FU. n,2 run Pi.4 V] V 1*1. n, i. HUMAN BIOLOGY. HUMAN BIOLOGY. DESCRIPTION OF SMALL LITHOGRAPHIC PLATES. Plate 1 represents a back view of a part of tho nervous system exposed by removing th6 skin, some of the muscles, the back part of tho spinal column, and a portion of the back and lower part of the skull. Above, a small part of the lower and back part of the cerebrum is seen convoluted like a peach-stone. Below it. the smoother cerebellum is represented. From the skull the spinal cord is seen extending the whole length of the back, and from it on each side nerves are seen extending towards all parts of the body, the large sciatic of the leg being very conspicuous. Foi particulars, see description of largo Plato 3. Pl. 2 represents the muscles and tendons as they appear when the skin is removed, except that the external muscles are also removed from the left side. The direction of the stripes shows the direction in which the muscles and their parts contract, and of course the direction in which they have a tendency to produce motion. For particulars see description of large Plate 2. Pl. 3 represents a side view of the osseous skeleton. 1. Frontal bone; 2, parietal bone; 8, its posterior border; 4, occiput; 5, nose; 6, eye sockets; 7, teeth; 8, lower jaw; 9,10, spinous processes of cervical vertobne; 14, clavicle or collar bone; 15, sternum or breast bone; 10, scapula or shoulder-blade; 17,18, ribs ; 19, humerus ; 20, ulna; 21, radius; 22, wrist; 23, metacarpus; 24, phalanges or finger bones; 25, femur; 26, patella or knee-pan; 27, tibia; 28, fibula; 29, ankle; 30, metatarsus; 31, phalanges of foot. For particulars see description of large Plate 12 {not yet published). Pl. 4, Fig. 1 represents a view of the large blood-vessels in their relative positions in the body. .Red represents arteries; blue, veins; splenic; 6, superior mesenteric; 7, capsulary; 8, emulgents; 9, inferior mesenteric; 10, lumbar; 12, medial sacral. E, common iliac A.; S, internal iliac; 1, obturator; 2, gluteal; 3, ischiatic; 4, pudic. T, external iliac A. U, femoral A.; 1, epigastric; 2, circumflex ilii; 3, profunda, a, external, b, internal circumflex, c, perforans. V. popliteal A.; 1, internal; 2, external superior articular; 3, medial; 4, external inferior; 5, internal articular. X. anterior tibial A.; 1, recurrens ; 2, internal; 3, external malleolar; 4 tarsal. V. posterior tibial A.; 1, external; 2, internal plantar. Z. fibular A.; 1, anterior; 2, posterior. Pl. 7. Front view of the system, with the skin and front part of chest and abdomen removed, r, temporal muscle; o, orbicularis; q, quadratus; p, platysma; s, sterno-cleido-mastoid; d, deltoid; B. biceps; s, supinator; c, sartorius; D. rectus; L, knee-pan; p, lungs; e, heart-case; d, diaphragm; s, stomach; / liver; c'c'e', colon; i, second stomach. Pl. 8, Fig. 1. b, y, r, candles giving off blue, yellow, and red light; it passes in all directions, but only such rays are represented as will enter the eye, which is hero represented without refracting media. 1 represents the optic nerve, terminating in thousands of points, which form the ideal retina. Upon these the light falls in direct 4 DESCRIPTION OF PLATES. lines, and that from each candle acts over much surface, and that from two different candles also acts upon some of the same nerves; distinct vision cannot therefore be caused with such an eye. Fig. 2 represents the eye and its refracting media. The light from each candle intensely acts on different points of the retina, producing clear vision, and also allowing the direction of objects to be judged. Fig. 8 is an exaggerated representation of a "long-sighted" eye. Tho light is not refracted sufficiently. Fig. 4 is an exaggerated representation of the " short-sighted " eye. Fig. 5 is an ideal representation of light from two points acting on one nerve d. !>., through which a single sensation would be caused, and apparently only one objeot seen. Fig. 6 represents two kinds of light acting on two nerves, through which two sensations are caused, and what was in fig. 5 one object becomes two in this. Thus is shown the distinction between mental and visual objects. There are two mental objects in both 5 and 6; one visual one appears in case 5 and two in case 6. Fig. 7 represents the white light of the sun streaming through a small hole into a dark room. The light would pass in the line \V. w. if it were not intercepted by the prism p, which shows that it is composed of three kinds of light, each of which is refracted more or less than the rest. The blue is refracted the most, and the red tho least. The separation of the three kinds is not in reality as perfect as here represented, and all shades of light aot upon the nerves n., producing as many kinds of sensation. Fig. 8. A circle intended to show what colors arc complementary to each other. Fig. 9 is for the purpose of showing why it has been thought that objects appear inverted. The light from i! acts at 1 in the eye, and the object I will seem to be downward. But the light reflected from 1 through the opening comes to eye 2 from above, and of course the object will to the observer 2 seem to be above him. The figures on the left of the page represent objects reflecting purple, blue, yellow, red, and white light, while the upper object does not reflect any light, and therefore appears black. The second is called a mirror, and its apparent color will depond upon the kinds of light falling upon it The other objects will appear dark except when receiving their own light. Colored objects soem to differ from white rather by what they do not, than by what they do reflect. HUMAN ANATOMY, PHYSIOLOGY AM HYGIENE. BY T. S. LAMBERT, M.D., LECTURER ON PHYSIOLOGY AT THE P1TT8FIELD INSTITUTE (FOR YOUNG LADIE6), GREENLEAP'S (BROOKLYN), RUTGERS INSTITUTE (NEW-YORK), ETC. ILLUSTRATED WITH NEARLY TI1REE HUNDRED WOODCUT AND LITHOGRAPHIC ENGRAVINGS. HARTFORD: BROCKET T, HUTCHINSON & CO. NEW-YORK: IVISON & PHINNBT. ROCHESTER: WANZER, BEARPSLEY ft C 0. ;-CIN"CINNATI: MOORE, ANDERSON ft CO.; DETROIT: KERR AND DOUGHTY ;-CHICHAGO: 8. C. GRIGGS ft CO.;— SPRINGFIELD I HUTCHINSON, CHAFFEE ft CO. 1854. Entered, according to Act of Congress, in the year 1853, by T. S. LAMBERT, In the Clerk's Office of tbe District Court of the United States for the Southern District of New-York. JOH.V F. TROW, Hkinikr & Sterkotvi-kh, 4(1 Ann-etreel, N.V. TO MULLER, BERZELIUB, HENLE, LEIBIG, 8CHWAN, TIEDEMAN, VALENTIN, VOLKMAN, AND WEBER ; TO AUZOUX, BECLARD, BERAUD, BERARD, BIOHAT, BONAMY, BOUSINGALT, BOUUGEEY, A. COMTE, AIT. COMTE, CRTTVELIIIER, DUGES, DUMAS, EDWARDS, FLOURENS, IIERSCHFELD, JOURMAIN, JOITRDAN, LONJET, LITTRE, MAG-ENDIE, OH. ROBIN AND SAPPEY; TO ARNOTT, BALY, BOWMAN, CARPENTER, COMBE, ELLIOTSON, KIRKES, LISTON, M. HALL, OWEN, PRICHARD, PAGET, QUAIN, SHARPEY, TODD, WATSON, AND WILSON, As most distinguished ornaments of their profession and humanity; TO JOHN AND CHARLES BELL, P ERE IRA, ORFILA, COOPER, LAWRENCE, GOOD, HOME, RICIIERAND, AND LAENNEC, (Who though dead yet live,) As those whose writings have given me the greatest pleasuro and much instruction; AND TO THE MEDICAL PROFESSION OP THIS COUNTRY, Whose members, as a body, I love and respect, from too many of whom to particularize I have been the recipient of courtesy, and from whoso works and conversation a rich store of knowledge has been gathered, and used with profit in the following pages; THIS BOOK 2s reaptctfulln 23«totrattn, With the intention of rendering honor whore it is so richly due, and as the best token of his admiration and indebtedness which can be presented by THE AUTHOR. PUBLISHERS' ADVERTISEMENT. The inconvenience consequent to a revision of a work is to be regretted. To use a book which is behind the times, or in any considerable degree inferior to what it may be made, is still worse for both scholar and teacher. The publishers feel assured, that the first appearance of this revised edition will secure it favor, and instantly remove any tendency to complain that may rise in any teacher's mind. A perusal of the book will certainly make it welcome. The last year or two has been remarkably fruitful in useful and interesting contributions to Biological Science, and in new and beautiful illustrations of it. The publishers could not therefore either conscientiously, or regarding merely their own interest, hesitate in respect to the course they ought to pursue. When, therefore, it became desirable to make a new set of plates, they determined to cause the work to be rewritten, and illustrated with the most liberal expenditure. They desire to call attention to the following improvements : 18 PUBLISHERS' ADVERTISEMENT. 1st. The typography and embellishments. The small type of the former edition has been replaced by larger, while the advance of science has allowed even more matter to be condensed within the former number of pages. We now present therefore fewer words, but more and clearer ideas. 2d. The arrangement, generalization and systematization. These are believed to be the best that have ever been exhibited, and show to what a degree of improvement the science of Biology has been advanced. 3d. The Nomenclature. The improvement in this respect is very conspicuous. It may be very positively said, that this, with the order and classification which has been made, will diminish the labor of teacher and pupil not less than half. There is no royal road to learning, yet there is a proper way. 4th. The analysis at the opening of new subjects —the synopsis at the close —and the heads of the pages, are considered important features. 5th. Questions have, at request, been placed at the bottoms of the pages. 6th. A very full glossary and index have been appended. TABLE OF CONTENTS. Chap. VI.—Body mu3t be kept at healthful temperature—Heat produced, circulated, preserved, and removed—Tableaux ..... 101 CnAP. V.—Tissues must be kept in repair—Useless substance removed—New substance deposited—Tableaux ....... 99 Chap. IV —Apparatus of Relation—Tissues, Bony, Cartilaginous, Secretory, Muscular and Nervous—Tableaux ...... 8S Muscles and Motory Nerves needed—Tableaux . . . .69 Chap. II.—To acquire knowledge Sensory Apparatus needed—Touch, Taste, Smell, Seeing, Hearing—Muscular Sense —Tableaux . . . . 6S Chap. III.—For protection, locomotion, handling, and speaking—Skeleton— Chap. I.—The Mind—To acquire, reflect upon, and communicate knowledge, its duty, pleasure, and profit—The Brain its immediate instrument, with which to feel, think, and cause motion—Brain progressively changing throughout life—Man differs from animals —Education—Illustrations—Im- Inferences ......... 50 GENERAL SURVEY OF MAN. PART I. Objects of Science —Classification—Relations of Physiology—Its divisions—Relations of Animals to Vegetables—Of Man to both —Subdivision of Human Biology—Anatomy, Physiology, Hygiene—Pathology, Therapeutics, Materia Medica, and Surgery—General and special Anatomy . . .35 INTRODUCTION. Objections to study of Physiology removed —Its present state—Extensive application—This work necessarily not a compilation—Arrangement of topics— The best—Its importance—Nomenclature—Confidence in Teachers—Truly scientific works best and easiest for them and Scholars —Modes of using this work—Why written —Thanks for the past—Request for future favors . 23 PREFACE. 20 CONTENTS. PART II. Chap. IV.—Sympathetic Nerves and Ganglia . . . .328 Chap. III.—Encephalon . 309 Chap. II.—Spinal Cord . . . . . . . .304 Chap. I.—Nerves • .294 NERVOUS SYSTEM. DIVISION II. Chap. II.—Muscular Systom ....... . 272 Chap. I.—Skeleton ......... 214 APPARATUS OF MOTION. DIVISION I. APPARATUS of RELATION'. BOOK I. SPECIAL ANATOMY, PHYSIOLOGY, AND HYGIENE. PAET III. Review of Part II 218 Chap. V.—Water—Food—Air—Blood—Heat^-Light—Electricity . . 19T Chap. IV.—Systems—Simple and compound Organs .... 189 Chap. III.—Tissues and Humors, simple and compound .... 151 Chap. II.—Organic Elements, simple and compound .... 140 Chap. I.—Chemical Elements, simple and compound .... 186 General Remarks . . . . . . . . 133 GENERAL ANATOMY, PHYSIOLOGY, AND HYGIENE. PART II. Review of Part I. ......... 182 Chap. IX.—Apparatus of Relation and Organic Life compose the Physical Man—Their influence upon each other and tho Mind—Tableau . . 129 Chap. VIII.—Apparatus of Organic Life—Nervous system necessary—Tissues— Tableaux .......... 126 Chap. VII.—Water, Food, Oxygen, and Clothing—Circulatory, Respiratory, Digestive, Eliminatory, and Nervous Apparatus necessary—Tableaux . . 104 21 CONTENTS. DIVISION III. ORGANS OF SENSE, Chap. I.—Organs of Touch . . . . . • • . 884 Chap. II.—Organs of Taste .887 Chap. Ill—Organs of Smell 389 Chap. IV.—Organs of Sight 841 Chap. V.—Organs of Hearing ....... 857 Chap. VI.—Organs of Muscular Sense ...... 365 Chap. VII—Organs of Internal Sense . . . . . .865 BOOK n. APPARATUS OF ORGANIC OR VEGETATIVE LIFE. GENERAL REMARKS. DIVISION I. CIRCULATORY APPARATUS. Chap. I.—Hearts, Arteries, Capillaries, and Veins . . . . .869 Chap. II.—Causes and Rapidity of Circulation of Blood . . . .882 Chap. III.—Sympathetic System . . . . . . .885 Chap. IV.—Closed or Sanguine Glands . . . . . .387 DIVISION II. RESPIRATORY APPARATUS. Chap. I.—Lungs and Air Passages ....... 891 Chap. II.—Chest and Respiration . . . . . . .895 Chap. III.—The Air 400 Chap. IV.-Speech DIVISION III. DIGESTIVE APPARATUS. Chap. I.—Mouth and Salivary Glands . . . . . .408 Chap. II.—Pharynx and Oesophagus 418 Chap. III.—Stomach 414 Chap. IV.—Second Stomach, Liver, Pancreas, and Lacteals . . .424 Chap. V.-Colon 428 22 CONTENTS. DIVISION IV. 13LIMINATORY APPARATUS. Chap. I.—The Lungs 480 Chap. II.—The Liver 480 CnAP. III.—Second Stomach and Colon . . . . . .431 Chap. IV.—Kidneys 431 Chap. V.—Skin and its Appendages . . . . . .432 Appendix . . . . . . . . . . 489 Glossary ........... 446 PREFACE. Four prominent objections are sometimes made to the study of Anatomy and Physiology. First Objection.- —" It tends to render the student a Materialist." Nothing, it seems to me, could have a stronger influence in the opposite direction than these same studies. But I propose to introduce two extracts, which will abundantly prove that the notion some people have upon this point is extremely erroneous. One is from the most illustrious of the modern French authors upon physiology, Achille Comte. The other from one of the most eminent of the English Physiologists, and indeed, it may with truth be said of the world, Kirkes. Says Comte: " Physiology, which occupies so honorable a place among the sciences that adorn the genius of the human mind, is a truly philosophical science, when putting God at the head of its researches, it considers in man not merely the mechanism of his organs, but still farther, the independent action of an immaterial agent, conscious of received impressions. The Physiologist, then, perceives the insufficiency of the entangling explanations with which materialists have abused the human mind, and feels that this machine which moves so perfectly is regulated by some other wisdom than his. As he knows not how to manage this organization, notwithstanding the knowledge he has of its parts, he is constrained to seek for a ruler above all physical causes, and his enlightened reason leads him to a divine intelligence, which harmonizes the action of all things, and 24 PREFACE. presides with constant and watchful care over the varied and wonderful phenomena of creation. Thus every one has observed that all the ancient and modern philosophers have studied the human organization With the deepest enthusiasm and the strongest emotion. Cicero has described, with all the richness of his style, the forms and beauty of this miraculous being. Fenelon, from the fulness of his Christian soul, most eloquently shows in the perfection of our organs the infinite perfection of our Creator. Bossuet raises himself to the very highest point of philosophical eloquence, when he treats upon this great subject, in his beautiful treatise upon the 1 Connaissance de Dieu et de soi-meme? which seems to have defied both time and the progress of philosophical science * * * * for it exhibits all the truths that can be found in the works of materialists, without presenting any of their wild notions." Kirkes says: " But while this may be true respecting things of sense, it would require much more and different evidence and arguments to make it probable that the cerebral hemispheres, or any other parts of the brain, are, in any meaning of the term, the organs of those parts or powers of the mind which are occupied with things above the senses. The reason or spirit of man, which has knowledge of divine truth, and the conscience, with its natural discernment of right and wrong, cannot be [has not been ?] proved to have any connection with the brain. In the complex life we live, they are indeed often exercised upon questions in which the intellect or some other lower mental faculty is also concerned; and in all such cases, men's actions are determined as good or bad, according to the degree in which they are guided by the higher or lower faculties. But the reason and the conscience must be exercised independently of the brain, when they are engaged in the contemplation of things which have not been learned through the senses, or through any intellectual consideration of sensible things. All that a man feels in himself, and can observe in others, of the subjects in which his reason and his conscience are most naturally engaged; of the mode in which these are exercised, and the disturbance to which they are liable, by the perceptions or ideas of sensible things; of the manner and sources of their instruction; of 25 PREFACE. their natural superiority and supremacy over all the other faculties of the mind; and of his consciousness of responsibility for their use; all teaches him that these faculties are wholly different not in degree only, nor as different members of one order, but in kind and very nature, from all else of which he is composed; all, if rightly considered, must incline him to receive and hold fast the clearer truth which Revelation has given, of the nature and destinies of the spirit to which these his highest faculties belong." — Kirkes and Pagetfs Physiology. If any thing more appeared necessary to prevent the reiteration of the most untenable of libels upon the medical profession and studies, the abundant and ardent testimony of the most able minds which do, or ever have adorned society, might, and should be heaped up to the very point of perfect conviction. Indeed, there is no department of science, not even Astronomy, which is more a handmaid of piety and morality than Biology. It conclusively proves the truth and fulness of that condensed but complete system of moral Philosophy and Theology the " Lord's Prayer." Second Objection. —" Unprofessional people only injure themselves by thinking of disease." The reason for the existence of this idea, is that by physicians generally, Anatomy and Physiology have been studied with reference to the cure of disease, and they are therefore thought to be of a professional character. They are not. A knowledge of them is chiefly useful to teach how to exercise and treat the various parts of the body, that they may be in the best possible condition for proper and desirable use. A blacksmith's muscles may be in health, and yet those of the left arm are not so powerful as those of the right. The organs of speech may be healthy, yet the voice harsher than necessary. The brain may be healthy, yet not equally adapted to every application. The brain of the woodchopper will be well nourished if he eats ham and corn cakes. The student requires other food. The greatest utility of Anatomy, Physiology and Hygiene has seldom been noticed. The more healthy any person is, the more can he apply them. They are not therefore professional but general. Third Objection. —" There is not time during our short school terms for such studies without neglecting elementary ones." b. 3—2. 26 PREFACE. What is elementary ?—Is it not elementary to produce or increase a relish for acquiring knowledge 1 "To please is the first step toward instruction."— Dr. Nbtt. This is, I believe, too much overlooked. The course frequently pursued induces the child to believe that the acquisition of knowledge is tedious. How can it be otherwise if he is never allowed to taste the pleasures of learning, but is restricted to the dry, abstract elements which task the memory without delighting the mind ? It is hardly better to excite the child to learn, by stimulating his ambition, by the hopes of reward apart from his study, or by fear of punishment. Well do I remember the picture in the spelling book, of a rugged hill, the crowning temple and the goddess Science, ready to bestow a wreath upon her successful votary; not a flower or fruit to beguile the early steps of the youthful toiler, nor reward of any kind for whoever did not reach the very summit. How utterly false this representation. Teach, oh teach the youthful mind to love to converse with nature's works and enthusiastically to seek for knowledge as one seeks for cool springs to slake his thirst, and thus help to save him from ennui and the seductions of vice and dissipation! No study will be more feasible for such a purpose than that which exhibits the wonders of his own system. Is the school short or does the parent, guardian or scholar think that a little schooling is all that can be afforded? Then it is so much the more important that the scholar should be excited to go on with his studies during his long vacations. Physiology is especially adapted to effectively convince the student that money cannot be " spent " in rightly educating the mind, but is most profitably invested. Its argument in favor of acquiring knowledge, is so cogent that it will induce a scholar not only to attend school longer than he otherwise would, but also to give better attention to his studies while there, at the same time it gives him many hints of how to prosecute them most easily and rapidly. It also exhibits so many favorable results of amiability, politeness and affability, and so clearly points out how to cultivate these desirable traits, that every scholar must be at least somewhat influenced, and the whole school managed, therefore, with less vexation and loss of time. 27 PREFACE. Cannot, also, a scholar learn, in part at least, to read and spell, by studying the sciences ? Fourth, Objection. —"Our scholars are not sufficiently advanced." Those who consider Anatomy, Physiology and Hygiene as professional, would naturally suppose that more mental maturity is required for the profitable study of those branches, than for the study of geography. But is not Anatomy the geography of the body ? Can a child form a more correct idea of unseen rivers, bays and oceans, mountains, prairies and deserts, than of its own heart or lungs, which can be exactly represented, or the like of which can be seen in any butcher's stall ? It is not of course desirable that the young scholar should study the dry details of Anatomy or the great philosophical truths of Physiology, or learned hypotheses and extended experiments. The general student needs only the general principles. These can be exhibited without perplexing verbosity, or occupying much time. As their application is personal, they will naturally secure assiduous attention; an allimportant point. These subjects are also especially adapted for oral instructions, particularly to the young. They can of course appreciate but few of the very many practical truths of Physiology. A more thorough acquaintance with its principles and details must be made when the mind is better prepared to appreciate the rich stores which can be here gathered. As soon, however, as the child is old enough to take care of itself at all, it should begin to learn how to do it properly. Its knowledge should advance as its charge advances. If it is absurd to give a steam engine into the charge of an engineer unacquainted with his business, it is much worse to intrust such a beautiful, delicate and complicated machine as the human body to an engineer perfectly ignorant of its constitution and the proper mode of managing it. PRESENT STATE OF PHYSIOLOGY. The rapid advance of chemistry and the perfection of the compound microscope, have developed and simplified Anatomy and Physiology to a truly wonderful degree. Nor are we less indebted 28 PREFACE. to the philosophical character of the minds which have concentrated their energies to work out the problems, so important to mankind. The last two or three years, in particular, have given us works of a most gratifying character —within that time more than 5000 octavo pages upon the subjects, have been produced in Eng land, France and Germany by the most classic minds. Physiology can no longer be considered an empirical science, but exhibits a completeness and systematic classification, which is exceedingly pleasing to the philosophical eye. EXTENSIVE APPLICATIONS OF PHYSIOLOGY. The aspect which Physiology now presents must also be very gratifying to every person; for its practical applications reach to every department of life, and are every day becoming more conspicuous. Its chief use has not always been understood. Many think it is in preserving health and prolonging life. It is vastly more important in teaching how to live and enjoy life, and profit by it. It teaches how to render our homes more delightful, and business more successful and easily accomplished, to increase personal attractions and exert favorable influences upon our fellowmen. It cultivates the heart and improves the mind. Its influence as a study is abundantly shown by the logical writers upon this subject, whose works adorn the scientific literature of the present day. Blackstone no longer stands alone. Dr. Sears has somewhere said that " the study of some books fits the mind to study any others." It is so with subjects, particularly Physiology properly treated. But more than all, Physiology exhibits a relation between the necessities and adaptation of the animal, vegetable and inorganic worlds, which convinces the mind that the universe is a perfect and complete whole. That the weather is governed by laws as uniform as those of the planets; that cold or hot, wet or dry weather, are no more accidents than an eclipse. Thus is the heart led to adore the infinite Creator whose will is the perfect law of all things. 29 PREFACE. THIS WORK NECESSARILY NOT A COMPILATION.' The recent works on Anatomy and Physiology are mostly professional, and arranged and applied accordingly. Indeed, I am not aware of one which occupies the position proposed for this. It should be complete, scientific, systematic, in accordance with the present state of Physiology, and adapted to the understanding and practical wants of the general student. There is therefore no copy to follow, at least but in part. It would also be almost impossible for any person to give particular attention to Physiology for the last few years without having many new ideas suggested to his mind, which it would be worth while to present. Daily experience in teaching general students, would also, of course, suggest arrangements, language, and applications, which would be of great utility. While, therefore, I am proud to refer to those persons mentioned in the dedication, as the sources of the greater part of the ideas presented in this work, I believe it exhibits features sufficiently distinct to give it individuality. In thus claiming some originality, not the least egotism is felt. To add something to the general stock of knowledge, is the duty certainly of every teacher. Who does it, is not to be commended; who does it not, like him who is wanting in any virtue, is to be condemned. Whoever constantly looks down, or through a microscope, may pride himself on his elevation; whoever looks up, or through a telescope, will grow sufficiently modest. ARRANGEMENT OF TOPICS. The body is so constituted, that it may be well considered under several arrangements of topics. Sometimes its Anatomy and Physiology are discussed in separate volumes. This is where the professional details require it. Sometimes they are divided into general and special, which are separately treated upon. The body is evidently divisible into two grand classes of Apparatus, one of which is used by the mind directly, and called the apparatus of relation; and the other adapted to keep the body in good condition, and called the apparatus of organic life. Either of these 30 PREFACE. may be treated upon first, according to the object in view, and either analytically or synthetically. But whatever the plan adopted, the system must be regarded as a whole, and the topics arranged in accordance with the plan and their dependence upon each other. The position of a topic in respect to others, is not accidental. The topics of any department of science are not more perfectly, or naturally connected, than those of Physiology. That lucid writer, Dr. Moore, says: Every organ of the body is developed according to a specific plan, and for a specific purpose, yet, though perfect in itself as an apparatus adapted to a particular end, it holds relation to other organs and their functions. All the body, united by one life, subserves one soul. Each part harmonizes with the rest, and the purpose of the whole is to furnish a fit medium through which the intelligent spirit may become acquainted, by actual experience and reasonable inference, with the properties of things, and thus supply its innate faculties with appropriate impressions. Ideas are but the images of objects which the mental principle perceives through the bodily senses. The body must, therefore, be fabricated in keeping with the world which it inhabits. Hence we find it subject to the common laws of matter, and only prevented from being resolved into its elements by the life that resides within it. The body is formed with peculiar reference to two principles— namely, motion and perception: motion administering to the desire of action ; perception, to the desire of knowledge. The simple idea of a being placed by Almighty Wisdom, within a body, in order to employ it for intelligence and enjoyment, would appear to require that the organization and functions of that body should be so exactly adjusted to the being using them, and so perfectly co-ordinate with the conditions of external nature, that no disorder might by possibility occur, and no pain be experienced, but rather that every perception should be pleasure, and every action happiness ; nor can we fully discern on what our well-being depends, without an insight into our formation, and some knowledge of the place which we occupy in the universe of God. BEST ARRANGEMENT FOR THE GENERAL STUDENT. It is always to be kept in mind that every thing is made for a purpose. The purpose is the leading idea. That arrangement which most clearly connects purposes with structure will be the best. " Paley's Theology " has always been so popular, intensely PREFACE. 31 interesting and instructive, because the course suggested is therein most conspicuously observed. The same general idea has been kept constantly in mind throughout this work. The general object of the work is set forth in this preface. In the introduction the objects of Science, Biology, Anatomy, Physiology, &c, have been exhibited, and a view given of the following portions of the work. Says Arnott, whose works are classic: " As no man can well understand a subject of which he does not carry a distinct outline in his mind, it is recommended to the reader to study the general synopsis, and the analysis placed at the heads of the chapters and sections, until the memory be well impressed with them." — ArnoWs Physics. Part I. takes a general survey of man. Says the discriminating and philosophical French anatomist, Cruvelhier: 8 Before entering on a detailed description of the numerous organs which compose the human body, it is advisable to present a rapid sketch of the whole. Such general views, instead of embarrassing the mind, at once enlighten and satisfy it, by exhibiting the objects of its research in their true relations, and showing the end to be attained." In this part the purpose has been shown and an apparatus constructed accordingly, till we find the whole human system before us. Part II. treats upon general Anatomy, Physiology and Hygiene. Littre, one of the most illustrious of modern Physiologists, remarks: 8 1 beg every reader to carefully observe the distinction between general and special Physiology, as, at present, a correct method is not always observed, and ideas very badly systematized are entertained on all sides; but to have a clear idea of what belongs to general, and what to special, Physiology, is to hold in the hand a conducting thread." These remarks are perfectly correct, nor would they be less so if applied to Anatomy. Though the distinction between general and special Anatomy and Physiology, has not been clearly made 32 PREFACE. in popular works, the present state of science will not permit it to be neglected any longer. Part III. presents the special Anatomy and Physiology of the system in the anatomical order. Thus the student is caused to view objects from different points, obtains a more correct idea of them, and becomes more deeply interested than if he should take but a single view. NOMENCLATURE. The present state of Anatomy and Physiology allows and has caused some very decided improvements in anatomical nomenclature. Every teacher and scholar will be glad of this. Technical terms are of course needed, for every name is a technicality. By the assistance of chemistry and the microscope, analogies and similarities in structure and use are found to exist between parts, which enable us to give generic and specific names, and which greatly facilitate the acquisition of knowledge. Whenever a name will express or refer to a use, it is better than a name dependent on position or some fancied resemblance to something out of the body. It is also exceedingly important that the term should be always used in the same denned sense. A variety of terms with the same meaning, is equally objectionable. A full glossary explains all terms used, gives their synonymes and relieves of difficulty on either point. CONFIDENCE IN TEACHERS. The pleasant acquaintance I have with many teachers gives me confidence, in submitting this work to them and others, that it will not be condemned because it does not follow in all respects the past, or repeat its errors. I wish them to examine it, read it, use it, and judge of it for themselves, unbiased by friendship or the opinions of any one, but solely with reference to the good of their scholars. It seems to me that truly scientific works are best and easiest for both teacher and scholar. Instead of being more incomprehensible and difficult, it seems to me they are clearer, and 33 PREFACE. more readily stored in the memory. If a work be a connected whole, a teacher can easily ask and answer questions upon any of its topics. He will find there is a why and wherefore for every part, book, division, chapter, section, and paragraph being as it is; and no one could, I believe, be dropped, or have its place changed, without some disadvantage. It is believed that he will find the arrangement, nomenclature, and language used herein diminishes the labor of acquiring physiological knowledge fully one-half. Is it replied, " There is no royal road to learning? " Are not all our schools, academies, and colleges for the purpose of pointing us to shorter, easier paths than, unassisted, we could find? " MODE OF USING THE WORK. Before commencing this work, the student should, if it is convenient, read the First Book of this series. It is small, but not on that account contemptible. It familiarly illustrates many ideas, and prepares the mind for advanced views of physiological science. Two books are sufficient for a class —one will answer. During the recitation hours of a week it can be read through. In that case, recitations would then be commenced with the Introduction of this book. This book is, however, complete. Part I. was introduced partly to avoid the necessity of using the First Book. If the scholar begins with this, it is recommended that he read the Introduction, and Parts I. and II., during the recitation hour, being asked some general questions. Let him commence recitation at Part III., and go on through the book, always going back to any references made. When he reviews the entire work, the Introduction and Parts I. and II. may be dwelt upon as the teacher shall think advisable. If the time be very short, the scholar may be enjoined to read over at home the portions anterior to Part III., upon which his recitation may commence the second or third day. WHY THIS WORK WAS WRITTEN. When the first edition of this work was written three objects were in view—to obtain a compensation, to gain the esteem of the 3 b. —2* 34 PREFACE. public, to benefit the community. In the revision the same motives have, doubtless, had their influence. There are, however, others of greater moment. The success of the work was then problematical, it is now historical. A degree of responsibility is now felt that could not be then. The ideas expressed will certainly influence the minds of thousands. It was then doutful how much might be ventured by either author or publisher. It is now a duty to exhibit physiological science in all its beauty,, accuracy, and utility. There is now an obligation to teachers to facilitate their labors, and to render them pleasant to the highest possible degree. I regret exceedingly that I am not better able to accomplish the task undertaken. The subject is worthy of the eloquence of the ablest pens. Such an one I do not control. The matter I vouch for the excellence of: I wish the manner was better. Those who find in it any thing to satisfy or gratify them will, it is hoped, consider that our best friends have faults, on account of which many times we love them the better, as they do not seem to be more perfect than ourselves. For the favors so generally shown to me heretofore I wish to tender my sincere thanks. They will be requited with pleasure in any way which lies in my power. Towards this revision I ask that the same good will may be shown as was bestowed upon its predecessor ; and if any service can be rendered in return, it will be a source of gratification to THE AUTHOR. HUMAN ANATOMY, PHYSIOLOGY AND- HYGIENE. INTRODUCTION. Objects of Science—Classification—Relations of Physiology—Its Divisions—Relations of Animals to Vegetables—Of Man to both—Subdivision of Human Biology— Anatomy, Physiology, Hygiene—Pathology, Therapeutics, Matoria Medica, and Surgery—General and Special Anatomy. 1. The Objects of Science may be embraced under two heads, Mind and Matter. 2. Matter exhibits itself as organized and unorganized. 3. Three Grand Departments of Science may be made: 1st, Mental Science; 2d, Biology; 3d, Cosmology.