous tissue. The areolar texture is not so extensively disseminated as the compact; nevertheless, it occurs in nearly every part of the skeleton. It is particularly abundant and well marked in the short bones and in the extremities of the long, and evi- dently results from an interlacement of osseous filaments, prolonged inwards from the canaliculated structure. The cells, which are thus formed, vary extremely in regard to their size and shape in different parts of the bony system ; but they all freely communicate Avith each other, as may be proved by pouring quicksilver into them. This spongy substance, Avhilst it contributes materially to the lightness of the skele- ton, subserves the more important purpose of a reservoir for the medullary membrane, and a surface of distribution for the blood-vessels. The canaliculated texture, Avhich is interposed between the compact and areolar, occurs in all the parts of the skeleton, but is least evident in the broad bones. It consists of an assemblage of small, tortuous tubes, of an irregularly cylin- drical shape, nearly parallel Avith each other, and the sides of Avhich are pierced Avith minute apertures. In the long bones, they pursue a longitudinal direction ; but, in the short, they run from one articular surface to the other. Many of these canals communicate together, and their office, like that of the canals of Havers, by which they are chiefly formed, is to afford passage to the blood-vessels, as they proceed from the compact to the less dense substance of the osseous system. Bones, deprived of their earthy matter, exhibit a homo- geneous appearance ; but by prolonged maceration in water they may be resolved, as before stated, into different layers, each of which will be found, upon examination, to consist of a series of filaments, disposed in a longitudinal, oblique, or horizontal manner. By continuing this process, the filaments vol. i. 42 330 BONES. [chap. IX. here referred to, will gradually become soft and swollen, and at length present an areolar texture, similar to the subcuta- neous cellular substance. It may reasonably be concluded, therefore, that this areolar texture is the nidus Avhich receives the hard, calcareous, inorganic matter which imparts to the osseous tissue its firmness and characteristic properties. Having premised this brief sketch concerning the organi- zation of the osseous tissue, which seemed necessary to a more perfect comprehension of its diseases, let us proceed, in the next place, to consider its various lesions. Of these the most important are the following : inflammation, suppuration, ulceration, gangrene, softening, fragility, hypertrophy, atro- phy, hydatids, aneurism, carcinoma, melanosis, and tubercle. The restoration of a fractured bone is effected by adhesive inflammation, analogous, in many respects, to that of the soft parts. The changes Avhich attend it, and which are among the most interesting in the whole range of pathological inquiry, may be referred to four stages, each of which will require separate notice. In the first stage, Avhich extends over a period of about five days, the efforts of nature are altogether of a preparatory character, being limited to the absorption of the blood, which was poured out at the moment of the accident. At the expiration of this time, a change supervenes, Avhich bears a close resemblance to inflammation ; that is, the soft structures around the fracture become hot and vascular, their vessels enlarged and deeply injected, and their cells infiltrated Avith thick, viscid lymph. The same substance is effused betAveen and arouud the broken ends, as well as Avithin the medullary canal, and in this manner all the injured parts are temporarily glued together. This sub- stance, which is of a light pink color, and of a soft, gelati- nous consistence, is what is named callus, the real nature of which was a source of so many disputes amongst the ancient pathologists. As the restorative process advances, bony mat- ter is gradually deposited upon the surface of the medullary membrane, until at length a dense, solid plug is formed, which fills up the internal canal, and holds the fragments in contact. Whilst these changes are going on in the interior, the matter which has been effused upon the surface of the broken pieces also experiences important alterations. At first, as was before intimated, it is perfectly soft and gelatinous ; but by degrees it becomes firm and elastic, like cartilage, and finally assumes all the properties of real bone. This sub- stance is termed the provisional callus. It completely encases SECT. I.] UNION OF FRACTURES. 331 the fragments, adhering firmly to their outer surface. The quantity of callus is ahvays in direct proportion to the amount of injury; and hence it is usually greater in an oblique or comminuted fracture than in one that is transverse. In the third stage, the broken bone itself becomes sensibly changed; the lymph which Avas effused betAveen the frag- ments, and Avhich until noAV experienced little alteration, acquires consistence and firmness ; numerous vessels are developed in it Avhich communicate Avith those of the sur- rounding structures; and at length, ossification being com- pleted, the two ends of the broken bone are firmly reunited. The period required to effect these changes, is greatly influ- enced by the age and constitution of the patient, the plan of treatment, and the nature and seat of the fracture; but, in general, from six to eight weeks may be said to elapse between their commencement and completion. In the fourth and last stage, embracing a period of several months, the provisional callus is gradually absorbed, the soft parts resume their natural state, the prominence formed by the new bone diminishes, and the internal osseous plug is Avrought into cells and cavities, by which the medullary canal is at last completely reestablished. Thus it appears, as has been already hinted, that the pro- cess by which a broken bone is reunited is truly analogous to that Avhich nature adopts in restoring wounds of the soft parts. The only difference seems to consist in the changes which occur in the surrounding parts, and in the formation of the provisional callus. But, in order to render this pro- cess effectual, it is necessary that the broken bone should be kept at rest, that it should be provided with a due amount of animal matter, and that the vascular connection between it and the adjacent structures should not be too much inter- rupted. If these conditions be absent, the restoration will be imperfect, or a false joint will be formed. Fractures of the neck of the thigh bone, the patella, and olecranon, rarely unite by osseous matter, but in almost all cases through the medium of a white, fibro-ligamentous substance. The causes of this imperfect reproduction are not very obvious ; though it is not improbable, I think, that they consist chiefly in a defect of periosteum, in inefficient nutrition,, and in the difficulty which the surgeon experiences in maintaining the fragments in proper apposition. That the union of internal parts greatly depends upon the changes which take place in 332 BONES. [CHAP. IX. the surrounding textures, is a fact Avhich has been abundantly verified by observation ; and that false joints are often pro- duced by bad and injudicious management is equally true. In the examples, then, before us, it may be supposed that these are the principal if not the sole agents, which interfere Avith the restorative process. In the case of the neck of the thigh-bone, the influence of the periosteum, in the production of osseous matter, is strikingly illustrated by the fact, that, if the fracture be seated partly Avithout and partly Avithin the capsular ligament, the former will unite by bone, the latter by fibrous matter. When a. false joint is thus formed, the ends of the broken bone are gradually rounded off, and converted into a smooth, secreting surface, Avhich discharges a thin, oily fluid, not un- like synovia. The surrounding cellular substance is at the same time condensed ; and in this manner it is made at length to answer the purposes of a capsular ligament. Osteitis Avas formerly supposed to be of very rare occur- rence ; there is reason to believe, however, that it is not only a frequent malady, but that it is present, in some form or other, in almost every affection of the osseous tissue, whether primary or secondary. The bones most commonly affected are those of the extremities, especially the tibia, which, from its exposed situation and consequent liability to injury, seems to be particularly prone to it. The inflammation may be primarily seated in the osseous structure, or it may be propagated to it from the soft parts: in either case, the periosteum and medullary membrane are apt, sooner or later, to become implicated in the disorder. The malady is gener- ally slow in its progress, and hence it often happens that a considerable period elapses before there are any appreciable alterations of tissue. At first, the bone is simply'enlarged; but, in a short time, it loses its density, becomes infiltrated with sero-sanguinolent fluid, and assumes a bright reddish hue, the capillaries being very numerous, turgid, and distinct. As the disease advances, the osseous fibres separate from each other, and the Avidened intervals are filled Avith a soft gelatin- ous substance, mixed with which it is not unusual to find small clots of blood. These changes are generally attended by an absorption of earthy matter, which has the effect of rendering the bone soft and spongy, at the same time that it causes an actual diminution of Aveight. This, however, is not an in variable phenomenon, — cases occasionally occurring SECT. I.] OSTEITIS --SUPPURATION. 333 where the phosphate and carbonate of lime are deposited in in- ordinate quantity, by Avhich the osseous tissue is made preter- naturally brittle. When the inflammation is superficial, it usually extends, as Avas before remarked, to the periosteum, Avhich becomes hot, red, and swollen, —in a word, manifests all the signs of ordinary inflammation. When the medullary membrane is implicated, it becomes bloodshot, and the adipous matter is either rapidly absorbed, or it is transformed into a soft diffluent mass, of a light reddish color, and of a peculiarly offensive odor. When the ossific inflammation is fully established, the engorged capillary vessels refuse to re- ceive injecting matter, and can be drained of fluid only after protracted maceration. The painat tending this disease, is commonly of a dull aching character, and is apt to be worse at night than in the day-time. When the periosteum is in- volved, it is more severe, — sometimes, indeed, almost in- tolerable. Osteitis sometimes terminates in resolution, but more fre- quently, perhaps, in suppuration, ulceration, or gangrene. Suppuration of the external substance of the bones is a very common occurrence ; but, as it is ordinarily complicated with periostitis, it is difficult to determine Avhich structure is the source of the purulent secretion. It is most frequently ob- served in connection with some constitutional taint, such as scrofula, syphilis, or the protracted use of mercury; but it may, and very often does, exist as a purely idiopathic disease. When suppuration takes place in the spongy texture of the bones, the pus is sometimes contained in a delicate, vascular cyst, composed of coagulating lymph. Several such collec- tions are occasionally found in a single bone. In a carious tibia which I inspected several years ago, there were three distinct abscesses in the upper extremity, the largest of which did not exceed a common almond, whilst the smallest was scarcely of the size of a pea. They were lined each by a soft, vascular membrane, and the bony texture in the neigh- borhood was unnaturally hard and white. The subject was a female, forty-five years old, who finally died of pulmonary phthisis. Abscesses of this kind, it should be observed, sel- dom attain any considerable magnitude : their formation is attended with severe pain, and their contents are dark-colored, thin, and offensive ; and, if seated near the extremity of the bone, the matter usually manifests a tendency to work its way into the contiguous joint. 334 BONES. [chap. IX. Ulceration of the osseous tissue is most generally met with in young persons, being rarely observed in the adult or very aged. The disease, Avhich is usually known in the books under the name of caries, is precisely analogous to ulceration of the soft parts, the most prominent feature of each being a loss of substance through absorption. It is always preceded, as Avell as accompanied, by inflammatory action, and may be owing either to local injury or to constitutional causes, such as syphilis, scurvy, scrofula, or deficient nutrition. It may also result from the pressure of aneurismal tumors, or from the spread of malignant ulcers in the soft parts. Every part of the osseous system is liable to caries ; but the pieces most frequently attacked are those which form the walls of the thorax and pelvis. The bones of the tarsus and carpus, the bones of the spine, and the heads of the cylindri- cal bones of the extremities, especially the lower. Various attempts have been made to arrange caries into different species, the distinction being usually founded upon the appearances of the affected bone, and upon the nature of the exciting causes of the disease. Mr. Mayo, one of the most recent writers on the subject, states that there are four kinds of caries, — the simple, syphilitic, strumous, and malig- nant. The older Avriters had a still greater number, and every one, indeed, seems to have as many divisions as suits his particular fancy. Without wishing to substitute any classification of my own, I believe that, for all practical pur- poses, it will be sufficient to divide the disease into tAvo species, — the superficial, and deep-seated; the one commencing in the compact, the other in the spongy structure of the osseous texture. Caries often goes on for a considerable period without there being any ulceration of the soft parts ; and, in such cases, the diagnosis is usually extremely difficult. In the majority of instances, however, the nature of the complaint is indicated by the dull, aching pain, the tenderness on pressure, and the red, inflammatory state of the skin. After some time, the superincumbent parts become loose and boggy, and at length one or more apertures appear in them, through which there is discharged a very fetid, dark-colored, or grayish sanies. The bone which is thus exposed, has a foul and corroded aspect, its texture being softened, and infiltrated with a thin brownish fluid, mixed with blood, or with a yellowish, ropy substance, not unlike ill-elaborated pus. The ulcers some- SECT. I.] CARIES. 335 times occupy quite a considerable extent of surface ; but, in most cases, they are small, and of a rounded or oval shape. Their edges are steep, elevated, or abrupt, and their bottom is generally studded Avith small, osseous points, Avhich have the effect of making it rough and irregular. The erosions have sometimes a very great depth, and in the broad bones it is not uncommon to see them involve both tables, giving them thus a singularly cribriform appearance. Occasionally they have a sinuous arrangement, the affected surface bearing a close re- semblance to the bark of a Avorm-eaten tree. The osseous texture in the immediate neighborhood of these ulcers is al- ways in a state of inflammation ; and the same may be said of the periosteum, which is either red and thickened, greatly indurated, or even converted into fibro-cartilage. Cases occur, in which the osseous tissue, although slightly softened, is in reality very porous and brittle, owing to an inordinate deposi- tion of earthy matter. This form of the disease, which seems to affect only the broad bones, is generally attended with little discharge, and hence the ancients were in the habit of calling it " dry caries." The matter which attends ulceration of the osseous tissue is commonly of a thin, Avatery, ichorous nature, highly irri- tating to the soft parts, and of an offensive odor. It always contains a large amount of earthy salts, on which account the instruments used in dressing a sore of this kind are usually stained black, especially if made of silver. When granula- tions sprout up, as is always the case Avhen the ulcer mani- fests a disposition to heal, the matter becomes less acrid, more copious and consistent, and, as the recuperative process ad- vances, it assumes all the properties of laudable pus. There are feAV topics connected with the diseases of the bones which are more interesting than that of gangrene, whether we regard the facility and frequency of its occur- rence, or the various phenomena Avhich attend its progress and termination. The disease may occur at any period ; but, in the generality of cases, it comes on between the fifth and the twentieth years,— seldom before, and still more rarely after. The parts of the osseous system Avhich are most frequently af- fected are the tibia, clavicle, inferior maxilla, femur, ulna, radius, and fibula, though no bone in the body is, perhaps, entirely exempt from it. Necrosis may be partial or entire, simple or compound ; that is, it may affect merely a part of a bone, or it may pervade its 336 BONES. [CHAP. IX. Avhole structure; and, again, it may be limited to one bone, or it may attack several bones simultaneously, or several dif- ferent parts of the same bone. The causes of the complaint are either local or general, and are not essentially different from those which lead to gangrene in the soft textures. Amongst the local causes may be enumerated wounds, con- tusions, fractures, and chemical irritants ; amongst the in- ternal, a scrofulous, or venereal taint of the system, the long- continued use of mercury, and the effects of protracted and debilitating febrile diseases. But a much more frequent source, perhaps, of necrosis than any other that I have yet mentioned, is exposure to cold. This, at least, seems to be the way in which children generally contract this disease in this country. A boy, for example, Avith his body perfectly heated, suddenly plunges into the cold water, and thus at once checks the perspiration. He retires to bed in good health ; but, towards morning, he is roused from his slumbers by a severe pain in his tibia, clavicle, or radius. The skin next becomes flushed, the part is tender on pressure, and final- ly there is a circumscribed tumor formed, which, ulcerating, gives vent to a thin, sanious fluid, similar to that which, at- tends caries. All these phenomena indicate that there has been osteitis; and, if the bone be carefully inspected, a con- siderable portion of it will be found to have perished. When thus induced, the complaint is often extremely rapid in its progress, aud soon comes to a crisis. It has been stated that necrosis is sometimes partial, or, in other words, limited to a part of a bone. In such cases, death usually arises from external causes, as a blow or contusion, or from denudation, and rarely extends beyond the outer com- pact structure. Exfoliation is not a necessary consequence of a bone that is stripped of its periosteum. If it be in other respects healthy, and enjoy a vigorous circulation, granulations will spring up and gradually repair the breach. If the denu- dation, however, be very extensive, even although the bone should be perfectly sound, exfoliation will be very apt to take place, owing to the injury which has been inflicted upon the capillary vessels of the part. The exposed part, suppos- ing that the disease has been occasioned by a removal of the periosteum, remains white and dry, and after some time exfoli- ates, or comes away in one or more thin scales, plates, or la- mellae. The surface from which the separation has been effected is covered with florid granulations, which by degrees SECT. I.] NECROSIS. 337 assume the ossific process, and thus finally replace, either in part or entirely, the lost substance. The exfoliated bone is either Avhite, grayish, or of a light brownish color, rough, often very porous, and so brittle as to fall to pieces under the slightest pressure of the finger. No vessels can be perceived in it, and the animal matter seems to be almost wholly ab- stracted. By maceration, its dark color gradually disappears; and, by immersion in dilute nitric or muriatic acid for a feAV days, its texture is completely broken up, being converted into soft, sandy particles. When necrosis pervades the Avhole thickness of a bone, as it is apt to do when it follows caries, exposure to cold, small- pox, or measles, the process of separation is much more com- plex and tedious, months often elapsing between the death of the part and its final exit from the body. The first step in the process is the formation of a sort of osseous shell, Avhich seems to be designed to answer as a temporary substitute for the old bone, at the same time that it serves to isolate it from the surrounding parts. Let us inquire how this is effected; how an organ Avhich has so greatly suffered is repaired ? The dead boge acting as an irritant or an extraneous body, excites inflammation in the circumjacent structures, which become thickened and pour out coagulating lymph, similar to that Avhich is effused around the extremities of a fracture. After some time, varying according to the age and vigor of the pa- tient, this substance acquires the properties of cartilage, and this again, in its turn, is finally replaced by osseous matter, arranged in the form of an irregular shell, from one to three lines in thickness. In this shell one or more holes are left, which communicate, by means of sinuses, Avith the surface of the limb, and form the channels through Avhich, in the com- mon course of events, the dead bone, which is noAV named the sequestrum, is ultimately to be expelled. Whilst thus situated, the eschar is bathed either in thin, fetid, sanious mat- ter, or in thick, white, inodorous pus; and a part of it is almost always absorbed by the vessels of the new bone, in the same manner, it may be supposed, as the fang of a dead tooth is absorbed by the gum which surrounds it. The surface of the sequester is usually rough, excavated, or honey-combed, and its color either grayish, brownish, or black. In the cyl- indrical bones, it is almost always more or less dense and dry ; whereas, in the short, it is commonly porous, remarkably brit- tle, and moist. vol. i. 43 338 BONES. [CHAP. IX. As soon as the sequester is removed, Avhether by nature or by art, the temporary shell contracts, and by degrees assumes the form of the old bone Avhich it is designed to replace. Whilst this change is going on externally, osseous matter is deposited upon the inner surface of the shell, and upon the extremities of the surviving portions ; and in this manner the vacant cavity is finally filled up, the time required being al- Avays in proportion the size of the eschar. The medullary canal, in case there Avas one previously, is seldom reestablish- ed; and the new bone, although it remains for a long period highly vascular, is not able to withstand the effects of in- flammation so Avell as the original. Are bones ever completely regenerated ? Respecting this occurrence various opinions have been expressed by patholo- gists, some denying, others strenuously contending for the possibility of it. The question, it is obvious, can only be decided by observation ; and, if this be taken as our guide, few Avriters will ever be able to determine the matter for them- selves. Here, as in many other obscure points in pathology, a candid appeal to facts, as they have been recorded by phy- sicians, will do infinitely more than a thousand conjectures. The testimony of the older Avriters, unfortunately, is of little avail, as they were in the habit, too frequently, of distorting facts to suit their own theories. The same objection arises against some of the moderns ; still there are many exceptions, and from these we must draAv our information. All parts of the skeleton do not seem to be equally capable of reproduc- tion. The short and broad bones are much more rarely re- generated than the long ; and among the latter the occurrence has been much oftener Avitnessed in the tibia than in any other of the cylindrical pieces. Moreau saw a case of com- plete regeneration of the clavicle; Chopart, of the scapula; Fowles, of the ulna; and Weidemann, of the lower-jaw. In 1832, I had an opportunity of seeing an Irish lad, from Avhom Dr. Cusack, of Dublin, had, about four years previously, re- moved the left half of the inferior maxilla, on account of an osteo-sarcomatous affection. In this case, nature had made an attempt at reproduction, though it was still imperfect at the time I made the examination, the part being replaced by a thick, rounded piece of cartilage, sufficiently strong, hoAvever, to subserve the ordinary purposes of mastication. Not long since, a young man showed me the upper half of his astraga- lus, which had sloughed away several years ago ; yet he had SECT. I.] ARE BONES REGENERATED? 339 the perfect use of his ankle, Avhich can only be explained on the ground of a perfect reproduction of the necrosed bone. At the time I saw him, the ulna of the left arm Avas in a state of gangrenous inflammation. No doubt can therefore be entertained, it seems to me, respecting the possibility of bones being regenerated. For my own part, I am fully convinced of it, and feel assured that Avhoever Avill candidly investigate the subject will come to a similar conclusion. At the same time, there is reason to believe that the occurrence is extremely rare; and no account should be received as true, unless it be vouched for by re- spectable authority. The symptoms of necrosis do not differ, at first, materially from those of caries ; and the diagnosis can seldom be deter- mined with any degree of certainty until there is a discharge of dark-colored splinters, or until some of the dead fragments protrude through the opening in the soft parts, or are visible on separating its edges. When these phenomena are present, there can be no doubt of the nature of the disease; but, in cases of an opposite character, the diagnosis is sometimes extremely difficult. In such cases, a careful examination should be made Avith the index-finger; or, Avhere this is impracticable on account of the tortuous course of the sinu- ses, or the narroAV state of the ulcerated orifices, a probe should be employed, with which the condition of the bone should be accurately ascertained. Softening of the bones was first noticed as a distinct dis- ease in 1688, by Gabriel. More frequent in the female than in the male sex, it occurs almost exclusively in adults, and has been knoAvn, in a few instances, to involve the whole skeleton. Of this, the woman Lussiot, whose case is described in the Memoirs of the Royal Academy of Paris for 1752, affords a memorable example: her bones were so soft that they could be bent like wax, and put in almost any position. In a case described by the late Mr. Wilson, of London, the only pieces which escaped this disease were the sacrum and the bones of the foot. More generally, the lesion is confined to particular bones, being especially apt to occur in such as are largely supplied with spongy matter. The osseous tissue in this affection loses its firmness and consistence, becomes soft and pliant, and may be easily cut with the knife. It is of a pale reddish color, often inclining to yellow, is specifically lighter than the healthy structure, 34U BONES. [CHAP. IX. and is infiltrated Avith a turbid, viscid serum, removable by pressure. Occasionally, the osseous fibres are Avidely sepa- rated from each other, so as to leave large cells, which are filled Avith a bloody-looking, adipous substance. When this is the case, the bone is sometimes remarkably pliant, bending like semi-concrete wax. Boiling completely dissolves it; and exposure to the air, by abstracting its moisture, diminishes its weight. Such are the principal changes observable in the osseous tissue. The periosteum over the affected part is pale and extenuated ; the marrow is converted into a reddish, greasy sanies ; and the medullary membrane is Avasted down to a few soft, cellular shreds. The softening generally involves the whole thickness of the bone ; but cases sometimes occur in Avhich the outer table remains unchanged, consisting of a thin, brittle shell. The disorder obviously consists either in an inordinate absorption of the phosphate of lime, upon which the solidity of the osseous structure depends, or in a deficient deposition of this matter into its meshes. It has been already mentioned, that the bones become specifically lighter in this disease ; and Dr. Bostock has ascertained the additional fact that they contain nearly eighty parts of animal substance in the hundred. The causes of this change are buried in entire obscurity. Does it depend upon inflammation ? Mr. Gendrin thinks it does not, and assigns quite a number of reasons in support of his opinion. But do not all the phenomena of this affection indicate the reverse of this theory ? Let the student compare the anatomical characters of ostitis and softening, and see if they do not strikingly resemble each other. We do not, by this, Avish to be understood to mean that softening is caused by active inflammation; all that we are anxious to convey is, that the disease in question is the result of a sIoav, chronic irritation, leading to lesion of nutrition in the osseous tissue. It is seldom that this disorder is attended Avith any pain ; and this may be regarded as another argument in favor of the opinion that it does not depend upon acute inflammation. The bones are liable to become preternaturally brittle, crumbling to pieces under the most trifling accidents. The disease, Avhich is technically called fragility, is most com- monly found as an attendant on old age, and is seldom re- stricted to any particular class of bones, though the cylindri- cal are perhaps most prone to it. The cause of this singular affection has been a source of much theoretical discussion. SECT. I.] FRAGILITY--HYPERTROPHY. 341 The best Avriters, however, agree in referring it to a lesion of nutrition, produced by a diminution of the number and vol- ume of the vessels of the osseous tissue. The validity of this opinion derives great plausibility from a contemplation of the changes which the bones undergo in the different periods of life. In childhood, the osseous tissue is remarka- bly flexible and pliant, and contains a large amount of animal substance ; in old age, on the contrary, it is very dense, hard, calcareous, and extremely liable to break, the slightest exer- tion or accident being often sufficient to cause this result. The number of fractures that are sometimes produced in this way, even in young persons, is truly astonishing. M. Dever- gie* states that he dissected a female, in 1818, who died under symptoms of fragility, in whose skeleton he found not less than eighty-three fractures. Dr. Gibson gives the case of a young man, nineteen years of age, in Avhom the bones of the arm, fore-arm, thigh, and leg, have all been repeatedly broken, from the most trivial causes. The clavicles have suffered still more frequently, having been fractured eight times. Fractures from this cause sometimes occur in the fostus in the Avomb. Chaussier has related a remarkable ex- ample of this kind, in which each of the long bones presented one or more of these lesions, some of which were recent, others beginning to unite, whilst others were consolidated. The child survived its birth only tAventy-four hours. Some- what similar cases have been reported by Gardner and Glo- kengieser. Bones affected Avith this disease are sometimes completely saturated with oily matter, which renders them unfit for preparations ; but, in most instances, they are dry and brittle, and crumble to pieces under the slightest pressure. In the latter stages of scurvy and scrofula, they become often ex- tremely fragile; and, if they be boiled, they break down into thin, irregular scales, or are almost entirely dissolved. The disease is rarely attended with any pain, and the general health is usually remarkably good. When fractures occur, they sometimes rapidly unite ; at other times, however, res- toration does not take place, or only after a very long period. Hypertrophy of the osseous tissue in different parts of the body may be either partial or general; that is, the abnormal growth may affect either a portion or the whole of a bone. * Dictionnaire de Med. et Chirurg. Practique, t. x. 1833. 342 BONES. [chap. IX. The latter, however, is a very rare occurrence, though per- haps not so much so as has been generally imagined. Cases, indeed, not infrequently occur, in which the broad bones of the head present an extraordinary degree of developement, being more than an inch in thickness, and so hard that it is almost impossible to saw them through. Under these cir- cumstances, the two tables are extremely compact, and the intermediate spongy structure is totally obliterated, or rather replaced by dense, earthy matter. Similar appearances are sometimes Avitnessed in the cylindrical bones of the extremi- ties. In an old femur in the museum of morbid anatomy in the Cincinnati College, the medullary canal is scarcely large enough to admit a common-sized quill; and the Avhole shaft seems to consist almost entirely of compact substance, in many places more than six lines in thickness. The bones of the male are always larger and more distinctly developed than those of the female ; and the bones of persons who take severe and constant exercise, than those who are indolent, or make but little exertion. By labor, their weight and dimen- sions increase; their spongy structure diminishes, Avhilst the compact becomes harder, of a closer grain, and acquires an almost rock-like solidity; the muscular prominences are ren- dered more conspicuous ; — in short, every thing indicates that they are in a state of general hypertrophy. When thus cir- cumstanced, the osseous tissue usually contains a due propor- tion of animal matter ; and hence it is always capable of re- sisting, in a very eminent degree, the influence of such agents as have a tendency to injure it. When the hypertrophy is partial, it constitutes what is called an exostosis, — a Greek term, literally implying an exuberant groAvth of bony matter. Tumors of very opposite characters have been described by writers under this head, and, as might be expected, much confusion has been the result. To avoid this, if possible, in the present instance, I deem it necessary here to state that, by the word exostosis, I understand, in common with the best pathologists of the day, simply a bony excrescence, similar in its structure to the osseous tissue in its normal condition. Nothing can be more unscientific, it seems to me, than the classification proposed by Sir Astley Cooper, who has described under this head some of the most malignant diseases to which the bones are subject. The bones most commonly affected by this species of SECT. I.] EXOSTOSIS. 343 hypertrophy are the femoral, frontal, parietal, and lower- maxillary,— the relative frequency of its attack being in the order here stated. No part of the skeleton, however, appears to be exempt from it ; and, in a feAV instances, it has been known to affect a large number of pieces at the same time, as if there had been an exostotic diathesis. Great variety prevails in regard to the size and shape of these tumors. In most instances, they look like small, irregular excrescences, with a rough, scabrous surface; but sometimes, especially when they are seated on the flat bones, they are of a spheri- cal form, and nearly or quite smooth. In other cases, again, they have a mammillated appearance; or they form flat discs, resting upon a short, narrow pedicle ; or, finally, they are rounded, nodular, or knob-like. Their size seldom ex- ceeds a small apple, orange, or potatoe, though examples are occasionally met Avith, Avhere they are as large as a cocoanut or a foetal head. In a specimen in our museum of morbid anatomy, the walls of the left maxillary sinus are literally studded Avith these growths, none of which exceeds a small grain of wheat, Avhich they also very much resemble in shape. In their structure, exostoses present all the varieties of the natural bone upon which they grow, being composed of a soft, spongy texture, enclosed by a layer of solid, compact matter. Occasionally, they are surrounded by a coat of cartilage; and very frequently they have all the firmness and density of ivory. In the healthy state, they are per- fectly insensible; but they are susceptible of inflammation; and it is probably when laboring under this disease, that they experience those changes Avhich have obtained for them the names of fungous, medullary, and cancerous, so much in vogue amongst some surgical Avriters. These tumors are formed in the same manner precisely, as the osseous tissue in other parts of the skeleton, passing always through the same stages of ossification. That this is the case, will appear sufficiently obvious, if Ave refer for a moment to the causes by which they are produced. Amongst these, the most common, perhaps, are the various kinds of external violence, such, especially, as blows or con- tusions ; though many contend for a scrofulous, gouty, or syphilitic origin. Induced in any of these ways, there must be local inflammation, either in the bone, or in the periosteum, or in both, — one of the effects of which is an effusion of 344 BONES. [chap. IX. coagulating lymph. This, after some time, is converted into cartilage, and this finally into bony matter. Some exostoses are extremely rapid in their groAvth, and soon attain a Arery considerable magnitude; most commonly, however, their developement is gradual, going on for many years Avithout causing any serious inconvenience. They are seldom attended with much pain ; indeed, it is only when they are very large or when they degenerate into cancerous affections, that they become a source of local annoyance and constitutional disturbance. Youth seems to be the period in which these groAvths are most frequent, though adults and old persons are by no means exempt from them. In atrophy, the osseous tissue undergoes partial absorption, as is evinced by its abnormal softness, lightness and porosity. The portions of the skeleton most obnoxious to this change are the long bones of the extremities, the compact structure of which is often remarkably diminished in consistence and thickness. In the museum of the Cincinnati College, are the cylindrical bones of the arm, fore-arm, thigh, and leg, of a colored woman, about forty years old, who died of tubercular phthisis, Avhich are reduced to mere shells, the cortex of several of them being scarcely as thick as Avrapping paper: they are all extremely light and brittle; and, during the maceration Avhich Avas necessary to clean them, they became so soft that they could be easily cut with the knife. The medullary canal was much enlarged by an absorption of its spongy texture, and contained a greasy, reddish substance, not unlike fresh adipocire. Pressure, steadily exerted for a considerable length of time, has a tendency to produce atrophy in the osseous tissue. This is Avell exemplified in the cranial bones, in tumors of the dura mater ; in the sternum and the dorsal vertebras, in aneurism of the aorta; and in the ribs, in cancer of the breast. In all these cases, the compact substance is reduced to thin, translucent plates, whilst the spongy texture is either Avholly destroyed or worn doAvn to a few slender threads. In old age, the bones are usually deprived of a part of their weight; their muscular prominences are partially wasted; and they no longer contain the same amount of animal mat- ter, nor the same number of vessels and nerves. In painful and protracted diseases, the bones seem to partake of the general emaciation ; and, in limbs that have been long anchy- losed or paralysed, they are often sensibly diminished in size and weight. SECT. 1.] HYDATIDS. 345 The bones are occasionally the seat of hydatids, occurring either separately or in small clusters. Their Avails are ex- tremely delicate, transparent, and slightly vascular ; and their contents, which are thin and limpid, are coagulable by heat, alcohol, and acids. They seem to be true acephalocysts, are generally of a globular form, and vary in size and number in different cases, being usually larger Avhen there are only a few than when there are many. The seat of this malady does not seem to be restricted to any particular class of bones, though the long ones are per- haps most subject to it. Its causes have not yet been satis- factorily investigated; nor are its symptoms such as to enable us, in the present state of our knowledge, to distinguish it from other affections. In the instructive case related by Mr. Keate, of London, to Avhom we are indebted for the first accurate account of the nature of this rare disease, the hyda- tids Avere developed in the frontal bone, Avhich formed a tumor immediately over the left eye, about the size of an orange. The patient was a young female, and the complaint had been coming on for a number of years.* In another case, mentioned by Cruveilhier, the disease Avas seated on the anterior part of the tibia, and had the appearance of an indo- lent steatomatous growth, Avith a hard, irregular border. On being laid open, it gave vent to a thick inodorous fluid, re- sembling the dregs of Avine. One of the most singular features of these cysts is their indestructible nature, being almost sure, unless completely destroyed, to be speedily re- generated. Another very rare and singular disease of the osseous tissue, which, in many of its phenomena, closely resembles the anastomotic aneurism of the soft parts, has been recently pointed out by M. Breschet, an eminent pathologist of Paris.f The complaint has since attracted the attention of other writers, and in my Avork on the diseases of the bones and joints it has been described under the term osteo-sanguineous, as most expressive of its true nature and character. It has hitherto been witnessed chiefly in young subjects ; and its most common situation is in the vicinity of the knee-joint, implicating the cancellated structure of the upper extremity * Medico-Chirurg. Transactions, vol. x. p. 178; London, 1819. t Observationes et Reflexions sur les Tumeurs Sanguinis des Os; Repertoire Generale d'Anatomie, &c t. ii. Paris, 182b'. vol. i. 44 346 BONES. [CHAP. IX. of the leg bones. The tumor varies in size in different cases, being sometimes small, sometimes large. In an instance mentioned by Mr. Bell, of Edinburgh, it measured more than nine inches in circumference, and more than six in length. The cellular texture of the diseased bone is either partially or wholly destroyed, and its medullary canal is enlarged and filled with coagulated blood, disposed in concentric layers, as in old aneurismal tumors. These clots form one or more cavities, each of Avhich communicates with a number of small arteries. Sometimes the blood is partly fluid, and partly coagulated; but, in the majority of cases, it exhibits the ap- pearance that has just been assigned to it. The external table of the bone is considerably attenuated, in many parts destroyed, and in some so flexible and elastic that it may be bent like cartilage. Very often, hoAvever, the part is extremely brittle, and may be crushed like the shell of an egg. The periosteum is generally thickened and in- durated ; but the joints Avhich are situated in the immediate vicinity of the disease are commonly healthy, even Avhen they are separated from it merely by a thin layer of cartilage. The vessels Avhich ramify through the substance of the bone are usually tortuous and brittle, increased in size, and open, as already stated, by numerous little orifices into the aneuris- mal sac in the centre of the diseased mass, as may be shown by filling them with minute injecting matter. The causes of this lesion are still involved in great ob- scurity, nothing being known with any certainty concerning them. In some instances, it has been attributed to a blow; in others, to a fall or jump from a considerable height. Either of these causes, by disturbing the vascular action of the bone, might produce the disease. Occasionally it is connected Avith a gouty or rheumatic diathesis, and then it probably depends upon inflammatory irritation. An osteo-sanguineous tumor is tense, painful, and tender on pressure. When fully developed, a deep-seated pulsation is observable in it, which is isochronous with that of the heart, and somewhat similar to the motion which is imparted by an anastomotic aneurism of the face. By compressing the main artery of the limb above the tumor, the pulsation ceases, reappearing immediately when the pressure is removed. This is an important fact, Avhich may be regarded as diagnostic of the nature of the disease. Cartilaginous tumors are sometimes developed in the SECT. I.] CARTILAGINOUS TUMORS --ENCEPHALOID. 347 spongy texture of the bones, or upon their outer surface. Their growth is generally rapid, and the pain which attends them considerable, sometimes very severe. The disease which is usually described under the vague name of osteosarcoma, is always of a malignant character, and seems to have a peculiar predilection for the bones of the extremities, and for the upper and lower-jaw. The tumor is commonly of a globular form, with a rough, nodulated surface, and not in- frequently attains an extraordinary magnitude. It is firm, dense, and elastic like cartilage, of a light grayish color, and contains a vast number of minute oblong cells, filled Avith a reddish, gelatinous fluid. In general, small spicules of bone are dispersed through it; and, in most cases, it is surrounded by a thin, porous shell, so soft that it may be cut without blunting the knife. Occasionally, the tumor is hard* and fibrous, or red and dense, like half-boiled beef, or fresh pork. Another variety of osteo-sarcoma, but of a still more formi- dable character, because more malignant, is the encephaloid, the fungus hasmatodes, or soft cancer of surgical writers. It generally, if not always, originates in the spongy structure, probably from inflammation of the medullary membrane ; and it most commonly attacks the long bones of the extremities, especially the tibia and femur, also the digital phalanges. No portion of the skeleton, hoAvever, seems to be exempt from it. Mr. Mayo has seen it in the ilium, the cranial bones, the sternum, and ribs ; and others have witnessed it in the clavicle, the scapula, the lower-jaw, and dorsal vertebrae. The most terrific feature of this disease is its tendency to recur in some other part of the body, after it has been dis- lodged from its original situation. On this account it is almost always fatal. It may occur at any period of life, but chil- dren seem to be most prone to it. Its progress is often fright- fully rapid, and the sufferings which it occasions truly agonizing. The tumor is generally disposed in rounded and lobu- lated masses, of the color and consistence of the medullary substance of the brain. Very frequently it contains small cavities, Avhich are filled either with clotted blood, Avith dirty looking serum, or with soft, gelatinous, oily, sebaceous, or melliceric matter. Occasionally one part of the tumor pre- sents the brain-like character, Avhilst the other has all the appearances of a dense coagulum; but, in the majority of cases, these two substances are pretty intimately blended together. 348 BONES. [chap. in. Vessels can often be seen ramifying over the surface of the morbid growth, but very feAV can be traced into its substance, at least not to any great depth. x\s in the preceding variety, so in this, the outer table of the bone is often expanded into a mere shell, or is even entirely destroyed by absorption. The skin is at first soft, glossy, and marked by numerous veins, which meander through it in various directions; but, at length, from the constant pressure Avhich is exerted upon it, it ulcerates, and alloAvs the fungous mass to protrude and give vent to its foul discharges. Melanosis is sometimes met Avith in the bones ; but the occurrence, I presume, is extremely rare, and I have never seen an example of it. It is deposited sometimes in small disseminated masses, sometimes in delicate nodules or clus- ters, sometimes in the form of infiltration. Mr. Halliday, an English physician, has reported an interesting case in the London Medical Repository for 1823, in Avhich the melanotic substance Avas diffused through the spongy texture of the parietal and occipital bones, the sternum, and ribs, dying them, in a great part of their extent, of a deep black color. In the generality of instances, hoAvever, the disease is devel- oped in the long bones, particularly in the femur and tibia. In its progress and mode of termination, it closely resembles osteo-sarcoma, its nature being decidedly malignant. Tubercles of the bones, although not of very frequent oc- currence, are yet sufficiently common to render them objects of particular interest to the pathologist. From the recent researches of some of the French anatomists, especially of Nichet and Nelaton, there is every reason to believe that what is named Pott's disease is owing, in most cases, to the devel- opement of these bodies. Nor are these heterologous forma- tions always confined to the vertebras: in many instances they affect the short bones in other situations, and they seem to be very often deposited in the articulating extremities of the long ones. The particular seat of tubercles is the spongy texture, though occasionally they are formed upon the outer surface of the bones, betAveen it and the periosteum. There are two varieties of form in Avhich this matter may be deposited. In one, perhaps the most common, the tuber- cles are encysted, the enclosing membrane, which varies in thickness from a fifth to half a line, being composed of coagulating lymph, very soft at first, but gradually becoming harder and harder, until finally, in some cases, it acquires the SECT. 1.] MELANOSIS. 349 character of fibro-cartilage. It is of a dull grayish color, is made up of delicate, inelastic fibres, crossing each other in every conceivable direction, and is furnished frequently with small vessels, passing into it from the surrounding structure. The number of tubercles is seldom very great; their size varies from that of a pea to that of a nutmeg; and in most cases they present a yelloAvish, opaque appearance. Occasion- ally these bodies become softened, when the matter will either work its way out, or pass, by a sort of fistulous route, into a neighboring joint, establishing thereby an analogy with pul- monary tubercles opening into the bronchial tubes. Some- times a spontaneous cure takes place, the heterologous sub- stance being absorbed, and the cyst contracting so as to ob- literate its cavity. In the second variety, the tubercular matter is deposited directly in the cells of the osseous tissue, forming grayish, semi-transparent, opaline patches, from one sixth of an inch to an inch in diameter. This infiltration has hitherto been noticed chiefly in the bodies of the vertebras, and, Avhat is remarkable, is frequently pervaded by numerous vessels, too delicate to be discerned Avith the naked eye. The bony tis- sue immediately around is sometimes deeply injected, but seldom otherwise diseased. In this, as in the preceding va- riety, the tubercular deposit, after having existed for some time, gradually softens, its vascularity disappears, and the cells in which it was contained are filled up Avith earthy mat- ter. This, however, is not ahvays the case ; for now and then the ulcerative process continues until the bone is totally destroyed. SECTION II. ' Of the Periosteum. The outer surface of the bones is every Avhere closely invested, excepting at their articular extremities, by a tough, fibrous membrane, which is hence called the periosteum. In its structure, it strictly resembles the dura mater the peri- cardium, and the aponeurotic sheaths of the muscles, being, like them, composed of strong, dense, and inelastic filaments, 350 PERIOSTEUM. [chap. IX. which are matted together in the firmest and most inextrica- ble manner. Of the two surfaces Avhich this membrane presents, the external is rough, and covered by a small quan- tity of cellular substance, by Avhich it is connected to the surrounding textures: the inner, although not perfectly smooth, is much less flocculent than the other, and is joined to the bones by an immense number of little slender pro- cesses, which extend into the osseous tissue, and serve to transmit the nutrient vessels. In certain regions of the body, as in the mouth, nose, ear, and sinuses of the head, the peri- osteum is in immediate contact with the mucous membrane, to which it adheres Avith extraordinary tenacity. It consists every where of a single lamella, the thickness of Avhich varies from the fifth of a line to the twelfth of an inch, according to the age of the subject, and the situation in which it is located. The periosteum has a plentiful supply of blood-vessels, which are derived from the adjacent branches, and Avhich freely anastomose with those of the bones. Its nerves and lymphatics are few in number, and so excessively delicate as to elude the unassisted eye. In health, the membrane pos- sesses little sensibility; but, when under the influence of inflammation, the patient suffers the most acute pain, which is often relieved by dividing the diseased texture. In infancy, this membrane is soft, thick, and spongy, and may be readily detached from its connections. In adult life, it is more firm and compact, and adheres so intimately to the bones that it is separated with difficulty. In old age, it is extremely tough, and not unfrequently ossified on its internal surface. Its vascularity, which is at first rather obscure, also gradually increases as Ave advance in years, but again dimin- ishes in old age. The color of this membrane is likeAvise subject to considerable variation. In the young it is of a lilac tint, which becomes lighter towards middle life, and is finally replaced by a dull white. In persons Avho die from asphyxia, the color of the periosteum is generally a feAV shades deeper than in such as perish from lingering diseases. The morbid relations of the periosteum, although not un- like those of other fibrous textures, are too important to be passed by without due notice. The most common lesion to which this membrane is liable is chronic inflammation, fol- lowed by thickening, and the deposit of osseous matter, generally upon the internal surface, but occasionally upon SECT. II.] INFLAMMATION. 351 the external. Acute inflammation is also frequently observed, and seldom exists Avithout implicating the subjacent bone. Inflammation arises either spontaneously, from external injury, or from the operation of the syphilitic poison. In the acute form of the disease, the membrane becomes red- dened, its vessels are loaded Avith blood, and its substance is sensibly softened as Avell as slightly thickened. Its attach- ment to the bones is also considerably diminished, so that it can be much more easily peeled off, and the cellular sub- stance on its external surface is generally infiltrated with sero-albuminous matter. These changes are frequently ob- served upon the fragments of a broken bone, and in incised wounds of the muscles, involving the periosteum. This disease, especially the acute form of it, not unfre- quently passes into suppuration. This event is more par- ticularly apt to occur in periostitis of the inferior extremity, caused by the influence of cold upon a strumous constitution, or by the effects of mercury, or the action of the syphilitic virus. In either case, the suppurative process is remarkably tardy, and the pus is rarely of a healthy character, but almost ahvays very thin, bloody, and offensive, with flakes of curdy matter. As the fluid accumulates, the superincumbent integu- ments assume a red, glossy, and SAVollen appearance ; the part is excessively painful ; fluctuates distinctly under the pressure of the finger; and, when the abscess is laid open, the corresponding portion of the bone is usually found to be destroyed by ulceration. Another termination of acute inflammation is mortification. When this occurs, the normal appearance of the membrane is lost, and changed to a dirty ash-color, Avhilst its texture is softened, easily torn, and bathed in a foul offensive fluid, having the characteristic gangrenous odor. This termination, it need scarcely be observed, can never take place without the osseous texture participating in it. The best examples of it are witnessed in the periosteum of the alveolar processes of the jaws, from the abuse of mercury, and in that of the tibia from common necrosis. The sloughs, which are ahvays tough and shreddy, are usually thrown off with considerable difficulty, OAving to the tardy and imperfect action of the circumjacent structures. When the periosteum labors under chronic inflammation, it is very apt to become thickened, from the effusion of plastic lymph. The hypertrophy, for so it may be termed, generally 352 PERIOSTEUM. [CHAP. IX. occurs in association Avith induration, and often involves a considerable extent of surface, forming a diffuse, incompres- sible SAvelling, partly fibrous, partly cartilaginous, and partly osseous. In other cases, the hypertrophy is more circum- scribed, and either exhibits the mixed structure just specified, or it is entirely bony. These tumors are commonly of slow formation, and they seldom acquire any great bulk. During the progress of their developement, they are the seat of a constant, deep-seated, gnawing pain, which is most severe at night, Avhen the body becomes Avarm in bed. After continu- ing for an indefinite period they either remain stationary, or they gradually disappear by absorption, or they excite suppu- ration in the super-imposed textures. In old people, nothing is more common than to find this membrane ossified upon its internal surface, or even through its entire substance. When thus affected, the periosteum is of a dull drab color, resists the knife, and is Avith difficulty detached from the bone which it covers, OAving to the partial incorporation of their tissues. When dried, it exhibits very much the appearance of an ossified artery. In the extremi- ties, especially in the thighs, I have frequently seen consider- able nodules of bone spring from the outer surface of this membrane, so as to encroach more or less upon the muscles. In their shape, they are, for the most part, ovoidal, and in their consistence they fully equal the petrous portion of the temporal bone. Their color is usually a feAV shades lighter than that of the osseous texture in the healthy state. The periosteum has been found affected, in a few rare cases, with melanosis ; and occasionally, also, Avith the tubercular deposit. In carcinoma of the bones, the membrane is often implicated secondarily, but it is rarely, perhaps never, the original seat of this formidable malady. In a number of dis- sections Avhich I have made of encephaloid disease of the bones and soft parts, I have found the periosteum entirely un- touched, not even thickened or indurated. Hence Ave may infer that this fibrous lamella possesses an astonishing self- preserving power, much superior to what is enjoyed by most other tissues. SECT. III.] MEDULLARY MEMBRANE. 