* 4. Mental Science has naturally three divisions:—1st. Theology—which considers the relations of man to his Creator. It is the highest and most profitable which can absorb the attention of man. Its perfection depends upon Revelation. 2d. Sociology—which considers the relations * This classification is not intended to be rigid and inflexible. This is not the place to enter upon a detailed classification of tho departments of science. What is done, serves its purpose in this Work. It is not my intention to enter upon any debate. Have you read the preface ? Give a synopsis of it ? Give an analysis of the introduction ? How many and what departments of science may be made ? How many and what divisions of mental science ? 36 INTRODUCTION. Biology defined—Man not an animal. of men to each other. It depends for its development upon Revelation and upon history to a great degree, but in part upon the departments below it. 3d. Psychology.—This considers the relations of man to himself, the nature and powers of his mind, and the mode of developing it. It somewhat depends upon the departments above, but chiefly relies upon those below itself. By some, Psychology has been classed as a department of Biology ; but though the character of the mental phenomena will depend very much upon the body with which they are associated, they are not to be accounted as the offspring of the material combinations alone. 5. Biology, as the word signifies, is a discourse upon every thing exhibiting life, and may be divided into Vegetable (Botany), Animal (Zoology), and Human. Formerly, three kingdoms were made —viz., mineral, vegetable, and animal. Man was ranked with animals ; but man is no more an animal than an animal is a vegetable. The vegetable exhibits the processes of nutrition, development, and reproduction, and consequently life, to which they are essential. The same operations take place in all parts of an animal, however, which is in these respects merely a vegetable. Mus. —Sometimes a person loses all power of er and feeling in a limb, but yet it lives years; it is, however, a mere vegetative life. In the animal, two other things are noticable as hinted in the illustration; the power of motion and the possession of sensibility or capability if not of feeling, of having motion produced by the action of a proper cause. The animal then embraces the vegetable; so does man embrace both the animal and vegetable characteristics, but he possesses something infinitely superior. There is nothing I shall insist on more. If a person choose to call that mind which the animal exhibits, I will fall back upon soul. I care not for the word, but I cannot consent to any mixing of the ideas; I call all that the animal exhibits instinctive, and the same in man by the same name. By mind, I mean that which distinguishes Is the mind the result of organization ? How many kinds of biology ? Any other name for them? -Is man an animal? What processes are essential to life? Are they exhibited in the vegetable ? What else is characteristic of an animal ? 37 INTRODUCTION. Human Biology—Its Relations. man; the action of which is felt as distinctly as that of the light which shines in at the eye. It does not seem possible, nor do I believe, that I who write these lines am likeTyonder dog, except in degree. Who reads them, cannot be. 6. Human Biology is a complete discourse upon the human system. The relations of this department of science to those above and below it, will be perceived by reflecting, that through the body the mind acts upon, and is acted upon by, the world—that the food of the system is drawn from the animal and vegetable worlds—that the system exhibits the characteristics of animal and vegetable life,* and is constantly influenced for good or harm by the ever surrounding objects of nature. 7. The Relations of Human Biology may be best exhibited by the following tableau : Mind ; Body ; —World ; —Body ; Mind. Mind acts upon mind through two bodies and the world. Strictly speaking, however, mind only acts upon and is acted upon by itself and its body; but the body can never act favorably upon the mind, except a proper state of the surrounding world exists. This state is affected by the body of every person, and that body again by his mind; therefore, to best use and enjoy our own minds and bodies, and those of other persons, and also the world, harmonious relations must exist among them all. As those which exist between each man's mind and body and the world, are most important to him, so are they most under his control; but as every man must be very much affected by every other of his fellow-men, so is he necessarily and correspondingly interested in society. * Hence often illustrations can be drawn from vegetables and animals, whore the functions are more isolated and easily exhibited than in man. What is Human Biology? How are its relations perceived? Through what does mind act upon mind ? What effect does the world have upon tho mind ? Who are interested in society ? 38 INTRODUCTION. Animal Biology—Its relation to Human. 8. To render the relations of the Mind, Body and World most harmonious, three things must be understood; how to properly Educate the , Mind. j Exercise the , Arrange the Body j World. Arrange the World. These things correspond to the three grand departments of science : Mental Science ; —Biology ; —Cosmology. As all persons must act on the world, it cannot be arranged by one alone. It matters not, if it be properly arranged. Then it can be used, enjoyed, and in the best sense of the term owned by the educated mind, if its body be properly exercised. As well pay taxes on the moon in order to enjoy its shining, as on a neighboring fountain, flower garden, finely-proportioned house, or aught else adapted to please an educated mind. 9. Animal Biology describes animals. They are distinguished from vegetables, by exhibiting motion and sensation, and from man, by not exhibiting any sense of right or wrong, any desire to obtain knowledge, or any mental progress through life; and by having a history which terminates with each individual, while the history of man is the history of the race, and has not reached its conclusion. Many other things distinctly human might be mentioned. 10. The relation of Animal to Human Biology consists not so much in the influences which animals exert upon man, the comforts they furnish, and the necessities they serve, as in the fact, that a large number of physical operations exhibited by man, are of a purely animal character. They are plainly exhibited by animals, and can then be made out in the human body. What must be understood in order to render the mind, body and world harmonious ? What three departments of science are named ? What is Animal Biology ? How are animals distinguished from vegetables ? How from" man ? In what does the relation of Animal to Human Biology consist? 39 INTRODUCTION. Vegetable Biology—Relations to Human Biology further divided. 11. Vegetable Biology describes vegetable life. The characteristics of this are nutrition, development and reproduction, and nothing more. The distinction between animal and vegetable life is, therefore, very clear. Animal life always embraces vegetable life, and cannot exist alone. Vegetable life may be independent. 12. The relations of Vegetable to Human Biology are of a very prominent character. Not so much because, either directly or indirectly, our food must come from the vegetable kingdom, or because so many of the beauties of the world are produced by its vegetation, as because many of the' processes taking place in the human body are purely vegetative. The cells or corpuscles of the blood I suppose to be vegetable as truly as the cell called the yeast plant. Their office is doubtless vegetative, viz., the preparation of substance for use (see p. 184 The egg is also a vegetable, till, by the action of the heat, its components have undergone those changes and formations which permit motion and sensation to be manifested. A thousand things in the human system, otherwise obscure, become like daylight when the instruction gained from the vegetable world is brought to bear upon the knotty points. See Prof. Draper's admirable work upon "The Circulation in Plants." 13. Biology is also divided into Comparative and Theological, or Philosophical. The theological is also called Natural Theology, though this term is generally used in a more generic sense, and gathers its illustrations of the goodness, wisdom, and power of God from every department of nature. 14. Comparative Biology compares the various parts of man, animals, and plants, pointing out resemblances or dissimilarities, and drawing instructing or pleasing inferences. What are characteristics of vegetable life ? Compare animal and vegetable life ? Why relations of Vegetable to Human Biology important? What is Theological Biology ? How distinguished from Natural Biology ? What is Comparative Biology ? 40 INTRODUCTION. Theological Biology—Cosmology—Its Relations. 15. Theological Biology endeavors to lead the mind to form some correct conceptions of the character of the Deity, by conspicuously exhibiting the most remarkable beauties and perfections to be found in living things, more especially those adaptations which most impressively show design. 16. Cosmology completely describes the inorganic world. It embraces Chemistry, Natural Philosophy, Astronomy, Meteorology, Mineralogy, Geology, and Geography. 17. The relations of Cosmology to Biology are exceedingly important. Not only do vegetables derive their sustenance from the earth; and man not only breathes the air, and drinks the water, but his eye is acted upon by light; his ear by the waves of air; his skin by the genial warmth of spring or the chill blasts of winter; his foot by the ground ; his sense of smell regaled by odors; and his taste by savors. Every one of the departments of Cosmology may be made his useful servant, and with the general principles of all of them he should be perfectly familiar. It should be observed that I say general principles, not details. Here also it may be said that to understand the general principles of any of the departments of science which have been mentioned, an acquaintance with the principles of mathematics and languages will be essential. These may be, therefore, as they are called, elementary or fundamental; but it should also be remembered that they are only means. 18. The relations of all the departments of science will be best exhibited by the following tableau :*— * I somewhat hesitated in writing down Observation even as an elementary branch of science. There is so little attention paid to teaching a child to observe, and how to observe, that it was doubtful if my idea of its importance was not exaggerated; but What does Cosmology describe ? What embrace ? State some of the ways in which man is acted upon by the properties of the world ? With what should every person be acquainted ? Why ? 41 INTRODUCTION. Tableau of relations of Departments of Science. TABLEAU: ! theology ; (Revelation). sociology; (History). PSYCHOLOGY. _ j ANATOMY. I LITERARY -< PHYSIOLOGY. !J | HYGIENE. HUMAN - - - "\ ("PATHOLOGY. ANIMAL. ( PbofeSSIONAL I ™ ERAPE - CS ERAPEU'«CSVEGETABLE. jf™" 'chemistry. natural philosophy. ~ astronomy. Cosmology - < | meteorology. GEOLOGY. GEOGRAPHY. Mathematics. Language—Observation. I may be permitted to apologize for the simplicity of the above arrangement. It has been, however, of great advantage to my own mind, and seems to exhibit the natural order of dependence of one science upon another. The idea must not be conceived that a person can perfect himself in one without any knowledge of the rest. A person can obtain quite a good knowledge of an inferior without any, of a superior; but it would be quite ridiculous to endeavour to acquire a perfect knowledge of a superior without any, of those below it. The true idea is, that a general knowledge of all is necessary in order to have a perfect knowledge of any. The general and practical principles of all can and ought to be learned by every boy and girl throughout our land. Above all, let not languages and mathematics be despised as not practical. As well might the blacksmith despise his bellows —because not they, but the coal, heats his iron, and it is hard work to " blow" them. really it seems to me one of the most important things in a child's or youth's education. There is a systematic mode of observing which assists remarkably in disciplining the mind. A child can and does observe before it is old enough to read; and all through life a person can learn more by observation than in any other way. It is also the natural and most pleasant way of being instructed. Some part of every day What are the divisions of Mental Science ? What of Biology ? What of Cosmology? What is said of Observation by the Author? What by Parker, and quoted? What by Moore? Can a knowledge of any branch be obtained alono? What is the true idea? 42 INTRODUCTION. Human Biology subdivided—Quotation from Moore. 19. Human Biology is subdivided into literary and professional departments. 20. The literary department embraces Anatomy, Physiology, and Hygiene. it seems to me, a student should be exercised in such a way as to develope most advantageously and scientifically an aptness for observation. Says Parker, in the opening clause of his "Aids: "To acquire ideas, it is necessary to cultivate habits of observation; to use the eyes [and all the organs of sense], not only in noticing entire objects, but also their different parts; to consider their quality, operations, uses, and effects, together with their relation to other things. Thus employed, the mind acquires materials for its own operations, and thoughts and ideas arise as it were spontaneously." I cannot forbear adding a long quotation from " Body and Mind," one of the works of Dr. George Moore (Harper & Brothers), from which I shall often take excellent passages. I wish the works themselves were in the hands of every teacher and reading person: "Whatever suggests the appearance of living action is most agreeable and enduring in the mind. Our knowledge is intended to be associated with our feelings. Hence it is difficult to teach children the rudiments of language without associating even the forms of letters with their ideas of actual life and motion. Every lesson should be on objects. God's works and man's are what we have to learn, and he whose mind dwells in books without familiarity with things, lives in a dream ; his reason is unsettled, he has no true faith, for the world of true faith is a true world full of great facts of a palpable kind, which none but madmen would dispute about. Hence the importance of familiarity with physical science, and the positive operations of mind on mind, and the grand events of providence and history, to the formation of a true philosopher. " Natural objects seen in natural order, are far better remembered than what is merely heard ; and yet, if we properly attend, we generally retain the fact stated in a lecture much more distinctly than those related in a book, which we only curiously read; and this seems to arise from our imaginations being more called into action to realize what we hear, than what is merely presented to us in printed works; for spoken language is natural, and excites our nerves sympathetically, according to intonation of voice, but letters are altogether artificial and conventional, requiring an effort to interpret them; so that, to enjoy books thoroughly, it is necessary that the reader should be quite habituated to reading, and accustomed to constrain his mind to idealize. The prolonged attention to minute objects, as in print, is itself disturbing to the faculties, and requires a long labor to overcome its evil effects. Indeed, it is not improbable that great readers are invariably awkward and untoward men, because the habits of their minds are unnatural, that is, without proper sympathies, and some of their faculties benumbed by too constant a use of their eyes on print, instead of human faces, and the many eloquent objects of nature. The unnaturalness of reading is seen in the vast difficulty experienced in educating by this means, through the medium of books, those persons who have not been accustomed to apply the eye to the discrimination of minute objects. Even the children of such persons from hereditary formation are scarcely able, under the strongest motive, sufficiently to fix their attention on letters to learn them. This difficulty is especially observed among wandering tribes. Hence we learn the wisdom of that command, Go ye into all the world and preach. "Though the world of flowers and perfume is not created so much for man as for How is Human Biology subdivided ? INTRODUCTION. 43 Subdivisions of Literary and Professional Departments of Human Biology. 21. The professional department embraces Pathology, Therapeutics, Materia Medica, and Surgery. The above division has been made, because, though Anatomy and Physiology may be studied and used for professional purposes, they no more belong to the medical profession than Chemistry or Mathematics; Chemistry is nearer to Medicine than Mathematics; Anatomy is one step nearer than Chemistry; but the profession is not reached till after two steps more, and Pathology is begun; — Anatomy, Physiology, and Hygiene should, therefore, be taught in schools of general science as much as Natural Philosophy, and for the same purpose as well as others, viz., to fit a person for any situation in life or any profession. It would not have been advisable to enter upon a minute subdivision of the professional department. The generic heads only are given. 22. Anatomy describes the color, size, form, surface, density, weight, composition, number, position, connections, and safeguards of the body and its various parts. 23. Physiology describes the objects, purposes, functions, uses, and properties of the body and its parts, and the mode and effect of action. 24. Hygiene describes the means which can and should be used to preserve a healthful state not only, but such as will best allow every proper desirable action. 25. Pathology describes the state produced by disease. Comparative Pathology compares the state in disease with that in health, and the effects of disease in various animals. 26. Therapeutics treat upon the use of curatives. beings generally disregarded by him, yet he cannot scrutinize a blossom without improving his sense of beauty, or be influenced by a color without some corresponding change in the state of his affections. Let not this observation be thought a refinement of fancy; it is a fact that man cannot be intellectually acquainted with natural beauty, without acquiring a clearness of spirit and serenity of heart unknown to ignorance ; for thus, in truth, he becomes familiar with the mind of God." What does the literary department of Human Biology embrace ? What the professional ? What is said of the study of Anatomy as a professional study ? What does Anatomy describe ? Physiology? Hygiene? Pathology? Therapeutics? 44 INTRODUCTION. Anatomy divided—Special Anatomy defined? 27. Materia Medica treats upon the medicinal character of all substances, and their compounds.* 28. Surgery treats upon accidents and external diseases, manual operations and applications. Human Biology practical to the general student is chiefly found in the literary departments, but occasionally ideas and illustrations taken from the professional departments will be both interesting and profitable. Illus. —How to stop the flow of blood. How to restore animation in case of drowning—suffocation—choking, Body. Upon a review of the facts stated in this chapter, what important inferences arc to be drawn ? Of how many and what parts is the medium between the world and brain constituted ? What is a sensory apparatus ? 59 GENERAL SURVEY OF MAN. Functions of the Sensory Apparatus. Fig. 6. Fig. 6 presents a view of the brain and a number of nerves, and 2, one organ of sense: the eye. At the lower part is seen a large bundle of nerves called the spinal cord, from which branches lead into all parts of the body, Fig. 5. Thus are all parts connected with the brain, or placed in communication with it, and also with the mind. 64. The functions of the sensory apparatus are numerous. 1st, to warn us of dangers; 2d, to excite in the mind those elementary ideas by which, upon reflection, it learns the qualities and characteristics of things; 3d, to produce pleasant sensations. Says Le Cat in his treatise on the senses, when speaking upon the ear, " Life deprived of sensations as useful as those of hearing, would be a kind of premature death. A deaf man is necessarily Describe Fig. 6. What are the functions of the sensory apparatus ? Give an illustration of each case. Give a second under each head. Repeat what Le Cat says of a deaf man. 60 GENERAL SURVEY OF MAN. Several kinds of Sensory Apparatus required—Sense of Touch and Taste. a dumb man; and who can compute his loss 1 His never-sleeping guard, that warned him of a thousand dangers, is dead, and now, the tread of the midnight thief, the crash of the falling tree, the scream of the drowning child, and the mutterings of the coming storm, fall on his ear like the tear of sorrow on the brow of death. Who can compute his loss 1 The sweet echoes of the valley, the voice of friendship, the hallelujahs of the Sabbath, and the loud artillery of heaven, are alike condensed into barren nothingness; and, in the very excess of stillness, he loses all the pleasures of solitude." 65 Several kinds of Sensory Apparatus will be required: we desire to know whenever objects touch us, and what their temperature is; also, when any part is injured by being cut, bruised, or for too long a time compressed. These several things we learn by means of the apparatus of touch. Its organ of sense is the skin, and through it the world acts in this wise— "World —Skin, Nerve, Ganglion, Mind. > , < Body. 66. It is desirable that we should appreciate the qualities of Food. For this purpose the apparatus of taste has been provided. Its organ of sense is the mouth. The mind is acted on as follows: — World —Mouth, Nerve, Ganglion, Mind. Body. 67. Minute particles of matter, disseminated in the air, are sometimes very injurious. It is not only well that we can perceive them, but also the relishable character of agree- Why will more than one kind of 6ensory apparatus be required ? What do we learn by the apparatus of touch ? What parts of the body are concerned in touch 1 What parts are concerned in tasting 1 Of what use is the sense of smell ? . 61 GENERAL SURVEY OF MAN. Apparatus of smell, sight, and hearing necessary. able food. For such purposes, behold the apparatus of smell. Its organ of sense is the nose. World—Nose, Nerves, Ganglia, Mind. v , < Bodt. 68. The direction of Objects not in contrast with us it is essential to know. Since they are not in contrast with us they must cause something to act upon us. This is called light. Of this there must be several kinds, or minute objects, when very near each other, could not be distinguished. Illus. —A piece of white paper upon a white ground does not appear distinctly. A piece of charcoal does not make a perceptible mark upon a black board. 69. The Apparatus of Sight is necessary, that we may perceive the direction of objects not in contact with us. The eye is its organ of sense. World—Light, Eye, Nerve, Ganglion, Mind. Body. In one sense the light may be called a part of the world ; but the idea is better presented as above. 70. An Apparatus which shall be acted upon by the waves of air is quite essential to well-being and happiness. The waves of air are caused by every moving object, since the air surrounds us, and all things with which we are in immediate relation. The apparatus of hearing has the ear for its organ of sense. World—Air, Ear, Nerves, Ganglion, Mind. y Body. What is the organ of sense of smell ? Why must light exist ? Why must there be several kinds of light ? For what is an apparatus of sight necessary ? Of what is the hearing apparatus constituted ? 62 GENERAL SURVEY OF MAN. Apparatus of the muscular sense. The air may be said with correctness to be part of the world; but as it is not the cause of its own waves, the rationale of the whole operation will be better appreciated if the steps are noticed as above. 71. The density of objects the mind desires to know. It can learn by causing pressure upon them. The degree of pressure made, and the resistance felt, will indicate the degree of hardness. It is also desirable to know the weight of objects. The effort necessary to ascertain them will indicate the weight. The position of the various parts of the body, and the extent of motion they have made, it is also desirable to know* All these things are determined by the apparatus of muscular sense. Its organ of sense is the muscles. This is the name given to the parts which constitute the lean meat. Many of these are represented by Plate 2. They contract to produce pressure, to sustain weights, and to produce most of the positions and motions of the body. The contraction produces an effect upon the nerves, commencing in them, and thus the mind is at last acted upon, the effect depending on the degree of contraction. Muscle, Nerve, Ganglion, Mind. ' » : ' Body. It might at first seem that the properties of the world do not act on the mind through the muscles, because the effect is not direct, and the world is not brought into the chain in the tableau. The following figure will show that an effect may be produced. 72. These six kinds compose a class of apparatus by means of which the mind becomes acquainted with the external world. This is called the external or objective class. The same things are to be learned in respect to each kind How can the mind learn the density of objects? How the weight? How the position? What is the common name of the muscular part of man and animals? How many kinds of apparatus of sensation have been mentioned? 63 GENERAL SURVEY OF MAN. Things to be learned in Anatomy—Each kind of Sensory Apparatus. Fig. 7. composing it: 1st, the character of objects that act upon it; 2d, the constitution of the organs of sense; 3d, how in it the nerve commences and is acted upon, its constitution and course, and how it terminates; 4th, the constitution of the ganglia, their action upon the mind; 5th, the effect produced in it. 73 Our necessities require that the mind should have an idea of the state of the various parts of the body itself. An apparatus of internal sensations will be necessary. Its organs of sense are, every part of the body, viz.: Every part of the Body—Nerves, Ganglia, Mind. V , > * Body. 74. In studying this class we have to consider, 1st, how the nerves commence their course and termination; 2d, the ganglia, and their action upon the mind; 3d, the effect upon it. 75. Impression is the name given to the effect produced upon any nerve, e. g., impression of taste, smell, &c. 76. Sensation is the name given to the effects produced How many things are to be learned in studying each kind of sensory apparatus ? Why is an apparatus for internal sensations necessary ? In studying the apparatus of internal sensations what are to be considered? 64 GENERAL SURVEY OF MAN. Sensorium—Brain an organ of sense—Sensations grouped. by the ganglia upon the mind, e. g., sensation of touch, sight, &c. 77. Sensorium is the name given to the collective sensory ganglia. It must always be kept in mind that sensations are here produced. It makes no difference how the action of the sensorium is caused, sensation is always produced by its action. Since, then, the mind is not in the finger but at the sensorium, how shall it determine, when the finger is pricked, what part is acted upon ? The mind and sensorium must be so constituted that when a sensation is caused through any particular nerve, the mind shall refer the sensation to the point where the nerve naturally commences. It is so. It follows that if a nerve be pricked in some part of its course, as at a, fig. 8, the mind refers the sensation to the little finger, where the nerve commences. If the corner of the elbow strike a piece of furniture, the little finger feels numb, because the sensation is referred to that point. If we compress the large nerve, called the sciatic, b, fig. 8, by sitting uncomfortably, the foot will soon be " asleep." Hence, when a limb is taken off, as at c, fig. 8, and the nerve at or above the stump is touched, the mind refers the sensation to the position where the nerve naturally commenced ; and it seems to the person as if his hand yet remained. Since diseases frequently affect the nerves in their course, or the sensorium itself, reliance cannot always be placed upon sensations, or their apparent cause. 78. It should be borne in mind, emphatically, that the brain is an organ of sense which acts very powerfully upon the mind, perhaps through the medium of the nerves and the sensorium; perhaps directly. The sensorium, which is a part of the brain, is also to be included among parts of the body the action of which causes sensations. 79. All sensations may be grouped as pleasant, unpleasant, or negative. Pleasant sensations are produced when What is the sensorium ? When the finger is pricked, why does the pain seem to be in the finger? Can reliance always be placed on sensations? Is the brain an organ of sense ? How does it act ? How may sensations be grouped ? 65 GENERAL SURVEY OF MAN. Fig. 8. 66 GENERAL SURVEY OP MAN. Advantages derived from the Sensory Apparatus, and its study. the aetion of objects in the various parts of the body is healthful, and should be continued. Unpleasant sensations warn us of dangers. Negative sensations are those which are not perceptibly pleasant or unpleasant. The action of poisons and the exhilarated mind is frequently productive of pleasant sensations. The nervous system is then perniciously affected. Education, especially physiological education, is necessary, that the character of nervous influences may be discerned, since we cannot be, like the animals, correctly governed by sensations and instincts. 80. The sensory apparatus is one of the most valueable topics of Physiology. If we study its character, we see how important to a healthy action as well as happiness of the mind a healthy and properly active body is. All parts having been designed for that action which at any time of life is best adapted to present and ultimate mental improvement, produce the most pleasant sensations when they are properly exercised. The healthy lungs, receiving pure cool air, exert through the nerves that communicate with the brain, such influences upon it as make the mind enjoy life better, become more amiable and capable. The stomach which digests wholesome food in proper quantity, causes the most highly rewarding sensations. It is therefore foolish to eat food for the sake of enjoying its savor, when its effect on the stomach will be the cause of languor or irritability. Care should be taken that every function of the body be well performed, in order that we may enjoy life and render it efficient. 81. The study of the sensory apparatus will convince us that we should cultivate the senses to a high degree, and, so far as possible, properly arrange the world; that we should especially open and educate the senses to the world's favorable influences, and also educate the mind to enjoy the action of the world. Are all pleasant sensations healthful? What effect on the mind does a healthy and active body have ? What kind of action are all parts designed for ? Why should every function of the body be well performed ? 67 GENERAL SURVEY OF MAN. Advantages of educating the senses—Extensive practical field. This subject opens an extensive, practical field. Not only is it important to educate the senses to acquire knowledge, but to enjoy life. The school-rooms for students, the shops of mechanics, the farms, the offices of professional men, the stores of merchants, the dwellings for families, should have pleasant situations, and be surrounded and furnished with the causes of enjoyment to the educated, exercised senses, and educated mind. Music should be cultivated, and the fine arts. This study will teach a person that his happiness consists not in hoarding money, or in the exercise of coarse tastes; not in dissipation, or coveting the things of others, but in being refined, educated, and industrious; in opening to the mind free avenues for the reception of the gratuitous blessings which the Creator is every moment pouring in upon those who are ready to receive them. This study teaches, that true manhood depends not upon any artificial, comparative position in society, but upon personal development and refinement which is to be accomplished by each individual for himself. If not done, he cannot fully enjoy life, or profit by it, no matter what false ideas he may have. If done, he is a man, whether he hold the hammer at the anvil, the plough in the field, or pour forth eloquence to a delighted auditory. Would that all men could perceive and thoroughly understand how much they are capable of enjoying even through the properly exercised senses, if only the mind is properly educated, and how influential this exercise is upon the mind, especially in respect to amiability. Blest power of sunshine I genial day; What balm, what life are in thy ray I To feel thee is such real bliss, That had the world no joy but this, To sit in sunshine calm and sweet- It were a world too exquisito For man to leave it for the gloom, The deep, cold shadow of the tomb.— Moore. 82. The following tableau presents the sensory apparatus grouped. ! Organ of Sense, Nerve, Ganglion. That an objective sensation may be produced, there is needed an Object, Organ of Sense, Nerve, Ganglion, Mind. What will the study of the senses teach ? Apparatus of sense includes what ? 68 GENERAL SURVEY OF MAN. That a sensation may be produced, two things only are absolutely necessary,— Ganglion and the Mind. The farther from the mind the first cause of the sensation is, the more complicate the means necessary to produce it, e. g., "To see" the sun or a candle there are required six steps : Candle; Light; Eye; Nerve; Ganglion; Mind. 'Touch, Taste, External J Smell, or ] Sight, Objective Hearing, a«« a «»„ o««„„„+„„ i Sensations. I Muscular Sense. Apparatus of 1 ' internal or Subjective Sensations. Tactile. f Objects of touch, (taglk; Nerve.; Skinj&j*** Gustatory, l Disorganizes Ganglia; Nerves; Savors. B Olfactory. ' Ganglia; Nerves; v Nose ; Odors. Optic. ? .World. Ganglia; Nerves; Eyes; Light. re. Auditory. Ganglia; Nerves; Ears; Waves of Air. Of Muscular Sense. Ganglia; Nerves ; Muscles; Kesistance. Of Common Sensation. Ganglia; Nerves ; All parts ) Exercise, of the I Health, Body. ) Disease. Mind, Sensations, Sensorium; V , > Organs of Sensation. 69 GENERAL SURVEY OF MAN. CHAPTER III. For protection, locomotion, handling, and speaking Skeleton—Muscles and Motory Nerves needed —Tableau. Protective and Motory Apparatus. 83. If we suppose the brain and organs of sense adapted to the use of the mind in thinking and feeling, or acquiring knowledge, the next thought is, that such delicate apparatus will require very efficient protection. 84. The desired protection of the brain is found in the cranium composed of many bones (Fig. 9) locked together, Fig. 9. The bones of the skull separated.— 1, Frontal, only half seen. 2, Parietal (wall). 3, Occipital (back), only half is seen. 4. Temporal. 5, Nasal (nose). 6. Malar (cheek). *7, Superior (upper) maxillary (jaw).— 8, Unguis (nail form, being about the size and thickness of the finger nail). 9, Inferior (lower) maxillary (jaw). Between 4 and 6, a part of the sphenoid or wedge-shaped bone is seen. Another bone assisting to form the skull, but not here seen, is called the ethmoid (sievelike) from being full of holes, and situated between the sockets of Page 68.—What alone is sufficient to cause a sensation ? What does sensory apparatus include ? What does the delicate brain require ? In what is the protection of the brain found? 70 GENERAL SURVEY OF MAN. Protections of the brain and organs of sense. - and presenting an arch, the strongest of architectural devices (Fig. 10), in every direction where it is liable to fracture. Fig. 10. 85. The protec- tions of the organs of sense are found in bones added to the front, lower part of the cranium. In front, the sockets of the eyes are formed, and the air-passages of the nose. The lower edge of the upper jaw bones is formed with sockets for receiving the upper teeth. Opposing these, the teeth of the lower jaw are set in it, which is hinged to the skull in such a way that it can move up and down, and from side to side, thus causing the food to be comminuted and fit to produce the greatest effect upon the organ of taste. To the sides of the head very solid bones are united, called petrous (rocky) bones, or petrous portions of the temporal bone. These protect the apparatus of hearing. 86. In addition to the protection afforded by the skull, it is covered with the muscles, tendons, skin and hair; but if we conceive the head to be perfectly formed for protecting the organs of sense and brain, which are also perfectly adapted to the requirements of the mind, yet that it may the eyes, and forms the roof of the nose. 2, 4, 5, 6, 7, 8 are double, The small bone, seen in a line between 3 and 4, and others like it, are called ossa triquetra. In what are the protections of the organs of sense found ? How are they protected? How air passages formed? How the buccal cavity? How are the organs of hearing protected ? What beside the skull affords protection to the brain ? 71 GENERAL SURVEY OF MAN. Structure of a locomotive framework—The foot use its apparatus to any very extensive profit, it must be locomoted wheresoever the mind wishes to observe. For this purpose there must, first, be a framework. 87. The simplest and best locomotive framework would consist of two levers; one end of them must be adapted to rest upon any kind of ground, and the other to turning in every direction. It might be suggested that a wheel would best serve the purposes of locomotion. It will be seen that a wheel has a certain resemblance to the legs of an animal, but is a very clumsy representative of those superlative pieces of mechanism. The spokes are inflexible levers which are fastened into a continuous rim, which forms a foot for them all, if we may so disgrace a foot as to make this awkward comparison. If a piece of the rim was given to each spoke, the idea would be more conspicuous. Instead of these spokes swinging backward and forward like a leg, whereby only four would be required, they revolve, and some 50 are required. They cannot move from side to side, but must go right on. It is almost wonderful that some mechanic has not cast aside this human invention, and, imitating nature, produced something more perfect. 88. The lower part of the lever, which is adapted to the ground, must be composed of many small pieces jointed in the strongest manner, yet so as to slightly move upon each other. This is the case with the foot. Fig. 11. Fig. 11.