353 SECTION III. Of the Medullary Membrane. There is another structure, which, from its important re- lations with the bones, demands a few remarks before Ave finally close the present chapter. I need scarcely say that I allude to what is called the medullary membrane. This delicate and beautiful structure is generally described as being entirely restricted to the canals of the long bones,— an opinion which is not easily explained, when it is recollect- ed that the cells of the areolated texture of these organs are constantly filled with adipous matter, which it is the proper office of this membrane to elaborate. True, it is not so easily demonstrated in the latter as in the former situation; but the fact just referred to amply proves that it must exist there; otherwise it would be impossible to account for the presence of adeps. To display the medullary membrane, it is neces- sary to saAV one of the cylindrical bones in the longitudinal direction, and then plunge it into boiling water, or expose it to the action of some dilute mineral acid. The membrane will thus become detached from the parietes of the internal canal, and adhere to the adipous substance, so as to appear perfectly distinct. If it be now carefully inspected, it will be found to be essentially composed of cellular tissue, blood-ves- sels, nerves, and lymphatics. It is pierced by a multitude of minute foramina, and is so thin and delicate as to bear a striking resemblance to a spider's web. It is connected, on the one hand, to the parietes of the bones by very thin and slender processes; and, on the other, it detaches an immense number of septa, which, by their interlacement with the inter- nal cancellated structure, and with each other, form a vast mul- titude of cells, similar to those of the adipous tissue in other parts of the body, both as respects their structure and func- tions. The sensibility of this membrane is very obscure in the normal state ; and it is so delicate as to be very easily torn. Of the diseases of the medullary membrane, not enough is known to enable us to speak with any degree of decision. Acute inflammation is extremely rare, and is observed princi- pally in fractures of the long bones. The membrane in this vol. i. 45 354 MEDULLARY MEMBRANE. [CHAP. IX. form of the lesion assumes a reddish tint, and the secretion of fatty matter is not only temporarily suspended, but that which existed prior to the occurrence of the accident is generally absorbed. In violent cases, pus is effused, and forms an ab- scess in the interior of the bone. In necrosis, the medullary membrane, corresponding Avith the affected portion of bone, loses its vitality, and is gradually broken up into a dark-color- ed, oily putrilage. of a fetid, gangrenous odor. Chronic inflammation of this membrane, I have recently seen in the tibia and fibula of a man sixty years of age, Avho died from the effects of a sloughing ulcer, brought on appa- rently by intemperance. Both bones Avere in a state of ne- crosis at their middle ; inferiorly they were greatly expanded, but toAvards the knee they Avere of the natural dimensions, and contained a red, florid-looking marroAV, of preternatural hardness. The discoloration, however, was not uniform, but occurred in distinct patches, varying in diameter, from that of a pea up to that of a twenty-five cent piece. Since the adipous tissue of the bones bears the greatest re- semblance to that in other parts of the body, it is highly prob- able, I think, that it possesses certain modifications of struc- ture, leading to corresponding peculiarities in reference to its diseases. That this is the case, I am disposed to believe, from the fact that the medullary membrane is not unfrequently the seat of several of the heterologous formations, such as the scirrhous and encephaloid, which are never developed. So far as I know, in the adeps of the general system, the tuber- cular matter is also sometimes deposited here; and another argument in favor of this vieAV is founded upon the notable difference in the products of the two tissues, that of the bones being always of a thin, oily nature, and composed principally of elaine, the other, semi-concrete, and formed mainly of stearine. CHAPTER X. Of the Cutaneous System. SECTION I. Of the Skin. I. The Skin. — Number of Layers. — Epidermis. — Mucous Web. — Dermis. — Papillae. — Sudoriferous Glands. — Sebaceous Follicles.— Reproductive power of the different lamellae of the Skin.— Diseases. — (I.) Unclassifiable Lesions. —Keloid. — Melanosis. — Encephaloid. — Cartilaginous Tumors. — EiloTd. — Lepold. — Hypertrophy. — Corns. — Warts. — Horny Excrescences. — Gan- grene. — Sebaceous Tumors. —Hemorrhages.— (rr.) Classifiable Lesions. — 1. Exanthematous Diseases.—2. Pustular. — 3. Papular.— 4. Bullar. — 5. Tubercular. — 6. Scaly. — 7. Syphilitic Diseases. — 8. Stains. — II. The Nails. — Situation, Composition, and Arrangement. — Growth. — Reproduc- tive Power. — Inordinate Length. — Absence. — Malformation. — Vicious Situation.— Onyxitis.—III. The Hairs. — Similarity to the Kails. — Situa- tion. — Consist each of a Follicle and Stem. — Organization. — Polish Plait. — Regenerating Power. — Hypertrophy. — Female Beards. — Softening. — Fragility. — Changes of Color. — Accidental developement of Hair. With the situation and appearance of the skin all are familiar. Forming the general envelope for the body, it ansAvers the same purpose to the outer surface, that the mu- cous membranes do to the excretory canals, into the openings of which it dips, so as to participate in their structure. Vary- ing in thickness, from the sixth of an inch to the third of a line, it presents considerable diversity not only in different regions, but likeAvise in the different periods of life, being extremely soft and delicate in infants, more firm and resisting in adults, flabby and Avrinkled in old age. It is also more delicate in the female than in the male, and in health than in disease, when it is frequently hard, dry, and shriveled. Much contrariety of sentiment still exists among anatomists respecting the precise number of layers of which the skin is composed,—some, as Chaussier and Gordon, asserting that there are only two ; some, that there are three ; some, that there are four; and others, again, that there are as many as five, six, or even seveu. The second of these opinions, how- 356 SKIN. [CHAP. X. ever, is that Avhich has received the greatest number of advo- cates, and is the one, moreover, which accords best with the results of my own dissections. Adopting this view, we shall find that the external tegument is made up of three distinct strata,—an outer, middle, and inner, the first being named the cuticle, the second the mucous Aveb of Malpighi, and the third the dermis or true skin. The cuticle, also called the epidermis, or scarf-skin, is the most superficial layer of the three, being spread over the mucous Aveb like a thin varnish of gum shellac. Of a dull white color, it is elastic, hygrometric, transparent, and so yielding in texture, that it readily tears. It is rendered yellow, and finally dissolved by immersion in nitric acid, swells a little when macerated in Avater, emits a peculiar animal odor on being exposed to a red heat, is nearly impu- trescible, and is composed principally of albumen, with a small quantity of gelatine and salts. The epidermis consists every where of a single lamella, excepting in the sole of the foot, Avhere, from mechanical pressure, it is frequently separable into several distinct layers. Its thickness, which is greatly increased by continued exercise, varies in different regions of the body ; but, in most places, it is about the one sixth part of that of the corion, which it covers. Externally, the epidermis has a rough wrinkled ap- pearance ; it is covered, moreover, Avith innumerable hairs, and is constantly moistened by the secretion of the sebaceous follicles. The internal surface is slightly mammillated, and so closely united to the subjacent layers that it is impossible to separate it by dissection. It is readily detached, however, by putrefaction ; and when this is done, it is found to present, besides a great many little rounded projections, a considerable number of very delicate, transparent, and colorless filaments, the precise nature of which is still undetermined, though they are probably nothing more than little albuminous processes, which, extending from the cuticle to the dermis, serve to connect them more firmly together. It is the opinion of many anatomists, that the epidermis is porous, and such is no doubt the case. The fact that no openings, save those which give passage to the hairs, have ever been detected, even with the assistance of the most powerful microscope, does not prove that there are none ; for, as has been observed by a distinguished writer, it is possible that they might originally exist, and yet not be visible in the detached cuticle, on ac- SECT. I.] EPIDERMIS. 357 count of their being closed by its elasticity, Avhich, as was before stated, is one of its most strongly marked physical properties. But this is a subject Avhich scarcely concerns the present inquiry, and concerning which it Avould. be unprofita- ble to speculate. The epidermis was formerly regarded as being composed of scales, and this opinion has been recently revived by tAvo eminent French anatomists, Breschet and Vauzeme, in an excellent little work on the minute structure of the skin, published at Paris, in 1835. According to these writers, the scales of the cuticle have the general form of an irregular tra- pezium : they are striated, Avhite, and transparent, of uniform thickness, and placed upon a very thin pellucid membrane, evidently areolar in its structure. They further assert that the epidermis is the product of a peculiar mucific apparatus, situated at the bottom of the true skin, and composed of a small reddish gland, with an appropriate excretory duct. The matter secreted by this structure is at first perfectly fluid, but by degrees it becomes hard and dense, until it has acquired all the properties of the membrane under considera- tion. Dr. Gurtt, of Germany, who has more recently investi- gated this subject, has not been able to detect the mucific apparatus described by the French authors; and it must be obvious to all, that further researches are wanting before their statements can receive the sanction of the anatomist and physiologist. Few organs have afforded a wider field for the range of physiological fancy than the epidermis. At one time it has been considered as vital and organized ; at another, as desti- tute of the characteristics of living matter. The latter is still, from some unaccountable cause, the prominent belief of authors and teachers. That the organization of the cuticle is equal to that of the dermis and other similar textures, it Avould be absurd to presume, as much so as, in my opinion, it would to suppose it Avholly destitute of vitality. These circumstances may be stated here as illustrative of the views I Avish to inculcate in regard to the present subject. In the first place, we may conclude that the cuticle is organized be- cause the dermis, to which it is intimately attached, does not appear to be irritated by the connection, and makes no effort, consequently, to throw it off. Secondly, because it is con- tinually though slowly undergoing decay and renovation ; and, thirdly, because it is liable, as will be hereafter^seen, to 358 SKIN. [CHAP. X. a great variety of morbid changes, constituting an important class of cutaneous diseases. Neither vessels nor nerves have been traced into this membrane ; and in the healthy state, it is perfectly insensible. It is highly probable, I think, that its arteries are derived from those which are distributed over the free surface of the corion; but, owing to their excessive delicacy, they elude our vision, and are incapable of receiving the finest injecting matter. The second layer of the skin, the most delicate of all, is the mucous web, for the discovery of which we are indebted to the celebrated Italian anatomist, Marcellus Malpighi, Avho first found it in the tongue, and subsequently in the common integument. It forms a thin, soft, semi-fluid lamella, desti- tute of vessels and nerves, but, like the epidermis, permeable to other bodies. The thickness of the mucous web varies, not only in different regions of the body, but likewise in the different races of mankind. Thus, it is much greater in the neck and scrotum than in any other part, and in the negro than in the European, in whom, from its excessive delicacy and difficulty of demonstration, several anatomists have been induced, though erroneously, to deny its existence. The precise structure of this substance is not known. Though destitute, apparently, of vessels and nerves, it is reasonable to presume that it is slightly organized, its vitality being prob- ably on a par with that of the epidermis, to the inner sur- face of which it so closely adheres, both before and after it is detached from the corion. A recent French author, Dr. Gaultier, considers the mucous web as being composed of three distinct lamellae, the external and internal of which are white, whilst the intermediate one contains the coloring matter. This notion, however, is not universally admitted by anatomists. The mucous web is the seat of the coloring matter of the skin, which is white in the Caucasian, black in the African, yellow in the Mongolian, copper in the American, and taAvny in the Malayan. In its essential nature, it is supposed to assimilate itself closely to hematosine, modified by a sort of secretory process. The opinion of Blumenbach and Davy, that it is nothing but carbon, is perfectly unfounded, as is also that of Gall, who considers it as analogous to the gray matter of the brain. This substance, whatever it may be, may be temporarily removed, or perhaps rather blanched, by immersing the skin of the negro in water impregnated with SECT. I.] DERMIS. 359 chlorine: in a few days, the black color returns Avith all its former intensity. The fundamental portion of the skin, and consequently the most important layer of the three, both in structure and in function, is the dermis, also called the corion, or cutis. Unlike the cuticle and mucous web, it is a highly organized substance, being most liberally supplied Avith vessels, nerves, and absorbents, and possessing the most extensive sympa- thetic connections, — as much so, indeed, as any other organ Avhatever in the body. After a successful injection, the outer surface of the corion seems to consist of a uniform net-Avork of minute vessels, which are subdivided to an infi- nite degree of delicacy, and placed in such close proximity as to render it impossible to introduce the finest needle with- out drawing blood. The same test proves the equal abun- dance of nervous filaments, which are derived from the spinal nerves and from the ganglionic portion of the fifth pair of the brain. The sensibility of the skin is Avell displayed in sur- gical operations, and in accidental wounds, in Avhich the chief pain is always in the cutaneous textures, particularly in the corion. The absorbents are also extremely numerous ; they are very easily injected; and, when this is accomplished successfully, the Avhole surface of the skin looks like a sheet of silver, their distribution resembling a net-work more than a regular ramification. The corion, like the other lamella?, already described, has two surfaces, an inner and an outer ; the former of Avhich is of a grayish white color, and holloAved out into innumerable pits, varying in size from the eighth to the tAvelfth of an inch. Of a rounded, oval, or angular shape, these pits, technically called areola,, are placed close to each other, and are designed to receive granules of the subcutaneous fat, upon the quantity of Avhich depends the sleek or wrinkled state of the skin: they are wanting on the back of the hand and foot. They do not entirely pierce the corion, but termi- nate each in a sort of cul-de-sac, the bottom of which is perforated by numerous oblique apertures, for the passage of hairs, vessels, nerves, and absorbents. The outer surface of the corion is of a pale reddish flesh color, being much more vascular, as well as more smooth, than the internal. Numerous furroAvs, lines, or grooves are to be seen upon it, the size of which varies in different regions: in some situations they are so small as to be scarcely 360 SKIN. [CHAP. X. perceptible, whilst, in others, they are at once large and con- spicuous. Specimens of nearly all the lesser varieties are to be found on the back of the hand, where they intersect each other so as to form various angles, from the most obtuse to the most acute. On the bulbs of the fingers, the groves are arranged in concentric semicircles ; in the palm, they are for the most part oblique, a few only being transverse. Projecting from the external surface of the cutis, yet at the same time embedded in its substance, are the cutaneous papillce, which were first described by Malpighi in 1686, in his work, " De Externos Tactus Organos," and the existence of which has since been generally admitted by anatomists and pathologists throughout the Avorld. They consist of a vast number of minute eminences, covered by the mucous web and epidermis, Avhich thus defend them from the injurious contact of extraneous and hurtful agents. Varying in vol- ume, from the sixth to the twelfth of a line, they are of a conical shape, their base being fixed in the substance of the dermis, the summit terminating in a blunt point. Generally speaking, these bodies bear a pretty close resemblance to the villi of the intestines, excepting that they are smaller, and of a more florid tinge. Like them, they are composed essen- tially of very delicate ramification of vessels, nerves, and absorbents, connected together by cellular texture. Under ordinary circumstances, the papilla? are relaxed, and on a level Avith the dermis ; but, Avhen in action, they become erect so as to elevate the superincumbent structures. When the surface is chilled, as happens in the cold stage of intermittent fever, the corion shrinks, Avhilst the papillae either continue unchanged, or contract less proportionally, and thus give rise to the appearance described under the name of goose-skin. The aggregate of these little bodies, it may now be observed, constitute Avhat is called the papillary texture, which has been regarded by many as a distinct membrane. The cutaneous papillae constitute the true organs of touch and sensation, and are therefore most thickly planted where these senses are most acute and fully developed. They are very large and numerous in the palm of the hand and the sole of the foot, especially on the tips of the fingers and toes, where they have a concentric arrangement. In other regions of the body, they are irregularly disseminated ; and, in many parts of the corial surface they are so indistinct that their existence is inferred rather from analogy than from actual SECT. I.] SUDORIFIC GLANDS. 361 observation. These little bodies are often very conspicuous, as well as exceedingly painful, in inflammation of the skin, arising from the application of a blister, or some other irritat- ing substance. Besides the little bodies now described, the dermis contains an immense number of sudorific glands, so small as to be scarcely perceptible to the naked eye. Their structure is extremely vascular, and their form is that of a distended sac, with a tortuous, spiral canal, which winds its way to the surface of the epidermis, where it opens into a sort of pore. The existence of these glands, although suspected by some of the older anatomists, Avas first pointed out by MM. Breschet and Vauzeme, who are therefore justly entitled to the merit of the discovery. They exist in every part of the skin, but vary in size and form in different situations. In the palm of the hand, and the sole of the foot, Dr. Gurtt describes them as being of a roundish, oval shape, and considerably larger than elsewhere; in the skin of the head, they are more oblong. In the ox, the glands are very small and spherical, and every where uniform in size and shape. The office of these little bodies, it need scarcely be observed, is to secrete the sweat, and to convey it to the free surface of the cuticle. The dermis, thus constructed, is a dense, firm, and resist- ing lamella, possessed of a very extraordinary degree of ex- tensibility and elasticity. Considered in reference to its fun- damental texture, it is found to be composed of white, gray- ish-looking filaments, which intersect each other in every conceivable direction, being much more closely woven to- gether on the outer than the inner surface of the membrane. By protracted boiling, the corion may be converted into a viscid, glutinous substance, consisting mainly of gelatine under some peculiar modification. A portion of the skin, however, always remains undissolved; and this, by being subjected to the influence of tannin, is gradually transformed into leather. It only remains for us, in connection with the present topic, to present a rapid summary of the sebaceous follicles. Varying in size, between the smallest pin's head and a mil- let-seed, the number of these bodies is almost incredible. In a preparation deposited in the museum of the London College of Surgeons, by the late Mr. Chevalier, that gentleman counted not less than one hundred and thirty, on a surface of skin equal to the twenty-fourth part of a square inch. In vol. i. 46 362 SKIN. [chap. X. perceptible. These glands secrete a thin, whitish, oily humor, which is designed to lubricate the cuticle, to render it soft, and to impart to it the suppleness which is necessary for the per- formance of its functions. It is insoluble in cold water, does not readily burn Avhen exposed to the fire, and appears to be composed principally of ceraceous and oleaginous matter. By being retained too long, the humor becomes concrete, and may be squeezed out of the skin in the form of little, worm-shaped bodies, each having a small, dark point, so as to look like a head. We have already referred to the remarkable analogy be- tween the structure of the cutaneous and mucous textures, and to the facility Avith which the one is sometimes convert- ed into the other. Another subject, of still greater importance in a practical point of view, is the sympathetic connection between the skin and other parts of the body. The principal relationships may be thus enumerated: 1. with the mucous lining of the stomach and bowels ; 2. with the kidneys ; and, 3. with the serous membranes, especially the arachnoid and pleura. Examples, illustrative of the sympathetic connection between the skin and each of these organs, might be adduced * Sebaceous follicles and their ducts, double the natural size. t Orifices of the sebaceous follicles on the surface of the skin. SECT. I.] ITS REPRODUCTION. 363 without number; but they would be out of place in a Avork on pathological anatomy. The different layers of the skin possess the power of repro- duction, after they have been destroyed, but not all in an equal degree. The cuticle appears to be more readily regen- erated than any other: it is perpetually in a state of decay and renovation, small furfuraceous scales dropping off in pro- portion as others form beneath them. In scarlet fever and erysipelas, it often exfoliates in large pieces; yet, under such circumstances, it is generally very speedily reproduced, the neAV membrane being nearly as perfect as the one that was lost. The dermis and mucous Aveb possess the power of reproduction in a less marked degree. Indeed, many deny that the latter is capable of being regenerated at all, the opinion being founded upon the erroneous statement that the cicatrices of the negro always continue pale. That this is the case occasionally, I am fully aware from my OAvn exam- inations ; but that this is universally or even generally true, is Avhat no one Avho has investigated the subject will believe. Let any one inspect the skin of a negro who has had small- pox, and he will find that, whilst some of the scars are lighter, others are fully as dark, if, indeed, not more so, than the surrounding skin. So likewise with the scars of wounds and old ulcers, provided there has not been too great a loss of substance. The dermis is perhaps less perfectly regenerated than either of the other lamellae. We have already seen that it is abnormally thin and delicate, less flexible and elastic, and less capable of withstanding the effects of disease and the varying temperature of the surrounding atmosphere. Capillary vessels exist in great abundance, and are extremely liable to congestion on the slightest exposure; but as to sebaceous follicles, none whatever are to be found. Hence the skin, in such cases, is almost always unnaturally dry, and prone to become fissured. Are the sudorific glands ever re- produced, Avhen destroyed ? This is a question which has not been determined by actual observation: conjecture would induce us to conclude that these little bodies shared the same fate as the sebaceous follicles. I. UNCLASSIFIABLE LESIONS; Kelo'ides, a disease first described by Alibert, is occasion- ally observed, though, as yet, I have never seen an instance 364 SKIN. [chap. X. of it. Its most common seat is on the neck or shoulder, and front of the chest, where it manifests itself by a small reddish point, about the size and shape of a grain of barley, Avhich goes on increasing until it sometimes attains the diameter of an inch or more. The centre of the tumor is generally some- Avhat depressed, its surface wrinkled, and its margin radiated, having some resemblance to the claws of a crab, whence its name. To the finger it is hard and resisting, and in its color, it is either of a pale rose, or of a deep cherry-red. On dis- section, it exhibits a grayish, fibrous appearance, much like scirrhus of the female breast, the rays shooting out in dif- ferent directions. The progress of this growth is very slow : it rarely ulcerates ; and, in the majority of cases, it is unattend- ed with any particular uneasiness, though at times it is said to cause great pain and throbbing. Occasionally, as has been remarked by Alibert, it disappears, leaving merely a white, firm cicatrix. The most remarkable circumstance about this tumor is its disposition to be reproduced after removal. This may happen repeatedly, until the patient is at length worn out by it. Melanosis of the skin has been sometimes observed by physicians, either alone, or combined with other morbid prod- ucts. The most common form in Avhich it occurs is in that of small grains, of the size and color of a black eurrant. These little tumors, usually buried in the dermoid tissue, are sometimes extremely numerous, giving the cutaneous surface a singularly tuberculated aspect: their occurrence is very rare, and they seldom ulcerate. Deposits of the same substance almost always coexist in the subcutaneous cellular tissue, and in some of the internal organs. In the horse, this disease is of much more frequent occurrence than in man ; and it is also not uncommon in the skin of the ox, hog, and dog, as I know from my own observation. Encephaloid has never, I believe, been remarked as a pri- mary disease of the skin, although it frequently extends to it from the subjacent textures, producing a red, spongy, tuber- culated sore, more or less painful, and liable to bleed upon the slightest touch. This lesion, which it is unnecessary here more particularly to describe, is most apt to appear in the medullary sarcoma of the breast, testicle, and penis. Cartilaginous tumors are occasionally seen projecting from the skin, or growing within its substance. Mr. Mayo de- scribes a body of this kind, about the size of a chestnut, which SECT. I.] CARTILAGINOUS TUMORS--EILOIDES. 365 he removed from the ham, where it had been long in forming. It seemed to have begun in the very centre of the dermis ; Avas very painful Avhen handled, and possessed all the physi- cal properties of cartilage. Dr. Rayer, of Paris, has described a similar disease under the name of mollusciform cancer. In the interesting case reported by this physician, the tumors, situated on the face, trunk, and extremities, were of a deep red color, hard, lenticular, and considerably elevated above the level of the surrounding skin. Frequently these growths possess a real carcinomatous character, exhibiting, when cut into, a grayish, dense, crisp texture, intersected by a great number of fibrous filaments, and yielding a small quantity of lactescent fluid on pressure. In size, they vary between a pea and a pigeon's egg : they are either rounded, conical, or pedic- ulated, and occasionally they rest upon a large flattened base. They often remain stationary for many years; and, although they are sometimes of a reddish color, they are for the most part of the same complexion as the skin. A very rare affection of the skin has recently been describ- ed by Professor Warren, of Boston, under the appellation of eilo'ides, from its coil-like disposition.* When first seen, it presents the appearance of a small elevation, similar to that from a burn, which goes on gradually increasing, without pain, heat, redness, or ulceration, until it acquires a great size, and affects the patient's health. In a drawing which has been published by the able surgeon above mentioned, the disease is arranged like a triple coil of inflated intestine, the rolls lying in close contact, and being each four inches long, arising by a narrow base from the right side of the neck. The pa- tient was a negress, fifteen years of age, whose health was otherwise disordered. Soon after its removal, the tumor re- appeared in the former situation : it was again extirpated ; and, snowing itself a third time, it speedily destroyed the patient. Of the anatomy of eilo'ides nothing is known. The morbid growth, in all probability, takes its rise in the dermis, but in what particular portion of it has not been ascertained. Besides these tumors, there is another disease of the skin, also extremely rare, which it will be necessary to notice be- fore Ave conclude this branch of our subject. I allude to what is called lepoides, a Greek term, literally signifying bark-like. The most common situation of this disease is the cranio- * Surgical Observations on Tumors, p. 48. Boston, 1837. 366 SKIN. [chap. X. facial region, generally the forehead, cheek, or temple. Its progress is slow, and old age is its favorite period of attack. Consisting in an inflammation of the dermis, it makes its ap- pearance in the form of a small circumscribed speck, of a dirty color, which becomes covered with a very rough, brownish crust, resembling the bark of a tree. This falling off is soon replaced by another, of the same shape and color. Thus the disease is kept up for many successive years. Ulceration ulti- mately sets in, and the dermis exhibits a red, glossy surface, spicular, pitted, or granular, Avhich throws out a thin, ill- looking pus. On examining the affected skin, it is found to be almost of a gristly hardness, its internal surface being stud- ded with a number of small, whitish, rounded bodies, con- nected together by a dense, grayish texture. Very little pain attends this affection, and it often continues for many years before it manifests any malignant tendency. A not uncommon affection of the skin is hypertrophy. Occurring most frequently in old corpulent subjects, it is sometimes congenital, and involves either the whole thick- ness of an organ, or some one or more of its component layers. The integuments of the nose are particularly liable to enlarge and thicken ; and the lesion is also sufficiently common on the neck, breast, the arm, and back, forming rough pendulous folds, several inches in length, which are usually somewhat darker than the skin in the normal state. Hypertrophy constitutes a prominent feature in the Barbadoes leg, in elephantiasis, in burns, and in chronic ulcers of the inferior extremity. The enlargement, in some instances, im- plicates nearly the whole cutaneous surface, by which the movements of the body are impeded, and the individual ac- quires a hideous aspect. A remarkable case of hypertrophy of the several layers of the skin, admirably illustrative of the present subject, is re- corded by Andral. The subject Avas a female, seventy-four years of age, Avho died of pulmonary phthisis. She had for- merly had an ulcer on her right leg, but, for the last thirteen years, the sore had cicatrized, while the limb had gradually acquired a most extraordinary size, being hard and swollen, and the skin rough, and of a yellowish broAvn, verging here and there upon black. On dissection, the thickened integu- ments Avere found to be composed of the following layers: 1. the epidermis; 2. three subcuticular lamelhe ;"*3. the pa- pillary tissue; 4. the dermis. All these parts, though inti- SECT. I.] HYPERTROPHY. 367 mately united, Avere perfectly separable, indurated, and irreg- ularly thickened. The papillae Avere remarkably elongated, turgid, and so crowded together that many of them had lost their characteristic features. Immediately o\Ter them, as Ave have just seen, Avere three distinct lamellae differing from each other in their texture, their color, and their consistence. The first, the most superficial, was of a grayish hue, and presented a true horny firmess : this stratum, to which Dr. Dutrochet has applied the appellation of the horny layer, exists only as a rudiment in man, but is very perfectly devel- oped in the inferior animals. The second lamella was of a grayish, brown, or black complexion, reticular in its struc- ture, and composed of exceedingly delicate filaments, crossing each other in every possible direction. This layer, Andral supposes to be analogous to the colored layer in negroes. Lastly, there was a third stratum, placed immediately beneath the preceding, excessively delicate, of a white, undulating appearance, and made up of a cellulo-fibrous substance : it was closely connected Avith the papillary tissue, and was analogous to the epidemic layer described by Dutrochet. Such is a brief outline of this interesting case, which is so much the more instructive, as it serves not only to illustrate the present lesion, but also the various component lamellae of the organ in which it is located. The hypertrophy may be seated principally in the papillae. The affection is sometimes congenital, sometimes accidental, and is met with in various degrees of intensity. When it accompanies or follows burns, blisters, and chronic eczema, the bodies in question often attain a most extraordinary de- velopement ; their volume is five or six times above the natural standard ; they are of a pale brownish color ; and they present an uneven, mammillated appearance, not unlike the pile of coarse plush, which is rendered particularly conspicu- ous when they are plunged in Avarm water. The dermis, in these cases, is often very much thickened, as Avell as indurated, and is covered with thin micaceous scales, which are easily rubbed off, and constantly reproduced. Hypertrophy of the epidermis is best seen in icthyosis, — a disease which will be particularly described under the head of squamous disorders, amongst which it has been classified by some highly respectable European authors. A corn is a species of hypertrophy of the cuticle, on a small scale, which it Avill be in place to notice here. Corns, technically called tyloses, are hard, dry, insensible 368 SKIN. [chap. X. callosities, occurring mostly on the lateral and dorsal surfaces of the toes, especially the first and last : they are also some- times seen on the sole of the foot, between the fingers, and on the flexor tendons in the palm of the hand in Avorking people. Their morbid anatomy consists in inflammatory irritation of the cellular layer of the dermis, eventuating in the effusion of lymph, and the consequent thickening and induration of the cuticle. The texture of a corn, especially when old, is of a lamellated nature, and it is almost always more firm at the centre than at the circumference. By cutting away its superficial layers, a sort of internal nucleus is exposed, which has a Avhitish, horny-looking appearance, and often occupies a considerable portion of the substance of the dermis : it is generally more or less moist, and is now and then surrounded by a minute ecchymosis. The form of these callosities, although variable, is usually rounded, and their size rarely exceeds that of a five cent piece. Some corns are movable, others fixed ; and cases not unfrequently occur, in which they have a sort of radiating root, extending deeply into the subjacent cellular texture. Their remote cause is pressure, commonly that of a shoe, which, if continued for any length of time, inflames the cutis, and renders it excessively painful. The complaint is more frequent in females than in the other sex, and in the rich than in the laboring poor. As in some degree connected with the preceding subject, may be mentioned verruca, — an affection of the epidermis, characterized by hard, insensible excrescences, denominated warts. Of a conical form, their surface is hard, tuberous, fissured, and almost indolent; in size, they seldom exceed that of a common pea; in color, they are several shades darker than the sourrounding skin ; sometimes they are movable, sometimes fixed. This kind of vegetation is of a radiated structure, being composed of elongated, vascular papillae, encased in epidermis of variable thickness and density. It is the result, apparently, of a slow chronic irritation, and often occurs in immense numbers on the hand and face of young persons. In the latter situation, Avarts are apt, in the more advanced periods of life, to take, on carcinomatous action, either spontaneously, or from being pulled. In the young, they often disappear of their own accord. The skin is sometimes the seat of horn-like excrescences. These productions occur principally in those parts of the body where sebaceous follicles abound, and hence they are SECT. I.] HORNY EXCRESCENCES. 369 more frequently observed on the cranio-facial region than in any other. In seventy-one cases collected by Dr. Villeneuve, twenty-six were seated on the scalp, five on the nose, two on the cheek, one on the lower-jaw, four on the chest, four on the back, three on the anus and the penis, four on the buttocks, twelve on the thigh, two on the knee, two on the ham, one on the leg, and three on the foot. They have also been seen on the scrotum, the back of the hand, and on the pavilion of the ear. Although the reverse has been asserted, they appear with nearly equal frequency in both sexes, during the period which in- tervenes between the ages of forty and seventy: in a few instances they have been met Avith in young children. The magnitude Avhich some of these excrescences attain is surprising. (Fig. 35.) Bate- man states that there is one in the British Museum, which is eleven inches in length by two and a half in circumference. From three to six inches is by no means an unusual size. Their direc- tion is generally somewhat spiral, twisted, or bent ; and, in their ap- pearance, they oft- * A remarkable horny excrescence growing from the scalp. vol. i. 47 370 SKIN. [chap. X. en bear the closest resemblance to the horn of the sheep, being marked by rough circular rings Avith intervening de- pressions, indicative of the successive steps of Fjo. 36» their developement. In color, they vary from a dingy yellow to a dark grayish. They are of a firm, cartilaginous consistence, more or less flexible, conical in their shape, being large at their origin, and tapering to their terminal extremity ; and, Avhen burned, they exhale a characteristic animal odor. Now and then their surface is imbricated, knobbed, or covered with small pearl-colored scales. Internally they have occasionally a lamel- lated arrangement, as in Fig. 36. These excrescences, as was before intimated, are generally connected Avith the sebaceous follicles, and are directly tracea- ble to chronic inflammation, such as is produced, for example, by a burn, a Avound, or a contusion. When first observed, they are quite soft, transparent, and invested by a distinct cyst, Avhich, extending over their base, is gradually and in- sensibly lost upon their trunk. In the course of a few Aveeks, they become hard, assume a darker hue, and thus acquire the properties of the horny tissue. Their growth, on the Avhole, is very slow, from three to five years elapsing before they reach any considerable size. "When they drop off spontane- ously, as they have been knoAvn to do in a few instances, they invariably sprout out anew, pursuing the same course as their predecessors. The same thing happens when they are extirpated without the precaution of destroying the cyst from which they arise. Several such productions, it should be re- marked, are occasionally observed in the same individual. The production of gangrene of the external integument is by no means a rare occurrence. It is observed in different situations, and arises from a variety of causes, some of which seem to have a preference, so to speak, for this over other structures. Occasionally, therefore, it may occur as an origi- nal idiopathic affection ; but more generally it is the result of specific inflammation, or of that depending upon external violence. Of the former, Ave have an example in malignant pustule, in phlegmonous erysipelas, and in common carbuncle. As illustrating the present subject, we shall describe only one * A section of the horn, showing its lamellated structure. SECT. I.] MALIGNANT PUSTULE. 371 of these lesions ; and, as being more interesting than the rest, we shall select malignant pustule, — a disease which, as Avill be shown presently, seems to owe its origin to the operation of some septic agent. Malignant pustule, charbon, or anthracion, as it is various- ly denominated by foreign authors, although very rare in this country, is often observed in certain parts of France, particu- larly in Lorraine, Burgundy, Provence, and Languedoc. In the low marshy districts of these regions, the cattle are obliged to subsist upon bad and vitiated provender; and the conse- quence is, that many of them are seized Avith dynamic fever, accompanied \vith gangrene of the skin. In the summer season, indeed, the disease sometimes prevails epidemically. By dissecting animals that perish in this way, or by merely touching their hides or hairs, the disease is readily propagated to the human subject. There are numerous facts, also, which prove that malignant pustule may be communicated by intro- ducing the hand into the rectum, vagina, and throat of cattle affected with this malady; and similar results are often pro- duced by touching the blood, the secreted fluids, and the excrements, or by injecting the former into the veins. Shepherds, herdsmen, tanners, and butchers are most sub- ject to the disease ; and the parts most liable to be affected are such as are habitually uncovered, as the face, neck, and chest, together with the arms and hands, the legs and feet. With regard to the anatomical characters of this disease, Avith which Ave are chiefly concerned on the present occasion, they may be divided into three stages, each of which is marked by some peculiarity of feature, Avorthy of separate consideration. The time Avhich elapses between the inoculation and the developement of the disease varies from three to eight days. It commences in a small circular prominence, the centre of which soon degenerates into a minute vesicle, about the size of a millet-seed, Avithout heat, tension, or redness. As this vesicle enlarges, it assumes a brownish color, and, when rup- tured, discharges a few drops of a yellowish bloody serosity. At intervals, a good deal of itching is experienced, accompa- nied occasionally with a peculiar stinging sensation. This period lasts from tAventy-four to forty-eight hours, and con- stitutes the first stage of the disease. The second stage, which rarely endures beyond a few days, is characterized by the developement of a hard, movable, 372 SKIN. [chap. X. circumscribed tumor, of a yelloAvish livid color, Avith a rough granulated surface. This, in a short time, becomes surrounded by a purple, glossy-looking areola, on Avhich numerous phlyctense, containing a reddish serosity, are situated, which quickly run into each other. The disease, having penetrated the entire thickness of the dermis, now invades the subjacent cellular tissue ; and the centre of the little tumor presents all the features of an eschar. In the third stage, the gangrenous point rapidly extends, and the enlarging areola rises above the eschar, causing its centre to be depressed. The surrounding surface is tense, emphysematous, and of an erysipelatous red; the acrid heat and stinging are succeeded by a sense of Aveight and numb- ness ; the disease burroAvs deeply into the cellular texture ; and the mortified skin is of a blackish color, and of a firm, leather- like consistence. From tAventy-four to seventy-tAVO hours is the usual duration of this stage, which is commonly attended with high constitutional excitement. The size of the slough, at this period, varies from six lines to one or two inches. But it is not always that malignant pustule observes the regularity here ascribed to it. The different stages, as has been observed by a late professor of Paris, to whom we are indebted for a very excellent account of it, often succeed each other in rapid and indistinct succession ; and the disease has proved fatal in less than twenty-four hours after its com- mencement. When it terminates favorably, a red inflamma- tory circle appears, Avhich serves as a line of demarcation betAveen the dead and the living parts. From experiments performed by M. Berthelemy, a profes- sor in the Veterinary School at Alfort, near Paris, in 1816, it appears that the ichorous matter furnished by malignant pustule retains for a long time its nocuous properties. Hav- ing put some of the fluid in a corked vial, he preserved it for about eleven months, Avhen he inserted a portion of it into the skin of a stout, healthy horse. The consequence was, a gangrenous tumor, having all the characteristics of malignant pustule, and Avhich, notwithstanding the small quantity of virus, killed the animal in three days.* In ordinary gangrene, or in that variety of it which arises from excessive inflammatory action, the color of the skin changes from a florid red to a darker shade, acquiring, during * Dictionnaire de Medicine et de Chirurgie Veterinaire, t. iii. p. 713. SECT. I.] SEBACEOUS FOLLICLES. 373 the progress of the disease, a purple, livid, or blackish hue. Concurrently with this change of color, the affected part undergoes a decided alteration of structure. It feels soft, boggy, and emphysematous, and the cuticle is raised into numerous phlyctenae, filled Avith bloody looking serosity. When completely deprived of vitality, the skin sometimes becomes a shade or two lighter, and is detached, sooner or later, in soft, grayish, inelastic strips, which are often bathed with a thin, ichorous, and offensive fluid. " The ash-colored slough seems to occur most frequently in skin Avhich is moister, and the black-colored, in skin Avhich is more dry than common." There is a singular species of cutaneous gangrene, to which, from the peculiarity of its appearance, Ave may apply the term white. It generally comes on Avithout appreciable cause or preliminary symptom, occurring in irregular shaped patches, from one to three inches in diameter. The sloughs are of a dead milky color, and of a hard, dryish consistence, yielding little or no moisture on pressure. Any portion of the body may be the seat of this affection; but it would appear, from what has been published on the subject, that the arms, back, and chest, are the parts most frequently impli- cated. The true nature of the lesion is still involved in mystery. The sebaceous follicles do not seem to be very prone to disease. When inflamed, they augment in volume, their capillaries are greatly injected, and they pour out a preter- natural quantity of matter, which, in time, forms an unctuous, tenacious covering, not unlike a layer of semi-concrete wax. If it be alloAved to remain, this substance sometimes acquires the appearance of thick, imbricated scales, of a blackish color, which may be mistaken for those of ichthyosis, from which they differ, however, in being much more easily detached. Under this accidental covering, the skin is of an unusually red color, and the mouths of the follicles are either very much enlarged or obstructed, Avith hard sebaceous mat- ter. This disease, which is almost peculiar to youth and adults, may last for years, and the secretion Avhich attends it is occasionally of a sero-purulent nature, especially in obsti- nate cases. Another effect which sometimes results from inflammation of the sebaceous follicles, is the formation of encysted tumors, containing meliceric, atheromatous, or steatomatous matter, 374 SKIN. [chap. X. Fig. 39.t or several of these substances conjoined, (Figs. 37 and 38.) The mouth of the m _ 38, follicles being ob- structed, and the natural secretion going on, their cavity gradually expands, until the sac acquires, in some instances, the volume of an ap- ple, or even of a cocoanut. The parietes of these tumors are occasionally quite hard and thick, like the dura mater : and cases have been observed, though I believe very rarely, in which they were ossified, or transformed into fibro- cartilage, (Fig. 39.) Externally, they are rough, being connected to the surround- ing parts by cellular tissue ; Avhereas, internally, they are generally smooth and glistening. Small sacs are sometimes observed in the interior of these tumors; but these I suppose are rare, and I have never met with them. In their shape, these tumors are for the most part globular, and they are found more frequently, by far, on the face and scalp than in any other situation. Their number, although usually small, is sometimes very great. In a case which fell under my notice, nine years ago, I counted several hundred on the head and • trunk of a man about forty years of age. He informed me that most of them commenced Avhen he was quite young, soon after bathing in cold water, and that he had never experienced the slightest pain from them. The tumors were of the meliceric kind, and the largest were about the volume of a hen's egg, the surface of many being uneven, and here and there incrusted with hard, sebaceous matter, of a darker color. Tumors of this kind are commonly someAvhat movable, though in this respect much depends upon their location. * A sebaceous follicle in a state of incipient enlargement, its orifice being dis- tended with meliceric matter. t A sebaceous tumor laid open to show the thickness of its cyst. t Sebaceous tumor, with an ossified cyst. SECT. I.] HEMORRHAGE. 375 Sir Astley Cooper, Avho has written an excellent paper on these bodies, considers them in some degree hereditary ; but of this I know nothing from my own experience. They are usually unattended Avith pain, have no malignant disposition; and the skin covering them, although occasionally streaked with large vessels, generally retains its natural character. Sometimes the contents of these tumors are thin and watery, and exceedingly offensive. In other cases, short hairs, very soft, and provided with well-formed roots, have been found in them, (Fig. 40.) The sebaceous follicles, instead of se- creting their accustomed humor, occasion- ally deposit a hard, calculous substance. Meckel relates the case of a young lad, the skin of Avhose buttocks was com- pletely studded with small concretions of this kind; and similar bodies have been repeatedly found in the sebaceous follicles of the forehead and root of the nose.f Their chemical composition has not been deter- mined, but it is altogether probable that they consist mainly of phosphate and carbonate of lime, agglutinated by a minute quantity of animal matter. The skin is sometimes the seat of hemorrhage. The only form to which I shall allude, is that Avhich constitutes Avhat is called purpura. Of this I shall describe only three varie- ties,— the petechial, the simple, and the complicated, or, as it has been denominated by some, the hemorrhagic. These va- rieties are referable principally to the extent, form, and situa- tion of the effused blood ; and it is important to remember that they may all occur simultaneously or successively in the same individual. No period of life is exempt from this dis- ease. In a few instances it has been observed soon after birth. In the petechial species, the blood is collected in minute isolated points, situated immediately beneath the cuticle: they are of a circular shape, from the fourth of a line to a line in diameter, seldom or never elevated above the surround- ing surface, and usually of a pale color, though frequently of a deep red or purple. The lesion is generally concomitant of plague, typhus, scurvy, and dysentery, and is almost always * Cyst of a sebaceous tumor, with hairs in its interior. t Voigtet's Handbuch der Path. Anatomie, Halle, 1804. Erster Band, p. 85, 376 SKIN. [chap. X. most conspicuous on the chest, back, and inside of the arms and legs. I have recently seen a case of this kind in a young man, Avho died of enteritis, attended Avith profuse bleeding from the nose and bowels. In simple purpura, the parts principally affected are the ex- tremities, especially the inferior. The effusions take place slowly and successively, so that, whilst some are fading and disappearing, others are forming and increasing. They are at first of a vivid red color; but, in a feAV days, they acquire a deeper and more livid hue; and, in proportion as the blood is removed by absorption, they become greenish, then yelloAvish, and ultimately vanish altogether. They are also of a circu- lar shape, but much larger than in the petechial variety, being from one to eight lines in diameter, and seated betAveen the cuticle and mucous net-work, or in the dermis and cellular tissue, or in both these situations simultaneously. The dura- tion of the individual blotches is from six to ten days; of the disease, from one to tAvelve months. Cazenave and Schedel refer to a case in which the effusions succeded each other at short intervals for more than two years: the patient was a female, forty years of age, who Avas subject to dysmenorrhoea, and of an unusually plethoric habit. The essential difference betAveen the preceding and the complicated variety of purpura, consists in the effusions in the former being confined to the external surface ; whilst, in the latter, they not only occur in this situation, but also in other parts of the body, especially beneath the mucous and serous membranes of some of the principal organs. The blotches are likewise of a deeper color, larger, and less regular in their shape, and in many cases they bear a striking resemblance to the ecchymoses Avhich folloAv a bruise or contusion. Indeed, the slightest pressure is frequently sufficient to produce them, particularly in parts Avhere the skin is very thin and the cell- ular tissue abundant. When the effusion is considerable, the cuticle is sometimes elevated into small bladders, which, on breaking, give vent to black, semi-fluid blood. This occur- rence, hoAvever, is extremely rare, and, in the generality of cases, there is not the slightest elevation. This variety of purpura usually begins on the legs and thighs, from Avhence it gradually extends over the trunk and arms. The hands and face almost always escape. Are the above effusions the result of a rupture of the ves- sels, or are they caused simply by exhalation ? Of the two, SECT. I.] ROSECLA. 377 the latter supposition is, perhaps, the more correct; at all events, the researches of Fourneaux and others have failed in detecting any communication Avhatever between them and the neighboring vascular branches. The subject, however, requires further investigation ; for the morbid anatomy of this affection, to say the least of it, is extremely imperfect, and does not enable us to offer any satisfactory explanation, either in regard to the nature of its predisposing causes, the charac- ter of the primary local lesion, or of its complications. Besides the varieties noav described, there is another form of hemorrhage, in Avhich the blood oozes from certain regions of the cutaneous surface, in the same manner as it sometimes does from the mucous membranes. The discharge is most frequent in hysterical girls, about the age of puberty, and is usually vicarious, of some similar natural or morbid state in a remote organ, Avhich is almost ahvays the uterus. The skin appears as if covered with a sort of deAv, the blood being effused in minute globules, which, on being wiped aAvay, pre- sently exude afresh. The exhalation, especially Avhen it oc- curs in females, is commonly periodical, and shows itself simul- taneously or successively, at a number of points, as the face, chest, umbilicus, fingers, toes, the palm of the hand, and the sole of the foot. II. CLASSIFIABLE LESIONS. 1. Exanthematous Diseases. The exanthematous diseases are characterized by the occurrence of more or less inflamma- tory redness in the superficial portion of the dermis, which momentarily disappears under the pressure of the finger, runs its course in from tAvo to six days, and is always preceded and accompanied by constitutional symptoms. The efflorescence is sometimes circumscribed, sometimes diffuse, and occasion- ally, as in scarlatina, covers the whole body. The usual termination of these affections is by resolution and desquama- tion. Several of them are of a contagious nature, and occur only once in the same person. The diseases included in this group are roseola, urticaria, erythema, rubeola, scarlatina, and erysipelas. Roseola is characterized by rounded, circumscribed spots, closely set together, of a deep red color, and from four to six lines in diameter. These patches, which disappear in the course of twenty-four hours, are almost ahvays dependent vol. i. 48 378 SKIN. [CHAP. X. upon gastro-intestinal derangement, and are rarely folloAved by any appreciable desquamation. The disease is not conta- gious : it is commonly marked by febrile disturbance, and often covers only a part of the body, as the neck, trunk, ex- tremities. It may occur at any period of life, as Avell as in both sexes, but is most frequent in women and in children. Roseola seems to be seated in the most superficial portion of the dermis, and to consist in a transient injection of the cu- taneous capillaries. There is a singular variety of this disease, in which the spots are arranged in the form of rings, the cen- tres of which retain their normal color : two or three such rings, of variable breadth, are sometimes situated the one within the other. Urticaria, familiarly called " nettle-rash," is a non-conta- gious inflammation, the duration of Avhich varies from a feAV days to several months. It appears in the form of prominent wheals, of an irregular shape, paler or redder than the sur- rounding skin, usually of short continuance, and ahvays attend- ed by a peculiar stinging sensation. In severe cases, the wheals are often very large, hard, and deep-seated, involving the subjacent cellular tissue with a tense, sore, and tumid state of the skin. The favorite situations of the eruption are the shoulders, loins, fore-arms, thighs, and knees. The disease frequently changes its position, appearing at one time here, and at another there ; and, as to the individual patches, their duration seldom exceeds twenty-four hours. The anatomical characters of urticaria are still imperfectly understood. Erythema is an uninfectious exantheme, the distinguish- ing traits of which are superficial blotches, of a deep florid color, lasting from a few days to a fortnight, irregular in their shape, and varying in diameter, from several lines to many inches : the redness momentarily disappears under the pressure of the finger, and is seldom attended with any appreciable swelling. The disease is most common in females, and young, Aveakly persons ; and the neck and chest, together with the superior extremities, are its most frequent situations. Erythe- ma occasionally occurs in regularly circumscribed spots, of a circular shape, and about the size of a split pea: they are slightly prominent, of a bright florid color at the commence- ment, and subsequently of a violet hue, especially at their centre. This constitutes the papular variety of Willan. Another form is the nodose, in which the patches, also con- siderably elevated, are of an oval shape, and from a few lines SECT. I.] RUBEOLA-- SCARLATINA. 379 to an inch in diameter. In other cases, the redness is annu- lated, marginate, or diffused over a large extent of surface. In Avhatever form it may appear the blotches seldom suppurate, nor are they always followed by desquamation of the cuticle. Rubeola is a contagious epidemic malady, occurring for the most part in young children, during the Avinter and vernal months. It rarely attacks the same person more than once. The eruption breaks out about, the fourth day from the com- mencement of the indisposition, and is first seen on the fore- head, face, and neck, from Avhich it gradually spreads over the rest of the body. It consists of small, red pimples, Avhich are slightly elevated above the surrounding level, and look very much like so many flea-bites. In the" progress of the disease, the little speck becomes more prominent: their color is heightened, and their diameter expands, until at length, coalescing with each other, large patches are formed, of an irregular semi-lunar shape, with small intervals of sound skin betAveen them. A minute vesicle occasionally appears at the centre of each spot, filled Avith a whitish, watery fluid. The swelling of the skin is commonly very trifling, and the red- ness, Avhich attains its acme in about tAventy-four hours after its first appearance, has always a shade of purple. The erup- tion lasts from three to four days, declining pretty much in the order in which it begun, and is constantly followed by a branny, scurf-like exfoliation of the epidermis. Rubeola, it would seem, is propagable by inoculation. Dr. Home, of Edinburgh, declares that he has repeatedly succeed- ed in communicating the disease in this Avay ; and similar re- sults are said to have followed the experiments of Dr. Speranza, of Italy. Dr. Chapman, on the other hand, denies this ; asserting, on the authority of numerous trials both with the blood, tears, and naso-bronchial mucus, that he has never been able to impart the affection by this expedient. The question may therefore be considered as still undecided. MeanAvhile, no doubt can remain as to its contagious character. The fifth and last disease that we shall notice under this head is scarlatina. Like rubeola, this is a contagious affec- tion, coming on from three to six days after exposure. At- tacking children in preference to adults, it often prevails epidemically, especially in winter and in spring, and in one form at least is a source of immense mortality. This form is the malignant, so termed from its being attended Avith great depression of the powers of life, and from being complicated 380 SKIN. [chap. X. with violent inflammation of the palate, tonsils, and pharynx. The efflorescence breaks out from twenty-four to forty-eight hours from the moment of the invasion of the disease, first on the face and neck, then on the trunk, and finally on the extremities. It consists of myriads of small red points, so closely grouped together that the Avhole surface exhibits a red scarlet hue, and feels rough to the touch, as if fine sand Avere streAved over it. The color is generally most intense in the evening, and has been compared, not unaptly, to that of a boiled lobster: it reaches its height about the end of the third day, begins to fade on the fifth, and disappears entirely about the seventh. With this efflorescence there is usually violent heat of the skin, Avith a sense of fulness, and more or less itching ; and, in many cases, the whole mouth and tongue, together Avith the throat, are of a deep, fiery color, evidently from an extension of the disease. Small vesicles sometimes appear on the eruption, resembling those that are occasionally noticed in rubeola, and containing a thin, sero-lymphy fluid : they seldom continue longer than four days, and it is not improbable that they are produced by some disbrder of the sebaceous follicles. Their number is sometimes immense. In the case of a young girl, twelve years of age, who came under my observation three years ago, the whole body was literally covered Avith them: they were about the size of a common pin-head, of a whitish color, and filled with a thin, tenacious fluid, which seemed to be gradually absorbed, as none of the little vesicles burst and discharged their contents. The desquamation, which is generally lamellar, begins about the seventh day, and is accompanied by a very disagreeable itching. The last disease that we shall describe under the present group is erysipelas. In the United States, as well as else- Avhere, this is an extremely common lesion, and takes place in all ages. I have seen it in new-born infants, in middle life, and in decrepitude. It more particularly occurs in per- sons of a deteriorated, worn-out constitution, and is usually preceded, as well as accompanied, by symptomatic fever. Although erysipelas may appear on any part of the body, the head, face, and legs are out of all proportion its most frequent situations. Of this disease, there are two important varieties, the simple and the phlegmonous. The first, which has its seat exclusively in the dermoid tissue, is characterized by diffused redness, with slight SECT. I.] ACNE. 381 swelling, increased heat, and a tingling, burning sensation. The discoloration is of a deep cherry hue, and disappears momentarily under pressure. When the inflammation runs very high, the cuticle is elevated, into vesicles, varying in size from a pin-head to a hazelnut, isolated or conglomerated, and containing a thin, straw-colored, or bloody serosity. The vesications usually appear within the first forty-eight hours, break in a day or tAvo after, and are replaced by thin, hard, yelloAvish crusts, which subsequently blacken. In milder cases, the disease subsides much sooner: the redness, about the third or fourth day, assumes a dusky yellowish tinge, the swelling diminishes, the skin becomes wrinkled, and the epidermis is detached in small bran-like scales. Few or no vesicles are observed. This variety is sometimes erratic, that is to say, it suddenly disappears at one point, and attacks another, leaving no other traces than a slight desquamation. In the phlegmonous variety, besides the phenomena above described, there is often great sAvelling of the subcutaneous cellular texture, with infiltration of acrid and bloody serosity, suppuration, or sloughing. This form of the disease I have seen most frequently about the eyelids, and the legs, in old, intemperate subjects. Great constitutional disturbance usual- ly attends : the affected part is exceedingly painful, and the dermoid and cellular tissues often slough in large patches, the latter coming away in dark-colored, dirty-looking shreds. 2. Pustular Diseases. Pustules are produced by inflam- mation of the dermoid textures, terminating in an effusion of matter, which elevates the cuticle into small, circumscribed tumors. The genera comprehended in this order are acne, sycosis, ecthyma, porrigo, impetigo, vaccinia, and variola. Some of these affections are acute, and others chronic ; some are contagious, and others not; some are discrete, and others confluent. Differing as they do in these particulars, they all resemble each other in the fact of their terminating in a scabby incrustation, varying in thickness and density in dif- ferent cases, and leaving, on dropping off, the surface to which it adhered, for some time, of a red color. Acne is a chronic inflammation of the sebaceous follicles, lasting from several Aveeks to as many years, characterized by the presence of small, isolated pustules, the most common seat of which is the upper and back part of the trunk, though they are often seen also on the forehead, nose, chin, and tem- ples. The limbs are seldom affected with them. The dis- 382 SKIN. [chap. X. ease is equally frequent in both sexes, and is particularly apt to occur about the age of puberty. The skin of the affected region looks dense and unctuous, the follicles are enlarged, their parietes are engorged Avith blood, and their orifices are marked by black points, giving the disorder its characteristic aspect. Each pustule is encompassed by a red areola; matter gradually forms in its interior, mingled with the natural secretion; and, after a short time, a thin scab appears, Avhich, on falling off, exposes a florid and slightly elevated promi- nence, that gradually sinks to the leA^el of the surrounding surface. Small scars sometimes remain ; and, in old chronic cases, the skin is often quite hard, and exhibits a rough, granulated appearance, Avith varicose enlargement of its vessels. Seated in the sebaceous follicles, and closely allied to the disease just described, is sycosis, the mentagra of Willan and Alibert. Its distinguishing feature is the successive evolution of numerous sharp-pointed pustules, scattered over the hairy scalp, upper-lip, the chin, lower-jaAv, and side of the face, occurring usually in adults, and preceded by considerable redness of the affected part, with a sense of heat and tension. Red vesicles soon become visible, Avhich, by the third day, assume a pustular form, standing out like circumscribed ele- vations, the summits of Avhich grow Avhite, and are gradually filled with pale yellowish matter. The prominences subse- quently increase a little in size, and, Avhen fully developed, are as big as a millet-seed. Between the sixth and seventh day, each pustule bursts, its sides shrink, and a slight dis- charge takes place, which dries into a brownish crust, that is feebly adherent to the skin, and insensibly lost in the adja- cent epidermis.* When the pustules are very numerous, they sometimes coalesce, and the inflammation is then apt to extend to the subjacent cellular texture, which is rendered hard and painful, and exhibits all the appearances of a true phlegmonous swell- ing. The pustules themselves are quite large: they rest upon a red, tuberculated base, often contain bloody matter, and are covered with thick, dirty-looking incrustations. The skin is sometimes very much altered, and sprouts out in the form of moist, vegetating excrescences. Arrived at this pitch, * Rayer's Treatise on Diseases of the Skin, p. 481. Second edition. London, 1835. SECT. I.] ECTHYMA-- IMPETIGO. 383 the disease is extremely intractable, and presents a most loathsome aspect: the hair falls out, and the part is constantly bathed with a thin, sero-sanguinolent fluid, often excessively acrid in its character. Fortunately, this affection is very rare in this country, and seldom attains the height it does in continental Europe. The disease next in order is ecthyma, Avhich, as has been already stated, is closely allied to rupia, being, indeed, con- sidered by some merely as a variety of it. It is an inflam- matory affection of the dermoid texture, non-contagious, and characterized, at its height, by large, rounded pustules, usu- ally distinct from each other, and resting upon a hard, florid base. All parts of the body are liable to be affected ; but the regions most frequently involved are the neck, chest, and shoulders. The eruption generally begins by small, reddish elevations, which rapidly augment in size, and become filled, in the course of a fe\v days, Avith sero-purulent matter, the base, in the mean time, extending in diameter, and exhibiting a bright scarlet hue. In this state, the larger and more ma- ture pustules have a conoidal shape, are hard and painful on pressure, and bear a close resemblance to small boils, their size being between that of a lentil and a big pea. A pseudo- membranous substance is also frequently to be distinguished in their interior, particularly towards their centre. In from three to five days, the contents of the pustules escape, and concrete into thick, whitish, adherent scabs, the disengagement of which, occurring at indefinite intervals, leaves the part of a red, livid color, each spot being from four to eight lines in diameter, and marked at its centre by a minute, superficial cicatrix. Acute ecthyma is often accom- panied by severe lancinating pains, and has only one crop of pustules; whereas the chronic form of the disease, which is by far the most common, has always a continued succession of them. Some of the pustules occasionally terminate in ulceration, producing ill-conditioned, painful sores, attended with a sanious, bloody discharge, and followed by thick, dark-colored crusts. Impetigo is a non-contagious, chronic disease, Avhich is exceedingly prevalent in this country, in young children during the period of dentition, especially in such as are of a scrofulous habit. It is most frequently observed on the face and legs, and next in order on the forehead, neck, and trunk. In some instances—and these are not infrequent — the dis- 384 SKIN. [CHAP. X. ease covers all these parts simultaneously, or gradually travels, as it Avere, from the one to the other. The pustules are small, irregularly circumscribed, Avith only a slight elevation of the cuticle, and terminate in thick, rough scabs. The disease is accompanied and produced by inflammation of the part affected, which continues for an indefinite period, and causes considerable enlargement of the capillary vessels, par- ticularly of the veins. At first, the eruption is vesicular; but, like that of small-pox, and other kindred disorders, it becomes pustular, the elevations being distended, in a few days, Avith sero-purulent matter, Avhich is often poured out in great abundance, and rapidly hardens into thick, semi- transparent, friable scabs, resembling fragments of dried hon- ey. Occasionally, the incrustations, instead of being of a clear yelloAvish color, are of a light greenish brown, or ma- hogany hue. The scabs having fallen off, the denuded skin is observed to be of a deep red complexion, slightly fissured, abnormally thick, tender on pressure, and to exude a consid- erable quantity of sero-purulent matter. Impetigo appears under two principal varieties of forms, — the small pustules that characterize it being, in the one, ir- regularly disseminated, with healthy or more or less inflamed intervals, — in the other, disposed in groups, generally of an oval shape, and resting on a tumid, rose-colored base. Each of these varieties is acute or chronic, according as there is only a single crop of pustules, or a successive reproduction. Closely as this disease resembles ecthyma in many of its features, it can always be easily distinguished from it by the smaller size of its pustules, their mode of developement, and the lighter color of their base. The term porrigo is applied to a chronic inflammation of the skin, essentially contagious in its nature, and character- ized principally by the appearance of its scabs, which are of a bright yellow color, very dry, thoroughly adherent, and of a circular shape, Avith a central, cup-like depression, and thick, prominent, and inverted edges. The most usual seat of the disease is the scalp, from Avhence, hoAvever, it often extends to the forehead, temples, chin, eyelids, and other regions, until, in some instances, it covers almost the entire body. Occurring indifferently in both sexes, at all seasons of the year, and at all periods of life, it is most common in infancy and childhood, and is ahvays of indefinite duration, lasting at one time only a few weeks, at another a number of SECT. I.] PORRIGO. 385 months, and, in a third series of cases, perhaps several years. Alibert describes five varieties of porrigo, Willan not less than six. These divisions are certainly uncalled for, as they differ from each other merely in the intensity of the diseased action, its location, and the distribution of the pustules. The mildest form of the eruption, and one which is extremely common in this country, affects the head and face of infants, and is usually knoAvn by the name of crusta lactea. Porrigo, in whatever form it may appear, or wherever situ- ated, always commences in very small pustules, scarcely rising above the surrounding surface, and covered, from the very first, with a thin yellowish crust, Avith a minute central pit. Examined at this period, the pustules are found to con- tain a drop of sero-purulent matter, Avhich, instead of escaping, as happens in most other kindred diseases, always remains, and dries in their interior. The scab, manifesting itself, as Ave have just seen, almost simultaneously Avith the eruption, goes on increasing until it reaches the diameter of a ten cent piece: its central depression in the mean time becomes re- markably distinct; and, in the course of a week or so, it ac- quires all the characters above assigned to it. When the pustules are confluent, the incrustations often cohere, and are detached in large yelloAvish masses, leaving the cuticle tender, red, elevated, and marked with deep lines. Excessive itch- ing generally attends this disease, and the scabs are often re- produced in great numbers and with astonishing rapidity. The odor of the scabs is peculiar. Alibert and Rayer state that it resembles that of the urine of the cat. When the scabs are softened Avith emollient poultices, the smell changes, becoming faint and sickening, and a good deal like that Avhich is caused by boiling bones with their ligaments. The substance of Avhich they are composed has been care- fully analyzed by Thenard, Avho found that one hundred parts contain seventy of coagulated albumen, seventeen of gelatine, five of phosphate of lime, and eight of water. Porrigo is supposed by some to be seated in the piliferous follicles, — an opinion which seems so much the more plausi- ble, Avhen it is remembered that the disease principally occurs in those regions which abound in these structures, and that a hair frequently occupies the centre of each pustule. How- ever this may be, the hairs are always considerably affected : they become dry, stinted in their growth, and many of them fall off. This is particularly apt to take place in chronic vol. i. 49 386 SKIN. [CHAP. X. porrigo of the scalp, the furfuraceous variety of Bateman, which is almost ahvays attended Avith permanent baldness. Occasionally, the piliferous follicles remaining, a neAV crop of hairs is produced, which are thin, Avhite, and doAvny. Vaccinia, usually called cow-pox, is a contagious disease, which is transmitted by inoculation from one individual to another, and Avhich is characterized by the developement of Jarge, multilocular, pearl-colored pustules, surrounded by an erythematous areola, and followed by a brownish scab, Avhich falls off about the twenty-fifth day, leaving a pitted scar. Three well-marked stages are to be observed in the progress of this affection. The first stage commences on the fourth day after the in- sertion of the virus, and terminates on the ninth. At this time the true vaccine inflammation first manifests itself, and the puncture, Avhich until now resembled a mere scratch, as- sumes a pale rose-color: it is somewhat conical in its shape, rises a little above the surrounding surface, and presents the appearance of a flea-bite. By the fifth day, the point has augmented considerably in volume : it is of an umbilical form, with a slight central depression, and its cuticular covering is elevated by a minute quantity of transparent fluid into a firm and resisting pustule. On the sixth day, all these characters are more distinct, and the affected part stands out in bold re- lief. The vaccine tumor is increased in all its dimensions, and its inflamed surface has a more transparent and polished aspect. The pustule, which until noAV was quite small, occu- pies a circle of about a line in diameter; its surface has a ra- diated, argentine appearance; its edges are smooth and round- ed ; and its centre is not only more depressed, but it is hard, dry, and of a darkish color. From this time on, the pustule gradually augments in size, the margin becomes more promi- nent, and the centre exhibits a concave cup-like form. During the second stage, that is to say, from the ninth to the eleventh day, the pustule attains its most perfect devel- opement, about four lines in diameter, and projecting from one to two lines above the surrounding level. It is encircled by a vivid red areola, often several inches in extent; its margin becomes more full, and the central depression is either partial- ly or Avholly effaced. The erythematous surface around is the seat of a great number of minute vesicles, and there is marked swelling of the subjacent cellular tissue, extending generally to the axillary ganglions, and rendering the limb SECT. I.] VACCINIA. 387 stiff and painful. The virus, Avhich is now ripe for use, is still limpid; and, if the pustule be punctured, it Avill ooze out, drop by drop, until the little cells containing it are emptied. These cells, as has been ascertained by dissection, are ex- tremely small, as well as numerous, and perfectly distinct from each other, none of them communicating together. Gendrin states that they are arranged in two concentric roAvs; and that the centre of each pustule is occupied by a minute quan- tity of yellow muddy pus, contained in a sort of funnel- shaped receptacle just beneath the cup-like depression of the epidermis. On the eleventh day, the commencement of the third stage, the desiccating process sets in. The central depres- sion assumes the appearance of a light brownish crust, the contained virus acquires a muddy serous color and a viscid ropy consistence, the areola gradually fades, the swelling decreases, and the epidermis falls off in small furfuraceous scales. By the fourteenth day, the pustule is greatly dimin- ished in size, the scab is of a horny hardness and of a yel- lowish complexion, and the areola is reduced to a narrow purple circle not more than the eighth of an inch in diameter. From this period, the swelling and tension of the arm rapidly subside, the vaccine crust augments in density and depth of color, and is detached about the twenty-fifth day, counting from the insertion of the virus. The scar thus disclosed, is slightly depressed, of a circular shape, from three to five lines in diameter, and of a pale reddish hue, exhibiting a number of small honey-combed pits, indicative of the number of cells of the vaccine pustule. The cicatrix becomes ultimately Avhiter than the surrounding skin, and the pits remain in- delible. The fallen scab is of a brownish mahogany color, hard, dry, brittle, of a circular shape, and more solid, as well as thicker and more opaque, in the centre than at the circum- ference. Its upper surface is smooth, convex, and somewhat polished ; the other, on the contrary, is rough, flattened, or slightly concave. Albumen is its chief ingredient. When recent, it can be cut into thin, grayish slices, Avhich expand by maceration, turn white, and exhale a sickening animal odor. Drying hardens it very much; and trituration with water converts it into a ropy cream-like mixture, which is capable of communicating the disease. The induration of the scab is much influenced by the atmosphere If the air SKIN. [CHAP. X. is excluded, the secreted matter is said to be throAvn off in small, soft pieces, Avithout the formation, frequently, even of a scar. Variola is an acute, cutaneous inflammation, consisting of numerous umbilical pustules, preceded and accompanied by fever. It is contagious, occurring generally only once in the same person, and running its course in about tAventy-eight days. When the pustules are situated at some distance from each other, the disease is said to be distinct, and confluent when they are agglomerated. It is also divided into natural and inoculated, according as it arises spontaneously, or from the introduction of the small-pox virus. The period Avhich intervenes between the infection and the developement of the disease varies from six to twenty days. The pustules not only cover the skin, but frequently also the mucous surfaces that are directly continuous Avith it, as the eyes, mouth, and pudendal lips. The eruption, Avhich is sometimes preceded by a general erythematous blush, usually takes place from forty-eight to eighty hours after the commencement of the indisposition, appearing first on the face and neck, then on the chest, abdomen, arms and legs, and lastly on the hands and feet. This order of invasion, however, is not constant ; for it not unfrequently happens that the disease first manifests itself on the trunk, and even on the extremities, before it invades the head, although it is on the latter region that it is always most violent. The eruption begins in small, red, circular points, having very much the aspect of flea-bites, and Avhich, although widely dispersed originally, rapidly multiply, and, in the course of a few days, complete their number, — the cutaneous surface being, in the mean time, hot, tumid, and shining. During the period Avhich intervenes between the efflorescence and the suppuration, embracing nearly one week, the elevations gradually increase, project above the level of the surrounding parts, and assume the appearance of distinct pustules, each of which exhibits a well-marked cen- tral depression. As early as the second day, these elevations are already bounded by a regularly formed ring of inflamma- tion : their form is umbilical, and their summit contains a drop of limpid fluid. In this manner, the developement pro- ceeds until suppuration commences, which it usually does about the sixth day. During this period, constituting what is termed the eruptive stage, the pustules have a cellular SECT. I.] VARIOLA. 389 structure,, being composed of little compartments, separated by thin partitions Avhich converge to a central point. The suppurative process having commenced, the pustules lose their umbilical shape and become hemi-spherical; their surface acquires a rough, whitish aspect; and their contents continue to groAV more and more opaque, being at first of a milky hue, and afterwards of a pale straw-color, Avith various degrees of turbidity. A small circular speck now generally appears in the centre of each elevation, which gradually ex- tends towards the circumference, until at length the whole superficies assumes the same purulent look. Whilst these changes are taking place externally, the internal cellular structure gives way, the little compartments are broken up, and the matter occupies a single cyst, with dense, resisting parietes. With proper care, this cyst can be readily lifted out of its situation: it is of a rounded shape, from two to four lines in diameter, and is deeply lodged in the dermis, project- ing a considerable distance into its substance. The suppura- tive process usually begins on the forehead and face, and ends on the hands and feet, where the pustules also remain much longer before they break, owing, no doubt, to the great thickness of the cuticle. The intervals betAveen the pustules, during this stage, are generally tumid, from the infiltration of sero-albuminous matter, and of a florid red, the inflammation being of a phlegmonous character ; and the patient experiences a sensation of tension and soreness, occasionally amounting to real pain. About the tenth day, the pustules have arrived at their full height; they are filled Avith thick, yellowish pus, and they present the appearance of so many little abscesses. The desiccating process always begins on the face, and gradually extends to the other regions of the body, occurring last on the feet and hands. It is usually accompanied with violent itching, and with a peculiar nauseous odor, not unlike that exhaled by the rattlesnake. The scabs, which fall off from the tenth to the fifteenth day after the appearance of the eruption, are of a brownish color, lamellated, dry, and of a horny consistence. The scars which are left by their detach- ment, and Avhich are commonly confined to the cranio-facial region, are depressed at their middle, and traversed by small, narrow ridges, which often greatly disfigure the features, especially in the confluent variety. In regard to the form, 390 SKIN. [CHAP. X. the utmost irregularity prevails, some of them being circular, some oval, others angular. Their depth is usually consider- able, presenting an appearance as if they occupied a goodly portion of the thickness of the dermis. These scars are at first red, but soon change to a dark purple color, which they retain for many Aveeks; by degrees, however, they grow Avhiter and Avhiter, but they always remain more pale and opaque than the rest of the skin. The skin of variolous subjects ahvays putrifies much more promptly than the cutaneous tissue in the sound state. By artificial injection, all the capillaries can be so completely distended as to give the affected part a red scarlet hue; but it is a singular fact, that none of the matter ever finds its way into the pustules, or even into the dermoid substance imme- diately around them, — owing to the circumstance, as is sup- posed by Gendrin, that all the vessels in this situation are either obliterated or wholly destroyed, the tissue itself being of a deep, uniform color, and infiltrated Avith blackish blood. If mercury be used, a portion of it is generally effused both around and within the pustules; yet none of it appears to penetrate into the vessels of these parts. As connected with the disease just described, is varicella, concerning which it will be necessary here to say a few words. Like small-pox, this disease is contagious, and usu- ally occurs only once in the same individual, attacking chil- dren in preference to adults. Preceded by slight fever, and other symptoms of derangement, the eruption generally com- mences on the body, though sometimes on the face and limbs, and gradually rises into small, red, circular points, which, in turn, are replaced by lenticular, globular, or conical pustules, somewhat analogous to those of variola. The pustules are sometimes discrete, sometimes collected together: they are surrounded by a red, rose-colored areola, contain a transparent serous fluid, which in time assumes a thick milky appear- ance, are soft and flaccid to the touch, and generally termi- nate from the fifth to the ninth day, with a thin, brownish, furfuraceous desquamation, which rarely leaves any cicatrix. The eruptive stage of varicella, is rarely completed under two or three days, and hence the disease is often prolonged to a fortnight, the parts on Avhich it first broke out being covered with scabs, when the pustules in other regions have scarcely arrived at maturity. SECT. I.] LICHEN--PRURIGO. 391 3. Papular Diseases. The lesions arranged in this order are characterized by hard, solid elevations, usually of the color of the skin, to which they impart a rough, uneven sensation, preceded and accompanied by pruritus, and termi- nating by resolution, desquamation, or slight ulceration. Their progress is commonly sIoav ; and there is no part of the cutaneous surface which is not liable to be attacked by them. The diseases belonging to this division are only two,—lichen and prurigo. Lichen is a non-contagious disease, which may appear on any part of the body, though in most cases it manifests a decided preference for the neck, face, hands, and fore-arms. It is distinguished by hard, firm papulae, generally of a white color, sometimes red, almost always clustered together, and accompanied with considerable itching, which is augmented by the heat of the bed, and liable to well-marked exacerba- tions. The elevations are seldom larger than millet-seeds; and, although commonly aggregated into irregular groups, yet occasionally they are united into circular patches, or into long, narroAv strips, stretched spirally around the affected part. The accompanying redness, if there be any, disappears about the end of the fourth day, though sometimes not until much later, and is followed by a slight furfuraceous disquam- ation, which may continue for several weeks, or even months. In violent cases, the papillas occasionally ulcerate, and dis- charge a thin, sero-purulent fluid, which gradually concretes into small, soft, yellow scabs, someAvhat rough, and easily removable. At other times, again, the elevations become con- fluent, and are surrounded each by a small, reddish border. In chronic lichen, the skin is harsh, dry, and sometimes considerably thickened. Deep fissures are also frequently observed, especially about the joints, and the cutaneous func- tions seem to be almost entirely suspended. Prurigo, in its essential characters, resembles lichen, but differs from it in the greater size of its papulae, the excessive itching, and the want of discoloration of the skin. It is ahvays chronic, its duration varying from one to many months; and its most usual seats in the neck, shoulders, and pudendal lips, where the desire to relieve the pruritus by scratching is frequently irresistible. Ordinarily, the papulae are very numerous, especially in young persons, and it is by no means uncommon to observe several successive crops of 392 SKIN. [chap. X. them, — new ones appearing as fast as the old ones heal. From the intolerable itching which attends them, they are apt to become torn by the nails, and replaced by small, black- ish, circular scabs. 4. Bullar Diseases. The bullar diseases Avhich are, properly speaking, only two in number, are marked by the formation of small bladders, of a circular figure, varying in size from that of a pea to that of a goose's egg, generally transparent, and filled with a serous, lymphy, or sero-purulent fluid, which is poured out between the dermis and cuticle. These small bladders attain their height in the course of seventy-two hours, Avhen they commonly burst, and are suc- ceeded by scabs, sometimes of considerable thickness. Their progress is generally chronic, and their duration varies from one or two Aveeks to several months. Pemphigus is characterized by the formation of large bullae, generally of a pale straw-color, isolated, and occurring simultaneously on several parts of the body. In regard to its symptoms and duration, pemphigus may be divided into two distinct varieties, the acute and chronic. This division is contrary to the classification of Willan and Bateman, Avho admit only the latter form of the disease, under the denomi- nation of pompholix. The disease is particularly apt to occur in adults and old persons, and is said to be more common in males than in females; but of this I know nothing from my own experience. In the acute variety of this disease, there are generally well- marked constitutional symptoms, Avhich, in the course of tAvo or three days, are followed by the eruption of small, red, cir- cular spots, Avhich, rapidly increasing in size, soon turn to a more dusky hue. They are then transformed into bullae, varying from the magnitude of a pea to that of a large hazel- nut, of a rounded shape, and encircled generally by a vividly red border, from one to several lines in width. Their number is variable, from a single one to many : they increase in size during the first twenty-four hours, and the contained fluid, which is at first thin and limpid, becomes yellowish, turbid, and even reddish. They reach their acme by the end of the third day, when they shrivel and dry up; or they burst, and leave small, thin broAvnish crusts. The spots exposed by these crusts are of a dull red color, of an irregular form, isolated, and liable, from time to time, to slight exfoliations. SECT. I.] RUPIA. 393 The duration of each bulla is about one week, and not un- frequently there are several successive crops of them on dif- ferent parts of the body, so that the disease may be protracted for tAvo or three Aveeks. Chronic pemphigus differs from the acute principally in the greater tardiness of its progress, by the absence generally of the red areola, and in the peculiar mildness of the antece- dent and accompanying constitutional manifestations. The bullas, also, are generally somewhat larger ; and, in some rare cases, they cover the Avhole surface of the body, though they are for the most part confined to particular regions. In three or four days from their first developement, they usually break, pouring out a thin yelloAvish or reddish fluid, so acrid, in some instances, as to irritate the surrounding parts. The sores thus exposed present a red, inflamed aspect; and, as the epidermis dries over them and exfoliates, neAv bullae spring up in their neighborhood, and follow the same course. In this Avay the disease may last for several months or even years. Old people are most liable to it, especially those whose constitution is exhausted by debauch and intem- perance. Rupia presents several varieties; but, as has been justly observed by Cazenave and Schedel, they differ from each other merely in their extent and intensity; and hence, for pathological purposes, it will be as Avell to consider them under one common head. The affection, which is very analogous to ecthyma, usually occurs in a chronic form, its course being seldom run under several months. It is charac- terized by small, isolated, flattened bullas, about the size of a shilling, Avith or without redness of the skin, and filled Avith a serous fluid, which soon becomes opaque, puriform, or sanguinolent; and to Avhich succeed thick, rough, dark- colored crusts, someAvhat thinner at the circumference than at the centre. Ulcerations, either superficial or deep, general- ly exist under these scabs, which fall off in the course of a feAV days, and are speedily succeeded by cicatrization. Such, however, is not ahvays the progress of this disease. In some instances, the sores remain open for a considerable period, forming scales Avhich are removed as fast as they desquamate. Occasionally the disease disappears without the developement of scabs ; but this, I. presume, is a very unusual occurrence. Rupia sometimes terminates in gangrene. This is par- vol. i. 50 3U SKIN. [CHAP. X. ticularly apt to take place on the thigh, breast, abdomen, and scrotum of young, cachectic children. The bullae in such cases are generally preceded by small livid spots, and they often form with great rapidity, their contents being someAvhat acrid and of a blackish color. In a short time, the bladders give way, exposing extensive ulcerations, bathed with a bloody, ill-conditioned sanies, and encircled by livid and painful edges. Great constitutional disturbance usually attends this variety of rupia, and not unfrequently it termi- nates in death. Cicatrization is ahvays sIoav, and oftentimes the body is disfigured Avith ugly scars. Eczema is an inflammation of the skin, non-contagious, and partially liable to occur on the scalp, ears, breast, scrotum, arm-pit, groin, and pubes. Though usually limited to one or two spots, it sometimes occupies the Avhole surface of the body, and may be either acute or chronic. Biett states that the disease is more frequent in Avarm than in cold Aveather, and in women than in men. Arising occasionally without any assignable cause, it is often induced by sudden vicissi- tudes of temperature, exposure to the hot rays of the sun, dry friction, and by the internal or external use of mercury. Eczema is characterized, at its commencement, by an evolu- tion of very minute vesicles, closely crowded together, trans- parent, silvery, and reposing upon a surface which is either of the natural color, or else more or less red and inflamed. After having continued for some time, the disease either be- comes chronic, or it terminates in the absorption of the fluid, or in superficial ulceration, followed by furfuraceous des- quamation. Much itching and smarting often accompany this disease, and hence it is frequently mistaken for scabies. From this affection, however, it may be easily distinguished by its non-contagiousness, and by the agglomeration and peculiar shining aspect of its vesicles. In violent cases of eczema, the vesicles become confluent, and are liable to break, giving vent to a thin, sero-purulent fluid, which gradually concretes into soft, yellowish scales, often of considerable size and thickness. These are frequently denuded, leaving always, on being detached, a crimson sur- face, from which exudes a reddish serosity, which follows the same course until the inflammation subsides, — the scabs be- coming every time thinner and lighter, and the sore less red and sensitive. Cases of this kind frequently last for several SECT. I.] MILIARIA. 395 weeks, some of the vesicles drying as others appear; and they are usually preceded, as well as accompanied, by strongly marked constitutional symptoms. When the disease runs into the chronic form, the skin being perpetually irritated by the evolution of new vesicles, and the constant discharge of ichorous matter, continues deeply inflamed, at the same time that it is very apt to be- come chafed and excoriated, especially about the joints. The eruption, in such cases, sometimes persists for months, the secretion, in the mean Avhile, going on in full vigor; at other times, hoAvever, the discharge is either very slight, or the part is entirely dry, and covered with thin, soft, yellowish scabs, which, on falling off, expose a cracked and slightly inflamed surface. Miliaria is an eruptive disease, generally, though not al- ways, symptomatic of other affections, attended Avith profuse perspiration, and a feeling of heat and itching. Every por- tion of the body is liable to it, but the regions most frequently affected are the neck, breasts, and back, with the inside of the thighs. Its duration is from one to three days. The vesi- cles, Avhich are at first very small and transparent, are rarely confluent; but they often occur in irregular groups or patches, the surface over which they are scattered being either red- dened, or of the natural color. When fully developed, as they generally are in the course of thirty-six or forty-eight hours, they are of a rounded form, pearly in their appearance, filled with a milky fluid, and about the size of millet-seeds. The eruption sometimes covers the greater part of the body, but usually it is widely scattered, and confined to particular regions. From eczema this disease may be dis- tinguished by the rapidity of its progress, the shortness of its duration, and by the larger size and greater distinctness of its vesicles. 5. Vesicular Diseases. This class of cutaneous diseases is characterized by the evolution of small vesicles, acumi- nated or globular, distinct or confluent, and occurring gen- erally in irregularly circumscribed spots, the surface on which they appear being either of the natural color, or marked by inflammatory redness. The contents of the vesicles are at first thin and transparent, afterwards milky and opaque, and, in some instances, even slightly puru- lent. The eruptions arranged under this group may occur in any part of the body, are seldom serious, and may ter- 396 SKIN. [CHAP. X. minate either by resolution, desquamation, superficial exco- riation, and in the formation of soft yelloAvish scabs. Their duration varies from a feAV days to several weeks, or even months. Scabies is an inflammatory affection, contagious, accom- panied by an insect, and characterized by pointed vesicles, transparent at the summit, of a light rosy tint, and filled Avith a thin, viscid fluid. By scratching, these vesicles are easily broken, when their contents escape, and expose a correspond- ing number of small, red, inflamed specks, Avhich frequently run into each other. The eruption is sometimes very trifling, but in many cases it is very extensive, covering a large por- tion of the cutaneous surface. It never, hoAvever, appears on the face; and, what is singular, it is ahvays most abundant at the flexures of the joints and betAveen the fingers, owing, doubtless, to the great delicacy of the skin in these situations. In infants, the disease is usually developed in four or five days after exposure to the contagion; in adults, in from one to tAvo Aveeks. A slight itching is first felt in the parts, Avhich is invariably increased by the Avarmth of the bed, by sitting near the fire, or by stimulating food and drink, and, in plethoric habits, is sometimes almost intolerable. No fever attends this affection. It has been already stated that this disease is accompanied by an insect. Whether this is a constant occurrence is not fully determined, but that it is occasionally ob- served is established be- yond contradiction by the recent researches of Dr. Renucci, of Paris. The insect, the existence of Avhich Avas long ago sus- pected, if not actually de- monstrated, by some of the older physicians, is called the acarus, or itch-ciron, and is seldom to be found in the vesicle, but almost always in a small epider- mic canal, Avhich leads from it, and which is either SECT. I.] HERPES. 397 straight or tortuous, and sev- Fis- 42. eral lines in length. The acarus (Figs. 41 and 42) is of a white, opaque color, and about the size of the sharp extremity of the fin- est needle, presenting, when seen through the microscope, the form of a tortoise. It has eight small feet, and the head is a perfect retract- ing sucker : the belly pre- sents several dark-colored spots, and on the back are to be seen a number of eccentric lines, placed at short intervals, and having the appearance of joints.* Willan and Bateman have subdivided herpes into six spe- cies, — a circumstance which, considering that they all occur pretty much under the same states of the constitution, and require the same kind of-treatment, may be considered as a sort of " hair-splitting," certainly as unnecessary in pathology as it is injurious. The disease is characterized by distinct but irregular clusters of vesicles, Avhich are set in close proximity, upon a vividly red base, surrounded by intervals of sound skin. The spots thus formed vary in size from that of a guinea to that of the palm of the hand, and the vesicles from the smallest pin-head to that of a pea. The lymph of the vesicles, Avhich is at first clear and colorless, becomes gradually milky and opaque, and ultimately con- cretes into thin brownish scabs, Avhich fall off about the tenth day from the time of their eruption. Sometimes tedious ulcerations ensue, leaving strongly-marked cicatrices; and now and then the disease disappears by desquamation, the fluid being absorbed by the end of the first week. In the zonoid variety, vulgarly called " shingles," the vesicles are aggregated into irregular oblique patches, in the form of a half belt. According to Cazenave, the patches generally begin at the centre of the body, from whence they extend in * See American Journal of the Medical Sciences for February, 1835, in which is a full account of this insect, with two excellent figures. 398 SKIN. [CHAP. X. an opposite direction, Avithout ever passing the median line. Ring-Avorm is another variety of herpes, the characters of which are so distinct as to render any particular account of it unnecessary. Herpes lasts from one to several weeks, passing through a regular course of increase, maturation, and decline. It is generally very mild in its character, may be seated on any part of the body, and often coexists Avith other affections, either cutaneous or internal. 6. Tubercular Diseases. The diseases arranged under this head are characterized by the developement of small, solid, circumscribed tubercles, of a rounded or conical shape, of a reddish or purple color, generally isolated, and confined to particular regions. After having continued for some time, varying from a few months to several years, they either dis- appear, or terminate in ill-conditioned ulcers. The affections which properly belong to this division of our subject, and which are seldom seen except in tropical countries, are Greek elephantiasis, frambcesia, and lupus. Greek elephantiasis is a chronic affection, characterized by soft, prominent tubercles, Avhich are irregular in their shape, and of a red, livid color. In their size they vary between a pea and a walnut: they are either painful or indolent; and, as they grow older, they gradually assume a dirty bronze com- plexion, at the same time that they acquire a greater degree of hardness and density. When ulceration sets in, they be- come the seat of ill-conditioned sores, discharging a thin, sanious fluid, Avhich concretes into thick, adherent, blackish crusts. The most common seat of the disease is the face, the ear, nose, shoulder, buttock, and leg, which are often hideously distorted, both from the immense number of tumors, from the furrowed state of the skin, and from the great swelling of the subjacent cellular substance. Does elephan- tiasis consist in a hypertrophied state of the cutaneous pa- pillae ? This is highly probable ; nevertheless, the question has not yet been determined by dissection. This disease is generally complicated with other affections, and is almost al- ways incurable: Alibert asserts that it is occasionally hered- itary. It occurs indiscriminately in adults of both sexes. Frambcesia, vulgarly called yaws, is a chronic tubercular disease, indigenous in Africa, and extremely common in America and the West Indies. Although contagious, it can only be communicated by immediate contact, and is infinitely SECT. 1.] LUPUS. 399 more frequent amongst blacks than Avhites. The period which elapses betAveen the reception of the virus and the com- mencement of the eruption is not accurately determined, but does not probably exceed several weeks. The disease affects the same person only once during life, and children are more obnoxious to it than adults. The eruption, Avhich is generally preceded by slight con- stitutional symptoms, and which appears successively on dif- ferent regions of the body, is characterized by minute flea- bite-looking pimples; to which succeed irregular, prominent tubercles, which often present the shape, color, and size of a raspberry,— a circumstance from which the disease has obtain- ed its name. The A^egetations thus formed are usually distinct at their summit, but almost always united at the base : they are firm, and indolent, and covered with thin, dry, and ad- herent scales. Finally, after remaining stationary for weeks, months, or even years, they inflame, become soft, and spongy, and give rise to deep, foul ulcers, from which there is a con- stant discharge of a yelloAvish, acrid, and offensive fluid, which soon concretes into pretty thick scabs. Their most common seat is the head; but they also occur, though less frequently, in the axilla and groin, around the anus, on the scrotum, and on the pudendal lips. They likeAvise appear on the shoulders, buttocks, and limbs; but the scalp, forehead, and temples, scabbed and hideously disfigured, are the parts, of all others, which suffer most frequently. The last affection that we shall notice under this head is lupus. This is a truly malignant disease, seated, for the most part, on the nose, cheek, and chin, and Avhich, if allowed to progress, successively destroys the cutaneous and cellular tis- sues, and finally the cartilages and bones. It usually com- mences in a small red point, which is hard and prominent, and appears to affect only the more superficial layers of the skin. The progress of the tubercle is slow and gradual, a long time often elapsing before it attains its full developement. By and by, however, ulceration and scabbing commence: the sore is bathed with sanious matter, its edges are raised and indurated, and its bottom exhibits a foul, livid aspect. The tendency of the disease is to spread, both in depth and in diameter; hence it frequently happens that it invades a large extent of surface, and produces the most frightful ravages. The ulcer sometimes spontaneously heals,— the part of the skin over which the disease has passed remaining hard and red, like the cicatrix of a superficial burn. 400 SKIN. [CHAP. X. The number of tubercles varies. Most generally there is only one, but noAV and then there are a great many, almost the Avhole face being covered with them. . During the ulcer- ative stage, considerable pain attends, the skin becomes hyper- trophied, and the cellular tissue is distended Avith sero-albu- minous matter. The disease is equally frequent in both sexes, and is rarely met with after the fortieth year. Persons of a scrofulous diathesis are particularly subject to it. 7. Scaly Diseases. The scaly diseases, located in the outer surface of the corion, are characterized by the develope- ment of red spots, elevations, or blotches, over Avhich the scarf-skin, dry, opaque, and thickened, incessantly exfoliates and reappears, the process of renovation and decay sometimes going on for years. Easily distinguishable from the crusts which attend vesicular affections, they generally proceed in a slow and insidious manner, unaccompanied with much local or constitutional disturbance; and, although they are rarely dangerous, they are always very disagreeable, as they have a tendency, especially if protracted, not only to disfigure the skin, but seriously impede the movements of the joints. Four genera of lesions have been described under this order by Willan, Bateman, and others ; namely, lepra, pityriasis, ichthyosis, and psoriasis. To these may be added a fifth, namely, pellagra. Lepra most commonly attacks the arms and legs, especial- ly the superficial parts below the elbows and knees : it some- times occurs on the hairy scalp, but seldom exclusively. Commencing in small, red, shining points, scarcely elevated above the level of the skin, it soon forms pretty large patches, often an inch and a half in diameter, of an orbicular shape, disjoined or confluent, slightly depressed in the centre, and surrounded by a florid, prominent circle, from one to several lines in Avidth. The epidermic scales are at first thin, smooth, polished, and transparent ; but, in the course of a few days, they are replaced by others, which are lamelliform, hard, tough, opalescent, pearly, or of a pale straw-color. These scales fall off, and are incessantly renewed, the surface be- neath them being someAvhat rosy and inflamed, smooth in recent, and occasionally deeply chapped in old cases. This disease sometimes gets well spontaneously, the skin from Avhich the scales are detached acquiring at first a pecu- liar grayish color, which sometimes persists for a considera- ble period aftenvards. In the majority of cases, however, it SECT. I.] ICHTVOSIS. 