—View of upper surface of foot. 1 to 8, Bones of ankle. 9, Metatarsal or pre-ankle bones. 10 to 14, Bones of the toes. Why is locomotion of the hrain necessary ? How make a locomotive framework ? What objections to wheels to move the body 1 How must the lower part of a locomotive lever be made ? DescribeFig.il. 72 GENERAL SURVEY OF MAN. 89. The foot is so jointed to the leg as sometimes to form part of the lever, and again is a base to support the leg and the body above it. Fig. 12. Section of leg and foot bones. 1, Lower part of tibia. 2 to 5, Ankle bones. 6, Metatarsal. *7, 8, Toe bones. 9 to 18, Joints and synovial ligaments. The great toe has only two bones. Fig. 13. Fig. 13 represents, 1st, the feet and locomotive levers in several posi- 73 GENERAL SURVEY OF MAN. Fig.14. 90. The upper end of the lever must be finished like a ball that it may be re. ceived in a socket and turn in every direction. Fig. 15. Fig. 14 represents the thigh-bone. 2, The ball which fits the socket, S, of fig. 15, which represents a side view of the hip bone. 91. About the middle, the lever must have a joint of a hinge character, that the foot may be easily raised over obstacles, and that a person may go up and down stairs, a ladder, hill, &c. tions when walking. 2d, The bodies of the vertebrae of the back with spaces, which in life are filled with the beautiful springs called intervertebral substances. 3d, The natural curves of the spinal column. 4th, That the natural position is erect and dependent chiefly on the condition of the intervertebral substances. What are the advantages derived from tho ankle joint ? Describe Fig. 12. 18. 14. 15. Why should there be any joint at the middle of the locomotive lever? Which way should tho knee joint allow the leg to move? 3 B.—4 74 GENERAL SURVEY OF MAN. Use of hip bones—Brain protected from jars. 92. A heading must be adapted to receive the upper extremities of the levers. The hip bones, with a socket excavated from the outside of each, and strongly fastened together, are quite perfect. Fig. 16. Front view of pelvis. 5, Lower lumbar vertebra. 4, Cartilage between the vertebra and sacrum, S A. H, Hip bone. A, Acetabulum ; the socket of the hip. It might be asked why might not sockets have been excavated from the sides of the skull, and the head been placed directly upon the locomoting levers 1 1st. It would have been too violently jarred. 2d. There would not have been proper surface or positions upon it for the attachment of locomoting muscles. 3d. The partial cavity presented by the hips was needed for the protection and support of the abdominal organs. 93. To protect the brain and organs of sense from jars, the head must be supported upon an elastic apparatus placed upon the hip bones; for this purpose a strong wedge-shaped What is the use of the hip bones in respect to locomotion? Why might not sockets be excavated from the skull, or added to it, for receiving the heads of the thigh bones? How must the brain be protected from jars? Describe Fig. 16. 75 GENERAL SURVEY OF MAN. Vertebral column—Intervertebral substance—Sacrum. bone, called sacrum, is bound between and rests upon them at the back part, as in fig. 17. Fig. n. 94. Upon the sacrum is raised up a column composed alternately of bone and an elastic substance something like the ear, but which can be compressed without causing pain. The bones are called vertebrae, and the elastic substance, intervertebral substance (see fig. 13). The column thus formed has a double curvature, by means of which a part of the force which would otherwise reach the head, is scat tered. 95. The column is more elastic and stronger, as well as adapted to the organs within the chest and abdomen for these curvatures. It is also to be noticed that the irregular shapes of the bones and their flexions at the joints disperse Where is the sacrum situated ? Describe Fig. 17. Of what is the column resting upon the sacrum composed? What effect has the curvature of the column upon its strength ? 76 GENERAL SURVEY OF MAN. Force scattered—Osseous cancelli. the force which acts through the foot when it strikes the ground (see fig. 18). Fig. 18. Fig. 18. —This outline represents the skeleton walking. The dotted lines represent, in part, the dispersion of the force acting on the heel at a, viz.: a part of the force acting through the ankle, is lost in the direction of the dotted line a b, only a part of the force acting in the direction of the line a c ; of this, only a small part will act in the direction c f and of this, only a part in the direction eh; of this, only a part in the direction of g k ; and of this, only a part in the line i I. In fact, these lines represent but a small part of the directions in which the force is scattered ; for, by the curve of the thigh bone, its neck and the connection of the hip bones with the back bone, as well as the continued curvature of this, the head is saved from the sudden jar produced when the body is as erect as it can be; for instance, when a misstep is made, or a person falling strikes upon his feet. 96. Again, when divided, the bones are found to be full of irregular spaces or holes, called cancelli. (Fig. 19). Some bones exhibit large canals in their centre. These canals and cancelli are filled with marrow. This, with the want of solidity in the bones, is very effective in deadening the jars which would otherwise act through the bones. Exp. a. —Fill a glass vial or tumbler with water, and then with What does Fig. 18 represent ? In how many different directions is force scattered, as Bhown by the figure ? What is the structure of a bone ? Have you examined a bone to ascertain if the author is correct? What experiment is mentioned ? 77 GENERAL SURVEY OF MAN. Spinal column—Processes of its vertebrae. oil; if struck when empty the glass rings sharply, sounds dull when water is in it, and still more so when it contains oil. Exp. b. —Hang a bone between a row of ivory balls; raise one and allow it to drop against the rest, the bone will deaden much of its force; fill the bone with marrow and the effect will be greater. 97. But if the column were formed only of bones and elastic substances as already described, the head would be thrown to one side and the other with violence and danger whenever a person walked ever so carefully. The column must be stayed, and for this purpose its various bones must be furnished with projecting points called processes. Fig. 19. Fig. 20. Fig. 19.—A vertebra representing the body, the hole, the lateral (side) processes, and the spinous (spine-like) or posterior (back) process. Fig. 20.—Two vertebras erect, showing the bodies and superior (upper), inferior (lower), articulating (jointing), and spinous processes. 98. Some of the processes are very long,&n& connected by movable joints with the bones of the column. These are Have you tried the experiment a? What is experiment b ? Have you tried it? If the column was constructed as represented in fig. 13, what would be one bad effect of motion ? Why must the column be stayed ? Describe Fig. 19. Describe Fig. 20. 78 GENERAL SURVEY OF MAN. Ribs—Nodding and revolving motion of head. called ribs. They are curved, and connected by means of cartilage with a bone in front called the sternum or breastbone. Thus the framework of the chest is formed. When muscles are connected with the hip bones and processes of the spinal column and the ribs, the spinal column can be stayed upright or flexed in any direction. 99. But it is sometimes desirable to nod or turn the head quickly. For this purpose, the head rests upon the bone 1 (Fig. 21) in such a way that the nodding motion is obtained. The bone 1, called the atlas, rests upon the bone 2, 3, 4, (Fig. 21.) The point or tooth-like process 2, passes up through an appropriate hole in the atlas, and is fastened to the skull. The bone 1, with the skull it supports, partially revolves on bone 2, 3, 4, called the dentatus. Thus protection with great latitude of motion is obtained for the head, by the beautiful structure of the spinal column. Fig. 21. 100. To gain knowledge the mind requires a means of taking up objects and moving them from one place to another. A handling apparatus is needed to pick up objects, and grasp them securely; nothing could be better than four levers of What are ribs? How is the chest formed ? What is the form of ribs ? How is the nodding motion of the head obtained ? How the turning ? Why is a handling apparatus needed ? GENERAL SURVEY OF MAN. 79 Handling apparatus—Hand, arm, and elbow joint unequal length, with three joints, and finished at the free extremities with a sharp edge, and opposed by a shorter stout lever with two joints. They must be connected with a common centre, composed of several small parts, strongly joined, yet slightly movable. Such is the framework of the hand, together with the nails. A more admirable piece of apparatus cannot be found. If it had not been daily seen, but was to be first exhibited as a curiosity, it would be considered as the wonder of the age Fig. 22. Palmar (Palm) surface of the left hand. 1, Scaphoid. 2, Semilunar. 3, Cuneiform. 4, Pisiform. 5, Trapezium. 7, Trapezoid. 8, Magnum. 9, Unciform. 10, Metacarpal bones. 11, 14, First; 12, 15, Second; 13, Third; rows of phalanges. 101. To move the hand and the object seized, a lever will be required. To it the hand must be attached by a movable joint, while its upper extremity must be finished like a ball, that it may every way turn in a socket; near the centre, the lever must have a hinge-joint, and below this, the lever should be composed of two pieces. See Fig. 23. 102. One of these, properly speaking, belongs to the hand, and by partially revolving round the other, gives that useful What is the use of the nails? Of what is the hand composed? Describe Fig. 22. Why is a lever required? Why is an elbow joint needed ? Describe the two bones of the lower arm. 80 GENERAL SURVEY OF MAN. Socket at the shoulder—Scapula—Clavicle. motion seen when a key or a gimlet is turned. Of the two, the ulna only assists to form the elbow joint, and the radius that of the wrist. Fig. 28. Front view of bones of lower arm. 1, Shaft of ulna. 2, Greater; 3, Lesser sigmoid (S-shaped) notch. (The surface 2, is applied to the humerus.) 4, Olecranon process (point of elbow). 5, Coronoid process. 10, Ulnar Shaft. 11, Head. 12, Neck. 13, Tuberosity. 15, Inferior head. 16, 9, Styloid processes of Radius and Ulna. 103. But even with the ball and socket joint, the arm would not have sufficient latitude of motion. The socket itself must be movable. It forms part of the shoulder blade, the other part, which is thin, is placed upon the upper and back part of the chest, and serves for the attachment of the numerous strong muscles, which, through it, move the socket. See Fig. 24. 104. The socket must not be allowed to lie down in contact with the chest, but must be kept out by means of a brace. This is found in the collar bone, or clavicle, which is connected by one end and a movable joint, with the upper part of the breast bone, and by the other with the socket portion of the scapula. The clavicle represents a radius of a sphere, in the circumference of which the socket moves. Thus are we able to sweep the hands through a great distance, and by folding one part of the lever upon the other, to carry them to any point between the centre of their How is the motion when a key is turned produced 1 Describe Fig. 28. Why must the shoulder of the socket be movable ? Why must the socket De sustained away from the chest ? What is the clavicle ? GENERAL SURVEY OP MAN. 81 Lateral view* of spinal column—Hips, Chest, &c.—Speaking apparatus. sphere and its outer bounds, which by flexure of the back, is still farther enlarged. When I consider the beautiful mechan- ism of the human framework, and its curious adaptations, my mind is always overcome with feelings of admiration that cannot be expressed. Fig. 24. Lateral view of spinal column. Scapula. Clavicle. Chest. Hip bone. Lower portion of sacrum, and of coccyx. SB, Scapula. 1, Glenoid cavity. 2, 2, 2, Ribs. SP, Spinous process. H, H, Intervertebral substance. A, Acetabulum. 105. But the subject is not yet exhausted. To acquire and communicate knowledge, the mind still further requires the framework of a speaking apparatus. This apparatus must consist of a bellows, and intonating and articulating organs. The framework of the chest being movable, can increase and diminish its cavity : if it be lined, and closed at the bottom, a bellows will at once be formed. For a nose or tube an elastic substance is required, this we have in the windpipe, What advantages result from the bending of the arm at the elbow joint? Describe Fig. 24. Why is a speaking apparatus needed ? What is tift use of the chest in speaking ? What is the use of the windpipo ? 82 GENERAL SURVEY OF MAN. Larynx—Hyoid bone—Tableau of skeleton. or trachea, the upper part of which tube is composed of several pieces movable upon each other, and called the larynx. It is kept in place partly by means of a bone called the hyoid or U-shaped bone. In the larynx the tones can be produced, while articulation requires nothing more perfectly adapted than the various parts of the mouth. 106. The skeleton is a unit, or whole, each part of which is adapted to the purposes of every other part, and of the whole. Yet the framework is divisible into several classes of parts, which may without impropriety be spoken of as if designed for particular purposes, as in the following synopsis. Head, Rigid Protective Apparatus. Feet, Legs, Hips, | Framework of Locomotive Apparatus. The Skeleton is composed of Spinal Column, Framework of Elastic Protective Apparatus. Ribs, Breast Bone, Windpipe, Larynx, Hyoid Bone, Framework of Speaking Apparatus. Shoulder Bones, 1 Arms, > Framework of Handling Apparatus. Hands, ) 107. How shall motion of this beautiful, but by itself motionless framework, be caused ? Two things seem necessary That something be connected with it, and have the power of moving it. 2d. That some means exist of communicating between the mind and the immediate moving cause. Such an arrangement is found: What is the use of the larynx? Into how many classes of parts is the skeleton divisible ? . Give-the tableau of the parts and uses of the skeleton. Write it out on the black board. What two things are necessary to produce motion of the framework i 83 GENERAL SURVEY OF MAN. Muscles—Their peculiar property is contractility. 108. The lean meat of animals and man is composed of fleshy threads gathered into numerous bundles of various sizes and forms, called muscles. Ulus. —The drumstick of a fowl shows this arrangement. Plate 2 exhibits many of the human muscles^ 109. The muscle itself could not be directly and strongly connected with the frame. The connection is made by means of a strong, pearl-colored substance called tendon. Ulus. —The cords on the back and front of the hand are examples. Fig. 2R. 110. The peculiar and important property of a muscle is its contractility. That is, under the action of proper influences, it will contract, and in a short time relax. Thus will it move one or all of the parts with which it is connected. Illus. —Place the hand upon the front part of the arm above the elbow and raise the part below. The muscle beneath the hand will be felt to be in action. It is contracting, and causing the lower arm to rise. 111. Between four and five hundred muscles are found in the body, which is chiefly composed of them and their ad- Of what is lean meat composed ? What aro muscles ? What are the parts of the drumstick of a fowl called? How is the muscle connected with the framework? What is the peculiar property of muscular substance? What is contractility ? 84 GENERAL SURVEY OF MAN. Muscles grouped—Uses of muscles—Nerves. juncts. But the motions produced in the human body are much more numerous than its muscles; for not only can each one produce the motion peculiar to it, but the joint action of two or more can produce motions which neither could alone. 112. The muscles may be grouped very much as the parts of the frame to which they are attached. One group is for locomotion ; another for bending the back and head, or "staying" them«; another for speaking and expression; another for handling purposes. 113. The uses of the muscles are threefold. 1st. They serve the mind in gathering knowledge. 2d. They are used to obtain support for the body. 3d. By proper exercise they produce pleasant sensations. If the muscles serve the mind in gathering knowledge, they ought to be most active when the gathering of knowledge is most imperative, viz., in youth. Hence, the boy will run from dawn till dark without tiring. The old man desires to be quiet, and reflect upon the stores which his observation has gathered. The exercise of the muscles in youth is useful, not merely to develope themselves and other parts of the body, but also and chiefly to store the mind. If the muscles have been designed for exercise that the mind may gather knowledge, their best good demands that they should be exercised, not by the prosy walk, but in rambling among the works of nature, and observing them. Such time is not misspent or wasted, but well invested. The student who reads the book of Nature is equally studying as when he pores over the printed page. Gather knowledge in the natural way, and the best exercise of the muscles is necessarily secured. 114. White pulpy cords called nerves connect between the brain and muscles. Through these nerves an influence can be exerted upon the muscle which will cause it to contract and produce motion. It is called nervous influence, . , How numerous are the motions produced bymuscles ? How may muscles be grouped ?. What are the uses of -the muscles f How ought they to be exercised ? Are similar exercises requirod at different times of life ? What are nerves ? 85 GENERAL SURVEY OF MAN. Nerves grouped—How protected—Spinal cord. because exerted through nerves, —and motor-nervous, because motion results from its action; and the nerves are called motor-nerves from the same reason. "What this influence is, how produced, transmitted, or how it acts on the muscle, or how the mind causes it to act from the brain when desirable,,is not known. Two kinds of nerves are now seen to exist; one through which influences are exerted upon the brain, and another kind through which influences are exerted from the brain. 115. These nerves might be grouped as the muscles and different parts of the framework are; but it is not usual. They are usually counted and named in pairs, as they appear outside the brain and spinal cord. (See Fig. 5.) Those parts of the brain with which the motor nerves are connected are called motor ganglia, but their character and individuality have not been well made out. It is therefore rather from analogy than positive fact that we speak of motor ganglia of the brain. Some suppose, indeed, that the nerves which extend from the spinal cord do not reach up to the brain. This question will come up by and by. 116. The nerves which communicate between the brain and distant parts of the body must be protected from injury. No better place could be found than the canal formed in the spinal column when the spinous processes were built out from the bodies of the vertebrae, in order that they might be more easily stayed in an upright position. (See PI. 1.) Through each vertebra a hole was left, and of course a canal formed through the entire length of the column. 117. The nerves, for the most part, are gathered at the lower part of the brain into a large cord, which is situated in and extends through the canal of the spinal column. What is nervous influence? How many kinds of nerves exist? How may the nerves be grouped? What protects the spinal cord? Of what is the cord composed? 86 GENERAL SURVEY OF MAN. Beautiful Hydrostatic Apparatus of the Spinal Cord and Brain. Through holes in its sides, such portions of the nerves appear as extend to the neighboring parts. 118. The cord does not entirely Jill the canal, and is not, therefore, injured when the back is curved to the greatest degree. Within the canal, and beneath the brain, a hydrostatic apparatus of the most useful character is found. The space between the cord and wall of the canal is coarsely divided into areolae or small spaces which communicate with each other, and are filled with fluid; this affords the same result as if the cord were surrounded by a column of fluid. The same arrangement exists in the head, under the brain, which does not rest directly upon the skull. The areolae beneath the brain and around the cord communicate. Thus Ts formed one of the most curious and protective parts of the whole body. The brain reposes above, upon a hydrostatic or water-bed, with a column of fluid beneath, which, in this place, is the most perfect and delicate spring imaginable. If a person stoop, the curve of the spinal column will a little diminish its canal, and cause a portion of fluid to be pressed into the head, whereby the brain is firmly held from being jostled. No motion of the nervous substance can be quicker than that of the fluid; hence it is always between the brain and danger. If such wonderful contrivances have been made to protect the brain from harm, how important it must'be, and how much more important its duties. Gifted with a machine so beautiful, delicate, and well adapted for pleasure and profit, ought not every person to become familiarly acquainted with its exquisite workmanship 1 And when a person is acquainted with it, ought he not to feel that a momentous responsibility rests upon him if he permits it to become deranged 1 How do nerves extend from the cord to the various parts of the body ? Does the cord fill the spinal canal ? What exists about the cord ? What between the lower part of the brain and skull ? What effect upon the brain is produced by stooping? GENERAL SURVEY OF MAN. 87 Synoptic tableaux of Motory Apparatus. 119. The following tableau exhibits synoptically what is necessary for producing voluntary motion. Motory Apparatus. , » , Brain (Ganglia); Nerves ; Muscles (Tendons, &c.); Framework ; Mind; World. The motory ganglia collectively are called the motorium; the following view is therefore more brief: Motory Apparatus. , , Mind; Motorium; Nerves; Muscles; Framework:—World. The mind is thus seen to be the first cause of all voluntary motion. This is one of the most practical lessons which Physiology teaches, as will be seen in the following Chapter. 120. The facility with which the mind can act, exhibit its action, and produce an effect upon the world, will depend upon its education, and the exercise of the motory apparatus. Whether the exercise required by the motor apparatus is dependent upon the constitution of the muscles or nervous part of the apparatus, all do not agree. I suppose it is equally dependent upon both. One thing of great practical importance is certain, viz.: in order to combine the action of any number of muscles, or parts of them, frequent exercise is required; e. g., a person who is usually ill-natured will smile most melancholy when he attempts to play the agreeable, or win the attention of customers. On the other hand a person may be very amiable, and yet ungraceful, unless the muscles are trained by frequent exercise to combined action. The muscles of the eye being active involuntarily, are in part the cause of its being considered the window of the soul. The facial muscles are very easily acted upon involuntarily, and show the mind accordingly. The muscles of speech are more subject to the will, but when in action are apt to manifest the disposition. As the movements of the eye of an actively amiable person are sprightly and attractive, so will those of any part of the body be, if by exercise its muscles be subjected to a similarly easy influence of the disposition. What parts of the body are necessary for producing motion ? What is the name of the motory ganglia collectively ? What is the first cause of all voluntary motions? What facilitates mental action ? To combine the action of muscles what is necessary ? 88 GENERAL SURVEY OF MAN. Apparatus of Relation. CHAPTER IV. Apparatus of Relation—Tissues—Bony, Cartilaginous, Secretory, Muscular, and Nervous—Tableaux. Apparatus of Relation. 121. Three classes of apparatus have been exhibited. They have a general purpose, viz., to establish relations between the mind and the world. They may be, therefore, and are, grouped into one grand class called the Apparatus of Relation, as in the following tableaux : I Apparatus of Thought, a. —Apparatus of Relation, - - - < Sensory Apparatus, (Motory Apparatus. Motory Apparatus. t K ' \ •"/Motorium; . - Nerves; Muscles; Framework; \ • Tissue, Secretory, J How many tissues are found in the framework ? What is the property of muscular tissue? What tissue connects it with the bones? What is the use of areolar tissue ? What prevents the friction of tendons ? How is a bursa formed ? 99 GENERAL SURVEY OF MAN. Synopsis of tissues—Tissues necessarily undergo changes., 134". The nervous system is composed only of the nervous tissue, there being required to preserve it in form and position a certain proportion of fibrous tissue, and to prevent friction certain arrangements of secretory tissue. 135. The Organs of Sense are all composed of the already mentioned tissues, which, indeed, possess all the properties that are required in any part of the body. 136. The following tableau gives a synopsis of tissues. ' Osseous or Bony, Cartilaginous, - £ ibro f us > L Tissues. Secretory, Muscular, w Nervous, The Apparatus of Relation is composed of CHAPTER V, Tissues must be kept in repair—Useless substance removed—New substance deposited—Tableau. 137. All the tissues, but especially the nervous, muscular, and secretory, in the very act of being used, are becoming useless; no large amounts at any one instant, but a particle here and a particle there undergo changes which render them useless in the places which they filled. It is indeed supposed, that no one particle of the tissues mentioned above can be used more than once; precisely how or why the changes take place is not known. But as the components of powder which has been burned are no longer powder, or of use as powder, so the components of the nervous or muscular substance no longer form the same compounds they did before use. 138. The useless particles must be removed, and the Nervous apparatus is composed of what ? What tissues are found in the organs of sense? How many tissues in the apparatus of relation? Which tissues change most rapidly ? Do they undergo changes at once or gradually ? 100 GENERAL SURVEY OF MAN. Excretion—Elimination —Requirements for the nutrition of the-tissues. places they occupied be taken by new compounds to undergo the same changes as their predecessors. Some animals* are so small, and of such a nature, that any useless substance can easily pass to the surface of their bodies, and thus pass away altogether, and substance can pass inward in the same simple manner; but in case of the larger animals such a simple arrangement is not possible. 139. In the human system the removal of useless substance would seem to require two processes. 1st. It must be removed from the place it encumbers; 2d, it must after that be cast out or eliminated from the body. The first process I shall term excretion; the second, elimination. As substance is to be excreted by all parts of the body, there must be some means of withdrawing the substance from all parts. In the first place, a series of tubes might be placed in all parts, the tubes being so minute that useless substance might pass into them from all the minute spaces between them in the same manner as in case of the small animals spoken of. Larger tubes might open from these, and gradually uniting, at last bring all the substance together or into several places, where it could be acted upon, and if any thing of use was found, it could be appropriately disposed of, and what was worthless could be eliminated. 140. In the human system the renewal or nutrition of the tissues would seem to require, that substance should be prepared, taken into the body, carried to every part, and deposited in accordance with its wants. In case of the small animals mentioned, the food adapted to their wants is directly about them, and already prepared for their use. If what may be called food for the tissues, that is, substance prepared for their immediate nutrition, could be introduced into the minute tubes before mentioned, it would be so near the tissues they could easily obtain it. Indeed, it would then have the same relation to the tissues that the substance outside the little animal In what way Is substance removed from some small animals? For removal of useless substance from the human body what two things are required ? How could substance be withdrawn from all parts of the bodv? GENERAL SURVEY OF MAN. 101 Synoptical tableau of Repairing Processes—Preservation of Temperatures. has to its tissues. If a set of larger tubes communicated with the minute ones, and some force existed to press the nutritious substance on, all that would be wanted would be the prepared nutrition and its introduction into the large tubes. 141. The following tableau presents the subject of systematic repair synoptically. m, c • •' f That useless substance be removed. The process of repair requ.res, -j That new 8ubstance be deposited . To remove useless substance three processes j are necessary, / Elim^aS. {Preparation of food, Absorption, Circulation, Nutrition. CHAPTER VI. Body must be kept at healthful temperatures—Heat produced, circulated, preserved, and removed—Tableaux. 142. That the tissues may exhibit their properties, it is necessary that they be kept at healthful temperatures. 143. To raise the temperatures of the body, {Produced, Circulated, Preserved. 144. To lower the temperatures, {Prevented from being produced, Neutralized, Removed. When we wish to produce heat under ordinary circumstances, If nutrition were prepared and introduced into the large tubes, how could it be led to the tissues? What does the process of repair require? What processes remove useless substance? What are necessary to renew the system ? To raise and lower temperature of the body, what are necessary? 102 GENERAL SURVEY OF MAN. Production and Circulation of Caloric. we cause oxygen and carbon or hydrogen, or both to unite, when heat is given off; and also carbonic acid produced in the first case, and water in the last. nius. a. —When coal, which is, except ashes, composed of carbon, is burned, oxygen and carbon unite. \ Elus. b. —Wood is composed of oxygen, carbon, and hydrogen. When wood is burned, the oxygen of the wood unites with its hydrogen ; heat and water are produced, while any surplus oxygen with oxygen from the air unites with the carbon. Mus. c. —When a coalpit is made, the access of the air is prevented, and there is not oxygen enough to unite with the carbon which remains as coal. Mus. d. —When the oil of a lamp or substance of a candle is burned, the same process takes place as when wood is burned; the oil, tallow, wax, &c. being composed of oxygen, carbon, and hydrogen. 145. Heat may be produced in the human system by having oxygen unite with carbon or hydrogen, or both. Heat might be first produced and then circulated, or the materials by which it can be produced might be first circulated, and the heat then produced in all parts; or both plans could be combined, which would be the best. The substances which become useless as tissues, are found upon examination to be composed of oxygen, carbon, and hydrogen. Hence, if oxygen could be circulated in the minute tubes before mentioned, it would easily act upon any surplus carbon and produce heat and carbonic acid. For such a purpose, the two sets of large tubes before mentioned would be necessary, and also some means for causing the oxygen to enter them. If a sufficient amount of heat were not thus produced, more oxygen, carbon, and hydrogen must be introduced. 146. Heat might be circulated through the body by having a current of fluid constantly flowing here and there, which would take heat from one part and yield it to another. How do we ordinarily produce heat 1 What is the effect of burning coal ? Wood ? Oil ? How may heat be produced in the human system 1 If oxygen be circulated through the system, what will be the effect ? How may heat be circulated 1 103 GENERAL SURVEY OF MAN. Heat Preserved, Prevented, Removed —Tableau of apparatus and substances required by the Body. 147. Heat must be preserved by surrounding the body with non-conducting substances. 148. The production of heat can be prevented by avoiding exercise that causes a rapid change of the tissues, absorption of oxygen, and circulation in the system. In respect to neutralizing heat, all that can be said is, that persons take acids in warm weather, and with apparent profit. 149. Heat may be removed from the body, or any thing, by evaporation of fluid from its surface. That this evaporation might go on, it would be simply necessary that water should be introduced into the large vessels or tubes already mentioned; through these it could be forced into the minute tubes or vessels of the skin, thence exude to the surface and evaporate. 150. The same general apparatus and substances seem necessary to keep the body in repair and to regulate its temperature, as shown by the following tableau:— To keep the tissues in repair and at proper temperatures, there are required— « "Water; Food; Oxygen; A tubular and forcing apparatus to circulate the water, food, and oxygen ; An apparatus to prepare the food and introduce it into the tubular ; An apparatus for introducing water; An apparatus for introducing oxygen; An apparatus for elimination; _ Clothing. How may heat be preserved ? How is the production of heat prevented ? How may heat be Temoved from the body ? How can evaporation from the skin be carried on? What substances are necessary to keep the body in good condition ? What apparatus ? 104 GENERAL SURVEY OF MAN. CHAPTER VII. Water, Food, Oxygen, and Clothing—Circulating, Respiratory, Digestive, Eliminatory, and Nervous Apparatus necessary—Tableaux. 151. Water is one of the most variously useful of substances found in the body. 1st. It is necessary in the composition of the tissues. 2d. It serves as a means or vehicle of transportation from one part of the body to another— a, of the useless substance produced by the action of parts; b, of the nutritive substance which is to renew the tissues; c, of the oxygen which is to produce heat or serve any other purpose; d, of heat, receiving it from one part and yielding it to another. 3d. By exudation and evaporation it removes heat, and also assists in the elimination of all waste substances. The rapidity with which all processes take place in the body should vary very much at different times ; e. g., at one time the water should transport much more nutriment to, or remove more waste substance from a part, than is necessary at another. Now, this could be accomplished either by diminishing the quantity of water, or increasing the rapidity of its motion, or by both means together. Jllus. —If there be twenty pounds of water and nutritious substance together, of which two are nutrition, and the whole move through a given space at the rate of four pounds per minute, the whole would pass the space in five minutes, arid the two pounds of nutriment, of course, in the same length of time. If we remove four pounds of water, then the whole will pass the space in four minutes, and the two pounds of nutriment in the same time. If, instead, we add four pounds of water, the two pounds of nutriment will be six minutes in passing the space, which may be considered as representing the entire body. What are the uses of water? Should each process take place with the same activity at all times ? How could the activity of the process be regulated ? What would be the effect upon the circulation, of increasing the water in the blood four lbs. ? 105 GENERAL SURVEY OF MAN. The activity of Functions regulated by Water—Food a Nutriment 152. The quantity of water in the system affects the rapidity with which all the processes in it take place, and this is one of the most important things for every person to consider. There should be some means by which the quantity of water should be regulated. For this purpose it must be at times added to, and sometimes removed from the system. "Water is, therefore, sometimes to be considered a waste, useless, or even injurious substance in the body—hence it is to be eliminated as any other waste substance. If it exude through the skin and evaporate, it removes heat, and this is not desirable when we wish to elevate the temperature of the body. There must, therefore, be at least two eliminating organs by which water can be rapidly removed. If we consider, we shall be surprised to observe that when it is necessary to remove or add water for one purpose, every process is facilitated ; e. g., if any part requires nutriment in large quantity, there is also much waste to be carried from it, and, of course, to be eliminated. When, therefore, on any one of these accounts the water is to be diminished, so it is on account of all of them. When water should be added, the want should be indicated to the mind by a sensation which will draw its attention, as it is the purveyor of the body. Hence the advantage of thirst. 153. The less the quantity of water in the system (within proper bounds), the more rapidly all processes take place, except the removal of heat. When heat is to be rapidly removed, the other processes should not and cannot take place rapidly. 154. Food serves as nutriment to the various tissues. As the tissues are very different in constitution, it could not be expected that one kind of food, except it was very complex, would be equally good for all of them. The student, who decomposes his nervous system very rapidly, would, therefore, require different kinds of food from one who uses his muscular tissues to a corresponding degree. There must be different kinds or varieties of nutritious food. How does the quantity of water affect the activity of animal functions? What is the effect of romoving water through the skin ? What is the effect of diminishing the quantity of water in tho system ? Should all persons live on similar food ? 3 b.—5* 106 GENERAL SURVEY OF MAN. Nature of Food—Oxygen. 155. Food also assists in the production of heat. That this is true, is proved, 1st, by the fact that it is required. Heat sufficient for the wants of the body could not at all times be produced from the decomposed tissues alone. 2d. Certain kinds of food are composed of oxygen, carbon, and hydrogen only, which substances have already been shown to be adapted to the production of heat. . 3d. These kinds of food are eaten in much larger quantities in cold than in warm weather. 