401 slowly pursues its career, producing more or less thickening of the skin, and impairment of the locomotive powers. When leprosy is generally diffused, Bateman states that there is often considerable cutaneous inflammation, accompanied Avith extreme soreness, pain, and stiffness, amounting to such a degree sometimes as to render the motions of the joints im- practicable, and confining the patient to his bed.* According to the same authority, the nails of the toes and fingers are fre- quently much thickened, opaque, of a dirty yellowish color, incurvated at the extremities, and very irregular on the sur- face ; yet, even under all these circumstances, there is rarely much constitutional disturbance. Pityriasis is a superficial inflammation of the corion, — chronic, non-contagious, and attended Avith an exfoliation of the epidermis, in the form of very thin, irregular, Avhitish scales, Avhich are reproduced in great numbers and Avith astonishing rapidity. Considerable pruritus often attends this affection, leading to an irresistible desire to scratch. Sometimes the cuticle comes aAvay in a mealy, furfuraceous, or pulverulent desquamation ; and, in the generality of cases, the corion is singularly discolored, sometimes of a copper tint, brownish, or almost black. The scales, Avhatever may be their size and form, are always dry, easily detached, and spread over a large surface, the affected part being often many inches in diameter, and interspersed with portions of sound skin. The most common seats of pityriasis are the scalp, eyebrows, breast, and epigastric region, together with the arms and shoulders. Ichthyosis is a chronic, cutaneous affection, appearing in large continuous patches, Avhich occasionally cover the greater part of the body. It is characterized by the formation of thick, rough scales, of a grayish-Avhite color, and almost horny texture, without pain, heat or pruritus, and Avithout the deciduous exfoliations which belong to lepra and psoriasis. The whole skin seems to be deeply involved in this affection ; and hence, in the advanced stages, it is generally in an ex- tremely dry, stiff, and uncomfortable condition, at the same time that it is greatly hypertrophied and almost of gristly hard- ness, the different layers of which it is composed being no longer distinguishable from each other. In regard to their form, the epidermic scales present almost innumerable pecu- * Practical Synopsis of Cutaneous Diseases, p. 26. Second edit. Phila. 1821. VOL. I. 51 402 SKIN. [chap. X. liarities. Sometimes they are of uniform thickness, and seem to be merely elevations of the common lozenges of the cuticle ; sometimes they are flat, thin, and imbricated; sometimes they have short rounded necks, with broad irregular tops; and occasionally, again, though very rarely, they sprout out in the form of excrescences, of a horny texture, and most grotesque appearance. The quantity of these morbid excre- tions is, in some instances, immense, the whole body being literally encased with them like a shell. In old, inveterate cases, a considerable amount of calcareous matter is frequently poured out, both upon the surface of the scales, and in the intervals between them. The color of the scales varies not only in different subjects, but frequently in different parts of the same individual. As was before stated, most of them are of a grayish Avhite; but, in many instances, they are broAvnish, greenish, or blackish. They have also been known to exhibit a shining, pearly aspect, and to be surrounded by a blackish-looking border. During the warm Aveather of summer, this disease some- times nearly disappears, the scales dropping off in large quan- tities, especially at night. It is usually aggravated by arid states of the atmosphere, and is always most troublesome during the severe cold of winter. Unpleasant sores some- times attend ichthyosis, more or less painful, prurient, and discharging a thin, acrid humor : the general health is usually much impaired, and, occasionally, the whole body is said to emit a peculiar, fishy exhalation.* Occasionally, the patient is harassed with pustular eruptions. Ichthyosis generally begins very early in life; and, in a number of instances, it has been known to be hereditary. This fact is strikingly illustrated by the curious and instruct- ive cases published, several years ago, by Professor Francis, of New York.f The most usual seats of the disease are the outer regions of the extremities, both upper and lower, the sides of the trunk, and the shoulders. The flexures of the joints, and the inner surface of the thighs, are seldom affected with it. Psoriasis, vulgarly called the scaly tetter, consists of solid, inflammatory elevations of the skin, forming various-sized patches, isolated or united, covered with thin, white, shining * See Sauvage's Nosologia Method. t American Journal of the Medical Sciences, August, 1828. SECT. I.] PELLAGRA. 403 scabs, and commonly accompanied by some constitutional symptoms. The eruption sometimes affects a peculiarly tor- tuous, serpentine shape: in other instances, especially when it breaks out on the lips, it pursues a circular direction, ring after ring forming regularly beyond the surface last attacked. The corion is generally somewhat rosaceous, and, in bad cases, considerably thickened and chapped : a very disagreea- ble itching, attended occasionally Avith a good deal of pain, is pretty constantly present; and the scales, seldom very ad- herent, are frequently detached and reproduced. Sometimes the eruption is entirely confined to the limbs; at others, it covers the Avhole body; and, in such cases, the patient ap- pears, in the language of Cazenave and Schedel, to be liter- ally enclosed in a squamous envelope. Occasionally, the nails split, become yelloAv, and at length fall off; and the least movement frequently produces rents in the skin, followed by a flow of blood.* Occurring at all ages, it is liable to disappear, and recur at certain seasons; and, in some individ- uals, it never entirely ceases. The fifth and last disease we have proposed to notice under the present head is pellagra. It is very eornmon in certain districts of Italy, where it sometimes prevails epidemically, especially during spring and summer, but is entirely unknown in this country. Adults alone suffer, and both sexes are equally liable to it. Its course, which is always chronic, lasts from one to several years, the complaint becoming an- nually more and more aggravated, until the unfortunate patient, harassed and disfigured, finally sinks beneath its blighting influence. Dissection always discloses extensive lesion of the internal organs, particularly of the alimentary canal. More or less constitutional derangement usually precedes this affection, which manifests itself by small, red, shining spots, accompanied with slight tumefaction of the skin, to- gether Avith a sense of fulness and tension. By degrees, the color of these spots becomes deeper; their surface is covered with thin scales; and, as they augment in size, they unite, and form large, irregular-shaped patches. The skin, mean- while, is not only considerably thickened, but disfigured with deep rents and fissures. After remaining in this state for some time, the scales gradually drop off, disclosing a red, * Cazenave and Schedel, Practical Synopsis, p. 259. 404 SKIN. [CHAP. X. glossy surface, from Avhich there is a constant bran-like exfoliation of the epidermis. The neck and limbs are the parts most usually affected. 8. Syphilitic Diseases. The last group of diseases that we shall notice is the syphilitic. The disorders comprehend- ed under this appellation, caused by the influence of the venereal virus, manifest themselves under at least six varie- ties of form,—the exanthematous, vesicular, pustular, tuber- cular, papular, and scaly. They are occasionally primary; that is to say, they appear simultaneously Avith the affection of the genital organs; but, in the great majority of cases, they are not developed until some time subsequently, — gen- erally not under a few months; and they are therefore said to be consecutive. The eruptions appertaining to this group usually pursue a chronic course, are circular in their form, and present a characteristic copper color: though occurring on all parts of the body, they are principally observed on the forehead, nose, cheek, back, and shoulder, and are attended Avith thin, grayish scales, or with hard, thick, greenish scabs. In the exanthematous form, the spots are of a circular shape, and about the size of a quarter of a dollar: they are almost ahvays situated on the trunk and extremities, are of a dark copper color, do not disappear under pressure, are never confluent, and generally terminate by a slight exfoliation of the epidermis. Cazenave and Schedel describe a variety of this eruption, which is characterized by small, irregular, grayish spots, of a deeper red than the preceding, more tran- sient, slightly confluent, and disappearing, though slowly, under the pressure of the finger. The vesicular form is extremely rare. Rayer gives only a solitary example of it; Cazenave and Schedel also saw it but once; and Biett never met with it, except on three or four occasions. It begins in minute, circumscribed pimples, scat- tered over different parts of the body, to Avhich succeed small vesicles, filled with a transparent fluid, and surrounded by a red, copper-colored areola: their progress is very sIoav, and their contents are either absorbed, or they concrete into thin scales, which, falling off at different intervals, leave the sur- face of a dingy, yelloAvish hue. The vesicles are sometimes extremely numerous, and cover nearly the whole body. The third form of syphilitic disease is the pustular. This variety, as the name indicates, is characterized by the pres- ence of small tumors, containing an ichorous, serous, or puru- SECT. I.] SYPHILITIC DISEASES. 405 lent fluid. Their size and shape are subject to considerable diversity. Occasionally, they are as big as a hazelnut; but, under ordinary circumstances, they do not exceed the volume of a common pea, and, indeed, are seldom so large. In their shape, they are sometimes conical, sometimes oval, sometimes pediculated, sometimes rounded, and sometimes flattened, with a minute, central depression. Noav and then, all these varieties are observable in the same individual. Their num- ber is often immense, hundreds being scattered over a small extent of surface ; and, as they form successively, they may be seen and studied in every stage of their developement. Each pustule reposes upon a hard, copper-colored base: its internal structure is not knoAvn: it appears to be not unlike that of small-pox. After remaining for a short period, the contents of the pus- tules escape, concrete, and form hard, thick scabs, of a dark color, pretty firmly adherent, and sometimes circularly fur- rowed. In mild cases, the scabs fall off soon, and leave merely a chronic induration, a livid or grayish stain, or a slight cicatrix: in severe ones, on the contrary, deep, circular ulcers are exposed, with a foul, grayish bottom, and a hard, purple, and regularly-defined margin. In cases of the latter description, the scabs are frequently renewed, and are finally replaced by round, indelible scars. In the tubercular form — the most frequent, perhaps, of all — the eruption consists of small, red, copper-colored emi- nences, varying in size, betAveen that of a mustard-seed and an olive. Of a rounded, flattened, or conoidal shape, they are either isolated, assembled into groups, or arranged, into perfect circles: they are smooth and polished, produce little or no pain, and become covered, in a short time, with a dry, scaly incrustation, which is generally reproduced as fast as it falls off. In the more aggravated forms of this variety of syphilis, the tubercles are inordinately large, prominent, of a deep violet hue, from three to nine lines in length, and encircled. by a well-marked, copper-colored areola. After continuing thus for some time, varying from a few months to several years, they become painful, inflame, suppurate, and are re- placed by deep, foul, irregular ulcers, reposing upon a hard, purple base. A thick scab usually covers these erosions, Avhich is repeatedly reneAved, disclosing, each time that it is detached, that the sore is extending its ravages. When the 406 SKIN. [CHAP. X. tubercles are numerous, the ulcers, running together, often acquire a frightful size, and, on healing, leave disfiguring cicatrices. Papular syphilis is characterized by the occurrence of small, hard, solid elevations, containing no fluid, and termi- nating almost always in desquamation, seldom in ulceration, or in the formation of scabs. Of the tAvo varieties of this affection described by authors, one is acute and primary, the other chronic and secondary. In the first variety, which, according to Carmichael and others, sometimes accompanies gonorrhoea, the eruption ap- pears simultaneously on different regions of the body, and is completed in about forty-eight hours from the time of its first invasion. The papulae are extremely small, disjoined or grouped, of a red copper color, and of a slightly conical shape, being surrounded, here and there, by violet areolae, which are often confluent, and give the surface a character- istic yellow tinge. Ulceration rarely attacks these papillae: they disappear in a short time, and are followed by a furfura- ceous desquamation of the cuticle. In the other variety, the eruption is developed in a slow and successive manner, being announced by small yellow spots, which are particularly numerous on the forehead, scalp, and extremities. The papulae, which are of a light copper color, are larger than the preceding, flat, of the size of small beans, grouped, and devoid of an areola. In time, the sum- mit of each elevation becomes covered with a dry, grayish pellicle, which is regenerated as fast as it desquamates, until the disease finally entirely subsides. Meanwhile, the skin between the agglomerated papulae undergoes important changes: it assumes a dingy, yellowish color, has a dry, shriveled aspect, and is the seat of a constant exfoliation of the cuticle. The sixth and last form of syphilitic disease which we have proposed to notice is the scaly, which manifests itself, as the name imports, by dry, grayish imbrications, situated on small, copper-colored elevations. This variety, Avhich is always consecutive, persists for a long time, and terminates by desquamation. The eruption, in the plurality of cases, appears in patches, which, although they may occur on all parts of the cutaneous surface, are most common on the fore- head, scalp, and face. They are from four to eight lines in diameter, in shape irregularly rounded, ordinarily isolated, SECT. I.] LENTIGO--EPHELIS--ALBINISM. 407 smooth, polished, and someAvhat elevated : each is covered Avith a thin, hard, Avhitish scale, Avhich is very slightly ad- herent, and which, on falling off, exposes a small, shining, copper-colored eminence. 9. Stains. There are certain discolorations of the skin, which, from the frequency of their occurrence, rather than from any pathological interest, require to be mentioned in this place. Of these, the principal are ephelis, lentigo, albinism, and nigritism. They are seated in the vascular net-work of the skin, and no doubt depend upon some alteration of the coloring matter: some of these stains are congenital, and it is a singular fact that they seldom affect the whole cutaneous surface. Their duration varies from several weeks to many years. Lentigo, generally known by the name of freckles, is char- acterized by yellowish, faAvn-colored spots, varying in size, from a pin-head to that of five cent piece: they are most com- mon on the face, neck, chest, and hands, in persons with light eyes, and red hair; are usually congenital, and last through life. When the spots are very numerous, they sometimes run into each other, and thus form large irregular-shaped patches. In ephelis, the stains are of a yellow saffron-color, very irregular in shape, and much larger than in lentigo. Their most common situation is the neck, the anterior part of the trunk, and the inside of the thigh: they are never observed on the face, except during pregnancy, on which they are a frequent attendant. The spots which are often preceded and accompanied by considerable itching, are at first of a grayish color, small, and rounded: by degrees they assume a yellow tint, augment in size, and, from being isolated, they unite and form large, irregular patches : their duration varies from a few days to several months, and their disappearance is frequently followed by a slight exfoliation of the epidermis. The skin is sometimes converted into a dead, milky-white color, constituting what is termed albinism. This change, Avhich is confined to no particular race, depends not upon the absence of the pigment, but rather, I apprehend, upon some modification of its component elements. Persons who pre- sent this peculiarity differ, in many respects, from ordinary individuals. Their whole organization, both mental and phys- ical, seems to be imperfect; the body is covered with a soft, silky doAvn ; the hair is often of a snow-white color; the eyes are feeble, and unable to bear the light; and the iris and 408 SKIN. [CHAP. X. choroid are of a light rosy tint, from the absence of black pigment. There is a variety of albinism, Avhich is limited to particu- lar regions of the body, usually the head and trunk, to Avhich the term vitiligo has been applied. It commences in small, milk-white spots, Avhich go on enlarging until they sometimes cover the Avhole surface. The spots are generally oval or rounded, and now and then they have an irregularly striated arrangement. When the disease occurs on the scalp, axilla, and pubes, the hair participates in it, and becomes deprived of its natural color. Negroes Avho exhibit this peculiarity are called piebald. Nigritism is the term employed to designate the reverse of the condition just described. The affection is generally local, appearing in small, irregular-shaped patches, from one to sev- eral inches in diameter ; and the parts of the body most sub- ject to it are the genital organs of the male, together with the nipples of the female. The face is also sometimes the seat of it. Of this, the singular case recorded by Lecat, affords a striking illustration. The patient was a lady, about thirty years of age. The discoloration was first observed in the seventh month of her pregnancy, commencing on the fore- head in a grayish, dusky-looking spot, and extending by de- grees over the whole face, except the eyes and the margins of the lips, Avhich retained their natural complexion. The altered skin was very tender to the touch, but in other respects the lady suffered no inconvenience. The black color disap- peared two days after delivery, with a profuse perspiration, by which the sheets were stained black. The same phenome- non was Avitnessed during several succeeding pregnancies.* Cases of an analogous kind have been reported by Chomel, Goodwin, Rostan, Rayer, and other writers. The affection has hitherto been observed principally in females. It is well known that the nitrate of silver, if administered for a long time, has the effect of imparting a gray slate-color, not only to the skin, but also to accidental cicatrices, the con- junctiva, and to the mucous membrane of the alimentary tube. The discoloration generally remains during life, and is ahvays most conspicuous on the surfaces exposed to the light and air, as the face, neck, and hand. Hoav this change is produced, the present state of our knoAvledge does not enable us to ex- * Traite de laPeau Humaine, p. 136. Amsterdam, 1765. SECT. II.] NAILS. 409 plain. The most plausible conjecture is, that the coloring matter of the skin has a special affinity for the substance in question, by Avhich they combine with each other, at the same time that they undergo some alteration in their proper- ties. What gives countenance to this idea is, that the color remains after boiling, and that no impression can be made upon it by medicine. Mr. Brande asserts that he has detected oxide of silver in the stained organs. It should be added, that the discoloration produced by this substance is occasion- ally of a dirty bronze appearance. As appendages to those of the skin, it will be proper here to notice the principal lesions of the nails and hairs, though so little is known respecting them, that our account must necessarily be meagre and imperfect. SECTION II. Of the Nails. The nails, situated on the dorsal surface of the fingers and toes, Avith Avhich they correspond in number, are formed of a homogeneous substance of the same nature as horn. Their chemical properties are those of coagulated albumen, with the addition of a minute quantity of phosphate of lime, to which they are chiefly indebted for their hardness. In the sound state, the nails are semi-transparent, flexible, and elastic: each has a root, a body, and a free extremity. The root forms about the sixth part of the entire nail: it is very thin and soft, of a Avhite color, and is inserted into a groove of the dermis, at the same time that it is covered by a reflection of the cuticle. The body, intermediate between the root and the free extremity, is of considerable thickness, and constitutes by far the greater portion of the organ. Of its two surfaces, the external is longitudinally grooved, and transversely convex ; the other is concave, also furrowed, and closely adherent to the true skin. The free extremity is the thickest and strongest part of the nail: it projects a short dis- tance beyond the end of the finger, and is usually somewhat incurvated. The most interesting structure about the nails is the ap- vol. i. 52 410 NAILS. [CHAP. X. paratus determining their growth and direction. This is a peculiar papillary substance, from a quarter to a third of an inch in length, situated at their posterior extremity: it pre- sents a linear, striated surface, is extremely sensitive, and of a florid color from the immense quantity of its capillaries. When this apparatus is destroyed, no further growth takes place. The nails themselves have neither vessels nor nerves; none at least have ever been traced into them. When a nail is torn aAvay, it is gradually regenerated,— the period required for this purpose varying from three to six months, according to its size, and the violence inflicted upon the secreting apparatus. Eight or ten years ago, I received a severe contusion on my left thumb, the consequence of which was an exfoliation of the corresponding nail. As the old nail became detached, a new one gradually formed, and, in six months from the time of the injury, had acquired its full size and developement. Inordinate length of the nails is of very common occur- rence, and Avould be still more so, were it not for the con- stant paring to which they are subjected. Left to them- selves, they sometimes grow to the distance of three, four, or five inches, pursuing a tortuous, spiral course, so that they occasionally bear a much closer re- semblance to claAvs than to nails, (Fig. 43.) Their thickness, under such circumstances, is generally considerably augmented, from the superaddition of lamellae, which often overlap each other, like the scales of a fish. The extension and thickening of the nails form a prominent feature in icthyosis, lep- rosy, and elephantiasis. The nails, in these diseases, after having ac- quired a certain length, sometimes fall off, and are reproduced, though seldom perfectly. They are even said to become painful, so that they can be no longar cut, which, how- ever, is doubtful. In Polish plait, the nails both of the fingers and toes, often acquire a great size, and a yellowish, livid, or black complexion. Fie. 43. SECT. II.] ONYXITIS. 411 The nails are sometimes, though very rarely, entirely absent, as a congenital defect. More frequently, they are unusually small, or developed imperfectly, their place being supplied by thick, horny cuticle. On herpetic persons, I have repeatedly found them very short, scaly, and of a thick, rounded, button-like form. In strumous subjects, they are sometimes deeply grooved, enlarged, and of an indurated, horny consistence. In protracted paralysis, the nails are said to grow very sloAvly and imperfectly, probably from a defi- ciency of nervous energy. A vicious situation is occasionally observed. Thomas Bar- tholin has recorded an instance * where the nails occupied the anterior extremity of the metacarpus, the fingers being absent. In other cases, they occupy the lateral surfaces of the fingers ; and occasionally, though very rarely, they have been repro- duced on the second or first joint, after the partial or com- plete loss of the part on which they are naturally situated. In monsters, the nails of the fingers are sometimes con- solidated. 'The same deformity has been observed in adults. Otto saAV a case of this kind, in Avhich the four outer nails of both hands Avere united into one. In pulmonary phthisis, the nails are almost always incurvated, — a fact Avhich did not escape the observation of Hippocrates, and Avhich has been noticed by every practitioner of medicine since his time. The nails, as Ave have already seen, are the product of a soft, pulpy, vascular apparatus, which is situated at their roots, and may, from its office, be denominated the ungueal matrix. The structure here referred to is subject to various degrees of inflammation, attended with corresponding altera- tions of the organs under consideration. The causes of this disease, which I shall name onyxitis, are sometimes of a local but more frequently of a constitutional character. Amongst the latter, is a scrofulous, gouty, or syphilitic taint, which often exerts its influence for a very long time, and baffles our best-directed efforts for its removal. Onyxitis commences in a circumscribed sAvelling of the ungueal matrix, with pain and deep redness. In a short time, a thin, ichorous fluid issues from the cleft at the root of the nail, and at last the soft parts give Avay. The ulcer is very small at first, but gradually extends, until it finally involves the whole of the ungueal matrix, together with a * Hist. Anat. t. i. 291. 412 HAIRS. [chap. X. portion of the dermis immediately around it. The surface is broAvn and glossy, the margin thin and sharp, and the dis- charge fetid and irritating. The pain is sometimes intense ; at other times the disease is more indolent, and accompanied Avith little uneasiness. The nail is formed very imperfectly; it loses its natural form and color, becomes, irregular, dry, black, and at length falls off. When this happens, it is sel- dom completely regenerated. The surrounding skin is tense and livid, the affected extremity assumes a bulbous appear- ance, exceeding often double the normal size, and, in cases of long standing, the disease sometimes invades the subjacent bone. Onyxitis occurs chiefly in young persons, and attacks the thumb more frequently than the fingers or toes.* It may continue for years. SECTION III. Of the Hairs. Although the hairs bear a general resemblance to the nails, yet they differ from them in several essential par- ticulars. Like the organs just mentioned, they are of a horny consistence, but their color is darker, and their chemi- cal composition more complex. Besides an albuminous mat- ter, which forms the basis of both, Vauquelin detected in the former, a small quantity of oil, phosphate and carbonate of lime, oxide of manganese, iron, silex, and sulphur. With the exception of the palm of the hand and the sole of the foot, hairs are found upon almost every part of the body. In some regions, they are coarser than in others, and hence the distinction of them into two kinds, — the crinal and pilar. The former groAV on the scalp, the latter on the eyebrow, the margin of the eyelid, and on the body. Not only are the crinal hairs finer than the pilar, but they differ from them still further in regard to the time of their full developement, their color, and their length. * For an excellent account of this disease, the reader may consult the paper of Mr. Wardrop, of Edinburgh, published in the fifth volume of the London Medico-Chirurgical Transactions. He has described it under the name of onychia maligna, from the obstinacy and malignity of its character. SECT. III.] HAIRS. 413 A hair consists of a follicle and stem. The follicle is a sort of an ovoidal cup, occupying the substance of the dermis, which it traverses obliquely. Being perforated at both ex- tremities, at one for the exit of the stem, and at the other for the entrance of vessels and nerves, it is composed of two tunics, closely united together, but Avidely different in struc-, ture. The outer membrane is white, firrn, and intimately adherent to the dermis; the inner one, on the contrary, is reddish, extremely soft, and apparently continuous with the rete mucosum. Within this delicate lamella is the proper secreting organ of the hair, Avhich is of a conical form, highly vascular and sensitive, and bears a very near resem- blance to the pulp of a tooth. The stem varies in length as Avell as in thickness, in differ- ent regions of the body. It is of a conical shape, and of a dark color. One extremity is free, hard, and sometimes bifid; the other is soft, white, and hollowed out, so as to embrace the central pulp on which it grows, the part Avhich is first secreted being forced on by that which exudes last. The intermediate portion is a diaphanous, horny sheath, containing a dark, spongy, filamentous substance. It is either straight, twisted, or curled. The piliferous follicle, as Avas before stated, is implanted in the substance of the dermis, by which it is protected and kept in place. To secure it still further, the cuticle enters the external opening of the follicle, from whence, after hav- ing lined its margin, it is reflected upon the surface of the stem, upon which it is soon lost. With regard to the vitality of the piliferous follicle, there is no doubt; but, in respect to that of the stem, it is a matter of inference rather than of observation. It is uncertain whether the vessels of the secreting pulp are or are not, in the natural state, continued into the stem, so as to extend into its substance beyond the level of the cutaneous surface. In endeavoring to decide this question, reliance is to be placed mainly upon analogy and upon what occurs in disease. In phrenitis, the hair has been so sensible after an injury, that the slightest touch gave severe pain ; and, on clipping a stem, unseen by the patient, this was instantly felt, and occasioned a paroxysm of rage.* In the Polish plait — a disease which will be more particularly described in another paragraph — * Elliotson's Human Physiology, p. 277. Fifth edition. London, 1835. 414 HAIRS. [CHAP. X. the hair, it is said, sometimes bleeds ; and, if this is true, it is surely more consonant Avith the principles of sound physi- ology to suppose that the blood proceeds from preexisting vessels than from vessels of iicav formation. So much for what has been noticed in disease. If we appeal to analogy, we shall find that the hoof of the horse and other animals, although apparently unorganized, is abundantly supplied Avith vessels, not less so than the quills and feathers of birds. If the pulps of the quills of the por- cupine be Avell injected, vascular lines may be traced into the structure to almost any distance, and the same may be seen, even without the aid of a magnifying-glass, in the groAving feathers of our domestic fowls. The horn of the ox, when broken or sawed off, will occasionally cicatrize. Of this, a beautiful specimen is contained in my museum of morbid anatomy. It is about three inches long, and had evidently been broken when the animal Avas only a few years old. If we connect these facts Avith the circumstance, perfectly attested by many highly respectable authorities, of the hair losing its color in the course of twenty-four hours, the proba- bility is strong that the structure under consideration is organ- ized, though less perfectly, perhaps, than almost any other in the body. In the African lion, I have succeeded in tracing filaments of the fifth pair of nerves into the bulb of the whisker; and the same thing has been done by Rudolphi in regard to the mustachioes of the seal. Most of the lesions of the hairs are directly referable to inflammation of their follicles. In the plurality of cases, the inflammation pursues a chronic course ; but what particu- lar changes the structures in question undergo, is by no means ascertained. It is altogether! probable that the pilif- erous follicles are considerably swollen and injected, and that their poAver of secretion is either suspended, or at all events very greatly modified; so that the stem, instead of presenting its normal characters, is variously altered, both in , its consistence, its length, and thickness, and, above all, in its color. The Polish plait, as it is termed, a disease which is en- demial in Poland, Lithuania, and Tartary, seems to be an inflammatory affection. It generally attacks an immense number of piliferous follicles, which in a short time acquire an extraordinary size : they rise above the level of the skin, are painful on the slightest touch, and exude a large quantity SECT. III.] POLISH PLAIT--ATROPHY. 415 of viscid, broAvnish, and offensive matter, by Avhich the hairs are matted and glued into inextricable tangles, of great length. Even the stems are said to be swollen and increased in thickness ; their cavity is also larger than in the sound state, and their areolar texture is rendered unusually distinct. Dr. Schlegel, a German author, assures us that, in a case of the Polish plait, he found all the hairs of the body not only tumefied, but distended Avith yellowish-broAvn fluid, and at least six times as large as in the normal state. This disease gen- erally appears during the autumnal months, is observed chiefly in the lower classes, and is often extremely obstinate and persisting. Although the hairs of the head, generally alone suffer, yet those of the beard, axilla, and pubes, are sometimes similarly affected. It has been already intimated, that the hairs occasionally bleed in this disorder. This, however, is still a litigated point, and one Avhich can only be decided by further observation. The late Professor Meckel, of Halle, carefully injected the scalps of two persons that died while laboring under the Polish plait, and in neither did he succeed in throwing any of the fluid into the matted mass or horny portion of the hair. These experiments, hoAvever, are far from being conclusive; for it is obvious that vessels might have existed in the parts referred to, and yet, owing to their extreme minuteness, the artificial fluid might have failed in reaching them. When the hairs are plucked out, they are ahvays regener- ated, provided the secreting pulp remains unimpaired. When this structure is injured, the new growth is proportionably slow and imperfect. In old age, the piliferous sacs undergo a sort of atrophy; they lose their energy, diminish in size, and are at length completely annihilated. The same phe- nomena occurs in certain diseases, as, for instance, bilious fever, scarlatina, psoriasis, and secondary syphilis. The fall- ing of the hairs is often temporary, and probably depends upon some transient disease of the piliferous follicles. A few years ago, a friend of mine, after recovering from a severe attack of scarlatina, lost every hair on the body; in a few months, neAV ones sprung up, and in time acquired all the characters of the former. Persons seldom grow bald all at once. The crown of the head is generally affected first, whence the de- pilation gradually extends in different directions. The pilif- erous follicles in this affection seem to die gradually ; for, after the original hairs have dropped off, a new crop frequently 416 HAIRS. [chap. X. appears, consisting of a thin, soft, whitish doAvn, evidently formed by feeble attempts at reproduction. Another affection of the hair is hypertrophy. This is most frequently observed on the head, but may also occur on other parts of the body, as the beard and pubes. The most re- markable case of hypertrophy of the hair of the head, of Avhich I have any knowledge, occurred in a friend of mine, a young lady about tAventy years of age. From her earliest youth she Avas subject to cephalalgia, but did not appear otherwise unwell. Her complexion Avas unusually fair, her eyes light, and her hair of a flaxen hue. In consequence of her constant headaches, the hair was commonly kept short; but, to effect this, as it greAV with such extraordinary rapidity, it Avas necessary to cut it every few Aveeks. Within a year of her death, her general health gradually declined, without any assignable cause, save the astonishing developement of the hair, attended Avith severe cephalalgia. During the last three months, the hair, although it had been cut only a short time before, reached nearly down to the heel, and had a soft, oily feel : the pain in the head increased in violence, the countenance became blanched and almost transparent, and she died gradually exhausted, having, within a few days of her dissolution, exhibited symptoms of acute phrenitis. On examination after death, the only remarkable circumstance observed Avas a slight accumulation of water in the A^entricles, and on the base of the brain. It is impossible to doubt that this abnormal groAvth of the hair depended on hypertrophy of their follicles, inviting constantly an excess of blood to the head at the expense of the rest of the system. This is proved by the extraordinary developement of the hair, by the obsti- nacy of the cephalalgia, and by the symptoms which were present during the last feAV months of the young lady's ill- ness. The particular state of the piliferous follicles Avas not ascertained. Scarcely less extraordinary is the developement of the beard in the female. Of this species of hypertrophy not a few examples are recorded by authors. One that came under my own observation I will here mention. The woman, who is the mother of a numerous offspring, is seventy-eight years of age, and has always enjoyed excellent health. The sides of the face, chin, and lips are all thickly covered with coarse hair, which she is obliged to shave off regularly once a week. Her whole aspect is remarkably masculine ; and, but for the SECT. III.] ABNORMAL SITUATIONS. 417 length of the hair of the head, she might be easily mistaken for a male. The hair of the pubes sometimes attains an ex- traordinary developement, forming long, thick tufts; and similar appearances have been Avitnessed on the shoulders and buttocks. The hair often loses its normal formings, hanging about the head in soft, straight locks. Dr. Elliotson, of London, refers to several cases in Avhich the hair could not be kept in curl if there was the slightest indisposition; and similar ex- amples have been recorded by Alibert, and other Avriters. On the other hand, an instance is narrated in Avhich it always curled in a fit of the gout.* There are cases, again, wherein the hair, in consequence of some imperfection in its growth, becomes remarkably brittle. A curious case is recorded by Mr. Mayo, of England, of a young lady, Avhose hair, without any assignable cause, sud- denly broke, at a quarter of an inch from the head, and fell off in large locks. This singular process Avas repeated every three or four weeks. She Avas subject to a severe headache, but in other respects her health appeared to be perfectly good.f A change of color of the hair is a natural consequence of old age, but it also occurs in different diseases, and from the influence of the depressing passions, such as grief and fear. What alterations the pilous system undergoes under such cir- cumstances, Ave have no data to determine. The discolora- tion, though for the most part gradual, has been known to take place in the course of tAventy-four hours. When caused by age, it generally begins at the loose extremities ; and the same fact is observed in animals Avhich change their com- plexion for the winter. The restoration of color, on the con- trary, always commences at the root. An accidental developement of hairs is not uncommon. This is often seen upon congenital moles, as well as upon parts of the skin that have been for a considerable period in a state of irritation. As occurring in the stomach, bowels, and urinary bladder, numerous cases have been recorded by Haller and other authors. They have also been found in the gall-bladder, in cutaneous tumors, and in the ovary. In the * Human Physiology, p. 277. t Outlines of Human Physiology, p. 468. vol. i. 53 418 HAIRS. [chap. X. latter organ they generally coexist with dropsical accumula- tions, carcinoma, or extra-uterine foetation, and hence they are almost ahvays accompanied by adipocirous matter, by teeth, and by pieces of bone. In most of the situations here specified, though not in all, they perfectly resemble the normal hairs, both in their color, and in their structure, being composed of distinct roots and stems. Concerning their mode of origin, however, we have no positive informa- tion ; and in the absence of exact facts I refrain from offering conjectures. CHAPTER XI. Of the Nervous System. SECTION I. General Observations. I. General Observations. — Cerebral Envelopes.—Cephalo-spinal Liquid.— White and Gray Substances. — Chemical Composition.— Consistence.— Color. — Sensibility. — Vascularity. — Absorbent Vessels. — Speculations of Kellie and Abercrombie, respecting the Compressibility of the Cerebral Tissue. — Weight of the Encephalon and Form of the Spinal Cord.— II. Lesions of the Cerebral Envelopes.— Inflammation of the Dura Mater.— Suppuration.— Fibrous Tumors. — Bony Deposits. — Hypertrophy of the Glands of Pacchio- ni.— Arachnitis. — Hydrocephalus. — Tubercles. — Stages and Symptoms of Arachnitis. — Diseases of the Pia Mater. — III. Lesions of the Brain. — Wounds. — Encephalitis. — Suppuration. — Abscesses. — Gangrene. — Soften- ing. — Chronic Inflammation.— Induration. —Tjlceration. — Sanguineous Ef- fusions.— Tubercles. — Melanosis.— Encephaloid.— Cartilaginous Formations. — Calcareous Deposits. — Cysts and Hydatids. — Hypertrophy and Atrophy. — IV. Lesions of the Spinal Cord.— Inflammation.— Heterologous Formations.— Hydro-rachitis. — V. Lesions of the Nerves.— Classification. — Form. — Distri- bution. — Connection and Structure.— Restorative Power. — Neuritis.— Sup- puration. — Ulceration.— Hypertrophy and Atrophy. — Diseases of the Nerv- ous Ganglia. It Avill not be amiss, before we proceed to speak of the diseases of the cerebro-spinal axis, to prefix a short account of the organization and normal characters of this portion of the nervous system, as, without some information of this sort, it will be impossible to place the subject in a proper point of view, or to enable the reader to arrive at a positive conclusion in regard to some of the more intricate topics that are com- prised under it. Our materials for illustrating this branch of our inquiry are not of the most satisfactory kind ; much re- mains to be done ; the field is almost unexplored, and further investigations are not only necessary, but absolutely indispen- sable to the true interests of cerebral pathology. The cerebro-spinal axis consists of three parts, not separate and independent, indeed, of each other, but closely connected 420 NERVOUS SYSTEM. [CHAP. XI. together by continuity of substance, namely, the cerebrum, cerebellum, and spinal cord. Situated in the cranial and vertebral cavities, these organs are surrounded by different membranes, and Avrought into a variety of figurate bodies, which are perfectly alike on each side of the median line. These structures have always formed an interesting subject of study Avith the special anatomist; but, as a description of them Avould be out of place here, it will be sufficient to re- mark concerning them, that they impart to the cerebro-spinal axis the character of plural organs, each of Avhich, there is every reason to conclude, presides over a particular function, with the precise nature of Avhich we are still unacquainted. Of the envelopes of the brain and spinal cord, the pia mater, as it is termed, is by far the most important, as it is upon it that the groAvth and preservation of the nervous substance mainly if not Avholly depend. It is in this respect to the parts in question, what the neurilema is to a nerve, or the periosteum to the bones: if a portion of it be peeled off from the surface of one of the hemispheres, the denuded struc- ture Avill be deprived of its vascular supply, and speedily fall into a state of gangrene. In its texture, this membrane is essentially vascular, the vessels of which it is composed being connected together by the finest cellular substance, which, at the same time penetrates the nervous matter, so as to contrib- ute to its organization. Of the remaining envelopes, nothing need be said here, further than that the one is of a fibrous, the other of a serous nature. The serous tunic, called, from its excessive tenuity and tenderness, the arachnoid membrane, secretes a thin, limpid fluid, Avhich surrounds the brain and spinal cord, precisely like a sheet of Avater. The thickness of this aqueous layer is not the same in all parts of its extent. Being from one to tAvo lines on the cerebral hemispheres, it diminishes about the cerebellum, augments at the base of the brain and in the up- per part of the neck, decreases again in the back, and finally reaches its maximum in the lumbar region. If an incision be made through the dura mater in the latter situation, the vis- ceral lamella of the arachnoid, from the pressure of the con- tained water, will protrude across the opening like a hernial bag. None of this fluid naturally exists in the ventricles, or, at any rate, only a very small amount. The entire quantity of water in the normal state has been estimated at about three ounces. The old have more of it SECT. I.] CEPHALO-SPINAL LIQUID. 421 than the young; and it is also said to be more abundant in Avomen than in men. It is of a clear, limpid aspect, slightly saline in its taste, and nearly uncoagulable by heat, alcohol, and acids. When evacuated, it is speedily regenerated, gen- erally within four and tAventy hours. The seat of this liquid is the fine, delicate subarachnoid cellular tissue, — a circum- stance Avhich serves, in some degree, to distinguish it from that which is poured out upon the free surface of the serous membrane as an effect of inflammatory irritation. Although the existence of this fluid Avas announced, in the last century, by Haller and Cotunni, yet, as it was generally regarded merely as a pathological product, the facts which they communicated concerning it seem to have been entirely overlooked until a few years ago, when the attention of the profession Avas again aAvakened to the subject by M. Magen- die. In an able memoir * read before the Royal Academy of Medicine, at Paris, in June, 1828, this distinguished physiolo- gist has imbodied the results of his observations and experi- ments, from Avhich it clearly appears, that this secretion, in- stead of presenting itself merely in the form of a halitus, as it was formerly thought to do, always exists in an appreciable condition. He has designated it by the appropriate name of the cephalo-spinal liquid; and he supposes that it exerts an important influence upon the function of the brain and spinal cord, since the sudden loss of it in the inferior animals occa- sions dulness and immobility, which gradually subside as the water reaccumulates. The brain and spinal cord are composed of two kinds of matter, one of which is of a white appearance, the other of a pale ash-color. Upon the minute structure of these substances not a little attention has been bestowed; and, although the attempts that have been made for the purpose of unravelling it have not been altogether unproductive of useful results, yet it must be confessed that many interesting points concern- ing it are still veiled in obscurity. Until within a compara- tively recent period, anatomists generally believed that the two forms of matter exhibited the same structure and arrange- ment, the only difference consisting, as was alleged, in the greater vascularity of the one over the other. The fallacy of this opinion was first shown by Gall and Reil, who have * This memoir has been ably translated by my friend Dr. Joseph Gardner, of Pennsylvania, and published as an appendage to my edition of Hatin's Manual of Obstetrics. Philadelphia, 1828. 422 NERVOUS SYSTEM. [CHAP. XI. satisfactorily demonstrated the interesting fact, that the Avhite substance is essentially fibrous, and the gray essentially gran- ular. The texture of both appears to be made up of delicate globules, which are united together by a transparent jelly-like matter, the quantity of Avhich, always small, varies in differ- ent parts of the cerebro-spinal mass. Their arrangement in the white substance is linear, so as to give it its fibrous ap- pearance ; but, in the gray, they are disposed irregularly, Avith- out any assignable order. The white substance is uninterruptedly continuous in all parts of the nervous system, in which respect it may be said to resemble the cellular tissue, which is uninterruptedly dif- fused through the Avhole body. The fibres of which it is composed are, however, much more distinct in some situations than in others, owing either to the fact of their being larger, or, as is not improbable, to the greater laxity of the connect- ing element. They are made particularly conspicuous by the assistance of such agents as coagulate the albumen which they contain, such as alcohol, dilute nitric acid, a solution of corrosive sublimate, or of alum, and by the action of hot oil of turpentine. In many parts, however, they are sufficiently visible without artificial preparation, particularly at the Varo- lian bridge, the crura cerebri, the great commissure, and stri- ated bodies,— structures in Avhich they are uncommonly well developed. The recent researches of Ehrenberg and Raspail countenance the opinion of the existence of two distinct sets of fibres in the white substance ; the one being studded with minute knobs, the other, which is the larger, being distinctly tubular, and contained within a granular matter. The first is found in most parts of the encephalo-rachidian mass, as also in the sympathetic cord, the ganglia, and the nerves of the special senses : the latter belongs to the base of the brain, the cerebral crura, the motor nerves of the skull, and the spinal nerves, particularly such as are destined to motion. The nervous fibres assume tAvo principal directions, the ver- tical and horizontal. The first are seen in the spinal cord, from which they appear to ascend through the oblong me- dulla, Varolian bridge, and cerebral crura into the substance of the brain, properly so called. From the cerebral crura they pass along the outer side of the optic thalami, and thence di- verge in all directions to reach the convolutions on the sur- face of the hemispheres. The optic thalami and striated bodies are appendages to this vertical set of fibres, or, in the SECT. I.] ITS STRUCTURE. 423 language of Gall and Spurzheim, they perform the office of ganglia to them. These fibres, it may noAV be observed, are seen on the anterior part of the spinal cord, and they appear to constitute the pyramidal and olivary tubercles. Another set, ascending along the posterior portion of the cord, pass through the substance of the restiform bodies. Continuing their course, they form the crura cerebelli; after Avhich, pass- ing outwards, they diverge into the lobes of the cerebellum. Thus both the cerebrum and cerebellum are intimately con- nected with the medulla oblongata; and, by means of two oblique rods of white matter, technically termed the cerebel- lo-testicular processes, Avith each other. The horizontal fibres belong exclusively to the encepha- lon: they are found only in the callous body and the Varo- lian bridge, in which they run transversely, or nearly so ; in the anterior commissure, in Avhich they are arranged oblique- ly, and in the fornix, in which they run antero-posteriorly. By this arrangement, the ascending fibres, previously describ- ed, are brought into intimate relation Avith the horizontal, which thus subserve the purpose of so many commissures. The granular substance may be likened, in its mode of dis- tribution, to the adipous tissue, as it occurs only in isolated points, whilst the fibres of the other, as before stated, are every where continuous. Investing the surface of the cere- brum and cerebellum, it occupies the central portion of the spinal cord, and is also found in large quantity in the interior of the striated bodies, optic thalami and quadrigeminal tuber- cles. It enters, moreover, into the composition of the gan- glia, and probably also into that of the nerves; at all events, such is the conclusion I have arrived at from personal inspec- tion, and which coincides with the vieAvs of Monro, Gall, and several other distinguished anatomists. Much controversy has existed in relation to the intimate nature of the gray mat- ter ; but the idea is noAV pretty generally entertained, that it consists of a plexus of minute vessels, in the meshes of which is an irregular granular pulp, which assumes a somewhat fibrous arrangement as it approaches its junction with the medullary substance. Modern chemistry has ascertained that the nervous sub- stance is a peculiar compound, unlike any of the other con- stituents of the body. Water and albumen appear to be the principal ingredients ; it affords, besides, various fatty matters and cholesterine; it also contains sulphur, phosphorus, and a 424 NERVOUS SYSTEM. [CHAP. XI. small amount of osmazome. It is to the presence of albumen that the nervous substance OAves its coagulability on being immersed in alcohol, a solution of oxymuriate of mercury, or any of the dilute mineral acids. It is readily decomposed by exposure to a moist atmosphere ; and, when put in water, it is gradually converted into a greenish putrilage, remarkable for its fetid exhalation. The consistence of the cerebro-spinal mass varies not only in different parts of its extent, but at different periods of life, and under different circumstances of health and disease. In regard to the granular and fibrous substances, the latter, it is well knoAvn, is always more firm and resisting than the former, which is generally so soft, no matter in what situa- tion it be examined, as to be readily crushed by the slightest pressure. This is particularly true of the granular texture of the cerebellum, the cohesive power of which is invariably less than that of the brain, properly so called. The term pulpy, which was until recently employed to designate this form of nervous matter, is sufficiently expressive of its normal consistence. The fibrous substance is comparatively firm, and, when recent, even elastic. Broad, thin slices of it, from one to two lines in thickness, generally possess a sufficient degree of te- nacity to resist laceration : a keen knife is necessary to divide it, and the cut surface is usually somewhat rough. Exposed to putrifaction, the fibrous substance resists its invasion much longer than the granular, nor does it lose so much of its weight by desiccation. But in pure Avater it retains its con- sistence unaltered during a period varying from eight to twelve hours: subsequently it begins to soften, and, in the course of a few days, it is converted into a pulpy, greenish, and offensive mass. In the cerebrum the white substance is remarkably firm in the great commissure, the annular protuberance, and the as- cending crura, — parts, it will be remembered, in which the fibrous structure is unusually distinct and well developed. The interventricular septum, the fornix, and optic thalami, together with some of the other figurate bodies in the lateral cavities of the organ possess very little tenacity, and are fre- quently so soft, even within the range of health, as to render it difficult to demonstrate them. In the cerebellum, the sub- stance in question is more firm and dense in the diverging crura, and the ascending processes, than in any other situation. SECT. I.] COLOR. 425 Of the spinal cord, the oblong and cervical portions are the hardest and most resisting. As Avas before stated, the consistence of the encephalo^ rachidian mass varies considerably in the different periods of life. In the new-born infant, the component elements are soft and pulpy, like well-boiled pap, mashed turnips, or warm custard: they readily receive the impression of the finger, cannot be easily cut, except with a very sharp scalpel, and are freely impregnated Avith viscid serosity. By and by they acquire greater firmness and tenacity ; the interstitial fluid diminishes in quantity ; the line of demarcation between the white and gray substance becomes more conspicuous ; the figurate bodies are distinctly mapped out, and the whole mass is now compressible and elastic, but still too soft to bear much handling. At avhat period the seA^era! organs acquire their maximum of consistence, is a point which can only be settled by future observation : judging from my own dissections, I should think this did not occur, in the generality of cases, before the eighteenth year. In old age, the cerebro-spinal axis is commonly remarkably hard and firm, in accordance Avith a law of the animal economy, by Avhich the organs and textures are drained of their interstitial juices. Concerning the color of the cerebro-spinal mass, not much need be said in this place. In the foetus and neAV-born infant, the two substances are so nearly alike in their complexion as to render it difficult to distinguish them from each other,—a circumstance Avhich has given rise to the idea, so warmly advocated by Gall, Spurzheim, and Tiedemann, that they are not of simultaneous formation. As life advances, the lines of distinction become more abrupt, and the component elements assume the peculiar hues Avhich characterize them in the adult. The intensity of color of the granular texture is influenced by a variety of causes, the principal of which are referable to age and health. In early life, it is of a light rosy tint, Avhich is gradually changed into a cineritious complexion. In very old people, I have frequently seen this substance ex- hibit a drab-colored aspect, probably from the obliteration of some of its capillary vessels, followed by a diminution of blood. In dropsical subjects, and in such as are habitually bled, or exposed to profuse evacuations, of Avhatever kind, the gray color is much less intense than in such as are healthy; in many cases, indeed, it is nearly lost, the Avhole cerebro- vol. i 51 426 NERVOUS SYSTEM. [CHAP. XI. spinal mass presenting a remarkably blanched appearance. The fibrous texture is not so clear in children as in adults ; and, in the aged, it is often of a milky Avhite. In protracted jaundice, both substances have repeatedly been found of a light yelloAvish hue. Several examples of this kind have fallen under my own notice. We may conclude, from the investigations of Sir Charles Bell, and other physiologists, that the cerebral matter, in its normal condition, is insensible, but that, Avhen it is inflamed, it becomes extremely painful. It has not been determined Avhether in the latter state the suffering should be referred to the sensibility of the connecting cellular tissue, the distended vessels, or the compressed nervous fibres and granules. These are points Avhich it is difficult to ascertain, and concerning Avhich, in the absence of positive facts, it Avould be idle to speculate. The spinal cord appears to possess a different kind of sensibility, experiencing, when cut or pricked, the same feeling as a nerve. The cerebro-spinal axis is amply supplied with blood, more so, undoubtedly, than any of the other parts of the body. The amount of fluid distributed to the encephalon alone has been estimated at about one fifth of the entire circulating mass. This estimate probably exceeds the truth : the quan- tity is very great in proportion to the size of the organ under consideration ; but, as it does not admit of accurate apprecia- tion, no satisfactory statement can be made respecting it. The arteries engaged in carrying on the cerebral circulation are the vertebral and internal carotid, the first of which enter the base of the cranium at the occipital foramen, the other at the carotid canal in the petrous portion of the temporal bone. Having sent branches of intercommunication, the passage of Avhich is extremely tortuous, they immediately separate into an infinite number of tAvigs, which penetrate the -surface of the brain in the form of capillaries, — an arrangement which is of essential importance, when we consider the excessive deli- cacy of the nervous substance, and the immense amount of blood pervading it. The precise arrangement of the arterial capillaries in the cerebral substance, is not known : they traverse the organ in every conceivable direction, and at length terminate in cor- responding veins, which, after forming a net-work on the surface of the brain, finally open by eight or ten trunks into the sinuses of the dura mater. SECT. 1.] NO ABSORBENTS--COMPRESSIBILITY. 427 No absorbent vessels have hitherto been detected in the cerebro-spinal axis, notwithstanding the numerous attempts that have been instituted for that purpose. That they exist here, however, as elsewhere, is abundantly proved by Avhat occurs in apoplectic individuals. In cases of this kind, the effused blood undergoes a series of changes Avhich can only be accounted for on the assumption that there are appropriate absorbent agents. The red particles are gradually carried away, and the fibrinous mass, which is at first hard and solid, is finally wrought into a delicate cellular texture, the meshes of which are filled with yellowish serosity. In dismissing this branch of our subject, it will be neces- sary to say a few Avords in relation to the speculation of Kellie, Abercrombie, Clutterbuck, and others, that the en- cephalon uniformly contains the same amount of blood, no matter what may be the quantity of this fluid in other parts of the body, Avhether normal, increased, or diminished. The proposition of these pathologists is founded on the assumption that the organ in question is not only incompressible but wholly removed from the influence of the atmosphere, and that it ahvays accurately fills the cranial cavity. From these physical conditions, it follows, they allege, that no material variation can take place, within a short time, in regard to the absolute quantity of blood in the brain ; or, what is the same thing, that there can be no actual plethora or anemia ; and hence venesection, to Avhatever extent it be carried, can affect the cerebral circulation only secondarily, indirectly, or consecutively, that is to say, only by lessening the force of the heart. Granting that the encephalic mass is entirely in- compressible, as its very composition, indeed, abundantly proves, the idea that it accurately fills the cavity of the skull, and is completely protected from the pressure of the atmos- phere, is, I presume, a mere assumption, and susceptible of easy refutation. That there is a vacuity between the skull and the surface of the brain, or, in other words, that these parts do not lie in actual and close contact, is a fact Avith Avhich every one is familiar. During health, Avhen the circulation is in full activity, this space is small; but, in certain pathological states, as well as after death, it is often quite considerable, and ad- mits of ready demonstration. But for its existence, no effu- sions could take place into the arachnoid sac on the surface of the cerebral hemispheres, the ventricular cavities, or at the base 428 NERVOUS SYSTEM. [dlAP. XI. of the cranium ; unfortunately, however, this is not the case; for not only are such effusions very common, but they frequently exist to a very great extent. Add to this that the brain is in a state of constant locomotion, and there can be no difficulty in forming a correct conception of the vacuity under con- sideration. This movement is very apparent at the fontanelle of the infant, and is often seen in injuries of the skull, attend- ed with a loss of osseous substance : it is connected with respiration, and is characterized by a distinct rising and falling of the encephalic mass, produced, probably, by at- mospheric pressure. But it is alleged, secondly, that the brain is completely withdraAvn from the pressure of the atmosphere. This vieAv is only partially correct. There is, Ave admit, no pressure exerted above and at the sides of the cranium, but there cer- tainly is beloAv ; so that, in this respect, the brain is circum- stanced pretty much as the thoracic and abdominal viscera, which are subjected to the influence of the atmosphere only in certain directions, not in all. Thirdly, the experiments performed by Dr. Kellie, Avith the hope of illustrating this subject, are any thing but con- clusive. The turgescent state of the cerebral vessels observed by this physician in animals after being bled to death I have often noticed myself; but it is by no means, as he supposes, peculiar to the encephalic mass. The other internal organs usually participate in the plethora, Avhich is sometimes so great that the blood will escape in considerable quantity upon the slightest pressure. This is especially true of the liver, spleen, lung, and kidney. In these structures, as I have fre- quently had occasion to observe at our slaughter-houses, the vessels are as Avell filled as those of the brain ; sometimes, indeed, much more so. Nor is it generally true, as has been affirmed by Kellie and Monro, that, after strangulation, the vessels of the brain retain their normal appearance. Every one knows that, in the majority of instances, the reverse is the case. In twelve experiments, which I performed some years ago, on manual strangulation, the cerebral capillaries Avere every where deeply injected, the larger sinuses distended, and the vessels of the pia mater completely engorged. The subjects Avere dogs and rabbits ; and the hand was applied directly over the carotid arteries and jugular veins, until the animals ceased to breathe, __a circumstance Avhich fully accounts for the plethoric condi- SECT. I.] NO ABSORBENTS--COMPRESSIBILITY. 429 tion of the encephalic mass. In none of the cases Avas there any extravasation of blood.* Similar effects are produced in strangulation from suspension, excepting where the cord happens to be so placed as not to interfere materially with the return of the blood from the head to the heart. But, independently of these facts, of the truth of which any one may easily satisfy himself, daily observation fully disproves the conjectures of the British pathologists. In pro- tracted abstinence, the brain invariably partakes of the gen- eral deficiency of sanguineous fluid, becoming abnormally pale, and otherwise altered ; and similar phenomena are often Avitnessed in anemia, whether produced by innutritious diet, starvation, or lingering disease. In such cases, dissection rarely reveals any serous effusion. Analogous effects are fre- quently caused by excessive bleeding. Every practitioner must have met with instances of this kind. A most interest- ing one came under my notice several months ago. A gen- tleman, forty-four years old, Avas seized with symptoms strongly denoting cerebral apoplexy, for which he was bled, at different operations, to the amount of nearly six pounds, before his pulse began to flag. Under this treatment, assisted by purgatives, and external irritants, his sensibilities were to a certain degree restored, and in about thirty-six hours he began to speak. In a short time, however, his mind became greatly excited, and at intervals he raved under the most furious delirium. Finally, convulsions set in ; and, after repeated attacks of this kind, he fell into a comatose condi- tion, and expired on the fourth day of his illness. On exami- nation, I found all the internal viscera in a state of complete anemia, excepting the spleen, which was somewhat engorged as the effect of previous irritation. The brain, which was supposed to be the chief seat of the disease, was remarkably blanched, and every capillary appeared to have been drained of blood: the vessels of the pi a mater were empty, and the larger sinuses contained only a few drops of thin claret-looking fluid. A small quantity of serum, altogether not exceeding two ounces, existed in the ventricles and at the base of the brain.f From the foregoing facts, and the reasoning founded on * See the author's paper on Manual Strangulation in Western Journal of the Medical and Physical Sciences, vol. ix. p. 25. t Western Journal of the Medical and Physical Sciences, No. liv. p. 513. 430 NERVOUS SYSTEM. [CHAP. XI. them, Ave are fully Avarranted, I think, in concluding that, although the brain itself is really incompressible, and in some degree beyond the influence of atmospheric pressure, yet, notwithstanding all this, the amount of blood sent to it is liable to the same variation as in other parts of the system, and that it may consequently be diminished in the same ratio by bleeding, low diet, and other depletory measures. If this deduction be true, as there is just grounds to believe it is, the conjecture of Abercrombie and Clutterbuck, that we cannot lessen the quantity of blood in the head, in any mate- rial degree, by our evacuations, resolves itself into a " baseless fabric," void even of the shadoAV of proof. The preceding sketch of the organization of the nervous texture would be incomplete Avithout adding a few remarks on the weight of the encephalon and the form of the spinal cord. It need scarcely be stated that the size of the cere- brum and cerebellum is always in direct ratio to the magni- tude of the bony case Avhich encloses them. The mean weight of these masses has not yet been determined, nor is this a matter Avhich, in a pathological point of view, is of much moment, since it is generally very easy, for one accus- tomed to making examinations, to discern the boundary Avhich separates the normal from the abnormal state. In six adult brains, I found the mean weight of the cerebrum to be two pounds, five ounces, — the minimum three ounces less, and the maximum four more. In the same cases, the average weight of the cerebellum Avas six ounces, the minimum four ounces and a half, and the maximum eight ounces. The annular protuberance, placed between the cerebrum, cerebel- lum, and oblong portion of the spinal cord, forms about the sixtieth part of the central mass. In the foetus and child, the cerebellum is proportionably larger than subsequently ; and the same holds good in regard to the encephalon as compared with the rest of the body. In the adult, the spinal cord extends from the inferior border of the Varolian bridge as far as the level of the first lumbar vertebra. Occasionally, it reaches a little loAver down ; and, in one instance, Keuffel saw it end opposite the eleventh bone of the back. Its length may thus be said to vary from sixteen to tAventy inches, according to the stature of the subject. In its general outline, the cord is nearly cylindrical, its tranverse diameter, however, being someAvhat greater than the antero-posterior, which gives it rather a flattened appear- SECT. II.] DURA MATER; INFLAMMATION. 431 ance in the former direction. Its thickness, which is scarcely half an inch, is not uniform, from one extremity to the other. Three distinct sAvellings are observable in different parts of its extent. Inferiorly, it is enlarged just before it terminates, in the caudal prolongation: the second expansion corresponds with the interval between the third and sixth cervical verte- brae ; and the third forms what is termed the oblong medulla, which is properly only the commencement of the cord. The cranial portion of the cord, usually called the oblong medulla, is of a flattened cylindrical form, being broad and thick, superiorly, near the Varolian bridge, but tapering gradually towards the occipital foramen. Tavo longitudinal grooves, continuous with those of the cord below, and situated, the one on its anterior, the other on its posterior aspect, divide this sAvelling into two symmetrical parts, each of which consists of three distinct nodules, namely, the anterior pyramid, the olivary tubercle, and the restiform body. A transverse section of these prominences shows them to be composed of granular matter, invested by a thin lamella of white substance, the fibres of Avhich pass the tAvo median grooves obliquely, and so a decussation is produced between them. This intercrossing, which is very perceptible at the lower portion of the oblong medulla, enables us to account for the singular fact — at one time altogether inexplicable — Avhy a lesion of one side of the encephalon leads to paralysis and loss of sensation of the opposite side of the body. SECTION II. Of the Cerebral Envelopes. I. The dura mater is susceptible of inflammation. The disease generally occurs in irregular circumscribed patches of greater or less size, and but rarely exists, excepting as a con- sequence of external injury. When thus affected, many extremely fine vessels, filled with florid blood, are seen in the dura mater, running in beautiful arborescent lines. Often the redness exhibits a peculiar bluish tint, not unlike what we see in sclerotitis; and, although the injection is sometimes remarkably great, yet the inflamed portion is never so much 432 CEREBRAL ENVELOPES. [cHAP. XI. croAvded with capillaries as other membranes are Avhich are naturally more vascular. In most cases, the inner surface of the dura mater is covered with small masses of lymph; and, not unfrequently, it is lined by a tolerably thick, adventitious membrane. In this manner, extensive adhesions may be pro- duced between it and the other tunics, or even between it and the convoluted surface of the brain. Suppuration of the dura mater is seldom, perhaps never, met with, excepting as a consequence of external violence. The matter is commonly deposited upon the inner surface ; but instances have been witnessed in which it Avas found between its layers, or upon its outer surface. In the latter case, Avhen the fluid is considerable, long retained, or of an acrid quality, it may erode the membrane and escape into the arachnoid sac. Occasionally, too, it produces caries and per- foration of the cranial bones; but such occurrences must be extremely infrequent. Various are the morbid changes Avhich result from chronic inflammation of the dura mater. Of these, the most impor- tant, hoAvever, are thickening fibrous growths and ossifi- cation. The thickening, Avhich is almost ahvays conjoined with induration, varies extremely in degree, and is sometimes so great as to occasion symptoms of cerebral pressure. Bone- tus mentions an instance where it was nearly half an inch ; and similar examples are recorded by others. It is sometimes found in fatal cases of epilepsy, and paralysis. In one instance which fell under my notice not long since, the thickening was connected with caries of the frontal bone, the membrane presenting a very rough, fungous appearance. The reverse of this state is sometimes observed, the dura mater being remarkably thin and attenuated. Fibrous tumors, of the size of a small nut, sometimes grow from the dura mater, generally from its inner surface, to Avhich they either adhere by a narroAV foot-stalk, or, as sometimes is the case, by a broad base. They are of a gray- ish color, of a dense, fibrous texture, hard, inelastic, and seldom acquire any great bulk. One of the most common morbid appearances of the dura mater, as has been justly observed by Dr. Baillie, is the for- mation of thin plates of bone. These I have very frequently observed, and am inclined to regard them as originating rather in the subserous cellular tissue, than in the substance of the membrane itself. They are most commonly noticed SECT. II.] PACCHIONIAN GLANDS--ARACHNITIS. 433 in the great falciform process, where they occur in small, irregular masses, not larger than a finger-nail. In several instances, however, I have seen them of the size of a Spanish dollar; and cases are given, in which the ossification occu- pied nearly the Avhole of the dura mater of one hemisphere. These bony plates are generally very hard, of a yellowish color, more or less rough on the surface, and, when sawed, they occasionally exhibit a real porous structure, like the osseous tissue in other parts of the body. Various other kinds of morbid growths and depositions are described by authors, as being occasionally found in the dura mater; but their occurrence is so extremely rare, and their nature so little understood, that it is not worth while to give any account of them in this place. The Pacchionian glands are occasionally much enlarged, indurated, and changed to the appearance of grumous blood. The sinuses of the dura mater are also sometimes diseased. The most frequent affection, by far, is inflammation of their lining membrane. When thus affected, the serous tunic is unnaturally vascular, opaque, covered Avith lymph, slightly thickened, and occasionally even ulcerated. Ribes and Ton- nelle, tell us that they have sometimes seen the sinuses par- tially filled Avith pus ; and nothing is more common than to find them obstructed with firm, dense, fibrinous concretions. II. Arachnitis being a disease of very frequent occurrence, it will be necessary to dwell upon it at some length. The most important anatomical characters are increase of color, opacity, thickening, and preternatural firmness, with effusion of serum, lymph, pus, and sometimes even of blood. In the early stage of the disease, the membrane does not present any perceptible alteration, but remains thin and transparent as in the normal state ; and, what is remarkable, the pia mater is almost always affected first, being usually thickened and deeply injected, long before any change can be recognized in the arachnoid itself. All parts of the arachnoid do not seem to be equally sus- ceptible of inflammation. The portions most frequently im- plicated are those in the ventricles of the brain, on the con- vexity of the hemispheres, at the base of the cerebellum, the junction of the optic nerves, the Varolian bridge, and, lastly, at the internal flat surface of the hemispheres. Such, at least, is the result of my OAvn observations corroborated by that of some of the most distinguished pathologists of the age. vol. i. 55 434 CEREBRAL ENVELOPES. [CHAP. XI. The redness of the arachnoid is usually limited in its ex- tent, being restricted to a few points on the convexity of one or both hemispheres, at the base of the brain, or betAveen the lobes of the cerebellum. Occasionally, Avhen the in- flammation is very intense, the redness occurs in pretty large patches, and appears to be caused by a real extravasation of blood ; but, even under these circumstances, it is quite im- possible to trace any vessels into the affected membrane ; and hence I am inclined to think that Dr. Hope, and others who have delineated such vessels, are in error,—believing that they belong rather to the pia mater and the connecting cellular tissue than to the arachnoid itself. What strengthens this opinion is, that the color may frequently be removed by scrap- ing the part Avith a scalpel, or exposing it for a feAV minutes to a gentle current of water; Avhich could not be effected, did it exist in the substance of the membrane. With this augmented vascularity, if such it may be styled, is usually conjoined, at an early period of the disease, a loss of the natural transparency. At first there is merely a slight degree of opacity, scarcely appreciable without the closest examination; but, by degrees, the membrane assumes a whitish, milky asbect, interspersed, not unfrequently, with shining pearly specks, and small patches of red. Cases are recorded in Avhich the arachnoid is said to have exhibited a dark mottled appearance ; but of this I have never seen an instance. After the disease has existed for some length of time, espe- cially if it have been very violent, the membrane is found to have a real increase both of thickness and of density, so that it may be easily detached from the surface of the brain, and even from the' dura mater. These changes, although they sometimes occupy a considerable extent of surface, usu- ally occur in small patches, which are confined to some parts of the upper surface of the hemispheres, the cerebellum, or base of the cerebrum. In cases of this kind, the pia mater is not only deeply injected, but the cellular tissue between it and the arachnoid is infiltrated with various kinds of fluids, such as serum, lymph, blood, and occasionally even with pus. These substances may all be witnessed at the same time; but, in the generality of instances, the first two alone are met with. Occasionally, the subarachnoid tissue is em- physematous,— from Avhat cause it is unknown. The effusion of serum is sometimes very copious ; and, in SECT. II.] ARACHNITIS. 435 parts where the subarachnoid cellular tissue is very loose and abundant, as, for example, in the intergyral spaces, at the fissure of Sylvius, the Varolian bridge, and the junction of the optic nerves, the distention is occasionally so great as to raise the membrane up in the form of considerable vesicles, of a gelat- inous appearance. In quantity, it may vary from a few drachms to several ounces, being ahvays more copious in the ventricles than on the surface or base of the brain. In its appearance, it is usually limpid, but now and then opaque and milky, from the admixture of lymph. When the inflam- mation is very severe, we sometimes meet Avith depositions of pure blood, either in the subarachnoid cellular tissue, in the substance of the pia mater, or in the intergyral spaces. The presence of puriform fluid is always indicative of high vascu- lar excitement, and frequently attends Avounds, contusions, and other lesions of the head. Dryness of the arachnoid is occasionally observed, generally in small patches, of a hard, shriveled aspect. Their presence always denotes excessive cerebral irritation. The deposition of lymph is much less frequent upon the surface of the arachnoid than upon that of the pleura or peritonaeum. That it is very often met with, however, every anatomist, who is at all in the habit of making necroscopic examinations, must be fully aware. Nor is the effusion of lymph ahvays confined to the free surface of the membrane. In the majority of cases, indeed, it occurs in the subjacent cellular tissue, where it is frequently seen of great extent, communicating a yelloAvish tint, to a large portion of the hemispheres. In some instances, it follows the course of the pia mater, producing adhesion between the convolutions, and filling up the intervals between them : occasionally, though rarely, it is witnessed in the ventricles, covering the choroid plexus; and a very common seat' of it, according to Aber- crombie, is the superior surface of the tentorium. In its color, this deposit is generally more or less opaline, with various shades of green and yellow. When occurring upon the free surface of the arachnoid, the lymph is often moulded into a distinct membrane, the thick- ness, color, and consistence of which, are much influenced by the length of time it may have existed, no less than by the violence and extent of the inflammation. In a stout athletic man, thirty-five years of age, who died from acute meningitis, brought on by a most extensive fracture of the skull, the 436 CEREBRAL ENVELOPES. [CHAP. XI. exudation, which covered the greater part of the right hemi- sphere, Avas about the thickness of a common Avafer, of a pale straw-color, inclining to greenish, and of the consistence of the buffy coat of the blood, before it has undergone perfect coagulation. The rapidity Avith which this deposition may take place is strikingly exemplified in the case before us, in Avhich the patient expired in less than three days from the occurrence of the accident. In instances of long standing, the color is usually lighter, the consistence more firm, and the thickness greater. I have never seen these adventitious mem- branes organized; but Dr. Hooper has delineated one Avhich is beautifully transparent, and abundantly supplied with ves- sels from the dura mater. Such are the principal anatomical features of acute arach- nitis. In the chronic form of the disease, the alterations are still more varied, consisting of greater thickening and opacity of the arachnoid and pia mater, increase of firmness and tenacity, organized adventitious membranes, tubercles, car- tilaginous and osseous concretions, and, in some cases, of copi- ous effusions of serum,—giving rise to the disease named hydrocephalus. In acute arachnitis, as has been stated, the quantity of serum seldom exceeds two or three ounces ; in chronic, on the contrary, it is ahvays very considerable. I have myself, in several instances, removed nearly two pints of fluid; and cases are narrated in which the amount Avas much greater. Thus, Dr. Horner mentions an instance in which the lateral ventricles alone contained five pints; and Fabri- cius Hildanus gives another, in which the quantity was up- wards of two gallons. Chronic hydrocephalus not unfre- quently exists as an intra-uterine affection ; more commonly, hoAvever, it makes its appearance soon after birth, and goes on progressing until the head attains an enormous develope- ment, out of all proportion to the rest of the body. The fluid of hydrocephalus is generally perfectly clear and limpid, possessing, indeed, very much the same qualities as the serum of the blood, from which it is derived. In most cases, it is Avithout smell and without taste, though the latter is sometimes slightly saline; and, by exposure to heat, I have, in several instances, found it as perfectly coagulable as the water of ascites, hydro-thorax, or hydrocele. It should be stated here, however, as a general proposition, that the quantity of albumen is much less 'than in peritonasal and other serous effusions; and hence heat, alcohol, and acids seLdom exert upon it the same marked effect. SECT. II.] ARACHNITIS. 437 The specific gravity of this fluid, according to Dr. Trail, of Liverpool, is a little greater than that of common water, in the proportion of about a twentieth part. The best analysis that we have of it is by Dr. Marcet, Avho found the solid contents of one thousand grains of the fluid of the ventricles to consist of, — Water,..........990.80 Muco-extractive matter, with a vestige of albumen, . 1.12 Muriate of soda,........6.64 Sub-carbonate of soda, with a vestige of an alkaline sulphate, 1.24 Phosphate of lime, with traces of phosphate of magnesia and iron,...........20 1000.00 The fluid of congenital hydrocephalus has been recently analyzed, with great care, by Dr. B. G. Babington, of Lon- don, Avho states its specific gravity to be 1004. It does not coagulate by heat, alcohol, or acids, and consequently does not contain, as he supposes, albumen. Instead of this sub- stance, he detected a very minute quantity of gelatine. Chronic hydrocephalus is usually connected with softening of the cerebral tissue, which is not unfrequently quite pulpy and reticular. The parts most commonly affected are the great commissure, fornix, and interventricular septum. In young children, Avho are mostly the subjects of this accumu- lation, the bones of the skull are often widely separated, the brain unfolded, and the whole head remarkably distorted. In a case which I recently examined, a considerable number of minute apoplectic effusions were discovered, for the most part in the right crus cerebri, just in front of the Varolian bridge, where there were as many as ten or a dozen. The ventricles of the brain are variously affected. When the quantity of fluid is considerable, they are expanded into large sacs, frequently lined by a thin layer of lymph, into which vessels may be seen dipping from the subjacent parts. In such cases, the figurate bodies of the brain are sometimes wholly destroyed, the convolutions effaced, and the gray substance compressed, as it were, into a thin shell, occasion- ally not more than half a line in thickness. Not unfrequently, the free surface of the arachnoid is roughened with minute tubercles, varying from the size of a clover-seed to a common currant. Their most usual situation is the lateral ventricle, the fissure of Sylvius, and the interval 438 CEREBRAL ENVELOPES. [CHAP. XL between the lobes of the cerebellum. No part of the mem- brane, however, seems to be exempt from them. These little bodies, Avhich are generally of a whitish, semi-transpa- rent appearance, are of an irregularly rounded shape, and of a dense, fibro-cartilaginous consistence: oftentimes, they occur in thick clusters, and are surrounded by a yellow, concrete substance, the intervening portions of membrane being opaque and milky. Tubercles of the arachnoid almost always co- exist with tubercles of the lungs or of some of the other organs: they are seldom met Avith in adults, but are suffi- ciently common in children under three years of age. Arachnitis presents three stages, each of them characterized by a distinct group of symptoms. The first comprises the period of cerebral excitement, and is marked by increased sensibility to all sorts of impressions, Avith irritability of tem- per, headache, flushed cheeks, grinding of the teeth, knitting of the eyebrows, Avakefulness, a quick, jerky pulse, and irreg- ularity of the boAvels. In the second stage, which constitutes the period of reac- tion, or, more properly speaking, that in which the cerebral irritation is propagated to the muscular and nervous systems, the diagnostic characters are, great restlessness, agitation, and convulsions ; torpor of the bowels, nausea and vomiting, par- ticularly on assuming the erect posture ; intense headache, loss of memory, altered pronunciation, intolerance of light and sound, with quick pulse, hurried respiration, a circum- scribed flush on one cheek, and general fever. The convul- sions are commonly long and severe; and it is not undeserv- ing of notice, that, Avhen the arachnitis is seated on the con- vex surface of the cerebral hemispheres, delirium sets in very early, and becomes the prominent and characteristic symptom ; whereas, if it occur at the under surface and base of the brain, coma is the more usual attendant. The duration of this stage varies, from a feAV days to a Aveek or more. The third stage, which is that of collapse, is marked by immobility of the pupils, loss of sensation, more or less hemi- plegy, strabismus, paralysis of one or both eyelids, constant somnolency, oblivious state of the intellect, and convulsive twitchings of the muscles of the face, the trunk, or extremi- ties. The third stage lasts from a feAV hours to three or four days. The symptoms of chronic arachnitis, at the commencement, are generally not very Avell marked; they all, hoAvever, par- SECT. II.] ARACHNITIS. 439 take of the character of those mentioned as indicating the acute variety of the disease. Usually, the patient experiences some difficulty in articulating words; he is forgetful, his ideas are incoherent, and his Avhole gait is unsteady and vacillating ; the limbs are frequently agitated with convulsive tremors; and the intellectual disturbance, although slight at first, is regularly progressive, until at length it terminates in confirmed idiocy. Delirium and progressive paralysis are, according to Bayle, the constant attendants on chronic arach- nitis. III. The pia mater, on the whole, is not often diseased. In arachnitis, it is not unusual to see its substance inflamed, and its vascularity greatly augmented, with small masses of lymph adhering to its surfaces, especially the outer. Under these circumstances, the vessels of the pia mater are unnatu- rally conspicuous, are filled with florid blood, and form, by their anastomoses, a beautiful net-work. Most generally, this augmented vascularity occurs in considerable large patches, which are often of a bright red color, and easily detached from the convolutions of the brain. Small san- guineous effusions are occasionally observed; and, in some instances, the part presents an ecchymosed or blood-shot aspect. When the pia mater is inflamed to a high degree, pus is commonly formed, which sometimes spreads over the whole upper surface of the brain, or finally erodes the mem- brane, and gets in contact Avith the cerebral tissue. Ulcera- tion, however, and mortification are rare consequences of inflammation of the pia mater. Tubercles are sometimes seen growing from the surfaces of the pia mater. They have been found as big as an egg, though usually they are not larger than hazelnuts; are of a yellowish color, of a spherical shape, and break down ulti- mately into a puriform fluid, forming circumscribed abscesses on the surface of the brain. Occasionally they exhibit a cartilaginous texture, and are enclosed by a delicate vascular cyst. Ossification of the pia mater is very uncommon. Dr. Baillie never saw an instance of it; but states that the cele- brated Soemmering, who has published a German translation of his Treatise on Morbid Anatomy, with many excellent notes, has a specimen of this disease preserved in his collec- tion. Dr. Hooper has also seen an example of it, in the form of a small bifid mass, not larger than a split pea, which grew 440 CEREBRAL ENVELOPES. [CHAP. XI. from the internal surface of the membrane, and dipped down into the medullary substance of the cerebrum. Fungous, bloody, and encysted tumors are sometimes found in the pia mater, or between it and the arachnoid. Dr. Esquirol, of Paris, once met Avith an encysted tumor of the pia mater containing fat; and similar cases have been re- corded by other writers. All these diseased appearances, how- ever, are extremely rare, and it has never occurred to me to observe them. Diseased appearances are often noticed in the lateral ven- tricles, and especially in the choroid plexus. As a consequence of inflammation, the lining membranes are sometimes very much thickened and indurated, their vessels gorged with blood, and their free surface covered with patches of lymph, occasionally of considerable thickness and density. In the choroid plexus, the most common appearances are serous cysts, formed by a very delicate, vascular, and transparent mem- brane, filled with a clear, limpid fluid. I have never seen them very large, though ocasionally they attain a considerable bulk. Their number is often very great. In an old man, seventy-five years of age, ten or a dozen of them were clus- tered upon the right choroid plexus, the largest of which scarcely equalled a common cherry. Instances are recorded in which as many as a hundred of them were seen in the same individual. The ventricles of the brain occasionally, although I be- lieve very seldom, contain hydatids ; and there is reason to believe that the serous cysts which I have just described are frequently mistaken for them. The two varieties which have hitherto been observed are the headless and bladder-tailed; of the latter of which, five species have been seen by different pathologists in the choroid plexus. The vessels of the choroid plexus, it may be here stated, are sometimes greatly enlarged, tortuous, and almost varicose. SECT. III.] DOES THE BRAIN CICATRIZE ? 441 SECTION IIL Of the Brain. Various experiments have been instituted by pathological anatomists, with a view of ascertaining whether wounds of the brain and spinal marrow are susceptible of cicatrization; but Avith so little success that the knowledge Avhich has been thus obtained is comparatively unimportant. The cause of this is to be found chiefly in the fact that the animals, the subjects of the experiments, almost always die at an early period after the operation, from the effects of acute encepha- litis, thus alloAving the parts no chance for healing. If life be preserved for a few days, the edges of the wound are found to be greatly injected Avith blood, of a deep rose color, and considerably augmented in density, the induration often extending to the distance of three or four lines into the sur- rounding tissue. With these changes is usually seen a small quantity of soft, reddish lymph, Avhich is smeared over the incised parts, and serves as the basis of the future granula- tions, Avhich always spring up, if the animal survive the oper- ation a week or fortnight. Not unfrequently, the cerebral tissue, instead of growing hard and firm, acquires an unusual degree of softness, from the infiltration of serosity, pus, or blood, or from the influence of all these fluids united. In other cases, these two characters are combined, the edges of the lesion being dense and indurated, Avhilst the parts imme- diately around them are soft, boggy, and permeated with liquids. Appearances of scars, sometimes of very large size, are not unfrequently found in the brain after death, for which physi- cians found it extremely difficult to account ; that they are formed, however, by the same sort of mechanism as in the other textures of the body, is by no means improbable. Thus, when, for example, the cerebral substance is lacerated by an effusion of blood, the fluid, as will subsequently be shoAvn, occasionally becomes organized and incased in a distinct cyst, which either remains during the life of the individual ; or, what is more generally the case, perhaps, when the extravasa- tion is not very copious, it is acted upon by the absorbents, by whose influence it is gradually destroyed, or reduced to a vol. i. 56 442 BRAIN. [chap. XI. dense, fibrous texture. When this has been accomplished, there is generally to be found a true linear cicatrix, of a light citron color, and much harder than the cerebral substance, although softer than the scars which we find in most of the other tissues. These cicatrices have, in the majority of cases, a laminated arrangement, with a thickness from the third of a line to the eighth of an inch or more. Yet, not unfre- quently, they are perfectly cellular, moist, vascular, and filled with serous fluid. The brain is subject to various forms of disease, amongst which acute and chronic inflammation, suppuration, softening, ulceration, sanguineous effusions, and neAV groAvths, are the most common and important. Encephalitis, cerebritis, or inflammation of the brain, seldom exists as a primary, idiopathic, or uncomplicated affection: most commonly it is the result of previous disease, as fevers, especially such as are of an eruptive nature, apoplectic effu- sions, tumors, and external injury. When produced by vio- lence inflicted on the scalp and cranial bones, the inflamma- tion is generally limited in extent, although intense in degree. Never does it involve the Avhole organ at once; for such a condition would, it is reasonable to infer, be incompatible with the continuance of life. The disease may occur at all ages, and in all parts of the encephalic mass, though some are more obnoxious to it than others. The anatomical characters of the inflamed structure vary according to the duration and intensity of the disease. At first, there is merely a slight increase of vascularity, with a reddish rose-colored state of the cerebral substance. When sliced with a sharp knife, it presents a multitude of small red points, which give the section the appearance as if it Avere streAved with particles of vermilion. The capillaries are every Avhere greatly injected; and so firmly is the blood crowded into them, that it is with difficulty removed by ab- lution. Not unfrequently small ecchymoses are met with, caused by a rupture, no doubt, of minute vessels, in conse- quence of the violence of the inflammatory action. The extravasation oftentimes occurs in distinct spots, but occasion- ally it presents itself in irregular lines or streaks, which, when numerous, give the cerebral substance a singularly mottled aspect, Avith various tints of red, the color being usually more florid in the cortical than in the fibrous texture. At this early period of the inflammation, there seems to be no distinct line of demarcation between the sound and dis- SECT. III.] ENCEPHALITIS. 443 eased parts: in most cases they run insensibly into each other, the redness gradually declining in intensity as we proceed from the centre of the irritation toAvards the periphery ; and, although the affected structure is less tenacious than in the healthy state of the brain, it is firmer than usual, from the turgescence, apparently, of its vessels. As the disease advances, the vascular injection becomes more and more strongly marked, and the reddish color Avhich Avas displayed in the earlier stage, gradually deepens, until it acquires a broAvnish, claret, purple, and occasionally even a greenish or dusky yelloAvish shade. With this augmented capillary turgescence, amounting almost to complete obstruc- tion, the part becomes preternaturally soft, and assumes that peculiar alteration of character, Avhich has been described by Rostan, Lallemand, and other pathologists, under the name of cerebral mollescence. The substance of the brain, when thus affected, has en- tirely lost its natural properties : it has a humid, macerated appearance, from the infiltration of serosity, purulent matter, or blood, and is often converted into a soft, grayish pulp, bounded by a hard, vascular border, exhibiting all the signs of the first stage of inflammation. Several such disorganized spots are sometimes met Avith, either in close proximity, or separated by considerable intervals. When the affected struc- ture is pervaded by numerous globules of pus, it is very apt to have a citron hue, and then constitutes what Andral has termed the yellow softening of the brain ; from Avhich the red softening, another variety which he has proposed, differs only in being of a deeper color, the broken doAvn pulp vary- ing from a florid to a claret tint, with intermediate shades of violet, brown, chestnut, or cineritious. The different appearances now described are not unfre- quently met with in the same diseased portion. Thus, we may have the reddened, indurated state at the circumference ; next, that of serous infiltration; and, finally, that of purulent softening in the centre. The pus always occurs here, as else- where, at first in disseminated globules, and afterwards, if the patient survive long enough, in distinct foci. The red and - yellow softening are frequently combined, one portion of the inflamed structure presenting the bloody, the other the puru- lent infiltration. It has been already stated that the affected part, in the early stage of encephalitis, is, in the generality of cases, 444 BRAIN. [CHAP. XI. somewhat harder than it is in the normal condition. The degree of consistence is subject to remarkable variations, running through all the intermediate grades, from an indu- rated, firm, and elastic body to one of almost perfect fluidity. The softened mass, in such cases, is generally surrounded by the hardened, which itself is intimately, and, for the most part, insensibly blended Avith the healthy cerebral tissue. In the early stages of encephalitis, as Avas before intimated, the red color of the inflamed part cannot be removed by ablution, nor can the engorged vessels be filled with minute injecting matter,—thus presenting a striking analogy with what takes place under similar circumstances in the serous and mucous membranes, as well as in the liver, spleen, and kidney. The vascular and serous envelopes of the brain, are not unfrequently affected in this disease. When the cerebritis is located superficially, the inflamed portions always adhere to these tunics with unnatural firmness, especially in the early stages of the complaint; and hence, in attempting to peal them off, fragments of cerebral substance, traversed by red and distended capillaries, generally follow. The vessels of the pia mater, under these circumstances, are commonly much engorged ; the arachnoid is opaque and adherent; and the intergyral hollows are filled with sero-albuminous matter, Avith blood, or even with pus. From this rapid sketch of the anatomical characters of acute cerebritis, it Avill be perceived, that the first effects of the disease consist simply in capillary engorgement, in punc- tuated or striated redness, which is usually more conspicuous in the cortical than in the fibrous texture, and in increased hardness, varying in degree according to the intensity of the \ disorder; and, secondly, that if the inflammation be allowed to go on unrestrained, it finally passes into mollescence, in Avhich purulent, bloody, and cerebral matter, are in general intimately blended together, forming a mass of a semi-liquid consistence, and of a light brownish color, Avith various shades of yelloAvish, grayish, claret, or even greenish. Although all parts of the brain are liable to acute cerebritis, yet there are some which are much more frequently affected than others. The most common seat, seems to be the cineri- tious texture, the great vascularity of which strongly predis- poses it to inflammation and its consequences. Thus, of forty-six cases of this disease, collected by Lallemand, the SECT. III.] ENCEPHALITIS. 445 gray substance Avas the principal seat of the inflammation in thirty-three, and the white in only eight. The surface of the convolutions, which consist entirely of cortical matter, Avas affected in sixteen cases; the striated bodies and optic couches, in which the same substance predominates, in thir- teen ; and the Varolian bridge, which is made up chiefly of fibrous matter, only in four. Some influence must, also, no doubt, be allowed to the greater extent of surface of the gray substance, and to its intimate connection Avith the pia mater, which can seldom be much inflamed without the disease being propagated to the contiguous parts of the brain. Acute encephalitis usually reaches its full height Avithin three or four days from its invasion. When partial, the patient often recovers ; but should it occupy a large extent of surface, it generally proves fatal in a very short time, not unfrequently, indeed, in thirty-six or forty-eight hours. The early symptoms are violent headache, intolerance of light, delirium, and acuteness of all the senses, rapidly followed by convulsions, contractions of the limbs, profound coma, and death. Several writers have attempted to account for the various phenomena which arise during the existence of cerebritis, by a reference to lesions of particular parts of the encephalic mass. Thus, Dr. Martinet supposes,* that affections of the superior extremity are attributable to disease of the posterior fibres of the optic thalamus of the opposite side of the brain ; those of the inferior extremity to alterations of the anterior half of the striated body. Paralysis of both sides of the body, existing at the same time, depends upon disease of the central part of the Varolian bridge ; loss of speech, on the anterrbr lobes of the cerebrum ; deep and progressive coma, with entire absence of palsy and muscular rigidity, upon the great commissure, fornix, or interventricular septum. When the quadrigeminal tubercles of one side are inflamed, there will be squinting and rolling of the eye, with dilatation and immobility of the pupil of the other; if, on the contrary, the disease affect both sides at the same time, the phenomena just mentioned Avill usually be present in both eyes. Lesions of the pituitary gland, and cineritious tubercle at the base of the brain, by causing compression of the optic nerve of one side behind the point of decussation, may induce * Manual of Pathology, p. 139. 446 BRAIN. [chap. XI. blindness of the opposite eye ; Avhilst derangement of the respiratory, circulatory, and genital organs, Avithout paralysis of the extremities, indicate inflammation or other disease of one or both of the lobes of the cerebellum. Lesion of the crura cerebri is followed by the same paralytic symptoms as that of the optic thalamus and striated body, Avhich are prolonged from it. Disease of the medulla oblongata produces all the phenomena which arise from the joint affection of the cerebel- lum and cerebral crura; and, if Ave ascend still higher in the brain, from that also of the striated bodies, optic thalami, and cerebral hemispheres.* Inflammation of the brain not unfrequently passes into suppuration, the matter occurring either in the form of small yf Uowish globules, or in that of abscesses. The most com- mon seat of the disease is in the anterior half of the cerebral hemispheres, on a level with the great commissure: no por- tion, however, of the cerebro-spinal axis appears to be exempt from it, cases of it being mentioned by various writers as having been found in the cerebellum, posterior lobes of the cerebrum, spinal cord, medulla oblongata, Varolian bridge, and even the quadrigeminal tubercles and pineal gland. Collections of purulent fluid present themselves under several varieties of form. In one, Avhich may be denomi- nated the undefined abscess, the matter is contained in a cavity, the walls of which are formed by the surrounding brain, and partly, perhaps, by its membranes, if it be seated superficially or near the ventricles. The inner surface of the abscess, though occasionally smooth and even, is gener- ally rough, granulated, and shaggy, the purulent fluid adhering to it with various degrees of tenacity. The cerebral tissue immediately around the cavity is usually remarkably sbund; seldom is there any sign of inflammation, induration, or soft- ening. The size of these collections is variable. Not unfre- quently, they are as large as a walnut; but, for the most part, they do not exceed the volume of a pea, a grape, or an almond. Occasionally, a Avhole hemisphere almost is con- verted into a soft, purulent mass. The second variety of abscess is the encysted. The pus in this species, as the name indicates, is contained in a dis- tinct capsule, formed by the deposition of plastic lymph. The capsule, at first, is soft, delicate, and easily torn: in * Foville, in Diet, de Med. et de Chir. Pratique, art. Enciphale. SECT. III.] SUPPURATION. 