156. Some kinds of food are cooling. The most that can be said upon this point is, that acids are very refreshing in hot weather, and are most abundant then. 157. Some kinds of food are useful merely by their bulk. When the digestive organs are reasonably they can act more easily upon their contents than when containing but a small portion of substance. Jllus. —A person can grasp in the hand a stick of reasonable size better than a little one. 158. Food may, therefore, be regarded as a generic term. Of it there are several species, as follows:— {Nutritious, "1 Coding 0 ' | ea °k are varieties. Waste or bulk. J 159. Oxygen is a simple substance composing about one fifth of the atmosphere. It is of use in the body: 1st, in causing or assisting to cause the changes which constantly take place in all parts of the body; 2d, in producing heat. It may be useful in preparing the food for use in the various parts of the system. It is a component of every kind of food. 160. A circulating apparatus is needed for the purpose : What part of food is useful in producing heat? What substances do we use in warm weather more than in cool ? How many species of food are there ? What are the uses of oxygen in the body ? 107 GENERAL SURVEY OF MAN. Provisions for eliminating waste substance from the Body. 1st, of gathering the waste or useless substance from all parts of the body, and transmitting it to eliminating organs. 2d, of receiving and circulating the food and oxygen. It must of course be constructed accordingly. "We have already seen that three kinds of tubes, and an organ to force substance through them, would be needed in removing waste substance from, and transporting nutritious substance to the tissues; as shown by the following tableau. See also Plate 5, where the systemic arteries and veins are represented. Systemic Heart; (or forcing apparatus); . . . Systemic Arteries ; . . . Tissues, Systemic Capillaries ; Tissues ; . . . Systemic Veins; . . . . But three other things are to be provided for: 1st, the elimination of the waste substance; 2d, the introduction of food; 3d, the introduction of oxygen. The first object could be accomplished by having some branches of the arteries to lead some of the blood to organs adapted to eliminate. True, some of the substance must pass round many times before it would happen to reach the eliminating organs; but that would be of no consequence, provided it was eliminated as fast as it was produced. Such an arrangement exists in some animals which do not suffer from the accumulation of certain kinds of waste substance to a greater degree than would be consistent with the health in man, whose activity renders him more sensitive to the action of waste substance. 161. To circulate the waste substance to eliminating organs, branches of the systemic arteries lead to the minute capillaries of eliminating organs, as shown by the following tableau : What are the purposes to be served by a circulating apparatus ? How might substance be eliminated 1 Could all waste substance be eliminated by one circulation f How might eliminating substance be circulated to proper organs 1 108 GENERAL SURVEY OF MAN. Provisions for eliminating waste substanco from the Body. S Eliminating . 2 Capillaries; » Organs; § Systemic Veins; . Systemic Capillaries; . Systemic Heart; . . Eliminating E. Arteries; Capillaries; Veins; Organs ; Systemic Arteries; Also, there may be, as represented by the tableau, branches of the veins leading to eliminating organs, or both arrangements may exist. But, as the tissues are numerous, and composed of some different elements; it would be natural to suppose that the excreted substances would differ from each other in their nature and quantities. If the accumulation of any of them should be detrimental to the tissues, they must be removed before they return to the tissues. Illus. —If one half of the blood should pass through an eliminating organ which removed every particle of waste substance it received, and if there were two ounces of it produced in a given time in the tissues, the amount in the vessels would increase to four ounces, before the organs would remove it as fast as produced, as they would then receive but two ounces in the given time. 162. An arrangement may be made, by which all the substance which leaves the tissues shall pass through eliminating organs before it returns to the tissues, in either of the ways exhibited by the following tableau: Can the blood flow through the veins to eliminating organs ? Is the same kind of waste substance produced by all the tissues? If one, half the blood pass through an eliminating organ what will be the effect ? 109 GENERAL SURVEY OF MAN. Provisions for eliminating waste substance from the Body. Eliminating ... . Systemic Arteries ; Capillaries ; Veins ; . . . cc •r Organs; <» I 8 CO > >* . w OQ .' 8UVDUQ g • • • • '. 8mi!ia_ '• eraavnuvQ '. sanaA. oiwaxsig ' ' • But if the apparatus were extensive, and it were necessary that the substance should pass their rounds rapidly, one heart would not be sufficient; for if it were large and strong enough, it would seriously injure the nearer delicate capillaries. 163. If the waste substance must be rapidly removed, and as fast as it is produced, a second heart must be introduced, as follows: Tissues ; Systemic Arteries; Capillaries; Systemic Veins; Tissues; ' W s § « i I • 1 1 P 02 .' 6Uvffj,Q g ONiiVKiwna fsaiavnwvQ : saiaaxay omaiSAg fiuifvuiunjzr If a heart be introduced, the arteries which lead from it will be also necessary, as veins are not suitable for the force the heart exerts. But, as the waste substances differ from each other, it is not probable that this arrangement alone would be sufficient in all cases. The previous tableaux have represented what will be found in various animals, and is sufficient in them. 164. The arrangements exhibited under IT 161 and 163 What arrangement can be made to have all the waste substance pass through an eliminating organ before it returns to the tissues? Would one heart be sufficient in such a case ? If another heart be introduced, what else will be necessary ? 110 GENERAL SURVEY OF MAN. Tableau of Circulating Apparatus. may be combined, as shown by the following tableau. It exhibits the arrangement in the human body. _. Eliminating 1 issues; t y emB; Capillaries; \ SALIVARY GLANDS. (ESOPHAGUS, STOMACH, Digestive Apparatus, • second stomach, liver, pancreas, LACTEAL8, COLON. f Special, | KIDNEYS, Eliminating Apparatus, -j , LUNG8 [ Secondary, ¦< liver, ( SECOND STOMACH AND COLON. How many organs are adapted to eliminate waste substance from the blood ? Of what organs is the circulatory apparatus composed ? The respiratory? The dieestivo? The eliminating? 6 124 GENERAL SURVEY OF MAN. Review of the reasons for the existence of Circulatory, Respiratory, Digestive, and Eliminatory Apparatus. If we now review the necessities for these several kinds of apparatus, we shall distinctly perceive, that as the whole body is so large that substance applied to its surface could not readily make its way into the midst of the tissues except after a very long time, it was necessary to devise some means by which substance could be brought into the immediate vicinity of very minute parts. For this purpose an immense number of tubes were extended through every part of the body, and a forcing apparatus connected with them (Plate 5). These tubes were not less important in allowing all useless substance to be removed from the tissues. It must be seen, and distinctly remembered, that what is in these tubes is not, properly speaking, in the body, but on the outside of the parts to be nourished. The contents of the tubes is the nourishment. If these tubes should open from the surface of the body, there would be no difficulty in understanding this. It is all the same if the tubes form a complete circle. How shall the contents of those tubes be prepared and passed into them 1 It might be supposed that they could be prepared out of the body, and injected by means of a syringe. This is sometimes done. The blood of an animal is drawn, and by a syringe is carefully injected through an orifice made for the purpose into the vessels of an animal of the same species with the same results as when the substance enters in the ordinary way. But the oxygen needed in the blood exists abundantly in the air, in the midst of which we constantly live—and which we must use in speaking. Therefore, without any inconvenience a person may every moment introduce the oxygen, which needs no preparation, and save all trouble of introducing it at any one' time and having it in the vessels in larger quantity than is needed at the time. The chest must exist for other reasons, and its cavity may be advantageously occupied by the lungs, since they will assist a person in lifting, and in various ways. The quantity of water needed varies very much under various circumstances. It is made, therefore, very abundant, and with the slightest trouble we can pour or swallow into a portable pouch a small supply, that will, as needed, pass into the vessels. This pouch occupies a space which necessarily exists in the body for other reasons. Food must be prepared. The utensils for cooking it are too cumbersome to be portable. The kitchen is a fixture. But after the food has been cooked, a small portion may be taken into the body for farther Why is it necessary to devise means for bringing substance into the immediate vicinity of every minute part of the body 1 Is substance which is in the blood-vessels properly speaking in the tissues? GENERAL SURVEY OF MAN. 125 Apparatus of Organic Life. preparation, after which it can be passed into the vessels. Several hours are required for this preparation. What we eat does not, therefore, immediately nourish the tissues. Strictly speaking, the food we eat is not nourishment; nourishment is contained in food, which, however, mus! be prepared before it is fit to become blood. The food itself does not, therefore, pass into the body, strictly speaking; that is, it does not pass into the tissues. What is in the mouth, stomach, or second stomach, is outside the tissues; and when the nourishment passes into the blood-vessels, it is not yet in the body, or in the tissues, but outside them. If a large vessel opened from the stomach into an artery or vein, so that there was a direct and free passage, there would be no difficulty in understanding the idea. We carry with us, then, a small advance supply of food, and prepare it without inconvenience. A smaller store of water can be taken, while the air we breathe suffices only for the present moment. 197. Several different views may be taken of the blood. It is composed to a great degree of water. It is also composed of substance adapted to produce heat (and sometimes, perhaps, of substance adapted to cool the tissues), to nourish the tissues, and of waste substance. It is compounded from water, food, oxygen, and the decomposed substance of the body. CHAPTER VIII. Apparatus of Organic Life—Nervous system necessary—Tissues—Tableaux. 198. The apparatus described in the last chapter, has a common purpose, viz., to preserve the body in a condition proper for action. The several kinds are properly grouped into a grand class of organic or vegetative life, as the following tableau exhibits: How long after food is eaten before it becomes part of the tissues ? Why does it immediately satisfy and seem to strengthen ? Of what is blood composed ? What kinds of apparatus does the apparatus of organic or vegetative life embrace ? 126 GENERAL SURVEY OF MAN. Tableau of apparatus of Organic Life—Its Tissues. 199. Different parts of this class of apparatus are muscular, therefore a nervous apparatus will he necessary to excite contraction of the muscles. Also, the action of the different parts must he made harmonious; therefore, all of them must he united with a common centre, upon which influences shall be exerted, and from which they shall be received by all. ' circulatory, respiratory, The Apparatus of Organic Life includes the ¦> digestive, eliminatory, ' NERVOUS. 200. The various parts of the organic apparatus are composed of the same tissues as that of relation, with the exception of the bony. The cartilaginous is, however, required in very small quantity. The fibrous is very abundant. The muscular in medium quantity. The nervous is small in quantity. The secretory is in larger proportion than any. 201. The surface of the skin must be composed of secretory tissue. So also must the inner surface of the lungs, mouth, stomach, &c. The lungs, heart, stomach, and several organs must be suspended in the cavities they occupy, and their outer surfaces must be composed of secretory tissue, as well as the surfaces of the cavities in which they are. See Fig. 49. 202. Thus the surfaces which touch each other being free, and lubricated by serous fluid, glide over each other without causing any friction, and all the various motions of the trunk may take place, without in the least endangering the very delicate internal organs. Why is a nervous apparatus necessary as a part of tbe organic ? Of what tissues is the apparatus of organic life composed ? Of what kind of tissues is the surface of the skin composed ? "What kind of tissue must exist at the surface of the lungs ? 127 GENERAL SURVEY OP MAN. Serous Membranes of the Abdomen. Fig. 49.— Represents a section of the middle portion of the abdomen. Tho organs are somewhat displaced and dis- Eroportioned, the chief object eing to exhibit the peritoneal coat Commencing at 1, it can be traced up under, and lining, D, the diaphragm, from which It is "reflected" at 8, to the liver L, over the front edge of which it can be followed, and under the liver to 4, where it turns on to the stomach, and at 5 passes down in front of the abdominal organs to a greater or less distance, when it turns upward, forming a kind of apron, commonly called the caul,a beautiful thin membrane in appearance, netted over with fat, being the part butchers put upon the front quarters of veal to give them a better appearance, as the fat caul from a good animal can be made to improve the appearance of an indifferent one. It can be traced to the colon C, one part of which it covers, and then leaves it to go to the backbone, touching upon and gartly covering the duodenum », when again it comes away for some distance to form the outer coat of the small intestine; the general outline of its convolutions being shown by L The peritoneal coat can then be followed back to the spinal column, the two layers adhering at 10, forming the ribbon- Fig. 49. like part called the mesentery, between the two thicknesses of which the blood-vessels, the nerves, the lacteals, and the glands of the intestine are found. After continuing in a similar manner about the entire length of the second stomach, it follows down to 11, turns over the vesicle B, and passes up from 12 to 1, lining the walls of the abdomen, being there commonly called the film. The peritoneal coat, or peritoneum, adheres or grows to, or rather is a part of, those organs upon which it is found; the surface opposite to that which adheres, being "free," viz., not adherent to any thing, but continually moistened with a very glairy fluid. In general appearance, the peritoneum is a light pearl-colored, dense, strong membrane, rather easily torn off from the parts to which it belongs. If attention be again bestowed upon the figure, what appears another membrane, will be seen at 2, which passing down covers one part of the stomach, adhering at 4 to the peritoneum previously traced, and also at 5, from which it follows down, forming part of the caul, the two layers adhering to each other. It can then be traced up to the transverse colon; the surfaces between which 6 is placed not adhering, are moistened by serous fluid. It forms the outer coat of the upper part of the colon; adhering to its companion between the colon and D, the upper part of which it covers when passing over the pancreas, it is found at 2 again. Thus all the organs of the abdomen may move upon each other without the slightest degree of friction. The reader must not suppose that there are any spaces between the organs. They are in close contact, unless separated unnaturally. 128 GENERAL SURVEY OF MAN. Three kinds of free surfaces—Oil, Mucous and Serous Membranes. 203. All "free' 1 '' surfaces must be composed of secretory tissue. Upon reflection, it will be noticed that there are three kinds of free surfaces. 1st. That which is external. 2d. That which is internal, but liable to the action of the air, or food, or irritating, harshly acting substances. 3d. Internal, but moistened only by unirritating fluids. The first surface must be protected by an oily fluid. Hence the skin is called oil membrane. The second must be kept in good condition by a viscid substance of a watery character. It is called mucous, and the lining where it is formed is called mucous membrane. The third is moistened by the serum, or some bland fluid, and hence the membrane is called serous membrane. 204. Beneath the secretory tissue the dense network of fibres are found. See Fig. 43. The fibrous is therefore as extensive as the secretory. 205. Some muscular tissue is required in the entire length of the digestive canal; in the air-passages of the lungs; to compose the respiratory muscles, and to form the chief part- of the heart, while a little will be required in some of the vessels. 206. Cartilage is required only in the air-passages. 207. All parts require nerves. 208. The tissues of organic life must be kept in good condition; therefore in respect to their own tissues, the apparatus of organic life will be required to perform the same functions as in respect to the tissues of animal life. 209. Every part of the body is therefore composed of Of what are all free surfaces composed ? How many kinds of free surfaces f How are they distinguished ? How are they kept in a good condition ? What is found beneath the secretory tissue? Why is muscular tissue required? GENERAL SURVEY OF MAN. 129 The relations of the two grand classes of Apparatus. two classes of parts; one by which it may be said to be formed, and one by which it is preserved in a good condition. Mus. —The skin is composed of a cellular layer, basement, and fibrous membrane, and of nerves, that it may be an organ of sense. It is supplied with blood-vessels, lymphatics, and oil and perspiratory glands, that it may be kept in a good condition. CHAPTER IX. Apparatus of Relation and Organic Life compose the Physical Man—Their influence upon each other and the Mind—Tableau—Review of Part I. 210. The physical man is composed of two grand classes of apparatus, that of relation and that of organic life ; and it must be kept in mind, that in functions they are entirely distinct from each other. They always act in reference to each other, and are constructed for harmonious action; each may, however, in imagination, be entirely isolated, as the digestive organs of the fowl are, in Fig. 50, or as all those of the trunk in Fig. 51, which appear in their place. Indeed, we might go so far as to imagine the digestive organs left out of the body, and in some place, to prepare food against our return. The apparatus used for cooking may, in one sense, be called a part of the digestive apparatus, which is so left, or which the emigrant frequently carries with him. Such a portion of the digestive apparatus as is absolutely necessary under all circumstances, and no inconvenience in any case, being made a part of the body, as it is usually regarded. It has been already said that certain animals have no digestive apparatus. It is true, they have none connected with their bodies, but their food is prepared for their use, and whatever prepares the food, may be called the digestive apparatus of the animal, which it has no trouble about. Of what is the skin composed ? Do the classes serve the same purposes ? What might be imagined in respect to the organic apparatus? Would an apparatus of organic life alone, have any purpose or bo of any uso ? 3 b. —6* 130 GENERAL SURVEY OP MAN. Apparatus of Organic Life isolated. Fig. 61. Fig. 60. Fig. 61.— a. Maxillary gland. it. Parotid gland, b. Trachea, c. Pharynx. I. Oesophagus. /. Lung. g. Heart, e. Thorax, h. Aorta, i. Diaphragm, k. Liver. Gall-cyst. m. Stomach. «. Pancreas, o. Spleen, p. Kidney. *. Caecum, r, t. Colon, y. Second Stomach, v. Abdomen. x. Rectum. Fig. 50.—-a. Oesophagus, b. Crop. c. Ventricle. G. Gizzard. d. Liver, e. Gall-bladder. /. Biliary ducts, g. Pancreas, h, I. Second Stomach, k. Caeca, m. Colon, n. Renal duct r. Oviduct. «, t. Cloaca. In the same manner the circulatory and respiratory apparatus might be isolated, or they could be interwoven, as they are, with the exception of the vessels, in the body, for the purpose of being packed closely, and then the whole could be isolated as in Fig. 51. 131 GENERAL SURVEY OF MAN. Mutual Influences of the Mind and Apparatus of Organic Life. 211. The apparatus of organic life has no power of selfcontrol, nor can it supply its necessities except in respect to oxygen, and very slightly in respect to water. It must, therefore, have some means of acting upon the apparatus of relation, and through it upon the mind. 212. On the other hand, the influence which the mind should exert upon the organic apparatus, except when it requires to use the breathing apparatus in speaking, should not be very direct. Indirectly, the influence of the mind should be very great; for, as the action of the mind is, so will be the labor which the organic apparatus ought to perform. 213. Nothing is more certain than that the health and good condition of the organic apparatus will tend to keep the apparatus of relation in good condition, and enable the mind to use it effectually, and, on the other hand, that the healthy, vigorous action of the mind, and a good disposition tend to exalt and preserve the health of the organic apparatus. 214. To possess and preserve the health and vigor of all parts of the body, therefore, we must first regard the original constitution as of importance. 2d. We must educate and cultivate the mind intellectually and emotionally. 3d. Exercise all parts of the body properly. 4th. As whatever the organic apparatus accomplishes is done by the circulation of the blood, whatever will facilitate it must be regarded of great importance, a. The system should be rubbed often and thoroughly, b. The clothing should be loose and comfortable. 5th. The character of the air must be observed. 6th. The character of food and its preparation. Can the apparatus of organic life supply its own necessities ? Why must it act on the mind f Should mental influence upon the apparatus of organic life be direct? What effect have the mind and apparatus of organic life upon each other ? 132 GENERAL SURVEY OF MAN. Golden Rules of Health—Structure of Body simple. 7th. The utility of water must be noticed. 8th. Cleanliness of the skin must be esteemed of primary importance. 9th. Clothing must be proper. The following tableau will exhibit synoptically what must be daily noticed. ' cultivating the intellect and disposition, exercising all parts of the body properly, rubbing the system thoroughly, to preserve and pro- wearing loose dresses, mote Health we must < the character of water, daily give attention to the character of air, the character of food, personal cleanliness, _ wearing protective clothing. 215. Upon reviewing Part I. it will be seen that the structure of the whole body is much more simple than it is usually thought to be. Its complication arises from the different parts being interwoven with each other. There are, in reality, but a few kinds of parts, but there is an infinite number of divisions of them. They are all constructed upon the same principle, and all designed to accomplish a purpose which it is easy to understand should be accomplished. They are interwoven that they may be packed in a smaller space than they would otherwise occupy. Every place is usefully occupied. 216. Upon reviewing Part First, we see that the ends people wish to gain can be easily reached in the right way. Does the young lady wish to be beautiful ? Let her cultivate an amiable disposition, and her complexion will become more clear and her features more attractive. Does a person wish to enjoy life, let him simply be willing to let others enjoy themselves as well. To what must persons give daily attention in order to promote health, long life, beauty, strength, and happiness f Why does the body seem to be very complicated f Why are the parts of the body interwoven ? PART II. GENERAL ANATOMY, PHYSIOLOGY, AND HYGIENE. " It is said of Lord Bacon, that having collected a great number of books on gardening and rural affairs, and found them destitute of the information he sought, he caused them all to be piled up in his court-yard, uttering these memorable words: 1 In all these works I find no principles ; they can be of no use to any man.' To shield this humble work from condemnation on such grounds, has been the author's special aim."—Dr. Alonzo Potter. General Remarks. If any person takes a general view of the human body he will notice that it seems to be composed of many very dissimilar parts, designed for dissimilar modes of action and accomplishing different objects. But a more particular examination will convince him that similar substances are found in these differently appearing parts —the dissimilarity of these depending upon the number and proportion of the substances composing them. In the same manner as all the variety of musical pieces are produced from a few simple notes, so are the varied harmonies of this grand harmonic, the human body, produced by the combination of a few tissues possessing necessary properties. The close observer will perceive that the objects to be gained by the conspicuous parts first observed, require a combination of dissimilar properties. Jllus. —To act upon food as it ought, the stomach must be composed of a substance which can secrete gastric juice from the blood, of substance which can move its contents, of fibres which shall give it strength; viz., of secretory, muscular, fibrous tissues, » MUSCULAR 352. A simple organ is rather imaginary than real; it embraces those parts of an organ which form it, and render it fit for action, such as we have considered above, in case of the heart and diaphragm. 353. A compound organ includes not only the tissues which form it for action, but also those by which it is kept in a condition for action, viz., blood-vessels, lymphatics, simple glands, &c. Of course its growth and first existence is dependent on the receipt of blood, but we may easily and properly abstract in our minds the essential parts of an organ, by which it is fitted for action, from those which are common to all organs, as the bloodvessels, since they serve a property common to the tissues of all organs, viz., nutrition. The essentials of the heart are the serous and muscular coats ; and, when we are considering in special or descriptive Anatomy and Physiology the action of the heart, we pay little attention to the arteries, capillaries, and veins, which are in almost infinite numbers distributed among the muscular fasciculi and fibrils of this organ. Indeed it will be found that in the coats of these very minute arteries, vessels, especially capillaries, exist for the purpose of nourishing them. A compound organ is, therefore, composed of what may be called its own tissue, and also of repairing organs, which vessels are also composed sometimes of still more minute repairing organs. Like a beautiful watch, the principles for constructing which are exceedingly simple, but its works so minute, compact, and interwrought, that the child looks at the results w T ith astonishment, and sees no plan in what it is gazing upon; so is it with the human body, built up by the Supreme Architect of the Universe with Divine perfection. Wliat are the resemblances, and what the differences between the heart, stomach, and diaphragm ? What is a simple organ ? What is a compound organ ? What are the essentials of the heart ? Of what is a compound organ composed ? 197 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. Heat—Temperature of Tissues. Its various parts seem an inextricable confusion to gaping ignorance ; but, when unfolded by the Physiological Anatomist, microscope in hand, they exhibit in the strongest light that simplicity of means which, more than any thing, characterizes infinite wisdom, and awakens in the heart inexpressible emotions of reverential awe and love towards that Being whose attributes humanity can but dimly perceive—never fully appreciate. CHAPTER V. Heat, Light, Electricity—Food, Air, Water, Blood, Heat 354. The perfection of the tissues and the exhibition of their properties, requires a certain temperature—the importance of which increases as we ascend the scale from nutri tion through contractility to sensibility. The requirements of the tissues in different parts of the body are not similar, as the following tableau exhibits : Brain, 96° Throat, 98" Heart, 101° Stomach, 100 Hands, 94 Feet, 92 These degrees are not absolute and invariable. The general principle is, however, correctly exhibited. That temperature of one part which will cause pleasant sensations, will, through another, cause chilliness or unpleasant sensations of heat. The whole nervous system is particularly sensitive to irregularities of temperature; and, to preserve a proper temperature therein, is one of the most imperative duties of life. Elus. If the head becomes hot, the ideas become confused; when it is cooled again, the mind becomes clear. As much pains should be taken to lower the temperature of any part, if too high, as would be to raise it, if too low. Illus. A cool wet cloth laid for a little while upon the heated head of the diligent student, will allow him to sleep, when other- Hew do the parts of the body appear when unfolded by the anatomical physio'ogist ? What does the perfection of the tissues require ? What are the healthful temperatures of different parts ? Is the temperature of each part uniform ? 198 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Sources of Heat. wise he might toss about for hours, growing more weary instead of obtaining refreshment. I will again repeat, that, in sickness or health, one thing of prime importance is to produce a healthful temperature of all parts of the body; without it, a healthy action of the tissues cannot take place —it is a sine qua non. 355. Heat is received from without, and is produced within the body. 356. External heat is received from two sources—the sun, and artificial sources. Whether there is more than one cause of heat is not certain. Either there is, or the attendant circumstances with which its influences are exerted, make it appear to produce different effects in different cases. The genial effect which is produced by the pleasant spring or summer's sun is decidedly preferable to the same effect produced by the same temperature artificially obtained. Radiated heat is far more favorable than heat which has been conducted, and the heat of wood is preferable to that of coal. 357. Heat produced in the body is the most favorable to health, and promotes also the happiness of any person in no small degree. Whether it is because the heat differs in kind, or because it is more perfectly diffused through the system, it matters not; every one has felt the advantageous effect of thoroughly warming the body within its own means. It is the proper way. A person feels and is much better who produces and preserves his heat by proper means. 358. The action of all parts of the body seems to result in the production of heat. The common experience of every one demonstrates this proposition. Experiments have, however, been tried upon muscles in particular. It was found that their temperature always rises when they contract. This may arise from several causes. 1st. The contraction of the muscular fibrils and fasciculi would cause some friction and forcible compression of the parts, and thus heat might be Where are the sources of heat found ? Do similar degrees of heat produce similar effects, either sensations or healthful influences? Why should heat be produced in the body ? What is the effect of action in the various parts of the body ? 199 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER, Sources of Heat. caused. 2d. The action of the muscle causes an increased flow of blood through it, and heat being brought, would raise the temperature ; but this was found to rise during the continued contraction of the muscle, and of course the blood does not at that time flow into the muscle. 3d. The tissue in the act of contracting undergoes changes, and recompositions of its elements taking place, if any of its oxygen united with carbon or hydrogen, heat would be produced. The blood also brings oxygen from the lungs to the tissues, and it may unite with the carbon or hydrogen of the decomposing tissues; and, indeed, by its action may cause or assist in their decomposition. It may also be observed, that some of the decomposed substance of the body unburned in the tissue which yielded it may be transported to some place where it can be consumed, and produce heat in the act. In addition, it may be remarked, that every change which takes place in the body affects its temperature in some way. But as the action of the tissues is not as uniform as their healthful temperatures must be, their temperatures must not depend upon their activity alone. Provision has been made to supply the system with calorific food, which can also be stored up in the form of fat, serving the purpose of preserving heat while it remains, and being always at hand for use as a source of heat. In the body, therefore, there are three sources of hydrogen and carbon, which on the one side are calorifiers —viz., the decomposing tissues, the calorific food, and the fat which has been held in reserve. Oxygen is obtained from four sources —the three just mentioned, and the air breathed. The amount of heat produced in the system will therefore depend upon the amount of exercise, and food that may be used, upon the quantity of fat, —and especially upon the oxygen taken into the lungs. As the air when cold contains more oxygen in a given space than warm air, more of the effects of oxygen ought in cold weather to be exhibited. It is so; the colder the air, within reasonable bounds, the more heat will breathing it produce. The production of heat will also depend upon the natural constitution, upon the state of health, and upon mental influences. A cheerful disposition and warm heart greatly conduce to physical warmth. Let persons then have no fear of taking plenty of exercise in the pure, cold air. Neither let them fear that the night air is an insidious foe to the warmly dressed person; but let the whole atmosphere be a fountain from which to draw, night and day, the health-giving and health-producing oxygen. What effect has muscular action upon tho temperature of the muscles ? Do the temperatures of the tissues depend on their activity? 3. b.—9* 200 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Light—Electricity—Food. Light. 359. The especial influence of light upon or in the system cannot be exhibited except in case of its direct influence upon the eye. But it must not be concluded that light is unimportant in its influences. We see its genial influences upon the nutrition of the plant to be very great and conspicuous. It is also noticed in case of men, that sickness of any epidemic character is more fatal upon the shady side of the house than upon the side which receives the benefit of the sun's rays. Every room which is occupied should be so situated as to allow the sun to shine into it some portion of the twenty-four hours; health and comfort will be promoted thereby. The healthful and pleasant effect of some colors, and the unhealthful and unpleasant effect of others, will be shown in the chapter on the eye. Electricity. 360. The character of electrical influences produced by, or exerted upon the body is yet so uncertain, that no further remark can be profitably made upon it, except to say, that, without doubt, the electrical states of the objects around have frequently no small effect upon man's physical ability. Mus. —To many persons a change of weather will sometimes be indicated hours beforehand by pains of a peculiar character; indeed, a gouty person is a very good barometer. Food. " I tell you honestly what is the cause of the complicated madness of the human race: it is their gormandizing and stuffing, and stimulating the digestive organs to excess, thereby producing nervous disorder and irritation."— Abernethy. This is one of the most important topics to which the attention of the student will be drawn; for, though it is exceedingly injurious for any person to be constantly thinking about the quality and quantity of his food and trying to observe its effects, yet he should Can the influence of light be easily exhibited? Are its influences considerable? Which part of a house is most healthy, the shady, or that exposed to the sunlight ? Are the influences of electricity now definitely known ? HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. 201 Dr. Moore's Remarks on Food. well understand the general principles by which he should be' governed in the selection of food, not so much for the preservation of health, as that he may keep all the tissues in such a condition that he can use and enjoy them to the highest degree and in the best manner. I propose here to introduce several extracts from the most excellent —indeed superlatively so—works of Dr. Moore. " As before observed, the study of tho stomach is the study of morality. By investigating the influence of food and drink on our minds, we soon discover the strongest motives for self-denial, and learn many a forcible lesson concerning the nature and extent of our responsibility. The results of mismanaging the stomach typify all the effects of our abandonment to any other propensity; for it is most evident that if we do not keep appetite under control, the right use of our reason is abolished, and wo become more completely enslaved to our lusts than the most grovelling beast. The comfort and efficiency of intellect, nay, the moral perception, manliness, and virtue of the mind depend greatly on our use of aliment; and in the very means by which we sustain the strength of the body, or most directly disorder its functions, we at the same time either fortify or disable the brain, so that we shall be qualified to use our faculties with advantage, or else, amid the confusion of our sensations, be rendered incapable of rational attention. Who has not seen the bright dreams of his morning's philosophy clouded by the fumes of a tempting table, and the best resolves of calm thoughtfulness lost amid the sparklings of wine ? Man has invented most of his dangers ; he delights in exposing himself to artificial excitements, and he would rather run the risk of perdition than not try tho force of temptation; for alas! since selfconfidence first abased him, he has never believed that he could not conquer appetite according to his knowledge whenever he pleased, until he has found his will itself corrupted, and all his humanity helpless and undone. Animal instincts never conduct to such dangers; but the human mind, while it refines the sensations of the body by its own intensity, aggravates the evils amid which it riots, and by its greater capacity for pleasure twines the snare most cunningly around the soul, and by speculating in sensualities, raises a multitude of evil spirits, which at first appear in forms of delicious beauty, but as they weary his brain with their ceaseless presence, they gradnally assume disgusting appearances, and as they become more and more hateful, he is more and more in earnest to dismiss them, while they only the more closely haunt and more thoroughly torment him. Reason has been placed by the only wise God in the midst of seductive influences, that by thus perceiving the slender tenure of her power, she may be forced to look above the body for motives to sustain her in dominion over appetite. " The influence of diet on the moral and intellectual character of children has been extensively observed, because they present the best opportunity of witnessing the direct effects of bodily condition on temper, their feelings being undisguised. Of course, as their bodies are in the process of formation, their mental habits are also What is Abernethy's opinion of overeating? What is the effect of investigating the influence of food ? Why is there any connection between manliness of miud and aliment? Who is the cause of the dangers to which a man is exposed ? 202 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Influence of Food upon the exhibition of the Mental Powers. forming; and it is of vast importance that this subject should be well understood. It is, however, unfortunately, but little regarded in general, and education is conducted more frequently as a plan by which the mind may be forced into any shape by fear, than as a matter the success of which will be proportioned to the care with which the body is treated and the faculties encouraged, according to physical fitness for mental enjoyment. The work of mental improvement should commenco by improving the body. Let the soul be happy in its home, and it will soon expatiate amid ever varying ideas, and be ready to sympathize with all those who will lead it out to contemplate and enjoy the facts of creation and of history. This is tho whole mystery of education. It has been proved, by comparisons among large numbers of children, that those brought up in poverty and privation, having of course a bad physical condition, are much more torpid in intellect and irritable in temper than children of the same age who have been better fed and cared for. Under tho best and kindest teachers, the former cannot keep pace in mental advancement with the latter. This incapacity may be hereditary; for, alas 1 not the least among the numerous miseries of abject poverty is the physical deprivation which fastens on the souls of its children a tendency to mental aberration and degeneracy, by depraving the bodily constitution. We scarcely wonder that the wan and withered young mother, in whose breast starvation has dried up the fountain of nature's charity, should look with tearless but bloodshot eye upon her dead baby, and thank God for taking it away. This is no imagined possibility, but a bare, horrible, frequent fact. There are many such mothers, who, because labor is paid so grudgingly, witness no charm in the domestic circle; and many more who, after watching their infants through atrophies produced by their own hunger, have been rewarded for their affection and anxiety by the fierce ill-temper thus engendered in the boy or girl, whom neither weary wife nor cheerless husband has the wisdom or good feeling to soothe and manage; for, inured to the wretchedness of finding no pity from nominal Christians, they, too, seem to escape from the keener sensibilities of soul by indulgence in sensualities. Their moral nature has been starved by those whom God required to act as neighbors to them. Tet it is wonderful to see how the kindly affections generally triumph over these terrible evils of life, and how the noblest feelings flourish in the midst of the deepest poverty. Thanks be unto God, the poor have still a mighty faith in Him who feeds the sparrows, and in each other, too; so that they will, most of them, cheerfully divide the last small loaf with the needier, and then trust to Providence for the next meal. " All our knowledge of blood and nerve, and of the purposes they are to fulfil in Togard to the human soul in tins world of wants and supplies, if it be worth any thing, proves to us one great truth—namely, that tho dwelling of misery is not the home of virtue. Domestic comfort and privations are contradictions, and the wants of the body must be satisfied before the soul can find leisure for abstractions. It is a vain and aggravating mockery to preach, in words only, the doctrines of poace and lo\ ingkindness where fathers and mothers and children cling together in rags and squalor and hunger. No doubt, among such are often found the most heroic examples of How should education be conducted? With what should mental improvement commence? What effect does starvation diet have upon the tempers of young children ? What is the character of the poor for generosity ? 203 HEAT, LIGHT, ELECTRICITY, AIR, FOOD, WATER. Moderation in tho use of Food tho best Medicine. Christian manliness and affection, but alas! there also dwells with misery every form of reckless viciousness. But what has that to do with your conduct, O man of comfortable morality? What self-denial have you practised for the benefit of your brother? It is true that the Gospel supplies aliment for the deathless spirit, and enables it to bear wisely, meekly, nay, even happily, the famishing of the body. Wo have witnessed its triumph in such a case, where disease actually caused death by starvation; but still the best harbingers of the Gospel are food and clothing, and all the visible evidences of sympathizing human heartiness. Be ye warmed, be ye clothed, be ye fed, are words, not practical faith; but providing the means for those who need them is true living godliness, which nowhere teaches men to take verbally even truth itself, much less wordy trash, as a substitute for bread. He who fed the multitude of famishing unbelievers in the desert of Arabia with daily showers of angels' food, will not have men convinced by miracles alone, but also with common mercy; and therefore the power and the goodness are seen together, as in Him who is our spiritual bread, and who taught us what Ho meant by loving our neighbor as ourselves. If, then, we would have the heart open to faith, we must appeal to it through charity and hope, nor think to prove our interest in the souls of men, without doing our very best to render the body a comfortable abode for the sublime and mysterious tenant" "Moderation in the use of food is a far better remedy than medicine for an oppressed state of the circulation, whether arising from disease, or redundancy of supply. Fasting is tho natural cure of repletion; and it is a curious circumstance, that abstinence is so frequently forced upon those savage tribes who are addicted to excess, such as the American Indians and New Zoalanders. Their diseases are but few, except where they approach the confines of civilization, and in some measure adopt those habits which nature has rendered uncongenial to them. Among civilized nations, the use of purgatives is gradually taking the place of fasting. Hence the success of quackcry in the aperient department among tho English and Americans. We are an energetic people, and cannot be comfortable without abundant nourishment; but then, taking very refined food in largo quantity, without sufficient intervals of abstinence, we find our brains and our bowels both miserably sluggish, and then the pill-box supplies A handy sort of remedy for ills that common sense should have prevented. ' The peristaltic persuaders' of the gourmand are as essential to his happiness as is his dinner; but not only do these gross livers need such helps: the exquisite poet must also resort to the apothecary to antidote the cook. Byron says, ' The thing that gives me the highest spirits is a dose of salts.' It diminished that congestion and irritability of his brain which his habits tended to keep up. Ho was at one period of his life epileptic ; but he subdued the malady by extreme abstinence, frequently taking only vinegar and potatoes as his dinner. When he indulged in good living, and took stimulants, disorder of tho brain returned in another form, and his temper became morose. It was then that a dose of salts cheered him. Brisk purgatives often relieve melancholy; and that most powerful one, hellebore, was the ancient specific for this disease, which generally arises from congestion of the liver and bowels causing an impure state of the What is practical faith ? What is the use of moderation in diet ? What is a good effect of fasting? Aro tho diseases of savages numerous? What was the effect of high living upon Byron ? 204 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Foundations of Health and Happiness. blood. Tho frequency of a condition approaching to this is the secret of the demand for universal medicines, in the shape of strong purgatives. Here is the evil: many good men, who read and think very much, and fancy they understand physiology, because they have read about the blood, prove their ignorance of it by taking little exercise, and dolefully mismanaging their stomachs. They forget that moderation in eating and drinking, as well as meditation, is a Christian duty, and that fresh air, cheerful society, and an occasional fast, would more effectually relieve the burdened viscera than a whole box of vegetable pills. Instances are not uncommon, even among the highly, but yet partially educated, in which some real malady has fixed upon the vitals, and those pills are swallowed in large quantities with manifest mischief. It is a matter of feeling, not of reasoning, with such persons. Their faith in tho efficacy of the vaunted vegetables is grounded on ignorance, and confirmed by their sensations. Thus I have known a consumptive patient, of strong mind, obstinately persist in taking the pills, because they made him feel better, lighter, more cheerful, more happy. Of course, argument falls dead before such facts. Thus, in such forlorn cases, diarrhoea and purgatives hasten on the fatal issue; but then, by these means, the patients are kept just in that state which the highest degree of abstinence produces ; their bodies waste and waste, but their souls are full of bright thoughts, as long as exertion is avoided. The habit of their minds becomes exalted by holy reading, it may be, and there is not blood enough in their veins to excite their passions, or to call their muscles into action. There is only just fuel enough to keep alive a clear flame, until the fire burns quite out Such patients feel brighter and brighter to the last and the pills, say they, are the cause of it all. These are taken again and again; exhaustion proceeds, but they go on to feel better, that is, lighter; the body is no impediment, except from weakness; so they continue taking the pills, and feeling better and hetter, until they die." " The moral of this subject is comprifed in a few words: our hopes of health and happiness must always deceive us, unless founded on obedience to the laws of God, which are those of a rational faith as regards things spiritual, and of true science as regards things natural." 361. As the tissues are constituted of'a certain number of elements, it is evidently essential that food should be composed of the same elements. It will, however, be shown by and by, why the digestive organs can operate best when reasonably distended. Therefore, it may not at times be prejudicial, but highly beneficial, to eat food which either does not contain the nutritious elements, or contains more than is needed. Those which are nutritious would, of course, serve to distend the organs; but in respect to using them for such What do some very good men prove by their course of life ? Upon what is faith in vaunted vegetables grounded? What is the moral of the subject? Why must the food contain or be composed of the same chemical elements as the tissues ? 205 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. Elements which compose Food. a purpose, there would be three questions: 1st. Are they as'profitable or cheap as really waste substance ? the answer to which would depend upon their cost and relish. 2d. Would they not be digested in larger quantity than necessary, and thus overcharge the blood-vessels 1 3d. Would they not be detained in the digestive organs longer than waste and innutritious substance ? 362. As the tissues are constituted of different elements, and as they are active in different degrees, the existence of different elements in different proportions would be required, and the food eaten should depend upon the tissue demanding it. This is an exceedingly important idea. The man who is actively exercising his brain, does not require the same kind of food as the one who labors chiefly with his muscles; and it will be very unprofitable, mentally and physically, and pecuniarily, for them to live upon similar kinds of food. Farmers call pork and potatoes, and the like, food, and generally consider oysters, sardines and fish, as " trashy 5" while students, the world over, desire to live upon those kinds of food, with eggs and fowls, &c. A broiled chicken is no " richer " food than a piece of fried pork, nor is food prepared from the brain of the calf any more so than a piece of lean veal. It may be asked, are not all the tissues—the fibrin and nervous, as well as the rest —formed from the albumen of the egg? Not from the albumen alone. The fibrin undoubtedly is. What is usually called albumen of the egg. and well enough in ordinary phrase, is something more than albumen, the white as well as the yolk (for they are very similar) being composed of phosphorus and calcareous substances in greater proportions than are necessary to form albumen. When, therefore, the albumen of the egg is spoken of, it is called ovalbumen or egalbumen. For convenience sake, in expressing my ideas, I am in the habit of classing the nutritious food as a species, and making of it several varieties, viz., three, named from the most conspicuous characterizing element — Phosphorized. Nitrogenized, and Calcareous —corresponding to and being those which nourish, or are by their components adapted to nourish, the three most conspicuous compound tissues—the nervous, muscular, and bony. The terms are not perfectly dis- If nutritions food he used to distend the stomach, what three questions would arise r Upon what should the kind and quantity of food eaten depend f Do farmers and students need or oqually relish the same kinds of food 1 206 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Character of different kinds of Food. tinctive, for each of the three elements —phosphorus, nitrogen, and calcium —is found in each variety of nutritious food ; yet each is most conspicuous in the variety to which its name has been given. Bach variety of food may be supposed to be usable for nourishing either tissue ; for if calcium predominate in the calcareous variety, yet it may, by the elimination of part of its calcium, be fit for forming muscular tissue ; but it is evident that any variety which does not contain a proper proportion of calcium, cannot form perfect bone. It may be thought that such a classification of the varieties of food should be made as would distinguish those which are adapted to form the secretory tissues and the secretions. This is doubtless to be done at some future day, but at present our knowledge is not sufficiently perfect to permit it to be done, however important it may be. In fact, the remarks which follow are to be considered rather as suggestive than an exhibition of demonstrated facts. The great value of such a classification and nomenclature of the varieties of food will consist in directing the attention of parents to the food of children—of the muscular laborer to the importance of not relying upon calorific food to give him strength—of the student to the fact that certain varieties of food are better than others for him. 1st. It has long been noticed, that the bones of infants and children cannot be developed without they are properly fed, viz., with calcareous food, e. g., milk, eggs, and the like. It is, however, often noticed that fat, arrowroot, and the like calorific kinds of food, are very beneficial to children (see Appendix), especially before they are able to take active exercise, or if they are feeble. The reason for this is dependent upon another principle. Young children have not the capacity of receiving much air, and, as rapid development prevents decomposition, they cannot produce heat corresponding in proportion to the escaping surface, which is relatively greater than that of a grown person: they must, therefore, depend chiefly upon their food for the production of heat, and, as that is small in amount, it must be carefully preserved by a thick layer of fat; but it is very unfortunate for the bones, if, with fat-producing food, which increases the burden to be sustained, sufficient calcareous elements are not at the same time introduced. 2d. The man who labors with his muscles, in the winter requires calorific food in proportions according with his exposure; but in the summer, calorific food will be required in only small quantity ; but at all times nitrogenized food must be used in proportions cor- Are the terms used to distinguish the kinds of nutritious food perfect? Can we distinguish the varieties of food best adapted to secretory processes ? To whom wid a classification of the varieties of food be useful ? 207 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. Food adapted to wants of the Nervous System. responding with the muscular action. A dinner upon corn starch pudding or the like, would not sustain the labors of harvesting; while sour buttermilk from which the calorific fat has been removed, and in which the calorific sugar has been changed into acids, will be excellent. 3d. To sustain the labors of the student, phosphorized food seems necessary for the following reasons, a. The brain exhibits, upon decomposition, a proportion of phosphorus equal to one-twelfth, at least, of all its solid matter, b. Immediately after active mental labors, the excretions exhibit a large proportion of phosphates—e. g., Monday and Tuesday, in case of clergymen; and, at court time, in case of lawyers. Persons troubled with phosphatic deposits, are most likely to be so after unusual intellectual efforts. Moore remarks that " the condition of blood which precedes gout is so constantly associated with irascibility, that John Hunter says gout and anger are almost synonymous in some persons." Though in this case the state of the blood may have much to do with causing the irascibility, it is probable that this, by exciting the brain and causing its rapid decomposition, is the cause of phosphates being furnished to the blood which it usually deposits in the gouty joints, c. The common experience of students is, that they are fond of, and profited by, different food from what they most relished when daily and arduously engaged in labor of a chiefly muscular character. Many lawyers have told me that they were particularly fond of sardines at ' : court times" only—most often, also, they witness to their greater appetites at such than usual times—though sometimes they have told me that their cases caused too much excitement for them to wish for food then; but, after they returned home, they were correspondingly exhausted and hungry. Students also complain of having much more appetite during term than vacation time; and to think that they do not have enough to eat, when the probability is that they eat too much in quantity, but of improper quality; and the nervous system, not being perfectly nourished, gives signs of its necessities, before the time of another repast, by causing the sensation of appetite.* In my own experience, I have * In cool weather, many young ladies dress so thinly that but little heat is preserved, and there is almost a constant call for food to produce it. They wish therefore, on one hand, to eat almost constantly, and on the other, to have the temperature of their dwellings higher than is proper. Again, some keep their room (or clothing?) so warm that there is not a sufficient demand for calorific food, to produce a healthy appetite. Why is sour buttermilk good as food in hot weather ? What is the first reasons for thinking4)hospborized food profitable to the student ? What is the effect of intellectual activity upon the existenco of phosphates in the blood ? 208 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Food must be composed of Organic Elements. constantly observed the value of the kinds of food specified above. I have no hesitation and feel no inconvenience in lecturing 6, 7, or even 8 hours during the day and evening, from the beginning to the end of the week, as my business and custom is, if I can have a proper supply of the right kinds of food; but, if I do not, memory soon becomes treacherous, sharp pains and exhaustion are felt in my head, and, if the mental labor is continued, symptoms of paralysis will be felt—all of which evils can at once and always be removed by one or two hearty repasts of oysters, sardines, soft eggs, or fish. These kinds of food may not be equally serviceable to other persons; if they are, it is not certain that all of them contain phosphorus in remarkable quantity. Eggs most surely do; and a remarkable case was to-day mentioned to me in conversation with a professional friend, of one of the most valued and industrious students in the city who makes eggs his chief diet in periods of arduous labor.* If these kinds of food contain notable quantities of phosphorus, and are serviceable, it is not certain that their chief value is dependent on the phosphorus. This, however, is probably the case. 363. Food must not only be composed of proper chemical elements, but these must be compounded into proper organic elements. Phosphorus, important as it is, by itself alone would prove a violent poison; it must not only be compounded with oxygen and produce phosphoric acid, but this must also be united with other substances. Whether any merely chemical compound elements can be used in the human body, is uncertain as yet. Some suppose that compounds of iron are absorbed into the blood, and there combined with its organic elements, or used in the formation of them. It is probable that the chemical compounds of lime ** The qualities of egg in respect to phosphorus, will vary as much as in respect to other components. The farmor thinks that lime must be furnished to the chicken, because the shell is so conspicuous; but the honest-hearted hen insists on forming the contents of the egg first; but the difference in the taste caused by different eggs, is based on a reality, as is the color of the yolk. If the fowl h»ve plenty to eat of its natural diet, eggs are produced not only in abundance, but of a rich quality. The most natural food for fowls is bugs and worms, the phosphorized character of some of which is evident enough. If these cannot be had, fish is not only adapted to their palate, but to the profit of the keeper. Lean meat is known to be one of the best kinds of food for fowls, while grains are to a great degree waste, containing more starch and oil than the warmly-clothed fowl needs. What kinds of food have been specified ? Is it positively certain that the adaptedness of these kinds of food is universal or dependent on phosphorus ? Is it sufficient to eat the chemical elements uncompounded ? 209 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. Kinds of Food distinguished. which are fed to and eaten by fowls do, to a greater or less' degree, pass into their blood, and at last go to form the egg-shell. It may be, however, that such things are only useful in triturating the food in the gizzard, and that all the lime of the shell is obtained from Organic elements eaten as food. There is scarcely a doubt that common salt passes into, and becomes part of, the blood, as a compound chemical element. Yet. as a rule, the food of animals must be prepared in the form of organic elements by plants. Food should, therefore, be composed of these elements in such proportions as the action of the tissues or their requirements in respect to heat indicate. There is no difficulty in distinguishing the elements adapted to nourish the tissues from those which are useful in respect to heat. Fat, starch, saccharine substance, including gums and gelatin, are calorific. Alcoholics come under this head; for, though in all ordinary cases alcoholics cool the system in cold weather and heat it in summer, there are states of the health when the use of alcohol is followed by the rapid production of fat. and as the elements composing alcohol are oxygen, hydrogen, and carbon, there is no good reason to doubt that the fat is formed from alcohol. But under all ordinary circumstances the use of alcohol does not produce heat; it so acts on the nervous system as to cause sensations of heat, or prevent the production of sensations of cold, and thus cheats its victim. The abundance of acids which nature has provided in the southern climes, the great use of them in summer, the coolness which follows their use in hot weather, and the effect of a very free use of them in diminishing the quantity of fat deposited in the system, lead to the belief that acids are useful either in preventing the production of heat, or neutralizing it when produced. They are, therefore, counted as cooling parts of the food. For a person to attempt to reduce the quantity of his fat by the use of acids is not wise, as the general health will be injured. Let him rather abstain from the use of calorific food, and take plenty of exercise in the open air. The nutritious foodcannot be distinguished as accurately by organic elementary characteristics as the calorific can be, for, though chiefly composed of albumen, fibrin, and casein, yet with these are combined or mixed various chemical elements in a manner which has not yet been ascertained. The contents of an egg-shell are loosely called albumen, but there is something more. Of one thing we may be sure — viz., that the three mentioned elements are nutriment. The waste Does lime, if eaten as lime, or in the form of plaster or oyster-shells, &c., go to form the egg-shell? As a rule, how is the food of animals formod ? What is said of alcoholics ? What is said of acids ? 210 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Uses of Oxygen. portions of food include the cellulose and lignine of vegetables. Whatever portion of food has not been properly prepared, or is used in greater quantity than the system requires, is, properly speaking, to be added to the really waste food. A table of different kinds of food is given in the Appendix. Many of the organic elements require to be prepared for the use of animals. This is called the process of cooking. This has a double object—to render the food more wholesome, and to improve its relish. For this purpose several kinds of organic elements must sometimes be mixed, and flavored with chemical elements, useful or waste, and then, perhaps, exposed to the action of heat. The advantages of any such preparation will be better seen after the organs adapted to receive and act on the food in the body, and their mode of action, are described. Air. 365. The utility of the air is dependent on the quantity of oxygen it contains, and its freedom from every thing but that, nitrogen, and a proper portion of water. Water, however, is not usually estimated as a part of the air; yet it always exists, and is a sine qua non as a part of the substance breathed. 366. The oxygen is mixed with the nitrogen of the air, as it is with the water which the fish breathes. The analogy will be more perfect, then, if we say that man breathes the nitrogen to obtain the oxygen mixed with it; or it may be said that the nitrogen dilutes the oxygen for men to breathe, as water dilutes it for the fish. 367. The uses of oxygen in the system are two and perhaps threefold; it unites itself to the blood, as it is supposed, to the red corpuscles, the effect being to shrivel them somewhat and render them slightly biconcave; when the reflexion of light from them will be such as to give them a What is the utility of cooking food? Upon what is the utility of air dependent > Is water a necessary adjunct to the air? What is the number of uses to which oxygen can be applied in the system ? 211 HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER. Circulation of Oxygen—Density of Cold Air. bright red appearance. Thus the corpuscles become carriers of the oxygen. Some suppose that the oxygen unites with the iron of the corpuscles, but this would not account for the color, which has not been satisfactorily accounted for, until recently. It may be that the oxygen perfects the nourishment of the corpuscle or its contents, for it is not known with what part of the corpuscle or how the union is, and it may be that oxygen unites with other parts of the blood. 368. The oxygen borne by the corpuscles into the minute capillaries, exerts its strong attractions upon the unstable tissues, and assists in, or alone causes, their decomposition, and then unites with these elements, producing heat, water, and carbonic acid, which combine with the components of the corpuscles,—as some think with its iron, —causing them to become plump and biconvex, when the reflection of light causes them to appear dark. They carry the carbonic acid to the air, and it escapes from the blood at the inner surface of the lungs, and is expired with the breath. 369. The air is more dense in cold than in hot weather, and of course contains a greater amount of oxygen in a given cubical space than when it is warm, and the cold air expanded by the heat of the chest acts more energetically than if warm air be inspired. Mus. —When the air is blown against the burning coals, its oxygen unites more actively with the carbon. When the air is very much rarified by heat, it is difficult to prevent a slight feeling of suffocation. Inf. —It follows as a very important conclusion that cold air will produce more heat than warm, as ought to be the case; also, that when cold air is breathed, more carbonic acid will in a given time be removed from the system than when the air is warm. In cold Is it certain whether or not the oxygen unites with the iron of the blood? What effect on the tissues does oxygen have? What effect does carbonic acid have upon the corpuscles? What is the difference between cold and warm air ? 212 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Qualities of Air—Water. weather, therefore, we ought to breathe cool air to produce heat and clarify the blood, and clothe ourselves warmly to preserve the heat produced. 370. When air is warmer than that which surrounds it, it ascends. Inf. The air breathed from the lungs into cool air, rises rapidly and is not again received ; to preserve the air pure, it should be kept cool. It should never in winter be allowed to rise above 65° in an apartment for healthy people, properly clothed. 371. Air which is cold, contains less moisture than warm air. Inf. It is not, therefore, as damp towards morning as it is in the middle of the day. There is no danger, therefore, of breathing cool air because it is extraordinarily damp. 372. The air of a close room in which a person breathes, is soon saturated with moisture. Inf. —A room for being closed, is no drier than if ventilated. It may be asked, Is not the damp air colder apparently than dry air of the same temperature 1 Yes—because the water receives heat more readily than air. When, therefore, the air is damp, so much more pains must be taken to dress warmly, or the system will suffer from loss of heat. It is for want of this precaution that persons take cold, and attribute to the weather what should be imputed to themselves. If the system is in ordinary health, it will always be improved by receiving into its lungs the pure, cool air of the atmosphere. If the system, from infancy, from ill health, or from old age, be incapable of producing as much heat as is necessary to warm the inhaled air, it must be warmed, of course. Water. 373. Water is a necessary element of most of the tissues. As a solvent, it assists in the absorption of nutritious and excrementitious substance. By moistening the tissues, it What becomes of exhaled air ? Why does damp air seem colder than dry ? What is the use of water? What kind of water is best? How is water rendorod poisonous? HEAT, LIGHT, ELECTRICITY, FOOD, AIR, WATER, 213 Review of Part II. allows them without friction to glide over each other. It readily communicates and receives heat. 374. Pure soft water is the only kind of water which it is perfectly proper to drink. Water is frequently rendered poisonous by passing through lead pipes. The water which is obtained from springs is frequently loaded with impurities, especially compounds of calcium, as in the ordinary hard water. Rain-water is the purest and best of water which can be obtained. Rendered cool by any means, it is quite as palatable to the accustomed palate as hard water, which is productive of many diseases. Review. Thus, having hastily presented a view of the simple and compound chemical and organical elements which compose the tissues and humors of the human body, and shown what is meant by systems, as well as exhibited the properties of animal tissues to be sixfold —viz., nutrition, development, reproduction, secretion, sensibility, and contractility, all of which require that absorption should be free and the temperatures of parts healthy, and all of which depend upon the reception and preparation of food, and upon imbibition of w r ater, and the respiration of air—it is now time to consider the individual or special organs which are constructed from the systems in accordance with the use or action which they are required to fulfil. And as each organ or part is described, we shall see the necessity for employing peculiar tissues, w r ith peculiar properties, in each case. With the anatomical description of each organ, or even part of an organ, its use, or the why and wherefore of its being made as it is, must be immediately presented, as well the means to be employed for developing the properties required to the highest degree and in the best manner. Thus, and thus only, can the branches now before the student be easily understood, remembered, and practically applied. PABT III. SPECIAL ANATOMY, PHYSIOLOGY, AND HYGIENE. "There is something higher, then, than even the study of laws, which may be regarded as being themselves but a higher order of facts. There are three degrees, and the science that would tarry in the second must be pronounced spurious, as well as that trivial knowledge which finds its satisfaction in the first. There are facts, laws, principles. By the latter are meant those thoughts of the universal mind, of which the second may be regarded as the words, and the first the letters through which they are articulated. There is an intense interest in the question— What is it ?—its class, its order, its outward description, and hence its scientific name ? There is a higher interest in the question— Hoio is it ? —its law, its cause, its effect, its outward energizing life? There is a still higher interest in the inquiry— Why is it?— why is it so in itself? Why is it so in its relations to other things ? Why is it so in its relations to the Great Whole, of which, however minute, it forms a necessary part? Above all, Why is that Great Whole itself; whose ground, end, or destiny is the ultimate inquiry which makes the real value of every lower question?"—Raymond. BOOK I. APPARATUS OF RELATION. DIVISION L—MOTOR APPARATUS. CHAPTER I.—SKELETON. 0 ANALYSIS. Distinction between artificial and natural skeleton. The last embraces bones, cartilages, synovial membranes and ligaments — General characteristics of bones — Names of their parts — Classification of Joints and Ligaments — Division of skeleton into protective, speaking, handling, and locomotive skeletons — Division of protective into head and spinal column — Division of head into cranial and facial bones — Description of cranial bones — Occipital, Sphenoid, Ethmoid, Frontal, Temporal, and Parietal — Description of facial bones—Superior Maxillary, Malar, Nasal, Ossa Unguis, Turbinated, Vomer, and Inferior Maxillary—Division of spinal column into Cervical, Dorsal, Lumbar, Sacral, and Coccygeal regions — Cause of deformities of the column — The Chest — Ribs — Costal cartilages — Sternum — Latitude of motion of the ribs the important object — Cause* of deformity of chest — Thoracic eastremiiies — Clavicle — Scapula — causes of its prominence — Humerus — Radius and Ulna—Hand — Os Innominatum — Pelvis— Femur — Lower leg — Foot—Review. DIV. I.] 215 MOTOR APPARATUS SKELETON. General Remarks. 375. The complete assemblage or system of bones in an animal is called a skeleton. If they are fastened together by wires, they form an artificial skeleton. When they are fastened by their proper cartilages and ligaments, they, with those, form a natural skeleton. A consideration of the natural skeleton embraces, therefore, the bones, cartilages, joints, synovial membranes, and articular ligaments. There are several things to be said which are applicable to the whole skeleton, before we proceed to consider its individual parts; explanatory remarks upon the bones, joints, ligaments, their classification, &c, which may be closely observed or omitted, as is thought desirable. The nomenclature of the bones is very imperfect Names have been given to them, 1st, from their position; 2d, from a real or fancied resemblance to some object; 8d, from their size; 4th, from peculiarity of conformation; 5th, from the name of the author who has described them. Color. —The color of bones varies, from a yellowish to a decided white, as may be seen in any animal. The size of bones varies exceedingly, from (hat of a pin's head to that of the femur and hip. The form of bones, together with their size, has caused them to be classed as long, short, and broad. A long bone is divisible into a shaft and extremities. They serve the purposes of levers, and are, of course, found in the extremities. The ribs are also of this class. The short bones aro grouped together, to form any part where great solidity with slight mobility is required, as in the wrist, ankle, and spinal column. The broad bones are adapted to form tho sides of cavities. The surfaces of bones are so irregular, and present so many things to be noticed, that they must be very accurately divided. Thus the long bones, being prismatic, exhibit three faces and borders for consideration; the broad or flat, two faces, external and internal, and a circumference; the short, six faces, and all of them present angles. All these are named sometimes from their situation—superior, inferior, &c.; sometimes from what they contribute to form—as the orbital face, &c.; sometimes from relation to other parts—cerebral surface of the cranium, &c. The borders are divided bythree parallel lines, the middle called the interstice, the other two, the lips. The eminences of bony surfaces were by the ancients divided into apophyses and epophyses. This distinction was, however, founded upon limited observation. A better distinction is, into articular and non-articular. What is the difference between a natural and artificial skeleton ? What does a natural skeleton include ? The teacher may ask or omit the questions upon the descriptions in small tvpe; It is suggested that it will be sufficient for the student to read the descriptions. 