447 time it becomes dense, remarkably firm, and completely organ- ized, — vessels in great numbers ramifying through it from the circumjacent cerebral tissue. The outer surface of the sac at this stage is rough and flocculent; the internal is smooth, of a rose-color, and someAvhat villous, like the mucous coat of the stomach. Its thickness rarely exceeds that of the peri- cardium ; but instances occasionally occur in Avhich it is from a fourth to a half of an inch. In cases of very long standing, the cyst is often very firm and indurated, from its conversion into fibrous, cartilaginous, or osseous texture. Under such circumstances, it is not unusual to find it com- posed of several folds, intimately connected with each other, but differing remarkably in their color, density and thickness, the softest being generally internal, as if they had been secreted by the others. Cases, again, occur, in which the cyst is divided into numerous cells, formed by hard, grayish, intersecting bands. The object of these cysts evidently is, to serve as barriers to the extension of the puS Avhich they enclose. Rudiments of them are occasionally found as early as the end of the first week; and, according to Lallemand and Rostan, it is not uncommon to find them perfectly organized at the expiration of a month. Patients thus affected, not unfrequently live for a long time before the brain is so far destroyed as to render the continuance of life impossible. Professor Horner men- tions an instance in Avhich the interval between the infliction of the injury — a pistol Avound — and the fatal termination was nearly tAvelve months; Sir Everard Home, one of nine- teen months ; and Dr. Copland, one of upAvards of three years. Similar cases are to be found in the writings of Sir Astley Cooper, Hennen, and other surgeons. When the cyst finally becomes the cause of death, it is by exciting fresh inflammation in the surrounding cerebral texture ; or it may, acting in the capacity of a foreign body, excite inflammation in the arachnoid membrane, and destroy life by the conse- quent effusions. Abscesses of the brain, however, do not always terminate fatally, for numerous cases occur in which there is every rea- son to believe that the pus is absorbed, and the cavity of the cyst gradually obliterated by the approximation of its walls. The opinion, at all events, derives confirmation from the ap- pearances of the large cicatrices which are so often found in the brani of old persons, and from the intersecting bands 448 BRAIN". [CHAP. XI. which are occasionally seen uniting the sides of encysted ab- scesses. In respect to its appearance, the pus found in the brain dif- fers in no essential particular from that in other parts of the body. In the generality of cases it is of a pale straw-color, thick, and inodorous; not unfrequently, however, it is green- ish, reddish, or dirty Avhite, thin, and remarkably fetid: this is particularly the case in young subjects who die from the extension of inflammation of the ear to the brain. In scrofu- lous persons, the pus is generally very thick and tenacious, from the admixture, probably, of plastic lymph. Suppuration of the brain sometimes takes place Avith great rapidity. Dr. Abercrombie saAv a case in Avhich there Avere several small, undefined abscesses at the end of four days : Laennec asserts that he has knoAvn pus to form in less than twenty-four hours. The purulent fluid, when unencysted, often manifests a tendency to pass from its original situation to some other. Thus, when it is seated in one of the hemis- pheres, it may work its way gradually to the surface, or into one of the ventricles, destroying occasionally, in the former case, the lining membranes, with the contiguous bone. In 1827, I examined the body of a stout, athletic man, about forty years of age, who died nearly three weeks after the re- moval of an osteo-sarcomatous tumor from the nose by Pro- fessor McClellan, of Philadelphia. For the first tAvo Aveeks after the operation, the patient did remarkably well, and talked of returning to his friends who lived several hundred miles off, in the State of NeAv York. A few days, however, before he had determined on starting, he Avas suddenly seized with violent rigors, which were folloAved in a short time by deep coma, and he expired after an interval of thirty-six hours from the attack. On examination, Dr. Gardner and myself found a large, undefined abscess, filled Avith thick, offensive matter, on the loAver surface of the right anterior lobe of the cerebrum, with partial destruction of the cribri- form plate of the ethmoid bone and the intervening mem- brane in its immediate vicinity. Cases, in many respects similar, are narrated by Lallemand, Rostan, and other writers. The symptoms of cerebral abscess do not differ materially from those of the last stages of ordinary inflammation. Gangrene of the cerebral tissue is a very rare affection, and probably never occurs except as the result of external violence. As an idiopathic disease, I am not sensible that a single SECT. III.] SOFTENING. 449 instance of it is to be found in the writings of pathologists. In this affection, the cerebral substance is at first of a reddish broAvn color, but in a very short time becomes spotted Avith an immense number of minute grayish points, resting upon a lilac, violet, or purple ground. At a more advanced stage, Avhen the mortification may be considered as fully established, the affected part is converted into a soft, pulpy putrilage of a blackish, brownish, or greenish color, and extremely fetid, — a character which distinguishes this lesion from the simple softening presently to be noticed. The cerebral texture im- mediately around the sphacelated mass generally forms a hard, reddish belt, highly injected, and occasionally even slightly ecchymosed from sanguineous effusions. Softening of the brain, a lesion first accurately described by Dr. Rostan, of Paris,* is decidedly the most frequent dis- ease of the whole nervous system, —even more so, perhaps, than apoplectic effusions. It is very common in old subjects, but no age seems to be exempt from it; and, if Ave may credit the assertions of Billard, one of the most admirable Avriters on infantile maladies, there is reason to believe that it may exist also as an intra-uterine affection. There is no part of the encephalic mass in Avhich softening has not, at one period or another, been observed. The struc- tures, however, most liable to it, are such as are most obnox- ious to sanguineous effusions, as the fornix, interventricular. septum, great commissure, optic thalami, and striated bodies,— the frequency Avith Avhich they are affected being, according to my own observations, in the order in Avhich they are here enumerated. In the majority of cases, the figurate bod1 ies are alone implicated, the cineritious texture retaining its normal characters; yet instances sometimes occur in Avhich the Avhole brain and spinal cord are reduced to a soft pulpy matter, Avith scarcely a trace of their primitive organization. Lesions so extensive are occasionally observed in infants, but are very rarely met with in adults. Of this universal molles- cence, as it may be styled, a well-marked example came under my notice in 1836, in a man forty-five years old. Both the white and the gray substance had lost much of their natural firmness and cohesion. The Avhole of the fornix, excepting its anterior pillars, the interventricular septum, part of the great commissure, and the pineal gland, Avere completely dissolved. * Rcchcrchcs sur le Ramollissement du Cerveau. Paris, 1823. vol. i. 57 450 BRAIN. [CHAP. XI. The striated bodies, optic couches, and quadrigeminal tuber- cles, Avere likewise much softened ; and so tender was the base of the brain, that the medulla oblongata, cerebral crura, and roots of the nerves, Avere all left behind in the attempt to remove the organ from the skull. In the cerebellum, the parts Avhich were more particularly diseased, were the cere- bello-testicular processes, the Vieussenian valve, and the gray substance at the under surface of each lobe. The vessels of the pia mater in this case Avere excessively gorged Avith blood ; and the fibrous texture of the hemispheres, especially of the right, exhibited a considerable number of small rose- colored patches, dappled Avith black points, corresponding Avith the orifices of divided capillaries. No lesion, so far as could be discerned, existed in any other organ, and there is every reason to believe that death Avas occasioned by the diseased state of the brain. The appearance and consistence of the part affected vary according to the duration of the disease and the intensity of the exciting cause. In the early stages, the changes are always very slight, and can only be recognized by the touch. At a more advanced period, the continuity of the organic particles is sensibly disturbed, and the nervous substance is so soft that it may be readily broken doAvn Avith the finger into a thin, pap-like mass. It is no longer able to sustain the slightest Aveight, and has no more consistence, frequently, than so much cream or thickened milk : it may be easily scraped with the knife, but to cut it smoothly is impossible. Having attained this degree of softening, the cerebral tissue soon falls to pieces, forming thus a breach of continuity occasionally of very considerable extent. An odor like sulphureted hydrogen sometimes exhales from the disorganized mass; but this is very rare, and I have never met with it. According to Billard, it would seem to be more common in children than in adults. Although the softened parts are occasionally separated from the sound by a distinct line of demarcation, yet more commonly they run insensibly into each other. The color varies according to the time that has elapsed since the inva- sion. In the early stage, when there is usually a considera- ble degree of inflammatory turgescence, it is often of a uniform rose tint, studded Avith red dots, or marked Avith purple arbores- cent lines ; more rarely Ave find small hemorrhagic effusions, and patches of a dark leaden hue, produced doubtless by SECT. III.] SOFTENING. 451 intense capillary injection. At a later period of the disorgani- zation, the part is usually of an opaque Avhite, broAvnish, yelloAvish, or greenish color; or these tints are blended, dif- ferent shades of them occurring at different points, or even at the same place. The dull milky hue, which is so frequently observed in this affection, is supposed by Professor Lallemand to be caused by an infiltration of pus, — an opinion Avhich is evidently unfounded, as in the vast majority of cases no such fluid Avhatever is to be seen. This condition, which is often found after hydrocephalus, the cerebral mass seems to be perfectly anemiac, not a drop of blood oozing from the affected part when cut. In some instances, the color remains natural. When this happens, which, however, is rather rare, the softening is usually confined to the fibrous structure, and may readily escape notice. In this affection, the pia mater is sometimes seriously im- plicated. When the softening is seated on the convoluted surface of the cerebrum or cerebellum, or on the surface of the striated bodies, and optic couches, the membrane is generally preternaturally red, rough, and, on attempting to raise it, the disorganized gray substance often separates along with it. In other cases, I have found portions of the pia mater completely destroyed, or converted into a dirty broAvn- ish pulp, void of every feature of the original texture. These changes are particularly liable to happen Avhen the softening affects the surface of the figurate bodies in the floor of the lateral ventricles. In these cases, the arachnoid frequently experiences the same fate. Concerning the intimate character of softening of the brain, authors have expressed different opinions. Professor Re- camier views it in the light of a peculiar disease, not unlike certain alterations of the spleen, resulting from a morbid state of the Avhole system, the force of Avhich is particularly spent upon the encephalic mass. This opinion derives plausibility, in some degree, from certain circumstances to Avhich I shall take occasion presently to advert. Dr. Rostan, Avho has Avritten a most able treatise on this affection, considers it as a mode of disorganization very similar, in its essential fea- tures, to senile gangrene. He supposes it to be an effect merely of inflammatory irritation, referring, in support of his doctrine, to the various phenomena which are exhibited during life, as well as to the appearances which are revealed after death. Very similar to this are the vieAvs entertained 452 BRAIN. [chap. XI. by Dr. Abercrombie and Professor Lallemand. The latter of these distinguished writers, nevertheless, asserts that he has occasionally met Avith cases of mollescence, in Avhich the symptoms have followed so sIoav and gradual a course, and, Avithal, have manifested such a degree of mildness, as to preclude the idea almost of inflammatory action. Others, again, mistaking effects for causes, ascribe the lesion to con- gestion of the cerebral capillaries, or to an effusion of serosity into the intermolecular intervals. It seems to me to be de- cidedly of an inflammatory origin, —a conjecture which is abundantly borne out both by my oavii observations and those of some of the distinguished pathologists Avhose names have just been mentioned. Softening of the brain is often found in connection with ascites, pulmonary phthisis, diabetes, chronic pleuritis, maras- mus, and. protracted fevers. Grief, great anxiety, and intense study, are causes Avhich sometimes produce it. This Avas the appearance Avhich the brain of Sir Walter Scott exhibited. The softening involved nearly the whole of the medullary texture of the left hemisphere, Avhich was converted into a soft, flaccid mass, interspersed with numerous globules of Avater. This mischief was the result, in all probability, of a slow, chronic irritation, produced by the excessive intellectual labor to Avhich this great man subjected himself during the last five or six years of his existence, in consequence of his pecuniary embarrassments. Protracted confinement, with inactivity and low diet, also, have a tendency, it would seem, to impair the natural con- sistence of this noble organ. This circumstance has been remarked by different observers, and is particularly dwelled upon by Dr. Monro, of Edinburgh, in his treatise on the Morbid Anatomy of the Human Brain. Similar appearances have been Avitnessed in the cerebral tissue of idiots, lunatics, and epileptics. In an elaborate account of the anatomical changes found in the brains of maniacs and epileptic persons, published by Dr. Greding, a German physician, in 1771, fifty-one cases are detailed, in more than one half of which the organ in question was either partially or generally soft- ened. Observations confirmatory of these^have since been re- corded by other writers. How softening under the circum- stances here specified is induced, whether from diminished nutrition of the cerebral texture, or from irritative action, giving rise to an infiltration of serous fluid, into its inter- SECT. III.] SOFTENING. 453 molecular spaces is a point which challenges further researches. Old age, also, seems to predispose to this affection ; and the same may be said of arteritis and ossification of the vessels. As yet no pathologist has succeeded in pointing out any symptom or group of phenomena by Avhich this disease can be distinguished from other encephalic affections. It has been supposed by some, that the rigid contraction of the limbs, so often witnessed in patients who are laboring under this lesion, afforded a characteristic sign ; but the fact that individuals often die in Avhom the extremities are completely relaxed, is sufficient evidence of the fallacy of the opinion. The duration of the disease is variable. From the observa- tions of Professor Lallemand, it would appear that nearly one half die within the first seven days from the attack ; about tAvo fifths at the end of the second Aveek ; and the remainder at intervals of one, two, or three months. When it is chronic, it may last for years. No treatment seems to be capable of reaching it. An interesting circumstance in relation to this disease is the fact of its occurring, not unfrequently, in the horse and other animals, both in the brain and spinal cord. The con- sistence and appearance of the altered texture are the same precisely as in the human subject. Professor Dupuy, of Paris, by Avhom this fact was first ascertained, states, that the principal symptoms are, trembling of the limbs, general debility, and convulsive movements of the muscles, with tetanic stiffness of the neck, lower-jaw, or extremities, especially the hinder. Does mollescence of the brain ever get well ? This is an interesting and, practically speaking, a highly important question. As is usual in all such matters, a great contrariety of sentiment prevails among pathologists, which is the more surprising since upon whatever can be determined by direct observation there should always be but one opinion. Pro- fessor Andral, who has bestowed a good deal of attention upon the subject, doubts whether it is possible for a cure ever to be effected, especially if the softening have been fully established. In this view he is sustained by several of his countrymen ; whilst opposed to it is the high authority of Cruveilhier, one of the most eminent writers of the present period. "The cicatrization," says he, "of the gray sub- stance is marked by the developement of small cavities with a dense, yellowish scar; of the white, by the formation of 454 BRAIN. [CHAP. XI. minute cells, filled with a clear, gelatinous fluid, like thin size." Confirmatory of all this, it is asserted by Dr. John Sims, of England, that the cure of cerebral mollescence is not only possible, but very frequent. In twelve cases of this disease, occurring in old sexagenarian patients, he noticed all the characteristic marks of cicatrization, in different stages of its progress. When fully accomplished, the traces of the cure in the gray substance are a peculiar cribriform aspect of the convoluted surface of the brain, either alone, or combined with atrophy and flattening, and adhesion of the pia mater to the affected part. In the white substance, cicatrization is indicated by numerous little holes, containing a limpid fluid, and lined occasionally by a fine, delicate, transparent mem- brane, of a light faAvn-color. These cells have sometimes a worm-eaten appearance, and not unfrequently they seem as if they had been scooped out Avith a sharp instrument. In their size, they vary from a pin-head to the volume of a bean ; and, in their figure, they strongly resemble the pores observa- ble in new bread. The cerebral tissue in the immediate neighborhood of these cicatrices is either of the natural con- sistence, slightly softened, or, as is more frequently the case, considerably indurated, according to the period that has elapsed since the commencement of the healing process. Occasionally the white matter has a peculiar granular aspect. Such is the opinion of Dr. Sims, concerning the cure of mollescence of the gray and Avhite substance of the brain. As regards myself, my observations have been too limited to enable me to speak with that confidence Avhich should ever characterize the statements of the pathological anatomist. Without doubting the accuracy of the investigations of this gentleman, or calling in question the candor of his assertions, I am forced to reject his opinion, that cicatrization is a very frequent occurrence in this affection. At the same time I am far from agreeing Avith Andral and others, that it can never happen. That it does sometimes take place, is suffi- ciently proved by the phenomena observable in the molles- cence which occurs around apoplectic effusions, and in the neighborhood of morbid groAvths. The subject, however, requires further elucidation, and, until this be had, no theory, hoAvever plausible and ingenious, Avill be deserving of much confidence. Chronic inflammation of the cerebral tissue is much more common than acute, of which, indeed, it is not unfrequently SECT. III.] INDURATION. 455 the result. Its anatomical characters, though occasionally similar, are yet, in the great majority of cases, Avidely differ- ent ; and it is therefore necessary that they should be con- sidered under a distinct head. The most important feature of this disease, and one Avhich may be considered as strictly characteristic, is the augmenta- tion of density of the affected tissue, giving rise to that alter- ation of substance Avhich has been designated, within the last tAvelve or fifteen years, by the term induration. Not a little diversity is observable in regard to the degree of hardening. In the generality of cases, the consistence does not exceed that of concrete albumen; not unfrequently, hoAvever, the part is as firm as cheese ; and instances occur, although very rarely, in which it as dense and elastic as fibro-cartilage. The latter species of induration is generally seen in small, insulated masses around old apoplectic cysts, tubercles, and fungous groAvths. The other two, which often occupy a considerable extent of surface, sometimes coexist, running insensibly into each other. General induration has hitherto been seen chiefly in persons that have died of typhous fever ; and Andral tells us that he also witnessed it several times in persons who had been in the habit of working among lead, and Avho expired in a state of universal convulsion. The proximate cause of cerebral induration is unquestion- ably a deposition of lymph into the connecting cellular tis- sue, by Avhich the intermolecular intervals are filled up, and the fibres of the brain firmly cemented together. That this is the case, is not only analogically inferrible, but may be readily proved by examination with the microscope. A por- tion of brain thus affected possesses little or no moisture, re- coils with elasticity Avhen stretched, and tears with a rough and slightly granulated surface. The natural vascularity is usually very much diminished, probably from an obliteration of some of the capillary vessels ; and hence the ordinary color is yelloAvish Avhite, milky, or grayish, —seldom reddish, broAvn, or claret, as Ave find it to be in softening of the cere- bral tissue. Chronic cerebritis, after having existed for some time, may suddenly assume an acute character, and thence pass into suppuration. A shade of green usually announces this event; and, as the process advances, the part gradually acquires a yelloAV tinge, and a soft, pulpy consistence. The pus is rare- ly confined in a distinct cavity ; on the contrary, it is usually 456 BRAIN. [CHAP. XL diffused through the softened mass, oozing out of it, when a section is made, in the form of small globules. The progress of chronic cerebritis is generally very tardy, especially when it is limited in extent ; and I am not aAvare that any symptoms have yet been pointed out as diagnostic of its presence. From the several forms of inflammation, abscess, and soft- ening which have noAV been described, the transition to ul- ceration is at once easy and natural. This state of the brain, although of very infrequent occurrence, has been noticed by different observers, among whom it will suffice to mention Morgagni, Portal, HoAvship, Anderson, Scoutetten, Powell, and Andral. It has been found, hitherto, chiefly on the stri- ated bodies, the optic couches, and on the convoluted surface of the cerebrum, in the latter of which situations it is by far most commonly met Avith. The ulcers, Avhich seldom penetrate beyond the gray sub- stance, and which affect various forms, have generally rough, indented edges, with an irregular surface, covered, for the most part, with reddened lymph, in some cases with pus, and occasionally even with blood. Instances occur in Avhich they are hard and dry ; and sometimes, though rarely, they com- municate together by fistulous tracks, in the same manner as ulcers occasionally do in other parts of the body. In their dimensions they vary from a few lines to several inches, the largest being almost always seated on the external surface of the brain. In a man, twenty-four years of age, Avho died with all the symptoms of cerebral irritation, complicated with enteritis, Scoutetten found an ulcer, of a pale citron color, on the anterior lobe of one of the hemispheres, thirteen lines long, and seven broad, with a hard, dry surface, and edges singularly indented. The subjacent cerebral matter Avas perfectly sound,, as was all the rest of the brain ; but the arachnoid tunic was throughout deeply injected, and the part of it corresponding to the erosion destroyed. In a case re- corded by Dr. Anderson, an English physician, the ulcer Avas two inches and a half long, one and a half broad, and nearly one in depth. It was situated on the upper part of the right hemisphere, and contained several thin, broAvnish lamella?, filled Avith soft sabulous concretions, so brittle as to break upon the slightest touch. The cerebral tissue immediately contiguous to these ulcers, usually exhibits signs of inflammation, being of an unnatu- SECT. III.] APOPLEXY. 457 rally red color, and of varying degrees of consistence. The pia mater and arachnoid are also more or less affected, — a cir- cumstance from which some pathologists have been led to infer that these ulcers rather appertain to them than to the cerebral substance. This, perhaps, with a few exceptions, is true. Occasionally, the ulcer communicates with deep-seated abscesses. Ulceration of the brain is indicated by headache, partial convulsions, hemiplegy, loss of memory, hebetude, coma, and progressive debility, complicated, not unfrequently, with gastro-enteric irritation. There are few diseases, a knowledge of which is of more interest to the pathologist, or of greater importance to the practical physician, than that of cerebral apoplexy. Occurring at all periods of life, as well as in all parts of the encephalon, it frequently gives rise to the most serious lesions, and de- mands measures of the most prompt and energetic character. Hence, as might have been anticipated, the lesion under consideration has ah\rays been an 6bject of the deepest anxiety with the practitioner, and has elicited from time to time the researches of some of the ablest men of the medical profession. It is only within the last twelve or fifteen years, however, that any real and substantial light has been thrown upon its anatomical characters, its causes, and the nature of its symptoms. The term apoplexy is of Greek derivation, and literally signifies a stroke or bloAV. The lesion Avhich it serves to designate, and which invariably depends upon sanguineous effusion, exhibits a remarkable variety as to its seat and extent. In many cases, the blood is poured into the substance of the brain; in some, upon the external surface ; and in some, again, into the ventricles. Of these three forms, the last is by far the least frequent; next to this is the miningeal, or that in which the fluid is extravasated upon the surface of the brain; and the most common of all, is Avhere it is diffused through the cerebral tissue. It has also been found that certain parts of the encephalic mass are much more liable to hemorrhage than others. Of three hundred and ninety-two cases of this disease, collected by Andral from the writings of different pathologists, two hundred and two affected the inte- rior of the cerebral hemispheres on a level with the floor of the lateral ventricles; in sixty-one, it Avas seated in the striated bodies, and in thirty-five, in the optic couches. The cere- vol. i. 58 458 BRAIN. [chap. XI. bellum is rarely affected, and the same is true in regard to the rest of the cerebrum. Of the reason of this greater liability of some portions of the encephalic mass to sanguine- ous effusions than others, Ave are still in profound ignorance. That the difference depends, hoAvever, upon some difference of vascularity or upon some difference in the atomic constituents of the cerebral texture, it is both legitimate and philosophical to infer; yet that such is really the case, it Avould be highly extravagant, in the present state of our knowledge, to assert. Further observations are alone competent to determine the truth or fallacy of the supposition. In regard to the extent of these extravasations, the greatest possible variety obtains. Often the quantity is very trifling, not exceeding a feAV drops, or the volume of an ordinary pea; sometimes, hoAvever, the effusion is quite copious. In one instance, in a female fifty-six years of age, I found it amount- ing to nearly eight ounces ; and still more remarkable exam- ples are recorded by authors. The number of extravasations is also liable to much variation. Very frequently, there is only a solitary one, Avhilst at other times there are as many as ten or a dozen. When numerous, the sanguineous depots usually* exhibit different appearances, as if they had occurred at different periods. The appearance of the extravasated blood varies, as has just been intimated, according to the length of time which elapses between the attack and the death of the patient. When the apoplexy proves suddenly fatal, the fluid is dark colored, almost fluid, or in soft semi-liquid masses. If the individual survive for a longer period, the clot acquires a greater degree of consistence, and is of a pale red, grayish, or yelloAvish tint. At a still more advanced stage, it becomes hard, dense, and fibrinous, and is either organized, partially or entirely absorbed, or converted into a loose, drab-colored cellular substance, presenting, when cut, a peculiar appear- ance, not unlike that of a honey-comb. These changes usually begin Avithin the first fortnight after the attack, and are completed at the expiration of several months, the length of time being ahvays greater in proportion to the size of the clot. Riobe found blood in an apoplectic cavity after tAventy months, and Serres at the end of several years. The substance of the brain around the extravasated blood often presents important lesions, consisting chiefly in a change of color and consistence. Very frequently, it is softened, SECT. III.] APOPLEXY. 459 lacerated, and infiltrated with serosity, with blood, or even with puriform matter, or perhaps all these fluids are found in intimate combination. The color, in such cases, is either natural, reddish, yellowish, or greenish, according to the degree of capillary injection, or the amount of inflammatory irritation. In some instances, Ave find the apoplectic cavity intersected with shreds of cerebral substance, Avhich are so incorporated with the extravasated fluid as to be no longer distinguishable from it. In chronic cases, the surrounding parts are more commonly indurated and brittle ; but this occurrence is by no means constant, as every one can testify, who is in the habit of making post mortem examinations. Often the effused blood is surrounded by a distinct cyst, formed by a deposition of lymph, from the fourth of a line to the eighth of an inch in thickness. At first, the sac is soft, the substance of Avhich it is composed resembling very much that which is poured upon the edges of an inflamed Avound ; but by degrees it acquires greater consistence, and is finally completely organized, its parietes being abundantly supplied Avith vessels, which not unfrequently extend even into the enclosed clot itself. Its external surface is generally rough and flocculent, and the cerebral tissue immediately around it is variously altered, being sometimes softened, sometimes infiltrated with pus, sometimes indurated. In time, the sac becomes both an absorbing and a secreting tex- ture, as is evinced by the fact, that its interior is often filled with substances which are quite different from those that were deposited in the first instance ; and also by the circum- stance, that it is sometimes completely cicatrized, its Avails being brought so closely together as to leave merely a hard, fibrous scar. The number of these apoplectic cysts usually corresponds with the number of sanguineous effusions Avhich have at differ- ent times taken place ; and hence several of them are occasion- ally seen in different parts of the same brain. In examining, not long since, an old man Avho died of softening of the brain, produced by the irritation of a large clot of blood, I found as many as a dozen of such sacs scattered through various portions of the cerebral hemispheres, the biggest of which scarcely equaled a hazelnut: they Avere of a yellowish color, of the consistence of cellular tissue, and each marked off into several little cavities, filled Avith a thin, turbid serosity. All these facts are extremely interesting, as showing how 460 BRAIN. [CHAP. XI. much may be effected by the reparative poAvers of the sys- tem. No sooner has the effusion taken place, than nature sets up her Avork of reparation, and in this she is often so successful that in the course of a short time the clot is either absorbed, encysted, or so altered in its physical and vital properties, as to be no longer viewed by the organ in the light of a foreign body. There are several circumstances which favor the absorption of the coagulum, but none so poAverfully as a healthy condition of the whole cerebral cir- culation. This fact, as the reflecting reader will perceive, is one of great practical moment, as it loudly inculcates the importance of paying attention to the head, long after the apoplectic seizure has taken place. Concerning the sources of these sanguineous effusions, little need be said in this place. From the researches of Dr. Serres, a recent French Avriter, it appears that the blood may, in some instances, proceed from the minute A^essels of the brain without rupture, constituting that variety of the disease to which some pathologists have applied the term miningeal apoplexy. The fluid, in such cases, escapes from the pia mater into the intergyral hollows, or into the ventricular chambers, or, finally, into the substance of the brain, which itself remains sound. When blood is found in the cerebral cavities, it may be concluded that it has proceeded from the source just mentioned, or from rupture of the vessels of the choroid, or from a communication with an apoplectic cavity in one of the hemispheres. The hemorrhage, however, most usually results from rupture of the vessels, caused by a diseased condition of their tunics, and a consequent inability to Avithstand the shock of the circulating fluids. In several instances I have satisfac- torily traced the effusion to this source. Occasionally, the lesion is associated with aneurismal tumors,* laceration of the cerebral sinuses, or ossification of the meninges. In infants it is sometimes induced by the pressure which is exerted upon the head during parturition. The blood, in such cases, is usually poured upon the surface of the brain and spinal cord, in the form of a layer, of variable thickness and extent. Apoplexy has been observed at all periods of life. The late Dr. Billard, of Paris, has recorded an instance which * See the interesting case of aneurism of the basilar artery, by Dr. Serres, in " Archives de Medicine," vol. x. p. 419. SECT. III.] APOPLEXY. 461 took place in an infant soon after birth ; and Dr. Serres relates another which occurred in a child of three months. Stokes, Guersent, and Andral, have also met Avith cases at a very tender age. Nevertheless, the lesion is much more common in the old than in the young. Dr. Rochoux,* in an able essay on this disease, has shown that the most obnoxious period decidedly is between the sixtieth and seventieth years. In sixty-nine cases noticed by this distinguished pathologist, tAvo occurred between the tAventieth and thirtieth years ; ten between the thirtieth and fortieth; seven between the fortieth and fiftieth; thirteen between the fiftieth and sixtieth; twenty-four between the sixtieth and seventieth; twelve between the seventieth and eightieth; and one be- tween the eightieth and ninetieth. Similar observations have been made by Lerminier, Serres, and other authors. But this is not the only cause Avhich operates in the pro- duction of apoplexy in old subjects. The nervous pulp, in advanced life, frequently undergoes a remarkable degree of softening; and this lesion seldom exists very long, there is reason to believe, without being followed by sanguineous effusions. These depots were formerly regarded merely as a secondary lesion ; but Professor Lallemand, of Paris, has clearly shown that, so far from being the case, the softening general- ly precedes the hemorrhage, and is one of the principal causes of its occurrence. The form of the body, also, appears to give a predisposi- tion to the disease, as a large head, short neck, broad shoulders, and corpulency of habit; though this is probably much less frequent than is generally imagined. In the cases analyzed by Rochoux, only ten were fat and plethoric persons, whilst the rest were either spare and thin, or of the ordinary make of frame. Apoplexy is of more frequent occurrence in men than in women, — probably from the former being more ad- dicted to all kinds of excesses, both bodily and mental, than the latter. Of the greater prevalence of this disease in the male than in the female sex, the statistical tables of M. Falret furnish con- clusive evidence. Of two thousand two hundred and ninety- seven cases of apoplexy Avhich occurred amongst the inmates of the Lunatic Asylum near Paris, from 1794 to 1823, in- cluding a period of twenty-nine years, sixteen hundred and * Recherches sur l'Apoplexie, p. 418. Paris, 1833. 462 BRAIN. [CHAP. XI. seventy belonged to the former, and six hundred and twenty- seven to the latter, or in the proportion nearly of three to one. Occasionally there Avould seem to be a hereditary proclivi- ty to this disease, nearly as much so as in tubercular phthisis. Examples of this kind are related by Portal, Frank, and Cheyne, and must be quite familiar to every observant practitioner. It has been supposed by some, that cerebral hemorrhage is more common at certain seasons of the year than at others ; but this opinion appears to be directly con- tradicted by the observations of Rochoux.* Of the sixty- nine cases of this lesion observed by this able Avriter, sixteen occurred in the spring, nineteen in the summer, eighteen in the autumn, and sixteen in the winter. The symptoms of cerebral apoplexy being minutely de- scribed in our practical treatises, I deem it unnecessary to dwell upon them here. I will only further remark, therefore, in concluding this subject, that one of the most interesting and important circumstances connected with encephalic effusions, whether of blood, of water, or of matter, is, that the paralysis Avhich so often attends them occurs nearly al- ways on the side of the body which is opposite to that on which the extravasation has its seat. So common is this phenomenon that, in the language of an able pathologist,! it may be considered as a law, the most general, perhaps, of any in medicine. Thus, when there is a clot of blood in the right hemisphere, there will be palsy of the left side ; and, conversely, when there is effusion on the left side, there will be loss of motion on the right. The reason of this must be obvious to every one who has a knoAvledge of the decussa- tion of the fibres of the medulla oblongata; for it need scarcely be observed that it is upon this that it depends. The occurrence, however, is by no means invariable, — an anomaly for which it is difficult to account. In addition to the several forms of cerebral disease which have now been passed in review, and Avhich may almost all be considered, in some way or other, as the result of inflam- matory irritation, there are various morbid groAvths to which it will be necessary, in the next place, to turn our attention. Amongst these productions the most important, in a patho- logical point of view, are tubercles, melanosis, encephaloid, * Op. cit. p. 429. t Stokes, on Apoplexy. American Journal of Med. Science, vol. xvii. p. 188. SECT. III.] TUBERCLES. 463 cartilaginous transformations, calcareous depositions, serous cysts, hydatids, adipous and adenoid tumors. To each of these subjects, a feAV remarks will be appropriated; premising, however, that, as the symptoms Avhich they occasion are often extremely obscure, and never, perhaps, pathognomonic, nothing Avhatever will be said concerning them. Tubercles of the brain are found chiefly in childhood, being seldom observed in very young infants, and still more rarely in adults. The disease, there is reason to believe, is of very infrequent occurrence in the United States; for, extensively as I have been engaged in making post-mortem examinations, never have I seen it, except in one solitary instance. When present, it is commonly associated Avith a scrofulous habit of the constitution, and hence occurs most frequently in conjunc- tion with tubercles of the other organs, especially of the lungs, spleen, and mesenteric ganglions. The localities of the brain in which tubercles are most commonly found are, the cerebral hemispheres, cerebellum, great commissure, medulla oblongata, cerebral and cerebellic crura, the optic thalami, and striated bodies, — the frequency of their occurrence being in the order here enumerated.* They may occupy, indifferently, either the cortical or fibrous sub- stance ; and may occur either in groups, or, as is more com- monly the case, in disseminated masses. The number of these bodies seldom exceeds half a dozen ; nevertheless, cases occasionally occur in which we find as many as fifty, seventy-five, or even a hundred. In size, they vary from that of a pea to that of a ripe walnut, their magni- tude being generally in an inverse ratio to their number. Not unfrequently they are so large as to occupy the greater part of one of the lobes of the cerebellum, or of one of the hemi- spheres of the cerebrum. In form, they closely resemble tubercles in other organs and textures of the body. In some instances, especially when they are clustered together — which, hoAvever, is very rare— they are uneven, nodulated, and separated into lobes, connected by pretty dense cellular tissue. Their color is a pale yellow, white or bluish, and their consistence like soft cheese, though occasionally much firmer. Apparently void of vessels, these bodies exhibit no trace Avhatever of being organized ; yet that they are so, cannot, I think, be Avell doubted. In the generality of cases, if not * Andral, Pathological Anatomy, vol. ii. p. 185. 464 BRAIN. [CHAP. XI. always, they are surrounded by a distinct cyst, often remark- ably thin, but which now and then is of great thickness, and of a fibrous, cartilaginous, or even bony texture. Of the manner of their formation little is known ; but that they are here, as elsewhere, the result of a peculiar inflammatory pro- cess, is more than probable. After these tubercles have existed for some time, varying according to circumstances, they assume an opaque, dusky appearance, and are finally converted into a soft cheesy mat- ter, precisely analogous to that of tubercles in other situations. Numerous abscesses are thus occasionally formed, which may be readily discriminated from such as are of a simple in- flammatory origin, by the nature of their contents. The cerebral tissue around these tubercles is variously affected. During the early periods of their formation, it is not unfrequently quite natural; but, as they proceed in their developement, inflammation is often excited, which generally leads to induration, softening, or purulent infiltration. Melanosis of the brain has been noticed by different au- thors, but as yet I have not been so fortunate as to meet with an instance of it. All writers agree in the opinion that it is among the most rare productions to which this organ is liable. Both Hooper and Carswell have beautifully deline- ated this heterologous formation of the brain. Though it occasionally occurs in small dots and narrow streaks, the most common form under which it appears, is that of spherical masses, of a jet-black, brownish, or liver color, varying in size, from a mustard-seed to that of a hen's egg. They are distinctly circumscribed, but apparently without any cyst, and closely surrounded by healthy brain, from which they can be easily lifted Avith the forceps. Vessels may frequently be traced into their interior; and, Avhen they are seated on the convoluted or figurate surface of the organ, it is not un- usual to find them intimately adhering to the pia mater. Their softness is often remarkable, the black coloring matter which they contain being nearly as fluid as ink. If these tumors be divided Avith a sharp knife, and washed with water, the coloring matter disappears, and nothing but a soft, shaggy substance remains, probably of a cellulo-fibrous nature. This, no doubt, is the nidus in which the melanotic matter is originally deposited. Encephaloid is occasionally met Avith in the brain, though much less frequently than in other parts of the body. It SECT. III.] CARTILAGE-- CALCAREOUS DEPOSITS. 465 occurs chiefly in young subjects, before the age of twenty, in the form of soft, spongy, compressible tumors, enveloped by a distinct cyst. Their surface is frequently lobulated, and their interior closely resembles the gray substance of the brain, Avith a tinge of red. When cut Avith a knife, the sec- tion is smooth, and the instrument is covered with a soft, unctuous, cream-like matter. The capsule itself, varying in thickness from one to several lines, is often of a deep reddish color, liberally furnished Avith vessels, externally flocculent, and closely adherent to the surrounding parts. Solid masses of extravasated blood are occasionally intermixed Avith these tumors; and in many cases the cerebral tissue immediately around them is in a state of softening. Masses of cartilage have sometimes been found in the brain ; but they have never come under my own observation, and are very uncommon. Occasionally they attain a very considerable volume. In a case given by Dr. Monro, the tumor Avas as large as the two fists. They are generally of an irregularly rounded shape, Avith a rough, lobulated surface ; of a dense, gristly hardness; and of an opaque, bluish color; presenting, when cut, a radiating, fibrous arrangement, not unlike an unripe pear. When old, these cartilaginous tumors not unfrequently con- tain small cavities, filled with curdy, gelatinous, or sanguino- lent matter. Under no circumstances, so far as I can learn, are they enveloped by any cyst. Equally infrequent are those calcareous deposits which have been described by authors as being sometimes found in the brain. They may occur at all periods of life, but are much more common in the old than in the young; and con- sumptive subjects are said to be more prone to them than any other class of people. The form in which they mostly appear is that of scattered granules, about the size and shape of saw-dust ; often, however, they are seen in irregular nod- ules, varying in volume from a small pea to a large plum. Composed chiefly of phosphate of lime, in combination with a minute proportion of animal substance, these concretions are commonly of the consistence of dry mortar, and readily yield to the pressure of the finger. Cases have been observed in which they have been formed of alternate layers of chalky matter and solid albumen. Their color is ordinarily some- what reddish ; their surface rough, lobulated, or spicular ; and, in most instances, they are surrounded and connected to the vol. i. 59 466 BRAIN. [CHAP. XL contiguous cerebral substance, by a delicate, vascular mem- brane. The number of these granular concretions is sometimes immense. Dr. Hooper tells us that he has seen the greater part of the fibrous structure of one of the cerebral hemispheres converted into a soft, brownish mass, literally filled Avith small gritty particles, none of Avhich Avere visible to the naked eye, and Avhich felt betAveen the fingers as if sand were mixed Avith it. Some of the small vessels of the brain are occa- sionally ossified, so as to present the appearance of thin, Avhite bristles. Of this I have seen several examples, principally in very aged subjects. In one, an old man of upwards of sixty, they were extremely numerous, and occupied the greater part of the posterior lobe of the left hemisphere. Nowhere are these concretions so common as in the pineal gland. In this situation, they are almost always agglomerated into an irregular-shaped mass, varying in magnitude from a pin-head to an apple-seed, the largest being usually in the centre. They are of a yelloAV citron color, hard, rough, and gritty, and, what is remarkable, are never found until about the age of seven or eight years. After this period, there are few individuals in whose brains they do not occur. Their presence do not seem to occasion any particular inconvenience ; yet Descartes and some of his disciples thought that they might often be a cause of mental derangement. Small cysts, containing a transparent yellowish fluid, of the character and consistence of serum, are sometimes met with in different parts of the brain, especially at its base, on the floor of the lateral ventricles, and on the convoluted surface of the hemispheres. Of this variety of morbid groAvth, I have never seen but one example, which was in a child ten months of age, that died of hydrocephalus. The tumor, Avhich was situated at the posterior and inner part of the right ventricle, which itself was enormously enlarged, was about the size and shape of a hen's egg, with perfectly smooth, polished, and transparent coats, not thicker than the healthy omentum. The fluid which it contained was thin and colorless, like the clearest spring-water. But such are not ahvays the appearance of these cysts. Often they are quite opaque, speckled with grayish dots, and almost of the thickness and density of the pericardium. Their contents, in such cases, are of a milky Avhite, gelatinous, and readily coagulate by heat, which is not the case Avhen their struc- SECT. III.] ACEPHALOCYST--CYSTICERCUS. 467 ture is very delicate. Several such tumors are occasionally found in the same brain, either in different parts or in close proximity with each other. Hooper has delineated a case in Avhich three vesicles, each nearly as large as an orange, Avere embedded close together in the right hemisphere, occupy- ing almost the whole of the anterior and middle lobes. That these structures are organized, is sufficiently shoAvn by the fact that numerous vessels, of the most delicate appearance, are frequently seen ramifying through their Avails. There is another species of vesicular tumor which is occa- sionally seen in the substance of the brain, but the occur- rence of Avhich is much less frequent than the one I have just described. It is the acephalocyst, or headless hydatid. This animal, Avhich has a life of its OAvn, is enclosed in a distinct membranous sac, and seldom acquires any great size. Dr. Rostan mentions a case, hoAvever, in Avhich the cyst Avas five inches in length ; and a still more remarkable one is re- ferred to by Dr. Abercombie, in which it Avas of the dimen- sions nearly of a tin cup. It occurred in an old man, occu- pied the left ventricle, and Avas perfectly distinct from the choroid plexus. The fluid of this species of tumor is gener- ally remarkably thin and pellucid. Although it is stated by numerous authors that they have seen examples of this head- less hydatid, yet its occurrence is acknowledged to be ex- tremely rare ; and Dr. Hooper informs us that, although he has inspected several thousand subjects, he has never met with it in the brain. The bladder-tailed hydatid, the cysticercus cellulosus of naturalists, has never been found in the human brain; and, though cases of it are mentioned by authors, it is doubtful whether they are authentic. The adipous tumor is rarely found in the brain. It varies in size from a small hickory-nut to a hen's egg ; is rough and lobulated on the surface ; of the color of fat or adipocire, and of the consistence of spermaceti, tallow, or soft wax. A fine delicate, vascular cyst usually envelopes it; and, when di- vided, it is found to be composed of very minute and closely aggregated lobules. Occasionally it is made up of concentric layers, united by dense cellular tissue ; and Otto saAv a tumor of this kind which contained hair. Our knowledge concerning the precise nature of this tumor is still somewhat unsatisfactory. Chemical analysis, however, has shown that it consists principally of fatty matter, with 4 Iks BRAIN. [CHAP. XI. a minute amount of cholesterine. This latter ingredient is so much the more remarkable, as it has been ascertained, re- cently, that the human brain ahvays contains a small quan- tity of it in the normal state. The adenoid tumor does not seem to have been much no- ticed by pathologists, either ancient or modern, and hence we may justly adopt the conclusion that it is of rare occurrence. Most generally of the size of a small nut. and of an oblong shape, it is of a pale flesh color, hard, firm, but someAvhat spongy in its texture, and enveloped by an appropriate vascu- lar covering, having apparently very little connection Avith the cerebral substance. It may occur in any part of the brain, and in some instances is scattered in considerable num- bers through different portions of it. In a case mentioned by Mr. Earle, of London, not less than seven such tumors were found in the substance of the right hemisphere of a child under three years of age ; the largest about the size of an orange, the smallest of a chestnut. They were of a very firm texture, and of a dusky red color, like an absorbent gland, interspersed Avith streaks of Avhite. The origin of adenoid tumors is still involved in obscurity. Taking into consideration, however, their fibrous texture, and flesh-colored aspect, it appears to be not improbable that, in the generality of cases at least, they are the result of apo- plectic effusions, the blood being merely deprived of some of its red particles, and the remainder modified in such a way as to assume the characters which appertain to this sort of growth. The supposition certainly derives great support from the fact that the subjects of these tumors are for the most part persons who have labored, at one time or other, under symptoms of palsy, apoplexy, epilepsy, or mental de- rangement. The brain is sometimes hypertrophied. In this state, which Avas already knoAvn to Morgagni, and which has been more recently described by some of the French anatomists, espe- cially by Dr. Dance and Dr. Scoutetten, the convolutions of the brain are singularly compressed and flattened, and the intervals between them almost obliterated, — the investing membranes being at the same time partially stretched, and appearing as if they Avere too tight for the enclosed mass. The ventricles are very nearly effaced, and the various sur- faces of the organ deprived of their ordinary moisture. The cerebral substance is unusually firm, almost destitute of blood, SECT. III.] ATROPHY. 469 and appears remarkable dry when cut.* The hypertrophy commonly involves both hemispheres; occasionally, hoAvever, it is confined to particular parts ; and in some instances the increased growth is so great as to produce an evident enlarge- ment of the skull. No example of this affection has yet been met with, so far as I know, in the cerebellum ; Avhich, considering the functions of that portion of the great nervous centre, is rather extraordinary. It is chiefly witnessed in children and very young persons, particularly in such as are subject to frequent attacks of epilepsy : but even in them it is extremely rare. Dr. Copland states that he has met Avith it only three times in several thousand cases.f The opposite of this state, atrophy, is sometimes Avitnessed. In idiots, in cases of hydrocephalus, and in aged persons, the brain occasionally undergoes a remarkable diminution in all its parts, both gray and Avhite ; and the same circumstance is not unfrequently observed in young people who have suffered from long-continued wasting disorders. The marks by which atrophy may be recognized are, a flaccid and shrunken state of the convolutions, interstitial cellular infiltration, peculiar stringiness of the cerebral pulp, and dilatation of the blood- vessels, either empty or filled. Conjoined with these appear- ances are usually thickening of the cranial bones, and dis- tention of the ventricles. Like hypertrophy, the affection in question may be general or partial. The latter variety is most commonly seen in the striated bodies and optic couches. In place of the natural rotundity, the surface of these structures is remarkably flat- tened, contracted in its dimensions, or eAren scooped out, as it were ; and, on cutting into them, their substance appears loose and cellulated. Very frequent instances of partial atrophy are Avitnessed on the convolutions, which are either smaller and less numerous than usual, or almost wholly absent. In such cases there is often very little gray matter. Atrophy of the cerebellum is by no means uncommon, and sometimes amounts to almost entire absence of this portion of the ence- phalic mass. * See Dr. Dance's account of this affection, in the fifth volume of the " Reper- toire d'Anatomie," &c. Paris, 1828. t Dictionary of Practical Medicine, p. 218. 470 SPINAL CORD. [CHAP. XI. SECTION IV. Of the Spinal Cord. Having already dwelled at considerable length upon the anatomical characters and diagnostic phenomena of the vari- ous lesions of the encephalon, it only remains to make a few remarks concerning those of the spinal cord; and these will be so much the more concise, inasmuch as the foregoing observations embrace nearly all that might otherwise be necessary to be said under the present head. Suppuration of the spinal cord is attended by nearly the same symptoms and anatomical characters as that of the brain, making proper allowance, of course, for the difference of function of these two organs. The following case, Avhich I quote from the admirable work of Dr. Abercrombie, conveys an accurate idea of the phenomena which this disease exhibits before and after death. A young soldier, shortly after recov- ering from an attack of petechial fever, was affected with pain in the back, difficulty of moving the inferior extremities, retention of urine, and involuntary discharge of faeces, with general debility, and emaciation. This state of things was succeeded, in a few months, by perfect paralysis, first of the lower, and soon after the upper limbs. He then lost his speech, became completely immovable, and expired suddenly, a fortnight after, in the full possession of his intellectual faculties. On inspection, a large quantity of serous fluid flowed from the spinal canal, and the cord itself, at the part corresponding to the inferior portion of the dorsal region, was suppurated, and converted into a soft, pulpy mass. Above this point, the cord preserved its natural figure, but was much reduced in consistence. The investing membranes, and the periosteum lining the vertebral canal, were destroyed along the principal seat of the disease; but the bones themselves, and their ligaments, were sound. In another case, occurring in a woman fifty-six years of age, and narrated by Professor Velpeau, of Paris, the cervical portion of the spinal cord presented a cavity three inches in length by three lines in diameter, which was filled with soft, purulent matter, mixed with gray substance. The mem- branes were considerably indurated, and the walls of the SECT. IV.] SOFTENING--INDURATION--HYPERTROPHY. 