216 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. Articular eminences are called denticulations when they present a notched and Jagged appearance—fig. 9. They contribute to form immovable joints; heads when they present a portion of a sphere, joined to the body by a contracted portion, called the neck; condyles when they appear like an elongated head, or like a portion of an egg longitudinally divided. The non-articular eminences are mostly designed for the attachment of muscles. They are denominated—1st, prominences when slightly elevated, smooth, and extended equally in all directions; 2d, mamillary processes when they resemble papillae: 3d, tuberosities when they are of larger size, roundish, and uneven; 4th, spines or spinous processes when they are more pointed; 5th, lines when their length much exceeds their breadth ; when the lines are rough, or exhibit asperities, they are called Hnea3 asperioe; 6th, crests when they are elevated, with a sharp edge; 7th, apophyses or processes has been retained for those eminences which seem to be small bones added to others, and specific names designating such have been added, from various reasons, as, from resemblance; these are—tho clinoid, pterygoid, mastoid, zygomatic, styloid, coronoid, odontoid, coracoid, malleolar; from the parts they contribute to form—the orbital, malar, olecranon, &c.; from their direction—the ascending, descending, &c.; from their uses—the trochanters minor, major, &c. No part of anatomical language is more faulty than the names of eminences, the same names being applied to parts very dissimilar. "The size of these eminences corresponds to the strength of the muscles acting upon them, as seen by comparing a male and female skeleton, or those of a sedentary and athletic person. This has given rise to the idea that muscular action produced the eminences. This notion is easily refuted by facts proving that osseous eminences enter into the original plan of organization, and would have existed though the muscles had not acted Twice have I dissected the arms, paralyzed from convulsions in infancy, of individuals. The affected limb was hardly as large as that of a child eight years old, yet the smallest as well as the largest prominences were distinctly marked."—Cruvelhier. The cavities formed by the surface are divided into articular and non-articular. The articular are denominated—1st, cotyloid, as the socket in the hip bones: 2d, glenoid, as the shoulder socket; 3d, alveoli, as tho sockets for the teeth. Non-articular cavities are called—1st, fossm when widely excavated; 2d, sinuses when the entrance is narrow; 3d, cancelli and improperly cells when the cavities are small but numerous; 4th, channels or gutters when a semi-cylindrical, long, open canal exists; 5th, grooves when channels are lined with cartilage. A groove is called a trochlea or pulley if a tendon is changed in its direction by its means; 6th, furrows when the channel is very shallow; 7th, notches when the appearance is that of a notch. Perforations of the bone, or notches of different bones being so situated as to give an appearance of perforations, are called foramina or holes, and distinguished, 1st, when irregular, as foramen lacerum; 2d, when very small and irregular, as an hiatus; 3d, when long and narrow, as a fissure; 4th, when extending some way through the substance of the bone, as a conduit or canal. If they lodge vessels for nourishing the bones, they are distinguished as nutritious canals, though they are What Is said of the names of bones? Color? Size? Form? Surfaces? How are eminences classed? How many and what kinds of articuLir eminences? What are prominences? Mammillary processes? Tuberosities? Spines? Lines? Crests? Apo- DIV. I.] 217 MOTOR APPARATUS SKELETON. only largo Haversian canals. They are divided into three kinds: 1st Those which belong exclusively to the shaft of the long bones, and some broad ones. Each one soon divides into two branches, one the ascending, the other the descending. In each bone the minute anatomist points out the situation, direction, and couvse of each of these very particularly. 2d. Those which are found near the head of the long and the borders of the broad bones. Bichat has counted 140 in the lower end of the thigh bone, 20 in a vertebra, and 50 in the heel bone. They sometimes pass entirely through the bone, and sometimes communicate with the cancelli. 8d. Those which are microscopic—viz., those Haversian canals which open from the surface. When the periosteum is torn from the bone, the vessels entering there being severed, bleed, and show their position by minute dots of blood. The uses of the cavities are, 1st, to receive or protect organs; 2d, for surfaces of attachment; 3d, for the transmission of organs, vessels, nerves, &c.; 4th, to, increase surface In a small cubical space; 5th, for the easy movement of tendons, and to give them a new direction; 6th, for the nutrition of bones. In describing bones, 1st, the surface should be so divided as to present but few objects at a time; 2d, when they are divided, care should be taken to proceod from one side to the opposite; 3d, an invariable and regular order of the regions must bo followed; 4th, in symmetrical bones, first the objects in the median line, and second the lateral parts, should be described. Composition of Bones. —In Part II. it was shown, 1st, that the external surface of bones is covered with fibrous membrane called periosteum ; 2d, that the substance of the bone is composed of fibrous tissue and earthy compounds; 3d, that the long bones after the period of childhood exhibit a central medullary canal, which grows larger with advancing age; 4th, that about the canal, and especially towards the ends of the long, in the short and between the two laminse of flat bones, cancelli exist which approach nearer to the surface with maturing years, and in old age leave a very thin shell of solid bone at the surface. Though, by the deposit of ear thy substance, any portion of bone in an old person is denser than in youth, as a whole, it is lighter; 5th, that all the medullary cancelli and canals are lined with fibrous membrane which is lined by secretory membrane, the whole of which is called the medullary membrane, which secretes the marrow or medulla. The cancelli and canal being more extensive in old persons, there is in their bones more marrow, which prevents the jar that, through their more dense bones and less elastic cartilages, would be produced. The exhaustion of the marrow in debilitated persons renders them exceedingly sensitive to causes of jars; 6th, that the microscope reveals Haversian canals, canaliculi, and lacuna;; 7th, that in the membranes covering and lining the bones, nerves exist. They must be nerves of sensation, as nerves of motion would have no office. They are so constituted that in health no sensation is produced through them, but as soon as disease attacks the bone they become very sensitive, that the person may be compelled to allow his limb to remain quiet and recover. In case of fracture it is very unfortunate if the nerves do not cause pain, which is better than any "splint" for securing quiet If pain does not occur, the individual is very liable to have a bad limb, notwithstanding the care of the most skilful surgeon, whoso physes ? How are osseous cavities classed ? What cavities are called cotyloid ? Glenoid? Alveolar? Fossae? Sinuses? Cancelli? Channels? Grooves? Trochleas? Furrows ? Notches ? What is a foramen lacernm ? Hiatus J Fjssure ? Conduit or canal ? b. 3 —in 218 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. first anxiety, many times, will be to produce pain; 8th, that in the fibrous membranes of bones, arteries, capillaries, and veins are numerous. Lymphatics have not, as yet, been detected; 9th, that the organic element of bones is gelatin, combined, how is not yet understood, with chiefly phosphate and carbonate of lime. The following table, from Berzelius, shows the constitution in detail:— Animal Matter reducible to Gelatin by boiling, . . . 82.17 Animal Matter insoluble, 1.18 Phosphate of Lime, 51.04 Carbonate of Lime, 11.80 Fluate of Lime, (?) 2.0 Phosphate of Magnesia, 1.16 Soda, and Chloride of Sodium, 1.20 The situation of the bones is internal in man; in some animals the skeleton is external. The situation of particular bones is yet to be described, as are their relations. The connections of the bones are the joints, a description of which comprehends cartilages, synovial membranes, and ligaments. Several remarks common to each class of parts may properly be made. Articular cartilages are divisible into, 1st, Synarthrodial, which exists between bones denticulated together, or which form immovable joints. This cartilage results from the ossification of tho bone not having proceeded into it; 2d, Diarthrodial, where the cartilage adheres to the bone upon one side, but is perfectly free upon the other, as at the shoulder-joint; 8d, Interarticular, where an extra cartilage free upon both sides is found in the joint between the cartilages covering the ends of the bones, Fig. 92. Fig. 92.—Section of the joint of the lower jaw. 8, Cartilage dividing the joint Into two parts. 4, The upper, 5, the lower cavity, both lined with synovial membrane. 1, The socket in the bone which receives the upper surface of the cartilage. 7, A portion of the lower jaw, which moves upon the under surface of the cartilage. 6, The cartilage taken out of the joint. as in Fig. 92, representing one in the joint of the lower jaw with the upper. They are usually thick at their circumference and thin in the centre, or biconcave, and hence called a meniscus. In the above figure the upper surface of the cartilage is convex, to fit the concavity about it. They serve the same purpose as friction wheels in machinery, and also deaden jars; 4th, Amphiarthrodial, where the cartilage adheres to the bone upon each side, but by its own flexibility, and pliability, and elasticity, allows some motion. Attention should also be drawn to the fact, that the sockets of joints are many times deepened by a circlet of fibres round the edge. The surface of bone covered with cartilage depends upon the extent of motion required. Synovial membranes ar» closed sacs the outside of which adhere to the cartilages of the joint and the parts surrounding it, and are moistened on their inner surfaces with synovia, which they themselves secrete. How should unpainful broken bones be treated ? What is the constitution of bones, according to Berzelius ? Who is ho ? Situation of bones in man ? Connection* of bones are called what? What joints are called anarthrodial ? Diarthrodial? DIV. I.] 219 MOTOR APPARATUS SKELETON. They are, therefore, secreting membranes, compounded also in part of fibrous mombrane. At first they cover tho entire cartilage very conspicuously, but after the joint has been used some time they become so thin upon the contactile portions of cartilage, that it is doubtful whether they exist there at all. At certain joints there Is a cushion of fat upon one side, pushing the membrane into the joint, as in Fig. 93. Fig. 93 represents a section of the knee joint. 1, Lower portion of femur or thigh bone. 5, Upper part of tibia or shin bone. 3, Patella, rotulla or kneepan. 2, Tendon of rectus muscle. 4, Tendon connecting the patella with tibia. * Denotes the synovial membrane or capsule. 6 Indicates another capsule, or more properly a bursa between the tendon and tibia. 9, One of the ligamenta alaria. 10, Mucous ligament 11, Anterior crucial ligament. 12, Posterior ligament Fig. 93. This capsule, as the membrane is called, renders the joint air-tight and keeps its surfaces in close contact, except when much force is exerted, when the parts separate with a crack (the cracking of the joints.) The fat seems to be for the purpose of filling all tho spaces about the joint in case of any motions. The synovial membrane sometimes exists in folds at certain parts of the joint, thus increasing the extent of surface for secreting synovia. Articular ligaments are of two kinds, fascicular and capsular. Fascicular ligaments are those composed of fibres in the form of bands. The fibres are either yellow or white. The capsular are the names of those ligaments which com' pletely surround a joint; they are merely continuous fascicular ligaments. Joints are divided into the immovable, movable, and mixed, which classes are technically designated synarthrosis, diarthrosis, and amphiarthrosis. Synarthrosis; the characteristics of this joint are immobility, and a joining of the bones without any intervening synovial cavity; its varieties are, 1st Suture, which is subdivided into a, dentata, where the bones are united by long processes and deep indentations; 6, serrata, when the processes are shorter, and like saw-teeth; c, limbosa, where, with dentation, the margin of the bone is bevelled; d, iwtha, or false suture, when the juxtaposed surfaces are merely rough ; of this there are two kinds, one squamous, when the bevelled edge of one overlaps that of another, and one harmonia, where there is simple apposition. The cartilage of sutures has a tendency to become ossified, when they are obliterated. After fifty, some of those of the skull are almost always in this condition. 2d. Schindylosis is where the edge of a bone is received into a cleft or groove in or between others. 3d. Gomphosis, where there are such sockets as receive the teeth. Diarthrosis ; mobility, with synovial cavities, is the distinguishing characteristic of this class of joints. Bichat divided this class into the gliding, limited opposition, Describe fig. 98. What causes the cracking of the joints ? What is the use of fat about the joints ? What are fascicular ligaments ? Capsular ? What kinds of suture are there ? What kind of joint is Schindylesis 1 Gomphosis ? 220 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. circumduction, and rotation; the technical terms corresponding are v lst, Arthrodia. In this case the surfaces in contact are plane or slightly concave and convex, and the motion gliding, limited only by ligaments or some process of the bones; 2d, Ginglimus or hinge-joints, admitting only flexion and extension; 8d, Enarthrosis or ball and socket, permitting motion in every direction ; 4th, Rotatorius, the conspicuous characters of which are a pivot and ring, the last generally formed partly of bone and partly of ligament The development of bone is marked by three stages; 1st, the place of the bone is occupied by a jelly-like or mucous substance, exceedingly delicate; 2d, gradually it is changed into cartilage, yielding chondrin, how is not known; 3d, at sometimes one, and sometimes several points in the cartilage, called points of ossification, specks of earthy matter are at first deposited, and the substance of the cartilage at the same place becomes fibrous, yielding gelatin. The process extends till the whole bone is produced. Ossification does not begin at the same time in all bones, nor progress with equal rapidity in all where it has begun. The bones of the ear being earliest required for perfect use, are earliest perfected in structure. The ribs being needed in breathing, are ossified early, and so with other bones. This is another instance showing that structure is subservient to use, and that the idea of use should, in a natural order of thought precede that of structure. In infancy the walls of the cranium should, for many reasons, be yielding, and not perfectly ossified. Hence we find, for a long time, that a portion of the top of the cranium remains unossified; see fig. 94, where 1 represents the posterior, 2 tho midde, and Fig. 94. 8 the anterior fontanelles. At 4, ossification is not completed; 5, 5, are over the suture formed at those parts. Though ossification has not taken place at 8, the change from cartilage to fibrous tissue has occurred, and at 3 there is not cartilage, therefore, but a membrane. The uses of the skeleton, and how its wants should be provided, will appear in the descriptions to follow. 376. The natural skeleton is divisible into four classes of parts useful for 1st, protection; 2d, speaking; 3d, handling; and 4th, locomotion. Each class assists, and to a certain extent might be included in, What is arthrodia? Ginglimus? Enarthrosis? Rotatorius? How many stages In the formation of bone? Describe fig. 94. What evists at 8? Into what classes of parts is the natural skeleton divisible F DIV. I.] 221 MOTOR APPARATUS SKELETON. Fig. 96. the rest, but is named from its most conspicuous office. The old division of the skeleton into head and trunk was, and is very unphilosophical and improper; there is no reason for it, and it is no longer to be tolerated; it was hardly worthy of the dark ages. See Knox's Anatomy. 377. The protective parts of the skeleton embrace the skull and spinal column, and are correspondingly divided into rigid and elastic protections; see fig. 95, which presents a side view of the spinal column supporting the skull. 378. The skull is divisible into the cranium, and the facial bones. 379. The cranium is constructed of eight bones, one cuboidal and seven flat. These are all constructed of an external, middle, and internal layers, called tables. The external is tough and called fibrous; its edges are notched and dovetail into each other. The middle, denominated also the diploe, is wrought into cancelli and channels for vessels which extend from one bone to another, as if the diploe were continuous from one Fig. 96. 222 SPECIAL ANATOMY, ETC. —APP. OF RELATION. [B. I. bone to another; see fig. 96, where the fibrous table is represented as removed from the sides of the cranium, exposing the diploe; the temporal bone contains but a very thin stratum of diploe. The inner table is brittle, and called vitreous or glassy; it is not, however, as brittle as glass. Its joints are those of harmonia. 380. The cranium presents an arched form in all exposed directions; beneath,it is somewhat flattened, and its surface very irregular; see fig. 97, which represents the base of the skull. It also presents for consideration an external and in- ternal surface. Its exterternal surface, except at its base, is generally smooth, exhibiting prominences and ridges where the greatest strength is required ; it is also marked by the sutures. The internal surface is smoother than the external. It also exhibits ridges and prominences, but is as remarkable for its concavities as the external for its convexities ; indeed, there is a general correspondence between them. It is also deeply grooved for the situation Fig. 97. of large vessels. The bones of the cranium are covered with fibrous membrane called here the pericranium. They are lined with a thick membrane called specifically dura mater. What does the protective framework embrace? How is the skull divided ? How many bones compose the cranium ? Describe their general structure. Why is not the outer table of the temporal bone removed ? Describe the form and general character of the cranial surfaces. DIV. I.] 223 MOTOR APPARATUS SKELETON. Fig. 98 represents the externa], and fig. 99 the internal, surfaces of a cranial bone called the occipital. Its name is derived from its situation. It is situated at the lower middle and back part of the cranium—the hole 5 or 7 corresponding to that represented by 11, the black, in 97. It is remarkable, 1st, on account of the hole 6, called foramen magnum, through which the brain and spinal cord connect; it is of course directly over the spinal canal; 2d, for the condyles 6, 6, by which the head is articulated to the upper bone of the spinal column; 3d, 1, 2, 3, are the superior and inferior occipital ridges and protuberances so easily felt at the back of the head. The internal surface is remarkable, 1 st, for the concavities or fossa?, 1, 2, which receive the back part of the cerebrum and cerebellum; 2d, for the crucial ridges 5, 5, 3, 4, which at 6 form Figs. 98 and 99. Fig. 97.—The external or basilar surface of the base of the skull. 1,1. The hard Ealate. The figures are placed upon the palate processes of the superior maxillary ones. 2. The incisive, or anterior palatine foramen. 8. The palate process of the palate bone. The large opening near the figure is the posterior palatine foramen. 4. The palate spine; the curved line upon which the number rests, is the transverse ridge. 5. The vomer, dividing the openings of the posterior nares. 6. The internal pterygoid plate. 7. The scaphoid fossa. 8, The external pterygoid plate. The interval between 6 and 8 (left side of the figure,) is the pterygoid fossa. 9. The zygomatic fossa. 10. The basilar process of the occipital bone. 11. The foramen magnum. 12. The foramen ovale. 18. The foramen spinosum. 14. The glenoid fossa. 15. The meatus auditorius externus. 16. The foramen laccrum basis cranii. 17. Tho carotid foramen of the loft side. 18. The foramen laccrum posterius, or jugular foramen. 19. The styloid process. 20. The stylo-mastoid foramen. 21. The mastoid process. 22. One of the condyles of the occipital bone. 23. The posterior condyloid foramen. 224 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B /. Fig. 100. Fig. 101. Fig. 102. the internal occipital protuberance. To the crucial ridges, the tentorium and flaxare attached, as the expression is, as will be described hereafter. Connections. —The occipital bone is articulated with six others—the sphenoid, two temporal, two parietal, and the atlas, the upper vertebra? of the spinal column. Fig. 100 represents the internal and upper surface of the sphenoid, which is situated directly in front of the occipital; its name is derived from its being wedged between the other bones. It is a symmetrical bone; viz., composed of two similar halves; it is also composed of a body in the centre and a greater and lesser wing on each side; its upper surface is remarkable, 1st, for a deep fossa near its centre, 10, called the sella turcica, in which is lodged a part of the brain called pituitary gland, though it is not a proper gland ; 2d, for the bevelled edges 22 and 16, by which it overlaps the lower edges of the temporal and parietal bones, and acts as a "strainer" or "binder" to prevent them from spreading when force acts upon them ; a beautiful architectural device. Fig. 98.—Tho external surface of the occipital bone. 1. The superior curved line. 2. The occipital protuberance. 8. The spine. 4. The inferior curved line. 5. The foramen magnum. 6. The condyle of the right side. 7. The posterior condyloid fossa In which the posterior condyloid foramen is found. 8. The anterior condyloid foramen, concealed by the margin of the condyle. 9. The transverse process; this process upon the Internal surface of the bone forms tho jugular eminence. 10. The notch in front of the jugular eminence which forms part of the jugular foramen. 11. The basilar process. 12,12. The rough projections into which the odontoid ligaments are inserted. DIV. I.] 225 MOTOR APPARATUS SKELETON. Fig. 101 represents the external or under surface of the sphenoid, and is remarkable for, 1st, the long processes 13, 15, called pterygoid; one delicate branch of which, 14, is formed into a hook called hamular process,round which, as a pulley, turns the tendon of the tensor palati muscle; 2d, the sharp ridge, crest, or beak 1, 2. The body is remarkable for the large cells found in it Connections. —It articulates with all the bones of the cranium. Fig. 102 represents the ethmoid bone, seen from above and behind; its name .is derived from the sievelike appearance of its upper surface, 4; it is a symmetrical cuboidal bone, composed of a cribrifom plate and two lateral masses, in which there are many cells. This bone is Figs. 103 *104. situated on the median line in front of the sphenoid, and forms the roof of the nose; it is, indeed, as much a facial as a cranial bone. Its upper part only belongs to the cranium; its lower part will be spoken of in connection with the bones of the face; it is remarkable for its punctured plate, thro' which the nerves of smell extend, and for its lightness as it floats on water. Connections. —It ar- Fig, 99.r-The internal surface of the occipital bone. 1. The left cerebral fossa. 2. The left cerebellar fossa 3. The groove for the posterior part of the superior longitudinal sinus. 4. The spine for the falx cerebelli, and groove for the occipital sinuses. 6. The groove for the left lateral sinus. 6, The internal occipital protuberance which lodges the torcular Herophili. 7. The foramen magnum. 8. The basilar process, grooved for the medulla oblongata. 9. The termination of the groove for the lateral sinus, bounded externally by the jugular eminence. 10. The jugular fossa; this is completed by the petrous portion of the temporal bone. 11. The superior border. 12. The inferior border. 18. The border which articulates with the petrous portion of the temporal bone. 14. The anterior condyloid foramen. 226 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. ticulates with the frontal and sphenoid, and eleven bones of the face. Fig. 103 represents an external, and Fig 104 un internal, view of the frontal bone, named from its situation. It is a symmetrical bone, and remarkable for, 1st, the superciliary ridge 2, 3, and notch 3; 2d, its sinuses called frontal—situated within the ridge 2, 3, and opening into the nose. They exist only very unfrequently in females; their size varies from the diameter of a straw to half an inch; 3d, forming the vault of the eye-socket. Connections. —It articulates Figs. 105 & 106. will, twelve bones—the two parietal, the ethmoid and sphenoid, and eight bones of the face. l ( 'ig. 105 represents the external, and 106 the internal, surfaces of the temporal bones. They are named from their situations. There are two: each is divided into three parts —the squamous, mastoid, and petrous. Fig. 100. —The superior or cerebral surface of the sphenoid bone. 1. The processus olivaris. 2. The ethmoidal spine. 8. The lesser wing of the left side. 4. The cerebral surface of the greater w ing of the same side. 5. The spinous process. 6. The extremity of the pterygoid process of the same side, projecting downwards from the under surface of the body of the bone. 7. The foramen opticum. 8. The anterior clinoid process. 9. The groove by the side of the serra turcica; for lodging the internal carotid artery, cavernous plexus, cavernous sinus, and orbital nerves. 10. The sella turcica. 11. The posterior boundary of the sella turcica: its projecting angles are the posterior clinoid processes. 12. The basilar portion of the bono. 18. Part of the sphenoidal Assure. 14. The foramen rotundum. 15. The foramen ovale. 16. The foramen spinosum. 17. The angular interval which receives the apex of the petrous portion of the temporal bone. The posterior extremity of the Vidian canal terminates at this angle. 18. The spine of the spinous process; it affords attachment to the internal lateral ligament of the lower jaw. 19. The border of the greater wing and spinous process, which articulates with the anterior part of the squamous portion of the temporal bone. 20. The internal border of the spinous process, which assists in the formation of the foramen laeerum basis cranii. 21. That portion of the greater ala which articulates with the anterior inferior angle of the parietal bone. 22. The portion of l he greater ala which articulates with the orbital process of the frontal bone. Fig. 101. —The anteroinferior view of the sphenoid bone. 1. The ethmoid spine. 2. The rostrum. 8. The sphenoidal spongy bone, partly closing the left opening of the sphenoidal cells. 4. The lesserwing. 5. The foramen opticum piercing the base of the DIV. I.] 227 MOTOR APPARATUS SKELETON. The first two are seen externally. The squamous portion is remarkable for, 1st, its smooth, slightly convex surface 1: 2d, its thinness, being the thinnest part of the cranium; hence the great danger of blows upon this part of the head—both on account of fracture and violently jarring the brain; 8d, its bevelled edge overlapping the parietal bone above ; 4th, its long process called zygoma, so easily felt above the articulation of the lower jaw ; 5th, the temporal fossa formed behind the zygoma, in which the lower and thick part q.f the temporal muscle is found. The mastoid portion is remarkable for, 1st, its prominence called the mastoid process, felt just behind and below the ear; 2d, the cells exhibited within it; they open into the ear. This bone is also remarkable, externally, for exhibiting the passage 15, leading to the ear and the socket for the lower jaw. Inferiorly is seen 11, a long 108. lesser wing. 6. The sphenoidal fissure. 7. The foramen rotundnm. 8. The orbital surface of the greater wing. 9. Its temporal surface. 10. The pterygoid ridge. 11. The pterygopalatine canal. 12. The foramen of entrance to the Vidian canal. 18. The internal pterygoid plate. 14. The hamular process. 15. The external pterygoid plate. 16. The foramen spinosum. 17. The foramen ovale. 18. The extremity of the spinous process of the sphenoid. Fig. 102.—The ethmoid bone seen from above and behind. 1. The central lamella. 2. 2. The lateral masses: the numbers are placed on the posterior border of the lateral mass at each side. 8. The crista galli process. 4. The cribriform plate of the leftside, pierced by the cribriform foramina. 5. The hollow space immediately above and to the left, of this number, is the superior meatus. 6. The superior turbinated, 7. The middle turbinated bone: the numbers5, 6, 7, are situated upon the internal surface of the left lateral mass, near its posterior part. The interval between these parts Is the superior meal ns. 8. The external surface of the lateral mass, or os planum. 9. The superior or frontal border of the lateral mass, grooved by the anterior and posterior ethmoidal canals. 10. Refers to the concavity of the middle turbinated bone, which Is the upper boundary of the middlo meatus. Fig. 108.—A front viow of the skull. 1. The frontal portion of the frontal bone 228 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. Fig. 109. slender styloid process; internally, the petrous portion of the bone is conspicuous. It is remarkable for containing the internal organs of hearing, among which could be counted four bones in each ear—which are to be described with the ear. The whole inner surface of "the bone is very irregular, presenting many processes, s and fossae; and also when in its place, many holes, fissures, I. SPECIAL ANATOMY, ETC. APP. OF RELATION. back. The same thing would result if the discs were added and natural in fig. 131, compressed very much in the dorsal region in fig. 130, and throughout the column in fig. 132, and extended in fig. 133. Fig. 127, is a partially ideal representation of two vertebra? with the disc natural, viz., compressed only by the natural weight of the body. Fig. 128 represents the disc much compressed. Fig. 129, the same with all weight removed, and also extended. Care must be taken not to conceive that the articulating processes act as pivots upon which the vertebras turn. They are too delicate to bear the effect of much force. The mechanism of the motion, is this: —If the back is flexed forward, the front part of the disc is compressed, the central part is pushed back, and the back part of the disc of course somewhat thickened, and is the pivot; the posterior ligament, viz., upon the body of the vertebra? in the canal, restricts the separation of the vertebrae at that point; the yellow ligaments are at the same time stretched, and the capsules of the joints preventing the access of any thing to them, being made tense, cause the resistance of a vacuum to be produced. As soon therefore as the compressing cause is removed, the compressed front part of the disc, the thickened back part, the elastic ligaments and the pressure of the atmosphere, tend at once, forci bly, quickly, but gently, to restore the erectness of the column. If the column is flexed to either side, the same operations and forces are exhibited, though changed in direction. If the column is curved backward, the front part of the disc is stretched, the back part compressed; the anterior ligament now resists distension, while the posterior, elastic, and capsular are lax. There is therefore less power in the column to restore itself, and the powerfhl muscles which act through the long lever-like ribs, must add their assistance. The motion backward is restricted by the spinous and articulating processes. Those of the loins and neck, allow extensive motion, those of the back but little. The unprofessional world have been taught to believe that erectness chiefly depends upon the muscles of the back. This cannot, however, be true to any considerable degree, for—1st. Muscular action is always attended with considerable expenditure of substances, wherefore elastic tissues are used when they can be, and the discs can be made sufficient for the purpose indicated. 2d. Muscular action continued, is attended with discomfort, and the back must be supported the greater part of our waking hours. 3d. The muscles of the back are few in number, and small in collective size, compared with those of the lower extremities or of the neck. 4th. When What would be the shape of the column if natural discs should be introduced ? In which fig. would discs if introduced, be extended ? What is the mechanism in ope ration and exhibited when the back is flexed forward ? When to either side? DIV. I.] 243 MOTOR APPARATUS SKELETON. the head is large and must be supported, as in the cow, large elastic ligaments exist for the purpose. (See Fig. 27.) 5th. Experiment proves what theory indicates; for if every thing be removed from the spinal column, it not only maintains its erectness, but if forcibly flexed, will restore itself, and at the same time lift a large weight attached to its upper extremity. The muscles, therefore, rather guide than produce the erective motions of the back. They do however assist. But if the whole depended upon them, the practical conclusions would be the same; as what should be done for the health of the discs, should also be done for the good of the muscles. 392. The character of the discs and ligaments are dependent upon their natural constitution, upon the age and health of a person, and upon the treatment they receive. lllus. a. —By similar compression of the chest, two persons will produce very different results; one will become very crooked, the other may have her erectness but slightly affected. By similar causes, one person will have his stature shortened an inch, while the shortening of another is scarcely observable. Illus. b. —The front part of the discs in the lumbar region, are thicker than the back. This is especially noticeable in the case of the one between the sacrum and the vertebra. The discs of the dorsal region are just the reverse, while those of the neck are thicker at the front part. In the central part of the dorsal region, in the perfect form, the right side of the disc is slightly thicker than the left. By these varying thicknesses of the discs, the proper curvatures of the column are produced, which should and do differ in different persons, as they render the column stronger and more elastic, and allow proper positions to the organs in the trunk. The slight curvature of the dorsal vertebrae to the right, is thought by Cruvelhier to be for the purpose of giving room to the aorta. Bichat thought it was owing to the great use of the right hand, and Beclard declares that in case of those who are left-handed, the curvature is to the left. The probable reason is, however, that the ribs of the right side may be elevated and thrown out a little more than the left, and the whole body properly balanced, the What reasons are given to show that erectness does not chiefly depend upon muscles ? Of what use are the muscles in respect to erectness ? Upon what do the qualities of the discs and ligaments depend ? Is the column quite erect laterally ? 244 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. heavy and large liver being upon the right side. The practical results are, that the parts above and below must be slightly, though in a perfect form hardly perceptibly, curved in an opposite direction, and of course there is naturally a tendency in the column to curve badly when injurious influences act upon it. 393. The effects of age manifest themselves in infancy, when a person is growing rapidly, and in advanced life. Illus. a. —The back of the infant is round. This is because the discs have not yet become sufficiently firm to support weight. The action of the lungs ? digestive organs, and indeed all the contents of the trunk, require that the back be curved at this period. Inf. —Placing the hand against the back and pressing the child into an erect position must be injurious. Mus. b. —The young person who is " growing " rapidly is usually " round-shouldered." This seems to be owing to the slow process of growth which takes place in such structures as the discs. But it is also noticeable, that such persons are soon out of breath, and exhausted generally with light labors. That the curved form of the column is not an injury, but a benefit and a necessity, we may well believe, since it is produced in the ordinary course of nature. Breathing is easier when the column is curved, than when erect; and other reasons may be given for what we see. Inf. —When compressing clothing and supports are put upon the growing person, no good can, and much evil must, result. Illus. c. —Old people sometimes become very crooked. This is produced by the absorption and consolidation of the discs, which must result from the enfeebled circulation and digestion of old age. It ought to result, for the consolidated state of the bones would cause the brain to feel too severely the jars of even walking, if the column should be erect. There are several other reasons why the curvature should exist, and none why it should not. 394. The effects of disease upon the discs are proved Where does the slight curvature to the right exist? Why? When does age exhibit peculiarities in the discs? Why should the child's back be round ? What is the effect of forcing it to an erect position? DIV. I.] 245 MOTOR APPARATUS —SKELETON. from peculiar forms of the column being associated with certain diseases. Illus. —The slightly experienced eye can readily detect the consumptive or asthmatic patient by his form, which is very different from that of a person recovering from a tedious sickness, of the growing youth, of the sedentary person, or of old age. Many, from seeing the curvature and disease associated, have mistaken the cause for the effect, and vice versa. It is not the curvature which produces the disease, but the reverse; indeed, with the disease the curvature is nature's own blessing; cure the disease, and the curvature disappears, just as, when the growing person gets strength proportioned to his stature, his form becomes erect and manly. Inf. —It would be an absolute injury to make a person straight, if it could be done, while the disease continued. 