147 abscess hard, firm, and about the eighth of an inch in'thick- ness. The patient, in this case, Avas affected Avith sudden loss of power of the limbs of the left side, Avhich soon amounted to perfect palsy, Avithout deprivation of feeling. The speech Avas embarrassed, the voice very feeble, the respi- ration quick and humid, and the left arm oedematous. In four days, she could make herself no longer understood ; the strength rapidly failed, stertorous breathing supervened, and in a week she expired. Abscesses of the spinal cord are extremely rare, and, so far as I am aAvare, besides the abo\^e case, only two others are on record. One of these is by Dr. Carswell, of London, and the other by Dr. Hart, of Dublin. Both Andral and Aber- crombie state that they have never met with them. Softening of the spinal cord is not uncommon, and, as in the brain, may be either partial or general. In some in- stances, it is limited entirely to the internal gray substance; and cases occur in which the disorganized texture exhales an odor similar to that of sulphureted hydrogen. Induration of the spinal cord, although it chiefly affects the white substance, is yet sometimes entirely confined to the gray. The affection occasionally embraces the whole cord, from one extremity to the other. In such cases, the induration may be carried to such a degree as to enable the structure in question, after being divested of its tunics, to sustain a considerable weight. Of this, a remarkable case has been given by Dr. Billard, of Paris, in an infant that died soon after birth from convulsions. On inspection, the Avhole cord Avas found to be indurated, and so strong as to be able to support nearly a pound weight. The meninges were lined Avith a thick, adventitious membrane. Tubercles, sanguineous and serous effusions, and various kinds of tumors, are sometimes met Avith in the spinal cord, or in its membranes; but these it is unnecessary to describe, inasmuch as they are of the same nature precisely as in the brain. Ulceration of the spinal cord has not, I believe, ever been discovered. Hypertrophy of the spinal cord is sufficiently uncommon, much more so, indeed, than in the brain. The affection is characterized by the enlargement and extreme firmness of the cord, with diminution of the natural vascularity, and has hitherto been noticed principally in children. Occurring gen- erally in isolated portions, the hypertrophy is sometimes 472 SPINAL CORD. [CHAP. XL observed throughout the Avhole extent of the cord, and may attain such a degree as to fill up, completely, the cavity of the vertebral canal. Atrophy of the spinal cord is occasionally observed. Dr. Ollivier, of Paris, ghres an account of tAvo cases of this affec- tion, in one of Avhich the cord Avas reduced, throughout its Avhole extent, to about two thirds of the natural bulk, in the other to one half. In most instances, hoAvever, the atrophy is partial, that is, limited to particular portions. The spinal cord is sometimes absent as a congenital defect; and in- stances are occasionally observed, in Avhich it is hollow, at the expense, evidently, of the central gray substance. It only remains that we should add to this rapid sketch a few remarks on the subject of hydro-rachitis. This is a congenital deformity, consisting in a cleft condition of the vertebral column with a protrusion of the lining membranes of the spinal cord. The lesion, which is evidently caused by an arrest of ossification, and a consequent deficiency of the vertebral rings, is generally situated in the lumbar region, but occasionally it affects the dorsal or cervical portions, or even those of the sacrum. It is frequently associated Avith hydrocephalus, and is precisely analogous to all those malfor- mations Avhich originate from a Avant of union of the two halves of the foetus during utero-gestation, such as hair-lip, cleft-palate, and opening of the linea alba. The protrusion of the spinal envelopes generally takes place during the latter months of foetal life ; occasionally, hoAvever, it is not observed until some weeks or even months after birth. When the tumor first shows itself, it is perhaps not larger than a pea; but, as the disorder progresses, it gradually increases in size, varying in proportion to the deficiency of the vertebra?. Although, in the plurality of cases, the swelling does not exceed an orange, yet occasionally it reaches the magnitude of the fist, or even that of the patient's head. The skin is commonly very smooth, delicate and thin ; sometimes, however, it retains its normal thickness, or it becomes red, rugose, and horny: in a feAV rare cases, it has been known to be entirely wanting. The tumor is either soft, flabby, and fluctuating, or it is full, hard, and shining: when pressed upon, it gradually diminishes in volume, or even quite disappears ; but no sooner is the force removed than the fluid reaccumulates, and the part regains its pre- vious bulk. In its form, the swelling is globular, ovoidal, or SECT. IV.] SPINA BIFIDA. 473 pearlike, with a short, narroAV neck, by which it reposes upon the cleft bone. The fluid of a tumor of this kind is generally of a thin, limpid character, slightly saline in its taste, and almost unco- agulable. The best analysis that has been furnished of it is by Berzelius, according to which it consists of the following ingredients: Water,........97.8 Muriate of soda,......1.0 Albumen,........0.5 Mucus,........0.5 Gelatine,........0.2 100.0 In some instances, the fluid is of the color and consistence of synovia, or it contains flakes of lymph and particles of pus. These appearances are seldom present until after the tumor has burst, and discharged it original contents. In regard to its precise seat, it may be mentioned that it is most frequently found in the arachnoid sac, but occasionally it has been known to exist between it and the pia mater, between it and the dura mater, and sometimes, though rarely, in all these situations at the same time. The tumor usually con- sists of one, but in a feAV rare instances of two or more distinct cysts, as in the multilocular variety of ovarian dropsy. In such a case it would be difficult, if not impossible, to draw off all the fluid by a surgical operation. The contents of the vertebral canal, in the immediate neighborhood of the lesion, are variously affected. The portion of the spinal cord surrounded by the tumor is often very much softened or converted into a thin, diffluent sub- stance : sometimes it has been found abnormally hard; some- times it is not so large as natural; and sometimes it deviates remarkably from its accustomed route, being forced through the opening in the vertebrae, and partially contained in the swelling. The nerves are always more or less displaced, and, in some instances, they are dragged out of the spinal canal, and distributed over the internal surface of the cyst in a beautiful plexiform manner, ingeniously compared by Burgius to the fleshy columns of the heart. The arachnoid mem- brane and dura mater are usually not much altered in the early stage of the affection; but, as the fluid accumulates, they become excessively attenuated, and, together with the vol. 1. 60 474 NERVES AND THEIR GANGLIA. [CHAP. XL superimposed skin, finally give way in one or more places. When this happens, the parietes of the tumor shrink, and become greatly thickened, by the deposition of plastic lymph upon their interior. A thin, turbid fluid, mixed with pus, continues to exude from the part, and the patient is rapidly carried off by constitutional irritation. The preternatural aperture is ordinarily limited to the posterior surface of the bone, but sometimes it extends through its whole substance, so that the finger may be readily passed into the abdomen, or coils of intestine find their way into the tumor. SECTION V. Of the Nerves and their Ganglia. Considering their connections and functions, the nerves may be divided into two general classes, — the encephalo- spinal and the sympathetic. The former, as their name imports, extend from the encephalon and spinal cord to sen- tient and irritable textures, acting thus as sentients to the parts between which they are situated. The latter form a system by themselves, but freely communicate Avith the other by appropriate filaments: they reach from the cranium to the pelvis, lying along the vertebral column, and are particu- larly distinguished by a chain of ganglia, each of which is thought to be a special centre of the nervous influence. The distribution of their branches is very extensive, as much so, apparently, as that of the encephalo-spinal nerves ; and their chief duty is to preside over the functions of organic life. The form of the nerves is in general cylindrical; but, as they proceed to their termination, they become somewhat flattened, particularly those which lie immediately beneath the skin. The aggregate of their branches, like that of the blood-vessels, is greater than that of the trunks from which they arise; and hence they may be considered as gradually augmenting in size as they extend from their origin towards their points of destination. The encephalo-spinal nerves seem to be all implanted into the fibrous texture of the great central mass; but this is rather apparent than real; for, by a SECT. V.] ENCEPHALO-SPINAL. 475 careful dissection, they can be distinctly traced as far as the granular matter. This connection, which was first noticed by the celebrated French anatomist, Vicq d'Azyr, has been particularly insisted upon by Gall, and is iioav generally ad- mitted by the profession. Each cord arises alike by two roots, one from the anterior, the other from the posterior lateral groove. This remark holds good only of the spinal nerves : the origin of the encephalic nerves is less uniform and simple. In Avhat mode the nerves terminate is a point which has not been ascertained, excepting in the instance of the optic and auditory, each of Avhich expand into a soft, delicate, and transparent pulp, that becomes opaque soon after death. All that is known with any degree of certainty is, that, as they approach their final destination, they assume a peculiarly pulpy aspect, owing, no doubt, to the excessive attenuation of their neurilema. The encephalo-spinal nerves, vieAved in reference to their functions, are divisible into three classes,—the sensific, motor, and respiratory. The first set, Avith the exception of the olfactory, optic, and auditory nerves, all arise from the pos- terior part of the spinal marrow, and are connected each with a spherical ganglion, Avhich is situated within the vertebral canal, and the section of which deprives the parts supplied by their corresponding filaments of sensation. The motor nerves take their origin from the anterior column of the spinal cord, and are distributed to the voluntary muscles. The nerves of the third class are detached from the " respiratory tract," so beautifully delineated by Sir Charles Bell. This term is applied to a rod of white nervous matter which is interposed between the roots of the other nerves, from the annular protuberance as low doAvn as the first dorsal vertebra. The nerves which arise from it have single roots, but they all commence by a series of minute fibrils : they possess the power of associating the muscles upon Avhich they are spent, Avith the general respiratory movements, and their importance is therefore felt at every moment of our existence. They consist of the pathetic and facial nerves, the glosso-pharyngeal, spinal accessory, the phrenic, external thoracic, and the pneumo-gastric, — the latter of which is the great centre of the respiratory system. Although the nerves are distributed in every direction through the body, yet they do not terminate in all the tissues indiscriminately. The parts in which they are most abun- dantly found are the eye, ear, and nose, the external and 476 NERVES AND THEIR GANGLIA. [CHAP. XI. internal teguments, the voluntary and involuntary muscles, the lungs, liver, spleen, and kidney. The blood-vessels, bones, and fibrous textures, are sparingly supplied, particu- larly the tAvo last. The parts in which no nerves have hitherto been discovered are the ligaments and tendons, the cellular substance, the fibro-cartilages, and cartilages, the serous and synovial membranes, the humors of the eye, the epidermis, nails and hair, the lymphatic ganglions, and, lastly, the cerebro-spinal mass, — the source and fountain of all sen- sation. There are three modes by Avhich the nerves are connected Avith each other, namely, by anastomosis, by plexus, and by ganglia. Of these, the first is generally found between branches of the same class of nerves, but occasionally be- tween those of opposite ones. Thus, the intercostal nerves, as they are called, freely anastomose Avith the filaments of the sympathetic ; the branches of the fifth pair, which is a sensific nerve, with those of the seventh, Avhich is a respi- ratory nenre. A plexus (Fig. 44) is only a more multiplied and intricate anastomosis. The most remarkable example of this kind of intercourse is fur- nished by the reciprocal in- terlacement of the axillary nerves. Ganglia (Fig. 45) are small nodules, of a reddish gray color, which consist of an interlace- ment of fine nervous fibrils, held together by soft, cellular substance. In size, they vary in different parts of the body, from that of a pin head to that of a kidney bean; usually „. . they are somewhat flattened, and of an irregularly oval shape. They are of a firm consistence, yet easily com- pressed ; and, Avhen divided, they exhibit someAvhat of a pulpy appearance. Like the corresponding bodies in the b * A nervous ganglion: a, internal structure; b, proper envelope. SECT. V.] STRUCTURE. 477 lymphatic system, they are enveloped in an external covering, Avhich is quite dense, and connected with the dura mater, in the spinal ganglia, but very thin and indistinct in those of the great sympathetic. By boiling, the ganglia first harden, but subsequently they become soft and shreddy: the alkalies only partially dissolve them, and they resist putrifaction for a long while. Their vessels are derived from the neighboring branches, and can be readily filled Avith injecting matter. They are also ren- dered very apparent after inflammation. To this sketch of the ganglia it should be added, that those of the great sym- pathetic— to which the foregoing remarks are intended more particularly to apply — are all embedded in cellular substance, and that each of them may be viewed in the light of a small nervous centre, from which are detached filaments of com- munication to the encephalo-spinal nerves, and of distribution to the neighboring organs, bringing thus the nervous system into one harmonious whole. The chemical composition of the nerves is analogous to that of the encephalo-spinal mass. By immersion in alcohol, they are readily hardened, and a long time elapses before they yield to the influence of putrifaction. They are exten- sible, but unelastic ; void of irritability, but highly sensitive, — the pain Avhich results from their injury being often suffi- cient to induce the most dreadful convulsions. Every nerve is composed of tAvo principal elements, Avhich bear to each other the relations of contained and containing parts, (Fig. 46.) The first is of a soft, pulpy consistence, of white, yellowish color, and is made up of the same mate- rials as the white texture of the brain, with the addition, perhaps, of a minute quantity of granular substance. Like the former, it consists of ex- cessively delicate fibres, which are arranged in close parallel lines, and extend from one extremity of the nerve to the other, (Fig. 47.) Each filament is enclosed by a distinct sheath, Avhich is firmly united to those around it by cellular texture. The number of fibres entering into the formation of any one nerve is not ascertained : some have only a few ; whilst others, as, for example, the sensific portion of the fifth * A portion of nerve invested by its neurilema, and consisting of distinct fila- ments, one of which is drawn out and transfixed by a pin. 478 NERVES AND THEIR GANGLIA. [CHAP. XI. pair of the cranium, have as many as Fl§- 17* sixty or eighty. When relaxed, many of the fibres have a convoluted, zigzag arrangement, Avhich is particularly ob- servable in some of the inferior animals, as the horse, ox, dog, and deer. Wheth- er each filament is a solid cylinder, or a holloAV tube, is not ascertained. Thus constituted, each nerve has its appropriate envelope, as each fibril has its appropriate sheath. The nature of this investment has been a subject of much controversy ; but, Avithout stop- ping to inquire into the various opin- ions that have been advanced by au- thors, I will merely state that it appears to me to be distinctly fibrous in its structure, and consequently analogous to the coverings of the muscles. In its thickness, it varies in different regions of the body ; and, in some of the nerves, as the olfactory and auditory, it is either entirely absent, or so attenuated as to render it impossible to demonstrate it. Externally it is connected to the sur- rounding parts by cellular tissue, whilst from its inner surface are detached nu- merous processes, that form so many small canals for the reception of the pulpy substance previously described. These sheaths can be rendered appa- rent by injecting them Avith quick- silver after their contents have been dissolved in some di- luted alkali. The nerves are liberally supplied Avith blood. The arteries are derived from the neighboring trunks, and, as they approach the neurilema, each subdivides into tAvo branches, one of which pursues a fonvard, the other a retrograde direction. How the ultimate ramifications are spent it is impossible to say, though it is not unlikely, I think, that they all terminate in the sheath of the nervous fibrils, the latter having no par- * Nervous fibres deprived of their covering, and unraveled, showing their component filaments. SECT. V.] NEURITIS. 479 ticular connection Avith them. When the arteries are filled with size, colored Avith vermilion, the nerves exhibit a red florid appearance, and might be supposed to consist almost avholly of a tissue of vessels. The veins are numerous, and pursue, for the most part, a very tortuous course. As in the brain, no absorbents have yet been traced, excepting in the neurilema of a few of the larger trunks. The nerves are liable to acute and chronic inflammation, suppuration, ulceration, gangrene, hypertrophy, atrophy, and different kinds of tumors. When a nerve is cut across, restoration generally takes place in a short time by the adhesive process, the small cicatrice thus formed offering no obstacle to its functions. When a portion is removed, the divided extremities, in the course of tAventy-four hours, become enlarged and vascular, and the surrounding cellular tissue, taking on inflammation, pours out coagulating lymph, Avhich finally encloses and cements them together. After some time, varying according to the thick- ness of the nerve, and the distance between the divided ends, the matter thus effused is organized, assuming a whitish, gristly appearance, and the function of the organ is either partially or wholly reestablished. Sensibility commonly re- turns more quickly than voluntary motion. Mr. Mayo found that the sentient nerves, when thus mutilated, generally be- gan to regain their functions early in the third week, while the motor nerves did not recover any of their powers till after the fourth. It is proper here to observe, that, if the interval betAveen the divided extremities is very great, as from one to tAvo inches, the union is either extremely imperfect, being effected solely by condensed cellular tissue, or, Avhat is more commonly the case, nature entirely fails in her efforts, and the function of the part is thus forever destroyed. In acute neuritis, the nerves are of a bright reddish color, their capillary vessels, which run longitudinally, being united by thousands of transverse twigs, which, in the normal state, always elude our closest scrutiny. When the inflammation is very intense, the affected part generally assumes a dark violet tint, either uniformly diffused, or occurring in small patches, like so many ecchymoses. These changes are always most distinct in the neurilemous coat; but by degrees they extend to the interstitial cellular substance, which at the same time becomes distended with serous, bloody, or puru- lent fluid, the natural tendency of which is to separate the 480 NERVES AND THEIR GANGLIA. [CHAP. XI. filaments of the nerve, and give it a tumid aspect. As the disorder progresses, the affected part loses its peculiar texture, diminishes in strength and consistence, and resembles a cord of inflamed cellular substance rather than a nerve. This disease, which seems to occur much more frequently in the sciatic and facial than in any of the other nerves, is characterized by the most torturing pain, augmented by pres- sure, and accompanied generally by a peculiar numbness of the affected part. The pain often occurs in paroxysms, ob- serving a regular periodicity ; and, after it has existed for some time, it usually becomes less violent, but more constant. It would appear, from the researches of M. Gendrin, that inflammation of a nerve, when artificially induced, always has a tendency to excite inflammation in the organ to Avhich it is distributed. Thus, inflammation of the fifth pair will pro- duce opthalmia; of the eighth pair, gastritis ; but, what is remarkable, not pneumonitis. The reverse of this probably sometimes occurs, the inflammation being propagated from the organs to the nerves. The anatomical characters of chronic neuritis are, increased vascularity and consistence of the affected part, with slight SAvelling and friability. The neurilemous coat is considerably indurated, the interstitial cellular substance is infiltrated Avith serous fluid, and the capillary vessels are often so much loaded as to exhibit a truly varicose aspect. This affection, which is much more common, I am disposed to think, than has been generally imagined by pathologists, is almost always attended with seA^ere pain, and, like the acute form, may be confined either to a small portion of a nerve, or diffused over an ex- tent of several inches. Suppuration of the nerves has been noticed by different writers, though there is reason to believe that it is very rare. The matter, which is commonly of the character of healthy pus, is usually infiltrated into the interfibrillar cellular tissue, in which it appears to be originally developed, the nervous substance itself being little altered. Occasionally the pus lies immediately beneath the neurilemous coat, which it raises in the form of a little abscess. Bloody effusion was found by Martinet in the sciatic nerve of a man who had been affected with excruciating pain in the posterior part of the thigh, aggravated to almost absolute intolerance by the least motion; and Cotunni noticed, long ago, that serous infiltration is often connected with neuralgia. SECT. V.] ULCERATION--GANGRENE --CARCINOMA. 481 Ulceration of the nerves is still more rare than suppura- tion. It never occurs spontaneously after inflammation, but is ahvays dependent upon injury or disease of the adjacent structures. In a case of ulceration of the peroneal nerve, reported by Mr. Swan, of London, there Avas a fungous ulcer of the leg, Avith violent pain of the whole limb, which ren- dered it necessary to amputate. Gangrene of the nerves, like ulceration, is generally com- plicated Avith lesion of the surrounding parts, being seldom, if ever, present as a primary affection. In whatever manner it may be induced, the nerves are of a dark broAvnish color, highly offensive, and converted into soft, pultaceous cords, entirely destitute of their natural characters. The parts im- mediately above and below the seat of the disorganization are of a reddish tint, swelled, and infiltrated with serous fluid, — phenomena indicative of inflammatory irritation. Carcinoma seldom affects the nerves, at least, very few well-authenticated cases of this disease are to be found in the records of pathological anatomy. Marandel states that he has witnessed this in the external saphenous nerve ; Dupuy- tren, in the posterior tibial ; LeA'-eque-Lasource, in the trifa- cial ; Martin, in the median; and I have myself seen it in the optic nerve. The nerves are occasionally found in a state of hypertrophy. In chronic affections of the leg, nothing is more common than to see the subcutaneous nerves thickened and injected. In dissecting, not long ago, the left leg of a man, thirty years old, removed for caries of the tarsal bones, I found the pos- terior tibial nerve, nearly in its whole length, very much in- durated, and at least three times as thick as usual, all its fibres being extremely distinct and well-defined. Similar appearances have been noticed by Gendrin, Martinet, and Swan. The ends of the nerves, after amputation, often be- come very large, and have their sensibility morbidly increased. Occasionally the hypertrophy, although strictly local, affects a considerable number of nerves simultaneously. Of this a remarkable instance is recorded in the London Medical and Physical Journal for 1826. It occurred in a cretin, thirty- three years old, whose body Avas examined by Dr. Schiffner, of Vienna. The inferior maxillary and facial nerves, together with the eighth pair, and almost all the spinal nerves, presented numerous swellings along their trunks and branches, many of which were as large as a full-grown pea. The nerves also, VOL. I. 61 482 NERVES AND THEIR GANGLIA. [CHAP. XI. like the blood-vessels, are large Avhen the Avomb is exhausted during pregnancy, as has been satisfactorily shoAvn by Home and Tiedemann; and the same phenomenon is frequently ob- served in subcutaneous and other tumors. Atrophy of the nerves, a state the reverse of that Avhich I have just described, generally arises from mechanical injury, or the pressure of a tumor ; yet that it occasionally exists as a primary affection seems to be undeniable. Whenever an organ of sense is destroyed, the nerve leading to it wastes, usually by degrees, but sometimes with great rapidity. In such cases, the nerve assumes a peculiar buff-colored appear- ance, and often shrinks to less than one third its normal bulk, its pulpy substance being sometimes totally absorbed, so as to leave behind it nothing but the dense and indurated neuri- lema. Small tumors, the anatomical characters of which seem to be variable, are sometimes developed in the nerves, the com- ponent threads of which they separate from each other like the ribs of a fan. They occur most commonly in the nerves of the upper extremity, especially in the radial and ulnar, and are generally attended with severe pain and numb- ness. The origin of these tumors is still involved in ob- scurity : in some instances, they are evidently connected Avith the nervous substance ; whereas, in others, they arise, with equal certainty, from the neurilemous covering. In a case mentioned to me by Professor Parker, the tumor, which was about the size of a hen's egg, was developed in the centre of the ulnar nerve, the fibres of which it forced apart, and was of a compact solid texture, like fibro-cartilage. This, per- haps, is the most ordinary structure of all these swellings. In the case described by the celebrated Cheselden, it was of the hygromatous character, being composed of a dense cyst, filled with a transparent jelly-like fluid.* Their magnitude seldom exceeds a Avalnut; in most cases, indeed, they are not larger than a filbert or a peach-stone. After amputation, the ends of the divided nerves are sometimes expanded into white, semi-cartilaginous bulbs, which frequently become the seat of morbid sensibility and neuralgia. Concerning the lesions of the ganglia, very little is known with any degree of certainty. That they are liable, like the nerves with which they are connected and of which they are a part, to inflammation and some of its more ordinary con- * The Anatomy of the Human Body, p. 256. Boston, 1806. SECT. V.] GANGLIA J THEIR LESIONS. 483 sequences, would seem probable, from the similarity of their structure ; but what the resultant changes are, the present state of the science does not enable us to point out. Pro- fessor Lobstein,* of Strasburgh, has found the thoracic ganglia and the semi-lunar plexus repeatedly very much engorged Avith blood, and of a lively red color, from the effects, evi- dently, as he supposes, of inflammation ; and similar phenom- ena have been noticed by other observers. In the yellow fever which prevailed at Natchez, in the state of Mississippi, in 1823, disease of the thoracic and abdominal portion of the great sympathetic appears to have been exceedingly common. Of twenty subjects examined by my distinguished friend Dr. Cartwright, of that city, seventeen presented inflammation of the semi-lunar ganglia and their plexuses: their vessels were greatly loaded with blood. A number of examples of considera- Fi£- 48. ble increase of bulk of the ganglia of the sympathetic, from the influence of chronic irritation, are recorded. The enlargement which has been knoAvn to exceed six or eight times the normal size, is met with chiefly in the cervical ganglia ; but, occasionally, it has been seen in those of the thorax and pelvis. A remarkable case of hypertrophy of these bodies, probably produced by chronic inflammation, has been published by Professor Cruveilhier, which he ob- served in a subject in the dissecting- room of the " Ecole Pratique," of Paris, and concerning the previous history of which nothing Avhatever could be learned. All the cervical ganglia of the left side were enormously enlarged, especially the middle, which was tAvo inches and a half in length by one inch in thickness, (Fig. 48.) They were of a grayish white color, and of a very dense, compact consistence, creaking very sensibly under the knife. On further examination, they were found to * Treatise on the Structure, Functions, and Diseases of the Human Sympa- thetic Nerve. Translated by Joseph Pancoast, M. D. of Philadelphia, 1831. 484 NERVES AND THEIR GANGLIA. [CHAP. XI. be of a fibrous structure, arrayed in such a manner as to form a great number of cells, filled with a sort of gelatinous substance. The component nervous filaments were in a state of complete atrophy, the only part that was left being their neurilematic covering. The nervous cords between the dis- eased ganglia, as well as those Avhich passed off from them, were very much augmented in volume, of a pale grayish color, and abnormally firm in their consistence. Their color, which varied from bright florid to deep black, was so com- pletely dyed into them as to defy ablution. The cardiac and pulmonary plexuses were also affected, but much less fre- quently and extensively than those of the other viscera. In connection with these morbid appearances there was gener- ally more or less lesion of the cerebro-spinal axis, the duode- num, stomach, lung, or liver.* It is much to be regretted that Dr. Cartwright has not stated whether the nervous gan- glia and plexuses, in the cases which he inspected, had under- gone any change of consistence, or furnished any particular secretion, as this would have afforded us a much better op- portunity of judging in regard to the existence of inflamma- tion than the mere fact of their discoloration. * American Medical Recorder, vol. ix. p. 37. January, 1826. CHAPTER XII. Of the Eye. . I. Lesions of the Lacrymal Apparatus. — Preliminary Observations. — Lacrymal Gland. — Ducts and Sac. — II. Lesions of the Ball of the Eye. — The Con- junctiva. — Pterygium. — Lacrymal Caruncle. — Acute Corneitis. — Ulcera- tion and Ossification of the Cornea. — Fleshy Excrescences. — Alterations of Form. — Diseases of the Sclerotica. — Choroid Tunic. — The Retina. — Amaurosis. — Optic Nerve. — Membrane of Demours. — Hsemophthalmus. — Lesions of the Iris. — Alterations of the Pupil. — Capsule of the Crystalline Lens. — Liquor of Morgagni. — Varieties of Cataract. — Vitreous Humor. — Heterologous Formations. Several structures enter into the formation of the eye, which are entirely different from those to be found in other organs. Altogether, it is a most complicated apparatus ; and, as might be expected, the diseases to which it is subject are at once numerous and interesting. This renders it incum- bent on us to consider them somewhat in detail; and, as being first in order, we shall begin with those of the lacrymal ap- paratus. SECTION I. Of the Lacrymal Apparatus. The reader need scarcely be reminded that the lacrymal apparatus consists of the lacrymal gland, the two ducts of that name, the lacrymal sac, and the nasal canal. All these passages are lined by a prolongation of the mucous membrane of the nose, which, on its arrival at the lids, invests their posterior surface, extends into the Meibomian follicles and the excretory tubes of the lacrymal gland, and is finally re- flected over the ball of the eye, forming what is named the conjunctiva. This distribution should be carefully borne in mind, inasmuch as it enables us to account for the sympathy subsisting between the eye and the nose, and the facility with which disease is propagated from the one to the other. 486 LACRYMAL APPARATUS. [CHAP. XII. The lacrymal gland, placed at the upper and outer part of the orbit, is of an elongated oval shape, of a light pink color, and about the size of a small almond. Minutely examined, it is found to be made of a large number of rounded granules, similar in their appearance to those of the parotid, which are united together by delicate cellular tissue. It receives a considerable amount of nervous and vascular endoAvment; and the fluid it secretes is conveyed by a series of small tubes, from five to eight in number, to the surface of the eye, near its outer angle. This body, though so easily affected by mental emotions, does not seem to be very prone to disease. Richerand and Lawrence state that they have never seen it inflamed, and the testimony of Beer and Middlemore is nearly to the same effect. That the idiopathic form of this complaint, as it is termed, is extremely rare, no one can doubt; but that it occa- sionally exists, the experience of the profession fully attests. Resulting commonly from external injury, there is reason to believe that it occasionally succeeds to inflammation of the neighboring parts, especially of the conjunctiva; and the subjects of its attack are such chiefly as are predisposed to gouty and rheumatic affections. Owing to its infrequent occurrence, the anatomical charac- ters of inflammation of this body have not been minutely ascertained; but as far as our observation goes, they are similar to those of other glandular organs. In the early stage of the disorder, there is merely an augmented flow of tears, with slight uneasiness in the situation of the gland : as it progresses, however, the natural secretion diminishes, and the movements of the eye become constrained and painful. The vessels of the little body are engorged with blood, its sub- stance assumes a deep reddish complexion, and the inter- lobular cellular tissue is infiltrated with serous fluid, the swelling from this source being sometimes quite considerable. When the inflammation is violent, it may terminate in suppura- tion, which, however, is extremely rare, — Mr. Guthrie, Avho has written ably on the eye, having met Avith only one in- stance of it in nearly twelve thousand patients. When matter forms, it usually points above the upper lid ; occasion- ally, it escapes into the cellular tissue of the orbit, and gradually works its way out through a fistulous opening. There is a chronic form of the disease, in which the gland often becomes hypertrophied, and acquires a firm, compact SECT. I.] LACRYMAL GLAND ; DISEASES. 487 texture, not unlike an indurated pancreas. The enlarged organ either remains stationary, or it passes into tedious and imperfect suppuration : the disease is most frequent in scrofu- lous children, and is seldom attended with much pain. Chronic inflammation sometimes produces atrophy of this gland. I once dissected an encephaloid eye, in which this body Avas reduced to the size of a small bean, its substance being indurated, and of a yellowish drab color. The subject of the disease was a child ten years of age. The lacrymal gland is liable to scirrhus, forming a hard, elastic, lobulated mass, of the consistence of fibro-cartilage. Under these circumstances the organ is often much larger than a walnut, or even of the size of a hen's egg. Its sub- stance is of a white grayish color, dense, crisp, and intersect- ed by membranous bands, resembling the interior of an un- ripe pear. Small cyts are sometimes interspersed through the diseased mass, filled with a thin, glairy fluid, or with a firm, fatty, melliceric, or sebaceous matter. Scirrhus seldom occurs before the middle term of life ; the pain is severe and lancinating ; and there is more or less distortion of the eye, with dimness, and, in some instances, total loss of vision. Serous cysts, containing a thin, limpid fluid, are sometimes found in the lacrymal gland. Although generally very small, they have been observed, in a feAV cases, as large as a hen's egg. That this disease is rare, may be inferred from the fact that few oculists have ever met with it. Professor Schmidt, of Vienna, to whom is due the merit of first describing it, relates only two examples of it; and the celebrated Beer never saw it more than twice or three times. By some, these cysts have been supposed to be identical with hydatids; but the more probable opinion is, that they are nothing but dilated excretory ducts ; and this conjecture certainly receives cor- roboration from the fact that these tumors are generally dis- tended with a fluid possessing all the properties of the lacrymal secretion, being of a thin, watery consistence, and of a sharp, saltish taste. It occasionally happens that one of the excretory ducts of the lacrymal gland becomes dilated near its terminal ex- tremity, forming a circumscribed, elastic swelling, immediate- ly behind the upper lid, towards the temporal side of the orbit. It is semi-transparent, unusually delicate, of an ovoidal shape, and often reaches the size of a pigeon's egg, though generally it does not exceed a hazelnut. 488 BALL OP THE EYE. [CHAP. XII. The lacrymal ducts are liable to inflammation, which sometimes ends in suppuration, at other times in the oblitera- tion of their caliber. Similar lesions occur in the nasal canal. The obliteration here, however, is usually partial, existing in the form of a stricture. Though the nasal canal is scarcely three quarters of an inch in length, there are three points in its course at which stricture may be located, namely, at its junction with the lacrymal sac, at its middle, and at its en- trance into the nostril. The disease is produced in the same way precisely as stricture of the urethra; that is to say, by inflammation of the lining membrane, accompanied with effusion of lymph into its substance, and into the subjacent cellular tissue. Permanent obstruction, either partial or general, may also be produced by inspissated mucus, and by fibrin poured upon the free surface of the membrane. The diseases of the lacrymal sac do not require special notice, as they do not differ from those of other mucous tex- tures. Suppuration often occurs here, and the matter, being unable to find its way doAvn into the nose or up into the eye, is apt to escape through the skin, leaving a fistulous aperture, which it is always difficult to heal. SECTION II. Of the Ball of the Eye. The ball of the eye, situated in the anterior part of the orbit, is of an irregularly spherical figure, its antero-posterior diameter, which is not quite an inch, being about one line longer than the other. It is composed of a series of concentric membranes lying in close apposition with each other, and ar- ranged so as to enclose the humors of the organ. These latter are three in number, — the aqueous, the crystalline, and the vitreous, their names being derived from their appearance. The membranes, usually called the tunics of the eye, are the con- junctiva, the cornea, the sclerotica, the choroid, the membrane of Jacob, the iris, and the retina ; besides which are the cap- sules, as they are termed, of the different humors. The or- gan thus contains almost every variety of elementary tissue, SECT. II.] CONJUNCTIVITIS. 489 and hence the great frequency of its diseases, with the diver- sity of their progress and mode of termination. The conjunctiva is a thin, mucous membrane, lining the posterior surface of the lids and the front of the ball of the eye, Avhich it thus connects together. Near the inner angle it is folded upon itself, so as to form what is denominated the semi-lunar valve, and as it is prolonged into the lacrymal points, it may be considered as being directly continuous with the mucous membrane of the tear-bag and of the chambers of the nose. The conjunctiva is exceedingly delicate and transparent, devoid of follicles and villosities, loose and pale on the sclerotica, firm, and rose-colored on the lids. The membrane also covers the cornea, but its structure here is so much changed that it can no longer be recognized. At the margin of the lids, where it is continuous with the skin, it is reflected into the Meibomian follicles, — a number of narroAV, Avhitish, tortuous glands, designed to secrete an unctuous fluid for lubricating the eye. The connection between the conjunctiva and the sclerotica is established through the medium of a pretty thick layer of cellular tissue, Avhich, from the character it plays in the dis- eases of the eye, deserves to be dignified Avith the appellation of the ocular fascia. When carefully dissected out, it is found to be semi-transparent, strong and elastic, disappearing gradually upon the posterior part of the ball. It is remarka- bly Avell developed in the horse and ox, and I have always suceeded in making it out distinctly in the human subject. Considered in reference to its functions, it is of the same use to the conjunctiva that the cellulo-fibrous tunic, so well de- scribed by Cruveilhier, is to the stomach and boAvels. It is the exclusive seat, in most instances, of the vascularity Avhich characterizes inflammation of the sclerotic portion of the con- junctiva, and of the effusions attending it, whether of serosity, of lymph, of blood, or of pus. Acute conjunctivitis is announced by more or less redness, Avhich usually begins at the palpebral portion of the mem- brane, and gradually extends to that over the sclerotica. The injection is at first arborescent; by and by it becomes capilli- form, and, in certain cases, it is so close as to give the organ the appearance of being blood-shot. With this augmented redness, the membrane loses its natural polish, the temperature of the part is augmented, its sensibility is altered, and there is a suppression of the mucous as well as of the lacrymal secre- vol. i. 62 490 BALL OF THE EYE. [CHAP. XII. tion. The discoloration now becomes more and more vivid and intense ; the conjunctiva assumes a villous aspect; se- rosity is poured out into the cells of the ocular fascia ; the tears floAV in great abundance; and the mucous discharge is not only restored, but uncommonly copious. Blood is some- times extravasated beneath the conjunctiva ; and occasionally there is a secretion of lymph, by Avhich the margins of the lids are completely agglutinated. In violent cases, such as Ave have here described, the disease is frequently propagated to the other textures of the eyes, and the discoloration ex- tends backAvards to the posterior section of the sclerotica. Acute conjunctivitis often passes into suppuration. The matter, Avhich is at first merely puriform, becomes gradually purulent, thick, and of a yellowish straw-color. The quan- tity secreted is sometimes surprisingly great — much more so than in any other mucous membrane of equal extent — from four to eight drachms being discharged in the twenty-four hours. Like the matter of gonorrhoea, it is frequently of a highly acrid and irritating nature, and has the property, Avhen applied to the sound eye, of engendering the same affection. Many surgeons have disbelieved this; but the experiments of Guille, Hupsch, Kirkhoff, and others — Avhich consisted in inoculating different persons with matter taken from patients afflicted Avith opthalmia — have affirmatively settled the point. The disease, Avhen thus produced, usually appears in from one to three days. There is a variety of this disease in Avhich the effusion of serosity is so great, as to give the eye a truly cedematous aspect. The sclerotic portion of the conjunctiva is elevated into a soft, transparent tumor, forming a ring around the cornea, which appears deeply sunk in the back, and some- times almost entirely concealed : the effusion often encroaches considerably upon the lids, which are thus rendered tumid and everted. Very little vascularity attends this variety of ophthalmia. In severe cases, the conjunctiva has been known to form a tumor as big as a walnut, from this cause. In another series of cases, the mucous membrane is raised into small vesicles. Seated in the subjacent cellular tissue, they are produced by an effusion of serous fluid, and seldom exceed the size of a common pin-head: they are of a spherical shape, diaphanous, and are most frequent in that species of ophthal- mia which affects the conjunctival covering of the cornea. Their number is sometimes considerable : and, on bursting, SECT. II.J CHRONIC CONJUNCTIVITIS. 491 they leave an ulcer which it is often difficult to heal. This affection has been described by Gendrin, Avho states that it is of frequent occurrence, and indicative of mild inflammation. The corneal portion of the conjunctiva is also liable to the formation of pustules. Occurring in persons of all ages, they are most frequently met with in children, and some- times spread through Avhole families, being generally con- comitant of small-pox, measles, and aphthous affections of the mouth. The pustules are usually situated near the mar- gin of the cornea, are encircled by minute vessels, and appear like small dusky spots, of a pale reddish color, slightly ele- vated above the level of the surrounding surface. If the inflammation be allowed to go on, purulent matter is formed, their apex ulcerates, their contents are discharged, and a cavity is left, the edges of which are dense and opaque. The nature of these pustules is still unknown. The most plausible conjecture is, that they are the result of inflamma- tion of the mucous follicles, which we have reason to believe exist in the conjunctiva, although they have not yet been demonstrated there. Chronic, like acute inflammation, usually begins in the palpebral conjunctiva, and is often entirely confined to that part. The membrane, Avhich is of a uniform reddish color, verging on purple, is thickened by an effusion of lymph, and converted into a dense, fleshy-looking substance. Its surface is always more or less rough; and, in many instances, it is studded with small, spherical bodies, improperly called granu- lations. These bodies, although they are generally dispersed over the whole surface of the lids, are always most luxuriant along their edges ; and they seldom extend over the sclerotic and corneal portion of the membrane. Being of a soft, fleshy consistence, they are of a florid color, extremely vas- cular, highly sensitive, and liable to bleed on the slightest touch. Instances occur in which they are of the color and density of fibro-cartilage; and, occasionally, they resemble little clots of blood, being of a livid hue and of a fungous consistence. The magnitude Avhich they attain, in cases of Egyptian and venereal ophthalmia, is sometimes surprisingly great. On the Avhole, it appears to me that these vegetations are nothing but enlarged villosities, Avith which the surface of this membrane, like every other of a similar kind, is natu- rally covered. Villosities have not, it is true, been demon- strated here in the sound state ; but that they exist, in certain 492 BALL OF THE EYE. [CHAP. XII. pathological conditions, my own observations fully con- vince me. If the inflammation recurs from time to time, or is unusu- ally protracted, the vessels of the conjunctiva are apt to be- come permanently enlarged. The veins, especially, may be observed to be tortuous, of a dark color, and irregularly nodulated, like varicose veins in other parts of the body. Whether the arterial capillaries participate in the enlargement, I am unable to say; doubtlessly they do, in some instances. Added to all this, there is generally considerable thickening, Avith opacity and relaxation of the conjunctiva : the lacry- mal caruncle is hypertrophied, as are also the Meibomian follicles, and the secretion from these structures is unnaturally thick and copious. A new membrane occasionally forms on the conjunctiva, producing Avhat is called a pterygium, and is most common in old people, though no age is exempt from it. It is gener- ally of a flat, triangular shape, with the apex directed towards the pupil; has a fleshy look and consistence; and almost always grows at the internal angle, tending, in its progress, to encroach upon the cornea. Its vascularity is often quite great, the vessels running in a straight line, and presenting a varicose state, especially when of long standing. In most instances, the morbid groAvth is soft and movable ; now and then, hoAvever, it is found firmly adherent, thick, coria- ceous, hard, like parchment, or even cartilaginous. Mr. Ward- rop mentions a case in which there were two pterygia on each eye. The manner in which this membrane originates is still a matter of dispute. In most cases, it seems to consist simply in a hypertrophied state of the conjunctiva ; but, occasionally, it is probably an entirely new formation, commencing in an effusion of plastic lymph. As it increases, it generally appro- priates to itself a large supply of vessels, which thus nourish and support it. As an effect of inflammation, the lacrymal caruncle, as it is called, is sometimes hypertrophied. This structure is natu- rally quite small ; but, Avhen thus affected, it often acquires the volume of a pea, or even of a cherry. It is generally of a pale reddish color, and of a soft fleshy consistence, Avith a rough tuberculated surface. Sometimes it is very dark, and almost black. The cornea occupies the anterior sixth of the ball of the SECT. II.] CORNEITIS. 493 eye, and is of a circular shape, — its transverse diameter, how- ever, being a little longer than the vertical. Anteriorly, it is convex and covered by the conjunctiva ; behind, it is con- cave, and lined by the membrane of Demours. The proper substance of the cornea is of a fibro-cartilaginous nature, transparent, dense, elastic, and made up of five or six con- centric lamellae, connected together by short, cellular tissue, the interstices of which are filled with a clear, unctuous liquid. No nerves have yet been traced into the interior of this membrane ; and, in the sound state, it is perfectly insensi- ble.* Its vessels, which are derived from the sclerotic coat, naturally carry a colorless fluid, and are therefore indis- cernible. The cornea, provided it be sound, readily unites when divided, the process by which this is affected being the same as in other parts of the body. If a portion be removed, it is never completely regenerated ; but the chasm is filled up Avith an opaque substance, of a hard, cartilaginous consistence. Although acute corneitis occasionally arises Avithout any assignable cause, yet, in most instances, it is directly charge- able to external violence. In the early stage of the disease, there is scarcely any perceptible alteration in the part con- cerned, the only change being a slight degree of haziness. By and by, hoAvever, the membrane loses its transparency, assumes a bluish milky aspect, softens, and becomes distinct- ly vascular, — hundreds of vessels, extremely fine and delicate, running in every direction from the circumference towards the centre. In aggravated cases, blood is sometimes effused into the substance of the cornea, or the capillary injection is so great as to give the membrane the appearance of a piece of scarlet cloth. Very often a red zone is seen round the fore part of the sclerotic coat, formed by a wreath of vessels which freely anastomose with those of the cornea. The anterior surface of the membrane is occasionally quite rough; the movements of the eye are impeded, and there is deep-seated pain in the orbit, Avith intolerance of light; and, in the more violent grades, hemicrania. The conjunctiva is generally ex- tensively implicated; and, in strumous habits, the inflamma- tion frequently spreads to the iris, the choroid, and the retina, leading to great and permanent mischief. * Professor Schlemm, of Berlin, it is true, asserts that he has succeeded in tracing nerves into the substance of the cornea; but his dissections have not, I believe, been verified by other anatomists. (See American Jour. Med. Science, Nov. 1830.) 494 BALL OF THE EYE. [CHAP. XII. Acute corneitis passes sometimes into suppuration. The matter collects either immediately beneath the conjunctival covering, or else between the lamella? of the proper substance of the membrane, and generally appears in the form of a small abscess. This gradually increases in size, until it pro- duces a considerable prominence, Avhen it either bursts, or its contents are removed by absorption. The pus, Avhich is usually very Avhite and mixed Avith lymph, occasionally escapes into the anterior chamber. The parts immediately around the abscess are always more or less softened, vascular, and opaque. In violent grades of inflammation, especially Avhen occur- ring in persons of a strumous habit, the cornea sometimes loses its vitality, and is detached in grayish, dirty-looking eschars, leaving one or more openings through Avhich the iris protrudes. Some anatomists have doubted whether the cornea is susceptible of this change ; but the observations of Beclard, Saunders, Mirault, and others, have affirmatively settled the question. The change is most apt to take place in the pustules Avhich form on the eye in cases of confluent small-pox. In chronic corneitis, the membrane is opaque, of a grayish tint, condensed, indurated, and thickened, yet more easily torn than in the healthy state. Vessels may be traced over its anterior surface, Avhich are much larger than in the acute form of the complaint, and their contents seem also of a darker hue. Little pain is present; objects are perceived indistinct- ly, every thing having a hazy appearance ; and, if the cornea is incised, it is generally slow in uniting. There is now a patient in the Cincinnati Eye Infirmary, a young man thirty- five years of age, whose cornea Dr. Drake divided more than two Aveeks ago, and yet the adhesion is still very imperfect. Numerous vessels can be seen ramifying through its sub- stance from the sclerotic coat: it is of a cineritious color, and there is a total absence of pain. In cases of very long standing, the thickening and opacity of the cornea are some- times very great: the surrounding textures are deeply impli- cated, and the ball of the eye appears as if covered with a strong fascia, the fibres of which converge towards the centre of the cornea, and exhibit a yellowish pearly lustre, not un- like the inner surface of an oyster-shell. A deposit of lymph, produced, probably, by a sIoav chronic inflammation, is often seen around the cornea of old people, forming a regular SECT. II.] ULCERATION--CICATRIZATION. 495 circle which has been denominated the senile arch. It has been observed, in a few instances, even in young children. The cornea, like the other fibro-cartilages, is liable to ul- ceration ; and this is a very common consequence of the bursting of an abscess; but it may also take place Avithout any antecedent suppuration. A species of softening some- times precedes this process, leading to the formation of an immense number of erosions, so exceedingly minute as al- most to escape the naked eye : they are superficial, rough, irregular, and without any circumjacent vascularity. In the majority of cases, hoAvever, the ulceration presents a more decided character ; it is deep, well-defined, and of a pale ash- color, with high, jagged edges ; its surface is bathed with a thin acrid fluid; the part is extremely sensitive ; and the sore manifests a strong tendency to spread, in depth and diameter. In this manner the disease often progresses until the cornea gives way, and there is an escape of the aqueous humor, or, what is Avorse, a total destruction of the organ. In old people we sometimes meet with crescentic ulcers situated, near the circumference of the cornea, Avhich, however, seldom reach to any great depth. It is an interesting fact to know that ulcers of the cornea, whatever may be their form or extent, are susceptible of cicatrization. Frequently, after they have existed for a while, their progress seems to be suddenly arrested ; the eye becomes less irritable ; granulations sprout up; and the excavation is thus gradually filled up, the new texture assuming at length the properties of the lost substance. Most generally, how- ever, the reproduction is imperfect, — the cicatrix which is left being opaque, and depressed in the centre, and thus vision is often materially impaired. The lymph effused in inflammation sometimes remains unabsorbed, and gives rise to opacity. It occurs in every in- termediate degree, from a slight haziness to entire loss of trans- parency, and may be either superficial or deep-seated, circum- scribed or diffuse, punctiform or linear, circular or crescentic. In many cases, the opacity continues through life, the lymph upon which it depends becoming, no doubt, partially organ- ized. The cornea is liable to ossification. Wardrop saw a case in which the Avhole eye had changed its form, and the cornea contained a hard, smooth, oval plate of bone, weighing two grains. A piece of bone was also found between the choroid 496 BALL OF THE EYE. [CHAP. XII. coat and the retina of the same eye.* In another case, re- ferred to by Voigtel, a German author,! a piece of cornea, taken from a man sixty years of age, Avas converted into osseous matter. It Avas three lines long, tAvo broad, and weighed two grains. A still more remarkable example is reported by Dr. Monet, in the Nouvelle Bibliotheque Medicale for May, 1817. It occurred in an old man, and the cornea is said to have been ossified throughout. This transformation is by no means so frequent as the cartilaginous, of which a considerable number of instances are related by authors. Fleshy excrescences have been seen on the cornea. They are occasionally of a fungous character, and ,in several instan- ces they have been found to contain hairs. These morbid growths appear to have their origin, for the most part, on the conjunctival covering of the cornea. Alterations in the form of the cornea occur under two prin- cipal varieties, the conical and the spherical, Avhich, as they arise from different causes, require to be considered separately. The conical variety is sometimes congenital, or begins to appear soon after birth. More commonly, however, it does not come on until about the age puberty, and, what is very singular, it is said to be more frequent in females than in males. — for Avhat reason is not knoAvn. The alteration gener- ally advances sloAvly, and occasionally affects both eyes, though seldom in an equal degree. The cornea, which is at first only someAvhat prominent, gradually assumes the conical shape, and has a peculiar sparkling, crystalline appearance, preventing the pupil and iris from being distinctly seen. After a while, small whitish specks are seen, which sometimes coalesce until the whole structure is rendered perfectly opaque. In some instances, ulceration sets in, and is eventu- ally succeeded by a protrusion of the iris. The most extra- ordinary example of this variety of the disease is mentioned by a German author of the name of Brugman. He declares that both corneas were so prodigiously elongated that they reached down to the mouth like two horns ! % Both in this and in the next variety, the surface of the staphylomatous pro- trusion displays arborescent vessels, conveying red blood, and, where the tumor is large, acquires a cuticular incrustation. * Morbid Anatomy of the Eye, vol, i. p. 74. Second edition. London, 1834. t Handbuch der Pathologeschen Anatomie, b. ii. p. 92. Halle, 1804. t See Wardrop, Op. cit. p. 136. SECT. II.] SCLEROTICA. 497 In the other variety, which is the most common, and which usually follows the bursting of an abscess or ulceration, the cornea forms a whitish, pearl-colored projection, of a spherical figure, and often of considerable magnitude. The membrane is unequally thickened ; its laminar arrangement destroyed ; its texture generally more or less softened; and numerous vessels can be seen towards its circumference, and sometimes even towards its centre. In this variety the anterior chamber of the eye is annihilated ; the iris is torn into radiated frag- ments ; and vision is lost or impaired, according to the extent of the projection and the opacity of the membrane. The late Professor Dupuytren, of Paris, a feAV years ago, described what he calls an encysted tumor of the cornea. He observed it in a child Avho had been struck on the eye a few Aveeks before with a stone. It greAV between the lamellae of the membrane, and was distended with a serous fluid, which was reproduced in a fortnight after it had been evac- uated. This, I believe, is a solitary instance of such a tumor in such a situation. The sclerotic coat is a strong, dense membrane, belonging to the same class of textures as the pericardium, the perios- teum, and the dura mater. It is opaque, of a dull Avhitish tint, consists of a single lamella, and is composed of firm, inelastic filaments so intimately intenvoven as to render it impossible to unravel them. Behind, it is perforated by the optic nerve ; and, in front, it has a large opening, Avhich is occupied by the cornea. Externally it is convex, and cov- ered with fine, cellular tissue, which connects it with the con- junctiva : its internal surface is smooth, glistening, and lies in apposition with the choroid. The sclerotic coat has no sensibility in its natural state, and no nerves have been traced into it. The vessels which it receives are also few in number. A little behind the cornea it is pierced by the anterior ciliary arteries ; and the posterior ciliary vessels pass through it, around the entrance of the optic nerve. The veins Avhich form the vasa vorticosa of the choroid perforate it obliquely, about its middle. The sclerotic coat, like the other fibrous textures, takes on inflammatory action Avith great reluctance ; but, after having once set in, it is always obstinate, painful, and difficult of cure. The disease is generally confined to the anterior half of the membrane, is very apt to involve other parts of the eye especially the conjunctiva, the cornea, and the iris, and vol. i. 63 498 BALL OF THE EYE. [CHAP. XII. is most frequently observed in persons of a gouty and rheu- matic predisposition, its favorite period of attack being the spring. It is characterized by deep-seated redness of the eye- ball, verging ujton lilac, unaccompanied with thickening or opacity. The distended vessels form a beautiful zone about a line behind the cornea, whence they proceed backwards in a radiating direction, until they gradually lose themselves in the posterior part of the organ : they do not branch out like those of the conjunctiva, nor are they so movable under the folds of this membrane, — a circumstance which, together Avith the dull, aching, paroxysmal nature of the pain, may be con- sidered as almost diagnostic of the disease. Coagulating lymph is rarely poured out by the sclerotic coat when in- flamed, and it seldom, perhaps never, suppurates. In chronic cases, the redness is considerably diminished, the affected part is rendered preternaturally flaccid, and the Avhole eye-ball assumes a sickly yellow hue. The sclerotic coat is sometimes remarkably thin and flaccid, so as to be incapable of maintaining the globular shape of the eye. This state is usually connected Avith disease of the other membranes, and with disorganization of the vitreous humor. On the other hand, the sclerotic coat is sometimes unnaturally indurated and thickened; and, in a feAV instances, it has even been found partially ossified. It occasionally becomes attenuated by interstitial absorption, and bulges out in the form of a staphylomatous protrusion. Wardrop men- tions a case in which there Avere several little tumors of this kind, Avhich felt soft to the touch, and were of a dark bluish color. Scarpa states that he once met Avith such a protru- sion that Avas as large as a small nut; it Avas situated on the temporal side of the entrance of the optic nerve, and was of an oblong shape, the sclerotic coat being so thin at that part as to admit the light. The choroid coat may be considered as a cellulo-vascular membrane, as it is essentially composed of arteries and veins, connected together by extremely delicate cellular substance. Nerves are also plentifully distributed upon this tunic ; and its principal office appears to be that of secreting the black pigment which lies so abundantly upon its inner surface. Judging from its delicate organization, it might be inferred that the morbid changes of the choroid were extremely nu- merous and frequent, whereas quite the reverse is the case. The most important lesions to which it is subject are inflam- mation, dropsy, and ossification. SECT, n.] choroid; inflammation — retina. 499 In inflammation of the choroid, there is little external red- ness, and the enlarged vessels which appear on the white of the eye are deep-seated, corresponding to the posterior ciliary arteries. When the disease is violent, suppuration may take place ; and not unfrequently there is an absorption of the black pigment, or this substance is deposited in an altered and imperfect manner, or variously changed in color. The membrane is sometimes broken down in its texture, and its inner surface has been found coated with flakes of lymph. Varicose enlargement of the vessels occasionally attends this complaint; but this is a rare occurrence, and is seen only in cases of long standing. The disease is most commonly met with in strong, plethoric persons, is characterized by great intolerance of light, a contracted state of the pupil, and deep- seated pain darting through the head and temple. Portal states that he has found hydatids betAveen the choroid and retina ; and accumulations of water have been noticed in the same situation by Zinn, Ware, Wardrop, and other writers. The fluid is generally thin and glairy, like white of egg ; but sometimes it is Avatery, or of a pultaceous consistence. Ossification of the choroid has been observed by Haller, Morgagni, Bichat, Scarpa, and other writers; the occurrence, however, I presume, is quite rare, and has hitherto been wit- nessed only in persons far advanced in life. Though for the most part partial, the transformation sometimes affects the whole membrane, converting it into a thin, osseous cup, per- forated behind for the passage of the optic nerve. The disease has been supposed by some to have its seat in the membrane of Jacob, — an opinion which I am inclined to adopt from the fact that this tunic is of a serous texture, which, we know is particularly prone to this sort of transformation in almost every part of the body. The retina, the most internal of the concentric tunics of the eye, lies between the vitreous humor and the membrane of Jacob, and is generally regarded by anatomists merely as the expansion of the optic nerve. Two distinct layers seem to enter into its composition, one of which, the external, is a very soft medullary looking texture, of the consistence of mucus, whereas the other forms a delicate vascular net-work, being made up mainly of vessels, derived from the central artery of the retina. In the living subject, this membrane is perfectly transparent, but, soon after death, generally in the course of ten or tAvelve hours, it becomes pale and opaque. 500 BALL OF THE EYE. [CHAP. XII Observations are still Avanting to enable us to give a com- plete history of the morbid anatomy of the retina. That this membrane is liable to inflammation cannot be doubted ; but, as to the changes Avhich it undergoes when thus affected, nothing satisfactory whatever is known. Wardrop informs us that he once saw it of a buffy color, produced, as he sup- poses, by an effusion of albumen ; in another case, he found it quite opaque, tough, and thickened. Morgagni, Walter, and Magendie have Avitnessed similar examples. The latter Avriter relates an instance Avhere the retina Avas converted into a white, firm, fibrous structure, in every respect analogous to an aponeurosis. Cases occur in Avhich this membrane is partially atrophied, or even completely Avasted, as in persons Avho have long been affected with amaurosis. In amaurosis it not unfrequently happens that the vessels of the retina become enlarged and varicose. This change, as has been remarked by Mr. Wardrop, very probably takes place in those cases of the disease Avhich are dependent upon cephalic congestion, and Avhich are characterized by figures of various forms floating before the eyes. The disease may sometimes be relieved by depletion ; but, in the generality of cases, there is reason to believe that it remains permanent and irremediable. Amaurosis, it may be here stated, often depends upon a deranged condition of the chylopoietic viscera, by correcting Avhich, the patient speedily recovers his sight; in other cases, it is OAving to disease of the optic nerve, or even of the brain ; in others, it seems to arise from a palsied and disorganized state of the retina itself. The optic nerves are liable to become diseased. In per- sons who have been long blind, it is not uncommon to find them very much wasted, altered in color, and changed in consistence, being either firm and fragile, or soft and pulpy. In some instances, the optic nerves are flattened, like pieces of tape, and of a yelloAvish, cineritious, or broAvnish hue. Occasionally they are the seat of calcareous concretions, of fibrous tumors, and of hydatids, though these affections are extremely rare, and I have never met with them. There is a very singular structure, called the membrane of Demours, which funishes the aqueous humor. It is ex- tremely delicate, polished and transparent, and lines not only the posterior surface of the cornea, but the whole of the iris, terminating finally, as is supposed, on the capsule of the crystalline lens. No vessels can be seen in it in the natural SECT. II.] AQUO-CAPSULITIS. 501 state, and many anatomists have altogether denied its exist- ence. Like the serous tissue, which it closely resembles, the membrane of Demours is subject to particular morbid changes, a bare enumeration of which must suffice for our present purpose. When this membrane is inflamed, constituting what has been termed aquo-capsulitis, it becomes more or less opaque, and its free surface is covered Avith globules of lymph, some of which are frequently detached, and float about in the anterior chamber, or form adhesions with the iris. The aqueous humor is at the same time rendered turbid, and is secreted in such abundance as to give the eye-ball an unusual degree of prominence. Besides these phenomena, the poste- rior surface of the cornea often presents several milk-like specks, environed by a sort of disk. The specks in question, give the membrane a singularly mottled appearance, and may be regarded as the characteristic marks of the disease. No capillary injection has ever been noticed, I believe, in this opthalmia, though the vessels of the surrounding parts are often very much distended, especially those of the sclerotic coat, which sometimes form a beautiful zone just behind the cornea. Pus is occasionally poured out, but this is rare. The lymph that is effused in this disease varies considera- bly in quantity. When there is only a little, it is generally absorbed ; in opposite cases, it frequently remains, and gradu- ally becomes organized, red vessels passing through it in different directions. The form of the pupil is often remarka- bly altered by this substance, sometimes entirely closed up by it. The membrane of Demours is occasionally ossified; and, in a few rare instances, small pieces of bone have been found in the anterior chamber. The aqueous humor — the product of the membrane, the diseases of which have just been sketched — is sometimes altered, either in quantity or in quality. The fluid in the healthy eye does not exceed five drops; in old people, it is considerably less; and, in certain diseases, it is so much augmented as to constitute a real dropsy. The aqueous humor is sometimes quite acrid. Prochaska mentions a case in which it tarnished the extracting knife. The cellular hydatid has been repeatedly found in this fluid. Dr. Mac- kenzie gives not less than three cases of this kind, one of Avhich came under his own observation.* In the horse, espe- * Practical Treatise on the Diseases of the Eye. Second edition. London, 1835. 502 BALL OF THE EYE. [CHAP. XII. cially in India, it is sometimes inhabited by a worm, Avhich, in size and color, resembles the common ascaris. The animal, which has received the name of filaria papillosa, is about an inch long, of a grayish color, equal in size to a sewing- thread. The effusion of blood into the chambers of the eye from mechanical injury, is sufficiently common ; but its spontane- ous occurrence in persons in other respects well, although sometimes observed, is extremely rare. The lesion is techni- cally denominated hccmophthalmus. In some rare instances, the effusion seems to be vicarious of the menstrual function. Professor Walther, the celebrated German oculist, saw a case of this kind, in Avhich the affection recurred regularly at the monthly period, and supplied the place of the suspended menses. An example, in some respects analogous, occurred some years ago in one of the Parisian hospitals, and is de- tailed in the fifth volume of the London Medical Gazette. In Avhatever manner this apoplexy be induced, it generally disappears completely, in from two to eight days, leaving the chambers of the eye perfectly clear, and vision unimpaired. The iris is a thin, flat circular membrane, situated in the interior of the eye, between the cornea and the crystalline lens. Its external circumference is encased in the ciliary ligament, directly over against the margin of the sclerotic coat: the internal, which is free, is a little thinner than the other, and forms the border of the rounded aperture, denomi- nated the pupil. Both surfaces of the membrane are flat; the anterior has a doAvny, flocculent aspect, and is marked by a great number of striated lines : the posterior is contigu- ous to the ciliary processes, and besmeared with a dark bluish pigment, similar to that Avhich covers the choroid. When this substance is washed away, two sets of fibres may be observed, one being radiated, the other circular, the latter being placed around the pupil like a real sphincter. These fibres are supposed to be muscular ; and they are lined, as was before intimated, by a reflection of the membrane of Demours. The iris is abundantly supplied, both with vessels and with nerves, — the former being derived from the opthalmic artery, the latter from the lenticular ganglion. The vessels approach the membrane in four different directions, and, anastomosing freely with each other, form tAvo beautiful vas- cular circles, one around the outer, the other around the inner SECT. II.] ACUTE IRITIS. 503 margin of the iris. The veins pursue nearly the same course as the arteries, and terminate, for the most part, in the vorti- cose veins of the choroid. One of the most striking phenomena of acute iritis, is the vascular zone around the anterior margin of the sclerotic coat, formed by the minute ramifications of the ciliary arte- ries. This zone, which is not always complete, varies in distinctness, according to the intensity and duration of the disease. The vessels composing it seem to terminate ab- ruptly at the circumference of the cornea, very few of them extending fonvard over its anterior surface or into its sub- stance. The iris itself is discolored, dull, and thickened; the aqueous humor is more or less turbid ; and the pupil is contracted, motionless, and irregular. Very frequently, per- haps most generally, the anterior surface of the iris is cor- rugated, slightly bulging, and covered Avith globules of lymph, of a whitish, yellowish, or reddish hue. Vessels and spots of blood are sometimes seen upon it; and, occasionally, especially in the more aggravated forms of the disease, the Avhole membrane has a brick-colored, ecchymosed appear- ance. Minute abscesses also sometimes form, break and dis- charge their contents into the anterior chamber. The quan- tity of effused lymph is often considerable, and either floats about in the aqueous humor, adheres to the surfaces of the iris, or fills up the pupil, and ties it firmly to the capsule of the crystalline lens. Great intolerance of light, deep-seated pain, lacrymation, and more or less constitutional disturb- ance are the ordinary attendants on this disease. Permanent adhesion of the iris to the lens, and lesion of the internal structures of the eye, are among the dangers which occur if the inflammation be permitted to progress. There is a very slow, insidious form of iritis, which may be said to be chronic almost from the beginning. There is commonly very little redness, and the patient complains chiefly of dimness of vision, which is so gradually impaired that the sight is lost before he is aware of his misfortune. The most remarkable anatomical feature is the change of color of the iris, Avhich is almost always of a singularly greenish cast; the membrane is also thickened, rough, and puckered, and the pupil is irregularly contracted, and fringed with lymph. The aqueous humor retains, for the most part, its natural aspect: there is little pain or intolerance of light; and the other structures of the eye are little or not at all af- 504 BALL OF THE EYE. [CHAP. XII. fected. This form of iritis is generally present when the membrane protrudes from ulceration of the cornea. Prolapsion produces a sIoav change in the texture of the iris, rendering it unnaturally hard, and changing its form : a complete adhesion is often established betAveen it and the cornea : in many cases, it is incrusted Avith partially organized lymph; and occasionally it assumes a granular appearance, and resembles a piece of flesh. Small tumors, of the nature of polypes, are sometimes found on the iris : they seldom ac- quire a large size, and are generally exceedingly vascular, bleeding on the slightest external injury, or even without any assignable cause. The pupil is liable to various alterations, either congenital or acquired. Thus it has been found to be oval, rectangular, indented, slit-like, and even double; and, what is more re- markable than all, is, that these malformations are sometimes hereditary. Children are occasionally born Avithout a pupil. This arises from the persistence usually of the pupillary mem- brane, which has been known, in a feAV instances, to continue until the tenth, fifteenth, and even thirtieth year of age. The changes produced by disease have been already inciden- tally noticed, and need not therefore be reenumerated. The capsule of the crystalline lens is of a serous nature, be- longing to the same class of membranes as the pleura and the peritonaeum. It probably consists of a single lamella, the an- terior segment of which is much thicker, denser, and stronger than the posterior. No nerves have been traced into its sub- stance, and the only vessels that can be seen in it are a few small twigs from the central artery of the retina. The first change produced in the capsule of the lens by in- flammation, is a loss of transparency, arising from too great a fullness of its serous vessels. These vessels are arranged in the form of a wreath, composed of several distinct arches, situated about a fourth of a line from the pupillary margin of the iris. Running backAvards from this Avreath, in different directions, are numerous hair-like branches, which gradually lose themselves, at the circumference of the lens, in the iris, and the ciliary processes. From its excessive delicacy, this vascular arrangement can seldom be discerned Avithout the aid of a magnifying-glass; and, occasionally, there is reason to believe that it is altogether Avanting. Accompanying this injepted state of the membrane is an effusion of lymph, which has always a tendency, Avhen the disease involves the ante- SECT. II.] CAPSULAR CATARACT. 505 rior hemisphere of the capsule, to produce adhesions between it and the iris. At other times, the fluid is poured out in the form of small flakes, which float about in the chambers of the eye, where they are either gradually absorbed, or become attached to the surrounding parts. Occasionally the lymph connects itself at each side Avith the edge of the pupil, and shoots fonvard like a thin, narrow bar, which, in cases of long standing, has been knoAvn to have a cartilaginous, or even an osseous consistence. In regard to the membrane it- self, its texture is always remarkably altered, becoming thick, tough, and of a Avhite, opaque, milky appearance. Similar changes occur when the disease attacks the posterior segment, with the addition of much greater vascularity. The inflammation of this membrane ahvays observes a chronic course. It proceeds very sloAvly, and is attended Avith little or no pain. It is most common about the age of forty, and usually attacks subjects of a cachetic disposition, with light eyes. The iris, of a darker color than natural, is sluggish in its motions, and the pupil is contracted, irregular, and encircled by a black, narrow rim. When the disease has continued for a long time, the vessels of the capsule are apt to become permanently varicose. Pus sometimes forms, and cases occur in which the enclosed lens is completely dis- solved. Opacity of this structure forms a species of cataract, de- nominated capsular, a disease which is often congenital. As already hinted, it may affect either a part or the whole of the membrane; but, in the majority of instances, it is restricted to the anterior segment. The color of the cataract is very various. Sometimes it is of a dull milky appearance ; some- times Avhite and glistening ; sometimes mottled, grayish, yel- lowish, or broAvnish. Its texture also is very various, being at one time soft and pulpy, at another brittle and easily rup- tured, at another tough and elastic, or of the thickness and consistence almost of the cornea. In people advanced in life, the capsule is sometimes ossified, either in part, or through its whole extent. In the natural state, there is ahvays found betAveen the cap- sule and the lens a minute quantity of thin, pellucid fluid, which is called the liquor of Morgagni, from the illustrious anatomist who first detected it. This fluid occasionally becomes opaque, and thereby constitutes a species of cat- aract. It is also the seat, in some rare instances, of a species vol. i. 64 506 BALL OF THE EYE. [CHAP. XII. of thread-Avorm, the ocular filaria of Nordmann.* In one of the cases narrated by this Avriter, the animal Avas three quar- ters of a line long, extremely narrow, and of uniform thick- ness, like the most slender thread. It Avas spirally convoluted, and had a simple intestinal tube, with a mouth, a uterus, and a prominent anal aperture. In another patient, an old female, Dr. Nordmann found the eye occupied with microscopical entozoa, possessing distinct suckers, and appertaining to - the monostomatic genus of Rudolphi. The individuals, Avhich were eight in number, Avere situated in the upper strata of the crystalline lens, were one tenth of a line in length, and moved sluggishly on being placed in tepid Avater. The sub- stance of the lens was still soft, and retained a considerable degree of transparency. The crystalline lens, situated at the junction of the anteri- or with the posterior two thirds of the eye, is embedded in a depression in front of the vitreous humor, being placed imme- diately behind the pupil, and surrounded by the ciliary pro- cesses. It is a doubly convex body, but the convexity is considerably greater behind than before : its diameter is about the third of an inch, and its thickness about tAvo lines and a half. The shape, color, and consistence of the lens vary con- siderably in the different periods of life. In the foetus, it is nearly spherical, reddish, and very soft: in the adult, it is transparent, firm, and strictly lenticular; and, in old age, it becomes partially flattened, augments in density, but dimin- ishes in bulk, and assumes a yellowish amber hue. The substance of the lens is apparently of a homogeneous character, being soft and pulpy outwardly, but dense and firm within. When carefully examined, it is found to be composed of a series of concentric lamellae, six or more in number, Avhich are disposed similarly to the coats of an onion, and united together by fine cellular tissue, the whole being moistened by an interstitial serous fluid. No nerves or ves- sels have yet been traced into the substance of the lens ; on Avhich account some have imagined that it is not an organ- ized structure. The very fact that it is susceptible of dis- ease, is a sufficient refutation of this absurd notion. It is extremely doubtful Avhether the crystalline lens is sus- ceptible of acute inflammation ; but that it is often affected chronically is abundantly established by the changes which * Mikrographische Beitrage zur Naturgeschichte der Wirbellosen Thiere: Erstes Haft, p. 11—13. SECT. II.] LENTICULAR CATARACT. 507 it undergoes in its color, its shape, and its consistence. These changes generally occur slowly ; and, taken together, they constitute an important class of disease, termed lenticular cataract. Existing either singly, or, as is more frequently the case, in combination Avith an altered condition of the investing membrane, lenticular cataract has been observed at all ages, but is most common, by far, in young children and in old persons. Infants are often born Avith it, and in many cases it is hereditary. Wardrop kneAV a father, son, and grandfather affected with it; and examples of a similar na- ture are recorded by different authors. Jan son saw a Avhole family, consisting of six members, blind from this disease. Age exerts a powerful influence in the production of cata- ract. The observations of Fabini and Maunoir clearly prove that the period of life most liable to this affection is between the sixtieth and seventieth years. In five hundred cases ob- served by the former, fourteen occurred betAveen one and ten years, sixteen between eleven and twenty, eighteen between twenty-one and thirty, eighteen between thirty-one and forty, fifty-one between forty-one and fifty, one hundred and two betAveen fifty-one and sixty, one hundred and seventy-two betAveen sixty-one and seventy, and one hundred and nine after the latter period. In one hundred and twelve cases witnessed by Dr. Maunoir, eight occurred in persons under forty years of age, eleven between forty and forty-nine, twenty-five betAveen fifty and fifty-nine, forty-one betAveen sixty and sixty-nine, and tAventy-seven between seventy and eighty-tAVO.# Thus it would seem that more people are af- fected Avith cataract between the ages of sixty and seventy than at any other period of life. Children suffer compara- tively seldom, though more frequently, perhaps, than youth. Sex does not appear to exert any particular influence in the production of this disease ; but the male is certainly much oftener affected than the female, OAving chiefly, if not wholly, to the former being more liable to all kinds of exposure. This disease, as was previously intimated, generally pro- ceeds sloAvly, so that vision is not destroyed for several years. Occasionally, hoAvever, the reverse obtains, the patient be- coming blind in a very short time. Richter relates seven cases where people laboring under retrocedent gout Ave re entirely * Essai sur Quelques Points de l'Histoire de la Cataracte. Par Th. Mau- noir M. D. (Neveu.) Memoires de la Societe Medicale d'Observation, t. i. p. 70. Paris, 1837. 508 BALL OF THE EYE. [CHAP. XII. deprived of their sight in a single night, from the formation of a cataract; and Wardrop observed several instances Avhere this occurred in a few hours. The disease may go on simul- taneously in both eyes, but generally it begins in one, and in time attacks the other. Both sexes are equally subject to it. The starting point of the opacity is usually the centre of the lens, from whence it gradually extends toAvards its circum- ference. The consistence of a lens in a state of opacity may be natural, augmented, or diminished. An increase of consist- ence is most common in persons advanced in life. After the sixtieth year, and occasionally even before that period, the cataract is frequently so hard that it cannot be divided by the needle ; and cases are not AA'anting in which it is completely ossified. A natural consistence is of rare occurrence, and is seldom seen except in young subjects, or in persons in Avhom the disease forms Avith extraordinary rapidity. A diminution of consistence is most common in childhood, and is some- times very considerable, the lens being reduced to a thin milky fluid, or to a substance resembling half-boiled glue, arrow-root, or soft curds. The color of a cataract is extremely various. In children, the opacity is generally white, like milk; in older subjects, it is often of the hue of isinglass, a solution of starch, or half-boiled egg; in aged persons, still darker, of a yellowish amber color, grayish, or broAvnish. A mottled appearance is not uncommon ; and, in some cases, though this is rare, the lens presents a radiated arrangement, the opaque lines con- verging toAvards the centre of the affected organ. It is im- portant to remark that a diseased lens is seldom of the same color in the eye as it is out of it. A change of form is of rare occurrence, and cannot be regarded as a necessary consequence of opacity. The vol- ume of the affected lens may be natural, increased, or dimin- ished. An augmentation of size is seldom observed, and then chiefly in cases of soft cataract. Atrophy of the lens is very common in old people, and often takes place Avithout any accompanying opacity. The vitreous humor is surrounded by the hyaloid mem- brane, and lodged in appropriate cells formed by prolongations frorn its inner surface. Perfectly pellucid, it is heavier and more viscid than water, and is penetrated by a branch of the central artery of the retina. When evacuated, it is never SECT. II.] ENCEPHALOID. 509 reproduced. The changes which this fluid undergoes have not been much studied, and Ave know therefore very little about them. It is sometimes unusually thick or thin, in- creased or diminished in quantity, and more or less altered in color. The capsule itself, being of the same structure as the membrane of the aqueous humor, is liable to the same morbid states. These, hoAvever, have not been observed with sufficient accuracy to admit of description. The mem- brane has been found ossified. Wardrop mentions several examples of the kind, and others are related by Morgagni and Scarpa. We have thus taken the eye apart, as it were, and ana- lyzed the diseases of its different structures. Considered as a whole, it is sometimes affected with atrophy, and the seat of various malignant groAvths. Of these, the most frequent and interesting are encephaloid and melanosis. Encephaloid is a very common and fatal disease, which, although most frequent in children, is by no means confined to them, as has been intimated by some European writers'. I have noticed it repeatedly in adults ; and, lately, I saw my colleague, Professor Drake, extirpate an encephaloid eye from a lady, forty-two years of age. In this case, as in many others, the disease was evidently excited by external violence. For a Avhile, it grew very slowly ; but, on reaching the sclerot- ica, it advanced with great rapidity, so as to acquire, in a few months, a Arery considerable magnitude. In October, 1837, when the patient Avas admitted into the Cincinnati Hospital, the eye was of a cylindrical shape, ulcerated, and of a dark, livid color, being the seat of repeated hemorrhages. It pro- jected at least an inch and a half beyond the lids, but could still be moved by its OAvn muscles, and did not appear to be attached to the socket. Her general health was rather infirm. In this condition, the organ Avas removed; and, on dissection, I observed the following appearances: the entire mass, after being divested of the muscles and cellulo-adipous tissue of the orbit, all of which were quite healthy, was nearly three inches in length by five and a quarter in circum- ference, its weight being a little upAvards of two ounces. The eye itself was of the ordinary form and volume, but Avas considerably thrown out of its position by the morbid groAvth, which Avas of an irregularly oval shape, and sprung from, the inner side of the sclerotica, near its junction with the cornea. This connection, hoAvever, was rather apparent than real; 510 BALL OF THE EYE. [CHAP. XII. for, on tracing the heterologous mass, it became evident that it originated in the retina, which had itself almost disappeared. The anterior surface Avas closely invested by the conjunctiva, which had a rough, fleecy aspect, from the morbid enlarge- ment of its villosities : about its centre Avas an incrusted ulcer, about three fourths of an inch in diameter, around Avhich the parts were someAvhat knobby, and of a bluish livid color. On cutting through this portion of the tumor, it was found to consist essentially of vessels, some of which had been opened by the erosive process, and formed the source of the frequent hemorrhages with which the patient had been latterly affected. Posteriorly, the mass was of a much lighter complexion, as well as more soft, and exhibited that peculiar tuberoid arrangement so characteristic of encephaloid. The cornea, although still transparent, was considerably diminished in size, and adhered firmly to the iris. The sclerotica was of the natural thickness, extensively attached to the choroid, and of a yelloAvish buff color. The choroid itself was of a speckled, brownish appearance; at some points, it was completely disorganized ; and, at one part, nearly oppo- site the morbid growth, there was a thin, black layer of blood beneath it. The retina, as before stated, Avas almost entirely destroyed ; and, in place of the vitreous humor, there was a dense, solid, Avhitish mass, evidently the result of an effusion of fibrin. The anterior chamber of the eye was obliterated, and the iris transformed into a substance resembling fibro- cartilage. The optic nerve, near its entrance into the sclerot- ica, was slightly enlarged, bulbous, and pervaded by en- cephaloid matter. In this case, I have no doubt the retina Avas the primary seat of the disease, and such, if we may credit the assertion of Scarpa, Saunders, Panizza, Wardrop, Lawrence, and others, is probably the fact in almost every instance. In this respect, therefore, the above dissection is one of much interest. The case is also important in another point of view, as it shows that this terrible disease may occur after the meridian of life, and in consequence of external injury. The rapidity with which it runs its course varies from a few months to several years: when extirpated, it invariably returns. In regard to melanosis of the eye, I have no personal ex- perience, but it would appear, from the dissections of Burns, Wardrop, Wilson, and others, that the disease generally originates deep in the organ; and that, if it do not commence SECT. II.] MELANOSIS. 511 in the retina, it is closely connected with it. The optic nerve is frequently implicated, Avhich is another proof that the heterologous growth may arise in the manner here stated. In a case recorded by Mr. Allan Burns, the cord within the cranium was as thick as the little finger, and as black as ink. The disease usually coexists with the same affection in other parts of the body, and has hitherto been noticed principally in persons above the middle age. Like encephaloid, it gradu- ally involves all the textures entering into the formation of the eye-ball, finally protrudes, and terminates in destructive ulceration. CHAPTER XIII. Of the Ear. Preliminary Remarks. — Malformations of the external Ear. — Polypous Growths. — Lesions of the Tympanum. — Bones of the Ear. — Eustachian Tube. — The Labyrinth and Vestibule. — Diseases of the Auditory Nerve. The organ of hearing, situated partly Avithin and partly on the outside of the skull, is usually divided into three portions — the external ear, the tympanum, and the labyrinth — Avhich differ from each other widely, both as respects their structure, and the arrangement of their component parts. Almost every variety of tissue enters into the formation of this complicated apparatus ; and hence its diseases are not only frequent in their occurrence, but also proportionably diversified in their nature. Much, hoAvever, as has been written concerning acoustic disorders, very little, it must be confessed, is known of their anatomical characters. Nor is this surprising, Avhen Ave reflect upon the complicated struc- ture of the auditory apparatus, the fact that many of its com- ponent parts are Avholly out of the reach of ocular inspec- tion, and the rare opportunities afforded for dissecting the organ in a state of derangement. All these are serious obsta- cles in the Avay of improvement, and Ave can therefore at- tempt little in respect to a scientific classification, in the present state of our knowledge. The external ear, embracing the auricle and the auditory tube, affords a subject for pathological consideration chiefly on account of congenital malformation and polypous growths. The former of these is usually comprehended under the title of imperforation of the ear. It consists in the developement of a membrane, varying in extent and thickness, and either simple, or more or less complicated, Avith deficiency of the auricle and auditory canal. The commonest form in Avhich it is presented is that of a single skin-like membrane, with a central indentation, corresponding Avith the entrance of the natural orifice : the depth at which the septum is situated CHAP. XIII.] POLYPES. 513 varies from half a line to the third of an inch: occasionally, indeed, it lies almost in contact with the tympanum. In more complicated cases, there is not only such a structure as that here mentioned, but there is great malformation of the outer ear generally. Sometimes the outer ear is entirely Avanting. The malfor- mation is usually confined to one side, and is almost con- stantly connected Avith defective organization of the auditory passage. The hearing is not ahvays lost when this state of parts exists. Oberteuffer has recorded an example of total absence of the auricles in an adult, who yet enjoyed this function very well. Professor Mussey, of Dartmouth College, has published the particulars of a somewhat similar case, in a late number of the American Journal of the Medical Sci- ences.* Another deviation from the normal standard is the congenital absence of the lobule of the ear, or its adhesion to the skin of the head. An anomaly of an opposite character is the enormous developement of these parts. The auditory canal, as Avas before stated, is sometimes im- perforate : at other times it is very much diminished, and occasionally it is closed up by a dense, gristly substance, pos- sessing all the properties of fibro-cartilage. Contraction of the canal may depend upon malformation of the temporal bone, or upon thickening of the soft parts, particularly the cuticle. Deviations in regard to the direction of this passage are now and then observed; but this, I presume, is extremely rare, and seldom exists singly. Sometimes its orifice is a mere slit instead of a round opening, and instances occa- sionally occur in Avhich it is seriously encroached upon by the tragus, antitragus, and antihelix. The lining membrane of the auditory tube is sometimes the seat of polypes. Soft and spongy in their consistence, they are of a pale reddish color, possess little sensibility, are very prone to bleed Avhen injured, and seem to consist prin- cipally of a congeries of blood-vessels, connected by loose, cellular tissue, and enclosed by a thin delicate epithelium. As affecting the ear, they are generally of a conical shape, their attachment being by a narrow peduncle, Avhilst the body fills up the auditory passage, and sometimes projects a con- siderable distance beyond its orifice. Occasionally there are several such excrescences; and, in some instances, they have * For February, 1838. vol. i. 65 514 EAR. [chap. XIII. been knoAvn to be of the form, color, and consistence of a mul- berry. Their progress is sIoav, and they may exist for a long time Avithout destroying the function of the ear. When connected, as they often are, Avith the tympanic membrane, they are apt to produce permanent deafness. The exposed parts are commonly indurated, and of a Avhitish color, from the influence of the atmosphere. Polypous groAvths of the ear are always attended Avith an increase of the natural secre- tion, Avhich is often fetid and acrimonious. The tympanum, familiarly called the drum of the ear, is lodged in the base of the petrous portion of the temporal bone, being interposed between the auditory tube and the labyrinth, on which account it is not unusual for anatomists to speak of it as the middle ear. It is a narrow, irregularly cylindrical cavity, about three lines in length, and from five to six in breadth. Posteriorly, it receives the orifice leading to the mastoid cells, and, anteriorly, the opening of the Eusta- chian tube, Avhilst across its interior is stretched a chain of bones, the most delicate in the whole body. Throughout its entire extent, it is lined by a mucous membrane. The most important part of the middle ear, in reference to pathological anatomy, is the tympanic membrane. This membrane is of a circular shape, oblique in its direction, slightly concave externally, and proportionably convex inter- nally. Being extremely delicate and transparent, it is made up of three lamellae, of Avhich the inner is merely a reflection of the mucous lining of the middle ear ; whereas the outer which is easily detached by maceration, is continuous with the cuticular covering of the auditory tube. The interme- diate layer, that which gives the part its firmness and dis- tinctive character, is of a fibrous structure, being composed of a great number of the most delicate filaments running like radii from the periphery toAvards the centre, where they are fixed to the long handle of the malleus. The vessels of the tympanic membrane are unusually abundant, and they resemble, in their mode of distribution, those of the iris. Do wounds of the tympanic membrane ever cicatrize ? Daily observation has long since ansAvered this question affir- matively. Nor are there experiments Avanting to illustrate the subject. The celebrated Valsalva repeatedly perforated, and even lacerated, this structure in dogs, which, after some time, he killed. In every one, the wounds were perfectly closed and cicatrized. Similar experiments have been performed by CHAP. XIII.] TYMPANITIS --SUPPURATION. 515 other Avriters, folloAved invariably by similar results. Indeed, so fully are surgeons aware of this occurrence, that particular instruments have been devised for the purpose of preventing it. The period required for this reunion in the human sub- ject varies from six to eighteen days, according to the size and shape of the opening, and the state of the membrane at the time of the operation. Acute tympanitis is by no means unusual, and the rapidity of its course, as Avell as its mode of termination, is extremely variable. Generally only one ear suffers at a time, though it often happens both are affected simultaneously. The ana- tomical characters are increased opacity, and thickening, Avith perverted secretion. In mild cases, the redness is usually very slight, and only a feAV straggling vessels are to be seen ; but when, on the other hand, the inflammation is intense, the affected part is of a scarlet hue, and the capillaries are so numerous as to present the appearance of a beautiful net- Avork. The normal transparency also is destroyed, and the part looks swollen and protuberant. Although lymph is sel- dom found upon the free surfaces of the membrane, yet in very severe cases it is not uncommon for this substance to be effused into its interlamellar structure. The ceruminous secretion is frequently suppressed, but the auricle and auditory tube remain unaltered. This affection, which may affect either a part or the whole of the membrane, sometimes terminates in suppuration. The matter is rarely of a healthy character ; on the contrary, it is usually muco-purulent, thin, and fetid, and so acrid as to erode the structures with Avhich it comes in contact. Blood is occasionally blended Avith it,— the result, probably, inmost instances, of exhalation. If the suppurative process be al- lowed to pursue its course unmolested, ulceration is super- added, which often continues until the membrane is seriously injured. The part of the membrane most liable to be thus affected is that immediately around the insertion of the handle of the malleus, —for what reason is not known. The number of ulcers is generally small : they are, for the most part, of an oval shape : they vary in size betAveen that of a pin-head and a split pea ; and in many instances they embrace the Avhole thickness of the affected, part, leading to perforation and a discharge of the bones of the ear. No facts have yet been recorded, I believe, that go to shoAV that ulcers in this situa- tion ever cicatrize. 516 EAR. [CHAP. XIII. In chronic inflammation, although the vascularity is usual- ly much less than in the acute form, the membrane exhibits every shade of red, from a pale rose to a mahogany broAvn. Striking alterations in the texture of the affected part are also observed. It is opaque, uneven, and thickened; so that the concavity of the membrane is effaced, and the insertion of the malleus can no longer be recognized even in the strongest light. Minute granulations are often seen upon the inflamed surface, varying in consistence, from the softness of recent lymph to the density of fibro-cartilage, and in color, from a pale ash to deep red: they are seldom bigger than a clover- seed, and are generally excessively sensitive, as Avell as vascular, giving rise to considerable pain and bleeding on the slightest touch. Small openings are frequently observed ; added to which there is alAvays a muco-purulent secretion, Avhich is often discharged in great quantities, both externally and along the Eustachian tube. The matter is sometimes excessively offensive, particularly in scrofulous subjects, and of a greenish yelloAv color. In other cases, it is thin and glairy, like the white of eggs, and exhales a disagreeable ammoniacal odor. When the inflammation continues very long, the tympanic membrane, provided it is not wholly de- stroyed, not only becomes opaque and thickened, but acquires a dense, fibro-cartilaginous consistence. Examples of this kind, indeed, are not uncommon. In severe cases of this disease, it is not uncommon for the cellular tissue and periosteum of the middle ear to become involved. A destruction of the tympanic membrane, together with a discharge of the small bones, is the usual consequence of this state. In addition to all this, there is generally exten- sive suppuration; the middle ear, the labyrinth, and the mastoid cells are filled with acrid pus ; the petrous portion of the temporal bone is carious ; the adjacent part of the dura mater is thickened, discolored, and partially detached ; and the brain is softened and otherwise disordered. Pus, chalky, and tubercular matter are sometimes found in the cavity of the tympanum ; and Morgagni observed a case in which it was intersected by delicate membranous bands, — the result, probably, of former inflammation. Itard saAv it filled with thick, yelloAv lymph; and, in one instance, he noticed a thin, Avatery fluid enclosed in distinct cells. Rosenthal Avitnessed similar appearances in the tympanum of a deaf mute. CHAP. XIII.] EUSTACHIAN TUBE--LABYRINTH. 517 The little bones of the ear may be wanting as a congenital defect, or as the result of ulcerative action of the tympanic membrane. It is seldom that they are all absent, yet several such cases are on record. In a deaf child, three years of age, Bailly found the ossicles of only one third their proper size. On the other hand, Cotunnius once found them tAvice as large as natural: the foramen rotundum Avas obstructed, and the labyrinth otherwise diseased. Communicating with the tympanum is the Eustachian tube, — a passage leading obliquely fonvards, inwards, and doAvmvards, to the fauces, by the mucous covering of Avhich it is lined. It is about two inches in length, by a line and a half in diameter, and is made up of three parts, — the posterior being osseous, the middle fibro-cartilaginous, and the anterior membranous. The lesions of the Eustachian tube may be thus stated: 1. congenital imperforation ; 2. acute and chronic inflammation, with induration and thickening of the lining membrane; 3. partial stricture ; 4. the presence of chalky matter; 5. mucous obstructions. Similar lesions occur in the mastoid cells. The labyrinth is decidedly the most intricate structure in the body, and is therefore every way deserving of its name. It lies between the tympanum and the internal auditory hole, and consists of three compartments, — one of them being de- nominated the vestibule, the other the semi-circular canals, and the third the cochlea. Of the diseases of these cham- bers very little is knoAvn; it is certain, hoAvever, that they are infrequent, and that their anatomical characters have hitherto been very little studied. Nature may leave the structure of the labyrinth imperfect, or it may, so to speak, Avholly neglect its organization. In a case mentioned by Saissy, although the ear was Avell formed, the essential part of the auditory apparatus Avas entirely absent, there being no trace Avhatever of the vestibule, cochlea, or semicircular canals. The small bones Avere found, and the cavity of the tympanum Avas filled Avith a mucilaginous fluid. The Eustachian tube presented nothing unusual. The labyrinth is sometimes imperfectly ossified, exposing thereby a portion of its membranous structure ; and cases are occasionally observed, though this is very rare, in Avhich it is composed of a single cavity, closed naturally, and having no communication Avith the tympanum. Mal- formations of this kind are analogous to what externally occurs in the organ of hearing in crustaceous animals. 518 EAR. [CHAP. XIII. The vestibule, as well as the rest of the labyrinth, is occa- sionally filled Avith a substance resembling cheese. Dr. Haighton and Mr. Cline, of London, each met Avith an interest- ing case of this sort, attended Avith congenital deafness. Itard found the vestibule occupied Avith calcareous matter. Duverney states that he has often seen the labyrinth filled with thick, purulent fluid. This appearance is most common in the case of young children, and in nearly every case is connected with disease of the cavity of the tympanum. Another malformation of this portion of the auditory appa- ratus is that of the round and oval apertures. These open- ings are not only unusually small in some instances, but even entirely Avanting. The membranes closing them may also be diseased. Long-continued irritation has a tendency to render them thick, hard, and dry ; and several cases are now on record in Avhich they were completely ossified. We have already seen that the Cotunnian liquor is liable to degenerate into substances not naturally contained in the internal ear. Of the diseases of the auditory nerve we are totally igno- rant. That it is liable to be variously affected there can be no doubt; and that deafness, partial or complete, may be thus induced appears equally certain. The nerve is sometimes unnaturally small, soft, or hard. EXPLANATION OF PLATES. Plate I. Tubercle. Fig. 1; a portion of lung containing miliary tubercles. Page 155. Fig 2; an encysted tubercle, in which the tuberculous matter is contained in a eyst, usually of a fibrous nature. Page 156. Fig. 3; a portion of lung in which the tuberculous matter is infiltrated through the substance of the organ. Page 157. Fig. 4; stratiform tubercle. This, next to the miliary, is the most common variety, and is generally situated on a serous or mucous membrane. Page 157. Plate II. Melanosis. Fig. 1: a melanotic tumor, formed by the union of several small ones. Page 171. Fig. 2; a portion of lung with pedunculated melanotic tumors attached to the pleura. Page 172. Fig. 3; lamellated variety, which is deposited exclusively beneath serous membranes. Page 172. Fig. 4; a portion of lung in which the melanotic tumor assumes the dot4ike appearance. Page 172. Fig. 5; the same, in which the dots are so close as to resemble infiltration. Page 173. Plate III. Scirrhus. Fig. 1; section of a scirrhus tumor. Page 176. Fig. 2; laminated variety. Page 176. Fig. 3; mammary sarcoma. Page 178. Fig. 4; pancreatic sarcoma. Page 178. Fig. 5; lardaceous scirrhus. Page 178. Fig. 6; gelatinoid scirrhus. Page 178.: Fig. 7; fibrous scirrhus. Page 178. Plate IV. Encephaloid. Fig. 1; lobulated, or tuberoid variety. Page 186. Fie;. 2; a pedunculated encephaloid tumor hanging from a serous membrane. Page 187. Fig. 3 ; a portion of lung, the morbid deposit assuming a stratiform character. Page 187. Fig. 4; encephaloid matter infiltrated into the cellular substance. Page lh8. c I /■ y **■* -,:■:.-., »✓--. •*.*95.*\?iv- ~ y sc -~r ^*- ~- 'k^: $ ■1 !S *< V A ?;.°0 X ;'■>&»/*■/' XAi W. m£*