395. The use or treatment of the discs and ligaments affects their ordinary character, more than any thing. Any use or treatment which produces continued compression of the whole or any part of the disc, or extension of the ligaments, causes them to lose their natural elasticity, and to become permanently thinner in one case and longer in the other than is desirable. Whatever course, on the other hand, subjects the discs and ligaments, or different PARTS OF THEM, TO ALTERNATE ACTION AND REPOSE, PERFECTS THEM CORRESPONDINGLY. This must be so, from the nature of the case and the constitution of fibrous tissue. The discs do not contain blood-vessels, and the substance which nourishes them must slowly make its way into their interior. How can it pass into them compressed 1 If, however, as one part is compressed another is relieved from pressure or extended, the passage of substance into the uncompressed part will be facilitated; and if this action can be alternated upon the different parts, the desired perfect nutrition and excretion can be obtained. Facts, also, prove what is so clear even without them. Is the form of the column the same in different diseases ? Does the form produco the disease ? Which should first be done —the disease removed, or the form corrected? What treatment of the discs makes them thinner? What perfects them ? SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. ft 246 Illus. a. —A French physiologist declares that a son of his lost an inch in stature by dancing one night, which was regained in a short time. Mus. b. —Prof. Baird, of the Smithsonian Institute, told the author that, between eight o'clock in the morning and four in the afternoon, while hunting, his stature was diminished three-fourths of an inch, but the second morning after, he had regained his usual stature. Mus. c. —Frequently a person's occupation can be judged from the curvature of the column, it being caused by constant compression of one part of the discs. Mus. d. —Females are, nine cases in ten, more or less deformed, while a majority of men are erect. Inf. — Whatever causes any position to be continued must be considered a cause of deformity, while frequent changes of positions must surely tend to produce erectness of figure, and gracefulness of spinal motion. 396. The great causes of deformity are fourfold: 1st. Compression of the chest. 2d. Wearing the clothing suspended upon the region of the waist. 3d. Supports. 4th. Sedentary habits. If the chest be compressed, the necessary action of the ribs is, to produce continued pressure upon the front part of the intervertebral discs. The same result follows from the weight of the clothing acting through the ribs as levers; while if the chest be encased with whalebone or other supports, or if there be only " a few, just to keep the dress in place," the position of the dorsal portion cannot be much changed, and with fatigue must come deformity —for it is deformity, whether dressed in silks and satins or seen at the public hospital. That sedentary pursuits tend to similar results need not be argued. The person who takes but little exercise ought to have a curved spinal column. He ought to take more general exercise, and be straighter; but if he will not exercise, it is a blessing to be crooked. 397. Every kind of general exercise, with clothing loose, supported upon the shoulders, and free from every kind of stiffening, and easy, frequently changed positions, tend What does a Frenchman testify in respect to his son? What does Professor Baird's experience prove ? Who are most curved, men or women ? What do you infer from what has been said in respect to deformity ? What are its chief causes? DIV. I.] 247 MOTOR APPARATUS SKELETON. to produce an easy, elastic erectness, and mobility of the spine. * Inf. —If young ladies wish to be attractive by their comely forms or graceful movements, they must away with all things that constrict or support the chest, and take a great deal of exercise of various kinds. 398. The more feeble a person is, the more often and the longer does he require repose in order to promote the perfection of the spinal column. One reason why men are more erect and less deformed than females is, that they repose themselves when sitting or standing, leaning in this direction or that, as is most comfortable; while females endeavor to maintain an erect position, and fail to gain the desired object by attempting it in the wrong manner. Young men "grow up" without being forced to "sit up" as young ladies are. Young ladies are also so dressed, that when they attempt to rest it must be in a constrained position, not an easy, graceful position of repose and comfort. The chest being compressed, and too small a quantity of air received for the perfection of the blood, the brain is oppressed, and they are inclined to inactivity and quietness in very bad positions—which, indeed, any position is if continued for too long a time. Deformities will again be noticed under the description of the chest. 399. As an apparatus for protection, we may notice, 1st, the cancelli of the bodies of the vertebrae filled with marrow; 2d, the elastic character of the twenty-three thin discs between the thick bodies ;* 3d, the curvatures of the spine; and, 4th, the canal extending the whole length of the column proper, called the spinal, and also the rachidian canal. It is the largest where the movements of the column are most extensive, and is slightly larger at the upper and lower part than at the middle of each vertebra. The lower edge of the lamina of each vertebra overlaps the upper part of the one below, so that an instrument enters the canal only with great difficulty and force. * This is quite the reverse of what is seen under railroad cars—which, I suppose, is the reason why a patent was given I Is it desirable for young ladies to be attractive ? How can they become more so than usual ? When do the discs require most repose f In what respects is the column adapted for protection ? Where is the spinal canal largest ? 248 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. L 400. As an apparatus for motion, we may notice, 1st. The sensitive discs between the vertebrae. The weight which is placed upon them naturally is such as to render them exceedingly elastic. 2d. The processes to which are attached one extremity of the muscles, by which the flexions of the column are easily produced. The ribs are especially worthy of notice, for, though they are attached to the vertebrae by means of joints, yet the muscles attached to their anterior extremities, through them act upon the column with a very advantageous leverage, and flex the back very easily. Skeleton of the Speaking Ajjparatus. —A. Chest or Thorax. B. Vocalizing Apparatus. Fig. 134. A. Skeleton of the Chest or Thorax. 401. The skeleton oj the chest is composed of the dorsal portion of the spinal column, 12 ribs on either side, 12 costal or rib cartilages, and the sternum. 402. The vertebral portion of the chest is adapted to its purpose by means of, 1st. The facets on the bodies and transverse processes of the vertebrae. These Fig. 134.—An anterior view of the thorax. 1. The superior piece of the sternum 2. The middle piece. 8. The inferior piece, or ensiform cartilage. 4. The first dorsal vertebra. 5. The last dorsal vertebra. 6. The first rib. 7. Its head. 8. Its neck, resting against the transverse process of the first dorsal vertebra. 9. Its tuberosity. 10. The seventh or last true rib. 11. The costal cartilages of the true ribs. 12. The last two false ribs—the floating ribs. 13. The groove along the lower border of tho rib for the lodgment of the intercostal vessels and nerve. DIV. I.] 249 MOTOR APPARATUS SKELETON. receive the heads and tubercles of the ribs. 2d. Its elastic discs and ligaments. These assist in all the motions 1 of the ribs. 3d. Its spinous processes. These being inclined, prevent harmful motion of the chest backward. 403. The ribs have sometimes been classed as true, false, and floating, according as their cartilages were connected directly with the sternum, to those above, or with nothing. But, as the names do not convey a correct idea, I shall class them as the upper group, of seven; the middle group, of three; and the lower group, of two ribs. Sometimes there are but 22 ribs, and sometimes there are 26. There are as many in the male as in the female. The ribs are divided into the head, neck, tubercle, angle, body, and anterior extremity. The head is divided by a line into two surfaces, each of which is attached to its own vertebra by means of a synovial and ligamentous capsule. The first, eleventh, and twelfth are attached to only one vertebra, and have but one surface. The tubercle corresponds to the facet of the process. Just in front of the tubercle, the rib curves abruptly and forms its angle. The bodies of the ribs differ from each other from the first to the twelfth. The first is short, stout, very much curved, and nearly flat horizontally. The ribs increase in length to the seventh, and then diminish to the twelfth; and from the horizontal, the flatness soon becomes perpendicular. The ribs are quite smooth externally and internally ; they have a blunt, round edge upon the upper side, and a sharp, thin edge below, just within which a protective groove can be noticed. The eleventh and twelfth have no tubercle or groove, and are but little curved. The ribs have the external appearance of long bones, but internally they have not any canal, but cancelli. They have a great degree of elasticity for bone. The position of the ribs varies according to their relation to the first, which is nearly horizontal; they curve downward more and more, to the very lowest. The costal cartilages have the same breadth and thickness as their ribs, but differ from each other very much in length. The first is very short, the seventh very long; those of the eighth, ninth, and tenth unite to those above them, and thus form a broad, irregular cartilage. Those of the eleventh and twelfth merely tip them. These cartilages are of the cellular character, and very elastic. They connect between the ribs and sternum, the first and second nearly hori- Of what is the skeleton of the speaking apparatus composed? Of what is the skeleton of the chest composed ? How is the dorsal portion of the chest-skeleton adapted to its purposes ? How are the ribs grouped ? W hat parts do ribs exhibit ? 11* 250 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. zontally; the rest turn upward more and more. They are very useful in all the motions of the chest. The sternum in early life is composed of several bones, as indicated by the lines of the figure, but they are at last consolidated. The sternum remains however tipped with a cartilage, called the zyphoid, till a very late period of life. Skeleton of Chest, considered generally. On account of the vital importance of air, as well as on account of speech, the chest and its contents always attract attention, and is worthy of particular notice, because of its effect upon the form and movement, and also because many incorrect notions prevail. Fig. 135. Fig. 135.—Ideal view of a vertebra, ribs, cartilages, and sternum, c, body; p, facet of the body; d, process which is, in fact, articulated with the rib ; p I, body of rib ; 6, cartilage ; h, sternum. 403. The size and form of the chest are determined by three dimensions —its height, its lateral, and its antero-posterior diameters; and all these are at once affected by the positions of the ribs, which, of course, determine the capacity of the chest as well. The positions of the ribs are-partly dependent on their own motions, and partly on those of the dorsal vertebras. 404. When the ribs are depressed, the front of the chest is comparatively flat, and its capacity is correspondingly reduced. When they are elevated, the chest appears full and plump, and the capacity of the chest is enlarged. When the Describe the costal cartilages? Where is tho sternum? Why should the client attract attention? Describe fig. 135. By what dimensions may the capacity of tho chest be measured ? Upon v, hat ir otions are the positions of the ribs dependent ? DIV. I.] 251 MOTOR APPARATUS SKELETON. ribs are depressed to the utmost degree of their own motion, a compression of the dorsal discs will allow them to fall so much lower. On the other hand, when they have been raised, the expansion of the dorsal discs will elevate them still more. 405. Expansion of the chest is therefore entirely dependent upon a perfectly free and extensive motion of the ribs and dorsal vertebrae, and perfect breathing depends upon the same things, and requires that the chest be made as small on the one hand, to expel the air, as it is made large on the other to inspire it. In other words, perfect breathing depends more upon latitude of motion than absolute size— indeed permanent size is not of especial value. Whatsoever constricts the chest, not only injures breathing, but deforms. If the ribs be pressed inward, they will also be pressed downward ; this causes the dorsal discs to be constantly acted upon, and the curvature of fig. 130 is the result. But the ribs are a little less elastic or yielding on the right than on the left. The liver is on the right side, and the right cavity of the chest is usually a little broader than the left, the ribs upon that side not being quite as much depressed as on the left. When the chest is compressed, the left side, therefore, yields the most; the left side of the discs are most compressed becomes thinner than the other side, and thus lateral curvature is produced. Whoever therefore, thinks a small waist agreeable, should remember that deformity is also connected with it necessarily. Besides, if the chest be not allowed free motions, the action of the person cannot be perfectly graceful and charming. The greatest care should be taken that the girl do not acquire the very erroneous idea that a small waist is a sign of gentility, and an improvement upon nature. The contracted waists of dolls which are given to children frequently, must early plant wrong ideas in their minds. The publishers of magazines, with deformed fashion plates, are not a m.. ion little responsible, nor will they be held guiltless. SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 252 Fig. 187. Fig. 188. Here is an internal view, with the trappings removed. Fig. 138 is no exaggeration—it is an every-day reality—the result of the tight dresses, heavy skirts suspended about the waist, the whalebones worn in dresses, and sedentary habits. The young lady with chest like 138, all other things being similar, will not be, cannot be, any thing like as attractive as one whose chest is like 137. But other things will not be similar; a chest like that of 137, confers many beauties besides those of form. Let it be remembered that a freely moving, alternately expanded and diminished chest, is entirely different from the chest made large by fat. Fig. 138 does not exhibit all the deformity of the chest; the shoulders, especially the right one, project; the back is curved, and she has not her natural stature. I have now before me a skeleton in which all these deformities conspicuously exist. The discs of the dorsal region were so much compressed, and so constantly, that they had become as thin as paper, and as firm as bone itself. But we will return to this subject again. B. Skeleton of the Vocalizing Apparatus. 406. The skeleton of the vocalizing apparatus, is composed of the trachea, larynx, and hyoid bone. 407. The trachea is composed of four-fifths of cartilaginous rings, connected by elastic ligament, which also completes the tube, which is therefore flattened behind. The Describe figs. 136,137, and 138. What produces such chests as 138 ? What other evils not apparent in 188, exist? What classes of parts form the skeleton of the speaking apparatus ? Of what is the trachea composed ? DIV. I.] 253 MOTOR APPARATUS SKELETON. length of the trachea is unimportant to consider; it differs in different persons, but cannot be materially affected by their efforts. Its elasticity can be improved by exercise. 408. The skeleton of the larynx is constructed of the cricoid, thyroid, arytenoid and epiglottal cartilages, the cordse vocales and other ligaments, capsules, &c. Fig. 189. Fig. 189, represents a side view of the larynx and hyoid and a few rings of the trachea; c, cricoid, t, thyroid, v, its anterior inferior border, d, inferior, 6, superior tubercle; 8, superior, r, inferior horn; which has a synovial capsule connecting it to the cricoid; upon this, as a pivot, the thyroid turns; «•, Fig. 140. thyro-hyoid ligament; u, body: i, lesser, v, greater horn, of the hyoid bone. Fig. 140 represents a side view of the larynx, 12, trachea; 9, 9, cricoid: 8 thyroid. Fig. 141, view of cartilages separated; c, cricoid; h, its articular surfaces for receiving a of the arytemoid, *, thyroid which comes down upon c, and with its sides grasps the sides of c. Fig. 142, cricoid cartilage; 1, its body; 2, the cavity it forms; 8, its lower front edge, which is attached to the upper ring of the trachea; 4, the articular surface for the arytenoid. Fig. 148, posterior view of left, arytenoid cartilage ; 1, its surface; 2, its summit; 4, external, and 5, internal angle ; 3. articulating surface for the cricoid. Fig. 144, anterior view of 143. Fig. 145, lateral view of thyroid; 1, body; 2, inner surface; 3, superior border; 4, anterior notch; 5, anterior surface; 6, tubercle; 7, posterior border; 8, superior, 9, inferior horn. Fig. 146, front view of 145. Fig. 147, Epiglottis; 1. superior, 2, inferior surface: 3. superior, posterior, and 4, anterior and inferior extremity; 5, 5, its sides. It is situated above the opening into the larynx, and so as to close it when the rest of the larynx is raised against the epiglottis. See fig. 2 pi. 6. The tongue is also connected to this sort of valve, and when the tongue is thrust out or drawn forward, the epiglottis will be raised also, which is a fact of great importance in case of drowning. Fig. 148, front view of hyoid bone; 1 body; 2 major, 8, minor horns. Fig. 141. fw te-W a viewfroui above of the vocal cord 8, 8, andl, a space between, *' CrlCOi,1 • 2 aryten ° W Milages; 4, 5, 6 254 SPECIAL, ANATOMY, ETC. APP. OF RELATION. [B. I. 409. The various parts of the larynx form a kind of box, and by moving upon each other, they regulate the cavity within, the orifice through which the air passes out, and the tensity of the vocal cords, between the edges of which it passes. Fig. 142. Fig. 145. Fig. 143. Fig. 146. Fig. 147. Fig. 148. Describe figs. 139.140. 141.142.148,144 145.146. 147.148.149. What do the various parts of the larynx form ? What is their use ? DIV. I.] MOTOR. APPARATUS SKELETON. 255 410. The essential requisites for the easy and healthy production of voice, are exercise, and freedom from restraint. Any constrained position, or constricting clothing, is prejudicial. A drooped position of the head, tight neck bands, the shoulders held back, or in any particular position, the waist tightly dressed, injure the action of the speaking apparatus. Fig. 148.* Skeleton of the handling Apparatus, or Upper or Thoracic Extremities. 411. The skeleton of the handling apparatus includes that of the shoulder, upper and lower arms, and the hand. 412. The skeleton of the shoulder includes the clavicle, scapula, their joints, &c. 413. The clavicle or collar-bone, is a slender, somewhat flattened bone, of medium size, doubly curved. Within it Fig. 149.—Clavicle, a, Body. c. Inner or concave. 6, Outer or convex border. d, Acromial, e, Sternal end. tt [u^*^ a medullary canal of small size is found. It is situated in front of the uppermost part of the chest, by one extremity being articulated by a movable joint to the sternum, while the rest of the bone stretches out towards the tip of the shoulder. a medullary canal of small size is found. It is situated in front of the uppermost part of the chest, by one extremity being articulated by a movable joint to the sternum, while the rest of the bone stretches out towards the tip of the shoulder. It may be considered as a radius of a sphere of which the sternum is the centre ; the outer end describes the surface —or it may be considered as a lever, the sternal end resting as a pivot upon the sternum as a fulcrum —or it may be likened to a crane, by which articles are swept around from one position to another—or again it may be called a brace. Its position and proper use should be well appreciated. Cruvelhier says that more than any bone it exhibits What are the requisites for proper production of voice ? What injures the voice ? What does the skeleton of the handling apparatus include? What does the skeleton of the shoulder include ? Describe the clavicle ? 256 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. the effect of manual labor, and that he has many times detected left-handed persons by the greater comparative size of the left clavicle. It differs in length and size naturally in case of males and females being compared, and this is one reason why sweeping floors, and all labor requiring leverage, is so tedious for women, but easy for men, while taking care of children is easiest for women. Fig. 150. 414. The scapula presents for our consideration, a socket, body, spine, and acromion and coracoid processes. 415. The socket is the essential part of the bone, as to this the arm is attached, and the other parts of the scapula are for the purpose of guiding the motions of the socket, and by that means the motions of the arm. Little need however be said, as the eye reads the socket clearly by the various cuts of it, which see. Fi2 150 Back view of scapula. I. Supra-spinous fossa. 2. Infra-spinous fossa. 3 Superior border. 4. Notch. 5. Inferior border. 6. Head and glenoid cavity. 7. Inferior angle. 8. Neck. 9. Base of the scapula. 10. The spine. 11. Smooth surface. 12 Acromion process. 13. Foramen. 14. Coracoid process. 416. The body of the scapula, is a very thin plate of bone, the shape of which is readily seen and its size felt. The circumference is somewhat thickened,to give it strength. The body presents two surfaces. The under surface is somewhat concave, the degree of its concavity differing in different persons. By this shape it is fitted to the natural and proper form of the chest, upon which it is placed, and to which, so to speak, it is moulded. Inf. When the form of the chest is altered the scapula can no longer be adapted to its place, but must project in some unseemly way. What kinds of labor are comparatively easier for men than women ? What parts have we to consider in the scapula ? Which is the most essential part of the scapula f What is the body of the scapula ? How is it fitted to the surface of the chest ? DV. I.] 257 MOTOR APPARATUS SKELETON. 417. The outer surface of the scapula is divided by the spine into the supra and infra spinous surfaces, which offer nothing worthy of note here. The spine rises at the back part of the scapula, and gradually becomes that very prominent ridge that may be so distinctly felt. This terminates in a prominence above the socket, and shielding it, called the acromion process. To this the clavicle is articulated. The coracoid process springs out from the scapula near the socket, and serves for the attachment of muscles. The shoulder considered generally. 418. The scapula or shoulder blades are not jointed or articulated upon the ribs, but to the clavicles alone. The object of this is to throw out the joints to a distance from the ribs, and give to the arms greater sweep of motion, as well as to the muscles greater leverage. The flat bodies of the scapulas are merely broad processes, for the attachment of muscles, that through them move the shoulder socket. These muscles lie, in part, between the bodies and the ribs, forming in fact a kind of cushion for the shoulder blades. 419. The position of the scapula cannot, therefore, affect the absolute size of the chest. It is thought to do so, because when the shoulders are thrown back more of the chest appears in front; but it has diminished behind correspondingly. Besides, if the chest was thus made permanently larger, it would be an injury, for as before shown, it is desirable to have the chest alternately large and small; to wit, extensively movable; for this purpose, as shown, there must be no fixedness of any part, but freedom from restraint, and development of motion by proper exercise. 420. Form of shoulders. This is one of the most important points that physiology discusses. Form of the shoulders depends upon natural constitution, age, health ; but chiefly upon the dress and exercise, or want of it. What Is the spine of the scapula? What is the acromion process ? What is the coracoid process ? To what are the scapula? jointed ? Is the size of the chest affected by the position of the scapulae ? Why is it thought that they do affect it? 258 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. J. If the dress be tight about the waist, the dorsal discs will be compressed, and the column curved forward accordingly; this throws the head forward and downward; to correct the last inconvenience the neck is bent backward, which causes unnatural constriction of the vocal organs. But the head yet projects, and this causes the shoulders to appear as if projecting, when they are not perhaps as far back as they should be. The form of the chest being changed, the edges and angles of the shoulder blades present themselves unseemly. The natural curvature to the right, the liver upon the right side, and the unyielding character of the right compared with the left side in a downward direction, causes a real prominence of the upper part of the right chest; but since the left is depressed, the right shoulder will appear much the most prominent. 421. The real cause of prominence or deformity of the right shoulder is to be chiefly attributed to compressing the chest, suspending clothing upon it, to the use of whalebones, and to sedentary habits. If this be not so, why is not the right shoulder as prominent in case of men as in case of women ? I know it will be said, " I never did dress tightly." But persons merely mistake. Tight dress is used upon the little girl, till she becomes accustomed to it, and does not know what a tight or loose dress is. Beauty of person. or loveliness of mind, can never be possessed to the highest degree of which ladies are capable, till the obnoxious custom of tightly (only snugly ?) dressing is laid aside, and from infancy up, the whole system is allowed free motion. The clothing must likewise be suspended by straps, or still better by a waist upon the shoulders. The exhausting- effect of the weight of ordinary clothing would be too much for the stoutest man, and of course not a little of the ill health, deformity, and the want of beauty of complexion, and vivacity of mind among females, may be attributed to this ordinary custom. A most unfortunate fashion has been introduced among men, of laying aside suspenders. The tightness with which the clothing must then be worn, as well as even its light weight, are very prejudicial to health and form. Another cause of bad shoulders among females is, wearing dresses low about the neck, or perhaps even off the shoulder. This is more likely to be the case with children. This causes the What effect upon the shoulders Is produced by constricting the chest? How? Causes of deformity of the right shoulder ? How can ladies be rendered more beautiful and attractive than they even now are ? Effect of not wearing suspeaders ? DIV. I.] 259 MOTOR APPARATUS SKELETON. shoulders to become " shrugged," it confines the motions of the chest, and of course causes deformity of it and the shoulders, besides making the motions of a person awkward and stiff.* 422. To correct and prevent deformities of the shoulder, the clothing must be free, the position of all parts unrestrained, and plenty of various kinds of exercise taken. Upper and Lower Arms. Figs. 151* and 152.t * The humerus of the right side; its anterior surface. 1. The shaft of the bone. 2. The head. 3. The anatomical neck. 4 The greater tuberosity. 5. The lesser tuber osity. 6. The bicipital groove. 7. The anterior bicipital ridge. 8. The posterior bicipital ridge. 9. The rough surface into which the deltoid is inserted. 10. The nutritious foramen. 11. The rounded protuberance of the articular surface. 12. The pulley-like surface. 18. The external condyle. 14. The internal condyle. 15. The external condyloid ridge. 16. The internal condyloid ridge. 17. The fossa for the coronoid process of the ulna. t The two bones of the fore-arm seen from the front. 1. The shaft of the ulna. 2. The greater sigmoid notch. 3. The lesser sigmoid notch, with which the head of the radius is articulated. 4. The olecranon process. 5. The coronoid process. 6. The nutritious foramen. 7. The sharp ridges upon the two bones to which the interosseous membrane is attached. 8. The rounded head at the lower extremity of the ulna. 9. The styloid process. 10. The shaft of the radius. 11. Its head, surrounded by the smooth border for articulation with the orbicular ligament. 12. The neck of the radius.. 13. Its tuberosity. 14. The oblique line. 15. The lower extremity of tho bone. 16. Its styloid process. 423. The skeleton of the upper arm includes but one bone, the description of which * The reason why the dress is worn low, viz., to render a pers Is to me the very reason why it should be reasonably h gb. Jor thereis not one In a thousand whose arm or neck is so well formed or with' complex on so flue, that it is any credit to expose them; and, in the next ugnant woman so attractive as the most refined modesty, and there is nothing » wpngnwt as the least want, or appearance of the want of it. Imported fashions and manners Effect of low dresses in producing deformity ? How carreer of the shoulders f Describe figs. 151,152. How many bones in the upper arm ? 260 SPECIAL ANATOMY, ETC. APP. OF RELATION [b. I. is well enough made by fig. 151. At the hack part of the lower end of the hone, a deep fossa exists to receive the olecranon process of the ulna and restrict motion in a hackward direction; indeed the two arms cannot be brought into the same line. 424. The skeleton of the lower arm embraces two bones, the form, size, and proportions of which are at once described by fig. 152. They reach from the elbow to the wrist. One only, the ulna, assists in forming the elbow joint, while to the radius only the wrist is attached. 425. The connections between the two bones are peculiar. A ligament called interosseous extends between them, from the bottom nearly to the top of the space intervening between them, while two movable joints are found at their points of contact. 426. The mechanism of the motions of the radius is very simple, but usually confused by the use of wrong terms. There are two different kinds of joints. 427. The lower joint is a hinge, and the motion allowed by it is the same as that of a book lid when the other part is held fast, and if a hand should extend from the book lid, it could be made prone and supine by simply opening and shutting the lid. If to the open lid a rod, a foot or more in length, make us forget sometimes that words do not always mean the same in the Old World and New. There, where vice walks abroad in daylight, a person may be called and thought a lady, let her dress be what it may, if only fashionable; but it is the exceptionless and exalted opinion of American gentlemen (and I speak upon the authority of all classes), that lady, means a person too sensitive to appear in public with short sleeves or a dress low about the neck. I know ladies are not aware of this, but could they hear the remarks which are always made on such modes of dress, it would never be seen in any circles of well bred people. It might by some be expected that leaning upon the elbow would be mentioned as a cause of deformity. It has been, to be sure.said to be.but there is not a shadow of reason for truth in the statement Is not the left elbow leaned upon more than the right? Does it not first receive a patch, as a general thing? Do not men and boys lean upon the elbow as much as ladies and girls ? The idea is merely ridiculous. What is noticeable at the lower back part of the humerus ? How many bones in the lower arm ? What is the interosseous ligament of the fore-arm ? Of what kind is the lower joint of the fore-arm ? The motion by its means, is compared with what ? DIV. I.] 261 MOTOR APPARATUS SKELETON. be fastened near the hinge, and the end farthest from the book be held in the hand, motionless as far as possible, the motion of the upper part of the radius will be perceived when the lid is opened and closed. If another rod be fastened to the body of the book near the hinge, and the hands be placed side by side, the motion will be more perfectly exhibited. The only difficulty to obviate in this experiment is, that the hinge of the book is long, and the whole length of the rods will turn at once, except one is rather loosely fastened to the cover. It will be noticed that the hinge point of the bones is very small. If the bones be at hand, they can be fastened by a hinge very narrow and somewhat loose in its joint, and thus experiment the motion perfectly. 428. The upper joint is one of semi-rotation, though the motions are somewhat of an oblique character. 429. The lower arm bones are often fractured, and when this is the case with either of them, the arm very seldom regains its perfect form, owing to the action of the muscles in displacing the bones, and the inattention of people in observing the directions which are given to them: they not being aware of their importance. The Hand. That learned English author, Sir Charles Bell, did well to devote an entire volume to this truly wonderful piece of mechanism. No other part of the body proves more conclusively than.this that man possesses a mind, since it is needed to use the hand to the full extent of its adaptation. The corresponding part in other animals is a modification of the hand, but never with any additions. Its mOst singuar modifications are seen in the bat and bird. In both cases, wings being formed by the upper extremities, but of an entirely different character from each other. The field of Natural History is full of similar illustrations of the resources of the Divine Mind; space, however, does not permit me to enter into a particular description of the hand. If a skeleton of a hand were fastened to a book lid, when would the hand be prone and supine f Will you try the experiment with rods and book lid, cutting a piece of pasteboard to resemble a hand, or drawing the surfaces of a hand upon opposite sides of a book lid ? 262 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. i 430. The hand is constructed of six ranks of hones. 1st. The first includes the pisiform and the three hones which articulate with the radius. The three together are seen to form a kind of head which rolls in the socket of the radius. 2d. The second rank includes the remaining four hones of the carpus, which is thus formed in order to combine soli- Fig. 153. Fig. 154. Fig. 153, skeleton of bat, and outline of membranous wings; o, scapula ; cl, clavicle; k, humerus ; cu, ulna; r, radius; ca, carpus; po, thumb; ph, phalanges; /, femur; ti, tibia. Fig. 154, skeleton of bird; cv, cervical vertebra; cl, clavicles; ca, carpus; ph, phalanges; st, sternum; ti, tibia; ta, tarsus; cr, fore arm; h, humerus ; sv, sacral vertebra?; /, femur; ca. v, caudal vertebrae. W ho is the most elesant writer upon the hand ? Why does it prove the existence of a mind ? Of how many ranks of bones is it composed ? Which bones does the first rank include? What does the second rank include? Describe figs 153 154 DIV. I.] MOTOR APPARATUS SKELETON. 263 dity with elasticity to the highest degree. 3d. The third rank includes the five metacarpal pillars, upon the outer shallow socketed extremities of which rest. 4th. The third rank, including five hones, the first of the fingers and thumh. 5th. The fifth rank includes the four middle hones of the fingers, none being present in the thumb. 6th. The sixth rank includes the five terminal bones of the fingers and thumb. The first bone of a finger is called phalange; the second, phalangine; and the last, phalangette—the three a phalanx; and those of all the fingers and thumb are called phalanges. * A diagram showing the dorsal surface of the bones of the carpus, with their articulations. —The right hand. R. The lower end of the radius. U. The lower extremity of the ulna. F. The inter-articular fibro-cartilage attached to the styloid process of the ulna, and to the margin of the articular surface of the radius. S. The scaphoid bone: the numeral (5) indicates the number of bones with which it articulates. L. The semilunar, articulating with five bones. 0. The cuneiform, articulating with three bones. P. The pisiform, articulating with the cuneiform only. T. The first bone of the second row—the trapezium, articulating with four bones. T. The second bone—tho trapezoid, articulating also with four bones. M. The os magnum, articulating with seven. U. The unciform, articulating with five. The numerals, 1, 3, 1, 2,1, on the metacarpal bones, refer to the number of their articulations with the carpal bones. Fig. 156. The hand viewed upon its anterior or palmar aspect. 1. The scaphoid bone. 2. The semilunar. 3. The cuneiform. 4. The pisiform. 5. The trapezium. 6. The groove in the trapezium that lodges the tendon of the flexor carpi radialis. 7. The trapezoid. 8. The os as magnum. 9. The unciform. 10,10. The five metacarpal bones. 11,11, The first row of phalanges. 12, 12. The second row. 13, 13. The third row, or ungual phalanges. 14. The first phalanx of the thumb. 15. The second and last phalanx of the tbumb. Fig. 155* Fig. 156. What does the 3d rank include V 4th ? 6th r 6th ? Describe figs. 155,156. 264 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. 431. From another point of view, the hand may be considered as composed of a series of levers, radiating from a common centre, by which arrangement they can be brought to clasp, or pinch any thing which it is desirable to examine or move; and thus the hand becomes a very handy instrument. 432. The motions of the hand are produced by the motions of,-1st, the body upon the feet; 2d, the knee joint; 3d, the trunk upon the thighs; 4th, the vertebras upon each other ; 5th, the elevated and depressed chest; 6th, the shoulder bone; 7th, the rotating humerus; 8th, the elbow joint; 9th, the turning radius; 10th, the wrist joint. Thus it can be swept through a great extent of space, and also made to visit every part of the body. Skeleton of Locomotive Apparatus — the Lower, or Abdominal Extremities. 433. The skeleton of the locomotive apparatus is constructed of the hip, thigh, lower leg, and foot bones. Fig. 157. Fig. 157. The osinnominatum of the right side. 1. The ilium; its external surface. 2. The ischium. 8. The os pubis. 4. The crest of the Ilium. 5. The superior curved line. 6. The inferior curved line. 7. The surface for the gluteus maximus. 8. The anterior superior spinous process. 9. The anterior inferior spinous process. 10. The posterior superior spinous process. 11. The posterior inferior spinous process. 12. The spine of the ischium. 13. The great sacro-ischiatic notch. 14. The lesser sacro-ischiatic notch. 15. The tuberosity of the ischium, showing its three facets. 16. The ramus of the ischium. 17. The body of the os pubis. 18. The ramus of the pubis. Why may the fingers be called levers ? What produces the motions of the hand ? DIV. I.] 265 MOTOR APPARATUS SKELETON. Fig. 158. Ossa Innominata, 434. The hip bones are called ossa innominata. They are the largest broad bones in the body. Their form is very irregular, and their surface very rough. They are jointed to each other in front, forming the symphisis pubis. They are firmly locked to each side of the sacrum, which in two Fig. 159. directi o n s is wedged between.— They, with the sacrum com pi ete the kind of bony circle called the pelvis. 435. The external and internal surfaces of the pelvis do not correspond with each other. The external is adapted to receive the head of the thigh bone in its socket, denominated the acetabulum, and to allow the attachment of the muscles Fig.158. The sacrum seen upon Its anterior surface. 1, t< The transverse lines marking the original constitution of the bone of the four pieces. 2, 2. The anterior sacral foi amina. 8. The promontory of the sacrum. 4. The ear-shaped surface which articulates with the ilium. 5. The sharp edge to which the sacro-iscniatic ligaments are attached. 6. The vertebral articular surface. 7. The broad triangular surface which supports the psoas muscle and lumbo-sacral nerve. 8. The articular process of the right side. 9. The inferior extremity, or apex of the sacrum. 10. One of the sacral cornua. 11. The notch which is converted into a foramen by the coccyx. What is the common name of the ossa innominata? Where are they situated? What is the pelvis ? Do its surfaces correspond ? b, 3—12 266 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. appropriate to moving the thigh. The internal is adapted to lodge, support, and protect the pelvic viscera. There is, therefore, if the expression may be allowed, a double pelvis to be noticed, one of which is placed within the other} viz., the two laminae of the pelvic bones, the irregular space between the two being filled with cancellated bone, the cancelli of which are filled with marrow. These two laminae may therefore be called, one the abdominal, the other the locomotive pelvis. Fig. 160. Fig. 159. Front view of the pelvis from above. V Lower lumbar vertebra. S, A. sacrum, terminated by the coccyx. H. Os innominatum. Fig. 160. Pelvis. 5. Lower lumbar / vertebra. 4. Inter-vert e - bral substance, in this case, between the vertebra and sacrum. S, A. Sacrum. H. Os innominatum. A. Acetabulum. 436. The uses of the pelvis are therefore threefold: 1st. Locomotive. 2d. Abdominal. 3d. By its very irregular form, and cancellated, medullary character, it disperses much of the jar received from the thigh bone, and communicates but little of it to the sacrum. The holes seen in front of the pelvis make the bones lighter, while they do not weaken them. To what purposes is the external surface of the pelvis adapted ? To what the internal? Why may tho pelvis be called double? Describe fig. 159, and fig. lflit W hat are the uses of the pelvis ? DIV. I.] 267 MOTOR APPARATUS SKELETON. Femur. Fig. 161. Fig. 162! 437. The femur is divided into the head, neck, trochanters, body or shaft, and the condyles. The head forms rather more than half a sphere, and is perfectly adapted to the socket, so that, though it will turn in it with the greatest ease, about forty to fifty pounds' weight is necessary to draw it from its place when all the external ligaments are removed. A slight depression is found at the centre of the spherical surface, which furnishes attachment to one end of a short round ligament, which by the other end is attached to a corresponding depression a little to one side of the centre of the socket. This ligament Fig. 161.—The right femur, seen upon the anterior aspect. 1. The shaft 2. The head. 3. The neck. 4. The great trochanter. 5. The anterior intertrochanteric line. 6. The lesser trochanter. 7. The external condyle. 8. The internal condyle. 5). The tuberosity for the attachment of the external lateral ligaments. 10. The groove for tho tendon of origin of the popliteus muscle. 11. The tuberosity for the attachment of the internal lateral ligament Fig. 162. —A diagram of the posterior aspect of the right femur, showing the lines of attachment of the muscles. The muscles attached to the inner lip are,— p, the pectineus; a b, the adductor brevis; and a I, the adductor longus. The middle portion is occupied for its whole extent by a m, the adductor magnus; and is continuous superiorly with of. the linea quadrati. into which the quadratus femoris is inserted. The outer lip is occupied by g m, the gluteus maxlmus; and b, tho short head of the biceps. Into what parts is the femur divisible ? Describe the bead of femur? What and where is the round ligament ? Describe figs. 161,162, 268 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. Fig. 163. has no use in ordinary motion of the thigh, but checks extraordinary movement. The neck connects, by a very obtuse angle, the head to the body. The peculiar form of the neck is very admirable, strength being conferred by a very slight expenditure of material. The uses of the neck are, to throw the weight of the parts above to a farther distance from the centre of gravity, to give free motion to the thigh, to allow the muscles of the hips to act upon the thigh more favorably, and to disperse the jar received from the body of the femur. The trochanters serve for the attachment and more powerful action of muscles. The body of the bone is curved from the front backward, or is slightly convex in front,* and somewhat twisted. The peculiar reason for the twist has not been perceived. The condyles are two, called the external and internal. By their large size, they assist in forming a very secure joint at the knee 438. The knee joint is one of the most perfect hinges in Fig. 163.—The tibia and fibula of the right leg, articulated and seen from the front 1. The shaft of the tibia. 2. The inner tuberosity. 3. The outer tuberosity. 4. The spinous process. 5. The tubercle. 6. The internal or subcutaneous surface of the shaft. 7. The lower extremity of the tibia. 8. The internal malleolus. 9. The shaft of tho fibula. 10. Its upper extremity. 11. Its lower extremity, the external malleolus. * Some have supposed that this convex form of the bone was produced by tho weight of the foot and lower leg, and therefore recommend that children should have low seats, and touch the floor with their feet. There is no doubt about the value of this injunction; but if the weight of tho feet can bend the thigh bone, what will be the effect of jumping, walking, or even standing ? The idea is simply ridiculous. The femur is always curved to give it strength. How is the neck of the femur constructed? What is its use? What is the use of the trochanters ? What is there peculiar in the body of the femur ? Where are the condyles of tho femur? Of whrt kind Is the knee-joint? DIV. I.J 269 MOTOR APPARATUS SKELETON. the body. The incrustation of cartilage is thick ; two,interarticular cartilages, called, from their form, semilunar, also exist. At this joint the kneepan, patella, or rotula is also found. It belongs to the class of sesamoid bones, several of which exist at the smaller joints of the hand and foot. They are usually very small, but the patella is large. Its use is, to facilitate the motion of the tendon of the muscles which act upon the front and upper extremity of the tibia below. It also removes the action farther from a direct line, and therefore serves at the same time the purpose of a lever and a fulcrum. 439. The lower leg exhibits two bones, the larger called the tibia, and the smaller the fibula. The tibia is very large above, and alone, of the leg bones, assists in forming the knee-joint. Its form is triangular, one angle being in front, as most persons have had cause to know. The fibula is a slender, long bone, united above to the tibia by a scarcely movable joint, and throughout its length by an interosseous ligament. Thus, with small expenditure of material, great strength and great extent of surface, for the attachment of the numerous muscles which act upon the foot, with lightness, is gained. At the lower extremities of both bones, processes, called the malleoli, are seen. They guard the ankle joint. 440. The foot is constructed of the tarsus or ankle; metatarsus or pre-ankle, and the toes. The ankle is constructed of seven bones, with thin cartilages, synovial capsules, and ligaments, forming a strong, firm, and yet elastic piece of mechanism. The metatarsus is composed of five bones curiously locked together with the tarsus. It should be observed that they do not unite with the tarsus on a line. What are the peculiarities of the knee joint ? What is the use of the sesamoid bones ? How many bones in the lower leg ? What are the malleolar processes ? 270 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. The bones of the toes are three in number in the middle three; two in the great toe; sometimes three, and sometimes two in the small toe. Fig. 164. Fig. 166. Fig. 166. Fig. 166.— a, Articulating surface of astragalus. 6, Its anterior extremity. c, Body, d, Inferior posterior ; and e, anterior part of os calcis. g, Scaphoid. /, Cuneiform, m, Metatarsus, s, Inferior tuberosity, n, Phalanges. Fig. 164.—The dorsal surface of the left foot 1. The astragalus; its superior quadrilateral articular surface. 2. Tho anterior extremity of the astragalus; which articulates with (4.) the scaphoid bone. 8. The os calcis. 4. The scaphoid bone. 5. The internal cuneiform bone. 6. The middle cuneiform bone. 7. The external cuneiform bone. 8. The cuboid bone. 9. The metatarsal bones of the first and second toes. 10. The first phalanx of the great toe. 11. The second phalanx of the great toe. 12. The first phalanx of the second toe. 13. Its second phalanx. 14. Its third phalanx. Fig. 165.—The sole of the left foot. 1. The inner tuberosity of the os calcis. 2. The outer tuberosity. 8. The groove for the tendon of the flexor longus digitorum. 4. The rounded head of the astragalus. 5. The scaphoid bone. 6. Its tuberosity. 7. The internal cuneiform bone; its broad extremity. 8. The middle cuneiform bone. 9. The external cuneiform bone. 10,11. The cuboid bone. 11 Refers to the groove for the tendon of the peroneus longus. 12, 12. The metatarsal bones. 13, 13. The first phalanges. 14, 14. The second phalanges of the four lesser toes. IS, 15. The third, or ungual phalanges of the four lesser toes. 16. The last phalanx of the great toe. Of what parts is the foot constructed ? How many bones in the ankle f What fig. represents a section of the bones, capsules, &c, of tho foot? Describe figs. 164, 165, 166. DIV. I.] MOTOR APPARATUS —SKELETON. 271 Review and view of Skeleton in the Living Body. 441. In the entire body there are 243 bones. Or if the coccyges be considered as one, which is usual, there are 240— to wit: Cranium, - - - 8] Bones of ears, - - 8 I tt..,, -„' Facial bones, - - - 14f Head - * ' 62 Teeth, 82 J W Cervical vertebra', - - 7 c 8 Hyoid, .... 1 |JNecR, - - 8 g Dorsal vertebra;, 12 j © Costee, .... 24 V Chest, - - 87 2 Sternum, 1 ) ¦ g" tSSS* !• - • 8 • - 6 I Sacrum, ----11 P Coccyges, ... 1V Pelvis, - - 4 g Ossa Innominata, 2) p Lower extremities, 60 Upper extremities, - - - - - - 64. 442. If we take a view of the living skeleton, we shall perceive that it exists for the benefit of other parts. It is adapted to support and protect the softer organs of the body, and to serve the purpose of levers in the production of motion. A proper relation ought therefore to exist between it and the other parts of the body. 443. The character of the skeleton does very properly depend upon the original constitution of the body, and upon the exercise of its various parts. For as some persons are constituted with a predominant muscular system, so are they with a corresponding skeleton, while others constituted with a predominating nervous system, have naturally a smaller skeleton. Exercise of the muscles brings blood not only to themselves, but to the bones upon which they act as well, so that there may be a harmonious development of the two systems. Muscular exercise is then the panacea of an undeveloped bony system. Let the child who precociously loves How many bones in the metatarsus? How many in the toes ? How many bones in the entire body ? For what does the skeleton exist ? Upon what do the qualities of the skeleton depend? 272 SPECIAL ANATOMY, ETC. —APP. OF RELATION. [B. L to gather knowledge, he led to obtain it by observation in the fields of nature, not too much from books which may in a sedentary manner be perused. It is useless to say to the mind that loves to learn, " you will be injured, take muscular exercise." It will read, except it be equally or better satisfied. It is an appetite, which may be satisfied in the way indicated without harm, and the results will be every way good. 444. But the body is a republic, and while the skeleton serves the other parts, they must serve it. The stomach must receive and properly digest food, wholesome for the skeleton, the lungs must breathe a large quantity of pure air, the heart must fulfil its duties, the skin and kidneys must excrete. Then with a proper natural constitution, and exercise, day by day, there will be a harmonious adaptation of the skeleton to all the ages of life through which man passes, from the flexible and elastic skeleton of infancy, to the rigid framework adapted to old age. CHAPTER II. Muscular System. Tendons—Aponeuroses—Ligaments—Areolar Tissues—Bursas—Fat Analysis.— Molecular, Ciliary, Elastic, and Muscular motion—Denominative names, size, number, form, axis of direction, attachments, and uses of muscle — Muscles of relative and organic life — mixed muscles — Anatomical grouping of muscles—\st, of the head ; 2d, neck ; Sd, trunk; 4th, upper, and hth, lower extremities — Physiological classification, a the those of organs of sense, c those which move and stay the head and spinal column, d those of speech, e of the upper extremities, f of the lower extremities — view of living muscular system. General Remarks. 445. Four kinds of motion may be observed in the Human Body—Molecular, Ciliary, Elastic, and Muscular. Upon what does the flow of blood to the bones depend ? How can the bony system be developed? How may an appetite for knowledge be profitably satisfied? What things are essential to a perfect skeloton ? DIV. I.] 273 MOTOR APPARATUS MUSCLES. 446. Molecular motion. If almost any of the fluids of the body be examined beneath a powerful microscope} molecules will be seen darting with great rapidity from one place to another; or moving more leisurly without apparent cause, and as if spontaneously. It is, however, supposed that these motions are produced by unequal temperatures, or by chemical attractions. 447. Ciliary motion. Beneath the microscope the epithelial cells of certain membranes are seen to be provided with processes, which from their formal resemblance to the hairs of the eye-brow, are called cilia, (see fig.) In certain animals such cilia have a rotatory motion; in man they move backward and forward with great velocity. The use of their motion is, to move the fluids over the surfaces where they are in one direction. Their motion continues some time after general death, and after the cells are removed from their supporting membrane. The motion must therefore depend upon some property inherent in the cell, or the ciliated part of it; but how it is produced is not at present understood. 448. The motion of elasticity is always in response to some force which has disturbed the part exhibiting it. The elastic character of certain tissues seems to have been given for the purpose of causing them to maintain their ordinary positions without the expenditure of muscular power. It is also not a little useful for the purpose of restoring the parts where it exists to their natural positions, and is then actively exhibited. 449. Muscular contractility is the cause of by far the greater part of the motions exhibited in the body, and of all those which are subject to the will. What is molecular motion? What is the supposed cause of it? What is the cause of ciliary motion? What is the use of it? What is the motion of elasticity? What is muscular contractility ? b. 3.—12* 274 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I General Charater of Muscles. Muscle is the proper name of what is ordinarily called lean meat. In the ordinary acceptation of the term, it includes more than muscular tissue. The distinguishing characteristics of this is, that it is composed almost or entirely of fibrin, and possesses the power of contractility. The muscle being a bundle of fasciculated fibrils, includes the tissue, and the fibrous sheaths, areolar tissue, tendons, and aponeurosis, as well as blood-vessels, lymphatics, and nerves connected therewith. Using the term in its ordinary sense, a muscle is therefore composed of fibrin, albumen, and gelatin. The names of muscles have been given to them on account of, 1st, size: as, major, minor, , and oesophagus o, fig. 169. In this fig. a portion of the Fig. 169. front part of the diaphragm is removed, that the under or inner surface of the back part may be seen. In the sides of the relaxed diaphragm the fasciculi are nearly perpendicular, except in front; those are represented longer than the reality in fig. 169. But the contraction of the fasciculi not only shortens them, but changes their direction towards the horizontal. This muscle is only active in one direction; when it relaxes, other muscles cause its highly arched condition to be again produced. What is the diaphragm? Where is it situated? How is it constructed? To what attached ? What are the pillars of the diaphragm? In what previous figures is the diaphragm represented ? What parts are beneath it? What above ? 284 Lb. l SPECIAL ANATOMY, ETC. APP. OP RELATION. Against its under surface, the liver, and spleen, are placed. Its action is therefore resisted by the walls of the abdomen, which, directly or indirectly, make pressure against the stomach, liver, &c. If the windpipe be closed, the diaphragm cannot contract its sides without depressing the chest or causing a vacuum in it. Free action of the diaphragm requires the windpipe to be open, the abdominal muscles to be relaxed, and that nothing prevent the walls of the abdomen from distending. Compressing the waist and suspending the clothing about it prevents the healthful action of the diaphragm, while freedom from restraint and vigorous exercise gives it strength and extensive movement. 464. The intercostal muscles exist in two layers, which cross each other, and are obliquely connected with the ribs, as seen at w, in fig. 170. If the muscular fasciculi had passed perpendicularly from one rib to another, as at L, they could by shortening one-third their length have moved the ribs but to the Fig. 170. same extent; but now, if the muscles shorten one-third, the ribs almost touch each other. 465. Another view of the thoracic muscles would arrange them into those of inspiration and expiration. Those of inspiration embrace the diaphragm, the intercostal muscles, the muscles which connect between the ribs and shoulders or head, or the vertebrae above the ribs, including also the muscles by which the shoulders can be elevated, and all those by which the spinal column is straightened and the discs expanded. The diaphragm can increase the perpendicular ca- What is necessary for the free action of the diaphragm ? Describe the intercostal muscles. Describe fig 37. p 116 What muscles are inspiratory? What expiratory? What relations do the oblique and transverse of the abdomen hold to each other ? DIV. !.] 285 MOTOR APPARATUS MUSCLES. parity of the chest; the others, by elevating the ribs, increase its lateral and antero-posterior diameters. The expiratory muscles embrace the recti, pyramidal, external and internal oblique, and transverse abdominalis; the intercostales, which, now the lower parts of the chest are the fixed points, depress the ribs updn the same principles as they elevated it; and all the muscles which extend between the ribs and any point below them. The recti and oblique muscles directly depress the chest, and, with the transverse, also press the organs of the abdomen against the diaphragm, and return it to its relaxed arched position. The other expiratory muscles depress the chest. 466. b. The laryngeal muscles extend between different parts of the larynx, between it and the upper border of the chest and clavicle, and between it, the hyoid bone, the tongue, and the lower jaw. Exercise, repose, and freedom from constraint, perfect the action of these muscles. 467. The muscles of the throat and mouth include those of the palate, the tongue, and those which move the jaw. In speech their use is, to articulate the vocalized or expired breath. Exercise and repose perfect them. 468. The facial muscles are usually called the muscles of expression, but those of the eye should also be included: and in very forcible expression, not only do the voice, face, and eye similarly exhibit feeling, but all the muscles of the body may be made to exhibit the intensity of the mental action. 469. The muscles of the handling apparatus are subgrouped as those which move, 1st, the shoulders upon the trunk; 2d, the arm upon the shoulder; 3d, the fore-arm on the humerus; 4th, the radius in a rotary manner; 5th, What muscles are included under the name laryngeal ? What muscles are called facial ? How are the muscles of the handling apparatus grouped ? How are the muscles of locomotion grouped ? 286 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. ' I. the wrist upon the arm ; 6th, the fingers on the metacarpus; 7th, the parts of the fingers upon each other. 470. The muscles of locomotion may he sub-grouped as those which move, 1 st, the thigh upon the hips; 2d, the lower leg upon the thigh; 3d, the ankle upon the leg; 4th, the toes and their parts. 471. The muscles of the extremities require exercise under such influences as are natural, and due repose. The muscles of locomotion are intended for locomotion, to be sure, but for locomotion for certain purposes, viz., either to obtain knowledge, or to supply the wants of the body ; in either of which cases it would be natural for the mind to be deeply interested, and then the locomotion will be performed under proper influences, and will be both successful and healthful. The art of making exercise healthful is, to make it interesting and zestful. The formal procession is of doubtful benefit. The mind must play upon the muscles with all its energy, if it is desirable to have them perfect in action and exhibit graceful motions. View of the Living Muscular System. 472. A view of the living muscular system exhibits it forming a great part of the bulk of the body. It is separated from and loosely connected with the skin, except where the cutaneous muscles exist, by areolar tissue, in which fat cells are interspersed or thickly packed, making smooth the inequalities which the muscles would otherwise present. On the extremities, the muscles surround the bones, and those of the neck the cervical vertebras. On the trunk, the muscles close the sides of the abdominal cavity, and also the spaces between the ribs, while the diaphragm separates the abdominal from the thoracic cavity. At the front of the abdomen, the broad pearl-colored aponeuroses of the oblique muscles are noticeable, while the dorsal muscles form below a blended mass of tendon arising Under what Influences should tho muscles be exercised ? What exists between the muscles and skin ? What parts of what cavities are chiefly formed of muscles? What are annular ligaments, and what figures in Plate 2 refer to any ? DIV. I.] 287 MOTOR APPARATUS MUSCLES. from the sacrum and the hack part of the iliac crest. On the extremities, strong fascia inclose the body of the muscles, and send processes inward to separate and inclose them. The long tendons of the muscles are closely bound to the wrist and ankles by what are called the annular ligaments. See PI. 2. Wherever throughout the body the parts are liable to be injured by friction, as where the tendons curve round a pulley, pass under or over any part, producing considerable pressure, bursse are liberally provided. They are particularly numerous about the ankle and wrist. When they are distended by their accumulated contents, they seem almost as hard as bone, and are often mistaken for a swelling or displacement of a bone. Continued pressure is sometimes sufficient to cause the disappearance of these " swellings," also in common language called " weeping sinews." If this be not effective, the assistance of the surgeon should be required. 473. When we view the muscular system in action, sometimes a single muscle is noticed to contract, or even a part of one; but usually they are observed to contract in groups. It will also be noticed that there are two kinds of action at the same time : an intentional one, for gaining the object in view; and another, of which a person without particular attention is unconscious, adapted to the purpose of balancing the system, and sometimes exhibited by almost every muscle in the body except the cutaneous, sensory, vocalizing, and facial. This shows, of course, that all except those muscles are grouped under a single influence, which acts upon them simultaneously, and renders their action harmonious towards a desired end. 474. The active, living muscle exhibits and produces several phenomena worthy of notice. When contracting, its What is the use of the fascia of the extremities ? What is the use of annular ligaments? Where are bursa found ? Do the muscles act together or singly? Howls the system balanced ? 288 SPECIAL, ANATOMY, ETC. APP. OF RELATION. [b. I. substance undergoes corresponding decomposition; when relaxed, its nutrition is equally active. Heat is also exhibited. At the same time, an increased flow of blood to, through, and from the muscle is observed. This is caused by the pressure of the contracting parts of the muscle upon each other and surrounding parts of the body, which urges the blood from the muscular capillaries into the veins, and through them away from the muscle, while, for the instant, the flow of blood into the capillaries from the arteries is by the same cause prevented; but at the instant relaxation takes place, the gush of blood into the muscle occurs, and the nourishment is poured into the millions of minute ducts through which every portion is supplied. Inf. a. —Relaxation should quickly follow contraction, or exhaustion of the muscle will be produced; and it must continue for such a period as allows perfect nutrition to take place. Mus. a. —The meat of a deer " chased to death " is unfit to be eaten, and putrefies quickly. Mus. b. —Butchers sometimes " dog " cattle a short time before killing them, to make the beef more tender. Mus. c. —A horse driven quickly with a light load, is exhausted sooner than one driven slowly with a heavy load. A stage-horse frequently improves in " bad going." Mus. d. —The lady who quickly plies her needle, though upon the finest cambric, is soon weary, and her muscles ache. The work given to women, and which requires "nimble fingers," will wear them out quicker than the heavier muscular labors exhaust men. Inf. b. —Occasional longer intervals of repose, will allow the muscles to become more perfect and vigorous. Mus. a. —A farmer finds his hands will do more labor, if they have a "nooning." Mus. b. —The rest of one day in seven, is found to be a profit to man and beast. The complete aud long rest, allowing the muscles to W hat phenomena beside motion are exhibited by the contracting muscles 1 How long should a muscle be relaxed '< What effect in his muscles does an animal chased to death exhibit ? Mention other illustrations. 289 DIV. I.J MOTOR APPARATUS MUSCLES. become so much more vigorous, that more labor can be done in six than in seven days. It is better to work harder during the six, and then rest completely, than to rest one seventh of the time scattered through the week. The nutrition of the undisturbed muscles becomes more perfect, as it would seem. An occasional holiday besides is not amiss for the man who labors with his muscles, more than for the scholar, teacher, and professional man. The change of mental action, and the usual mode of muscular activity is genial to the health of both mind and body. Inf. c. —Rubbing the muscles during periods of repose, must assist in hastening the process of nutrition. Illus.. —A horse will travel much farther and easier, if not only daily rubbed, but also at such times as the traveller stops to rest himself, and his beast. It is a matter of surprise that the experience and common sense principles, which leads every person who owns a horse, to have him carefully groomed every day, should not have taught men that the same good thing should be done for the human body, which will in fact be more benefited by rubbing, than any animal. Every laborer with muscles or brain, every gentleman or lady of leisure, who cares to labor easily, enjoy comfort, or appear gracefully, should equally and daily, practise rubbing the body from head to foot. 475. But the same muscular action which circulates the blood through the muscle and produces heat there, accelerates the motions of the blood, and distributes heat throughout the body, requiring and producing increased action of the nervous system, the eliminatory, digestive, and respiratory apparatus. Inf. —The muscular system is thus seen to be a part only of a whole, the other parts of which are equally dependent upon, influenced by, support and influence it. The relations of the muscular system, and the respiratory apparatus are very conspicuous. The nervous system may be very active without particularly affecting the breathing, but it immediately When should periods of repose be taken ? Why should one day in seven be devoted to rest? What is the effectof rubbing muscles? What other parts beside muscles are affected by their action ? b. 3.—13, 290 SPECIAL ANATOMY, ETC. APP. OP RELATION. [B. I. becomes deeper and quicker when muscular exertion is made. The changeable capacity of the chest is also remarkable in the muscular man. All of which shows that there is an intimate relation between oxygen and the decomposition of muscular tissue. Inf. —One reason why ladies are so easily fatigued by exercise, is that their chests are constricted, while, on the other hand, movable chests cannot be obtained without exercising the muscles generally. 477. Muscular action influences the mind, as, on the other hand, the mind exerts an influence upon the muscles. Inactivity of the muscles produces a feeling of languor and ennui, which nothing but exercise can remove. Too active exercise of the muscles causes sensations of fatigue, and prostration or exhaustion. Exercise should never be carried to the point of weariness. It should be taken moderately at first, and gradually increased as the system can bear it. Proper exercise produces delightful sensations, a clearness of the mental vision, and elasticity of spirits, that the indolent never know. When the supply of nutriment for the muscles is exhausted, they produce the sensation called hunger, the pleasurable satisfaction of which is known only to industry. Review of Chapter. 478. The muscles of the body are very numerous, and may be brought into action singly or in groups, and either voluntarily or involuntarily. Their voluntary action is dependent upon the mind, and is excited through the nerves. Their healthy action is dependent upon their constitution, age, health, and use. They are constitutionally larger and more vigorous in some than in others, and should be used accordingly. In youth they are not large and strong, but active, and What relation is there between muscular action and respiration ? What is one reason that ladies are easily fatigued ? What is the relation between muscular and mental action ? Upon what is the healthy action of the muscles dependent? DIV. I.] 291 MOTOR APPARATUS MUSCLES. rapidly supplied with blood, and well adapted to carry t about the child, where he may see and examine the works of nature, and gather a store of knowledge. But he is disinclined to arduous and confining labor, which is injurious to him.* At mature years the muscles are firm, strong and enduring ; and are then best adapted to arduous labor. In old age the circulation of blood is enfeebled, and quiet, and reflection upon stores of knowledge already gained, is for the health of the muscles. Inf. —The same kinds of exercise are not therefore equally useful to all classes of persons, nor to the same persons at all periods of life. 479. The muscles should be regularly exercised, under proper mental influences, and proper periods of repose should be allowed, and when it is desirable to strengthen them, their exercise should be very gradually increased. The healthy action of the muscles requires an active intellect, cheerful disposition, good health of all parts of the body; wholesome food, water sufficient to satisfy thirst, pure cool air in large quantities, and loose warm clothing in cold weather, and loose thin clothing in warm weather. * Nothing is more cruel than to compel children to work as is done in some factories, and indeed on some farms, and in some shops. Neither is the constitution of females adapted to the amount of labor which they often undertake, viz., the care of a family, and support of it also. I am sure the men in the world are able to earn enough to support all the women and children in it, and they ought to be willing to do it Indeed it would be more profitable in the end, for there is enough for women to do, in taking proper care of families and what is earned; and it is economy for those things to be attended to. While also, if children spend their youth in being well educated, they will be better able as men to earn, or as women to take care of what is earned. Besides, the children have a right to be educated well. The public do educate them necessarily, and require them to fulfil duties. Children have a right to require preparation. They are in fact and in every proper sense, in part the children of the public, and have a right to require the public to be paternal. Again, when women and children are put to work, false compassion gives them light'work and little repose. The farmer takes a nooning quietly in the shade, his wife clears off the table; " it's only light woman's work." But rapid motions exhaust the muscles and make deep aches. What is the condition of the muscles in youth ? Are similar kinds and degrees of exercise equally good for all ? What does the healthy action of the muscles require f 292 [B. I SPECIAL ANATOMY, ETC. APP. OP RELATION. DIVISION II. Nervous System. Analysis— The purposes of sensation and motion require that all parts of the body be connected with a common centre or centres, in order that any motion which the safety of the body, or other cause renders necessary, may be produced as instantly as possible by a sensation or its causes. No other means of connection exist except the nerves. With this centre, the mind and its organs of 'thought ought to be associated, that it may appreciate the conditions requiring its action, and the instant a decision is made, cause the execution of its will. As the action of some parts only are to be grouped for gaining a particular purpose, there should be sub-centres for ordinary cases of action, and for those which require a uniform mode of action. With these the mind need not be directly associated. It should be indirectly, so that it may be acted upon in an emergency requiring its aid. The mind must therefore be directly associated with the sensory, emotory, intellectory, and motory nervous apparatus, and indirectly with the involuntary. They must also be associated with each other. Thus the nervous system is a whole, each part of which is directly or indirectly dependent on the rest, and they they are all so interwoven, that the anatomist finds it difficult or impossible to exhibit each distinctly, while the physiologist has quite as much difficulty in assigning to each its particular and distinctive office. If we notice the muscles contracting, there seems at first to be no cause beyond them to produce their action; it seems to be voluntary on their part; but we soon notice that muscles distant from each other, act in harmony ; and it is soon suggested to our minds that there must be some connection between them. The office of the blood-vessels is apparent, and there is no other means by which their conjoint action can be caused except the white cords called nerves. If an experiment be tried by cutting these, the muscles no longer contract as before, and at once they are proved to be the channels through which the contraction is caused; how, no person can yet tell; for, if the nerve be examined with ever so much care, no change or appearance can be detected which gives the least clue to their mode of action. From all the muscles, thousands of these minute white cords can be traced to the spinal cord, but they are constantly uniting with each other, and with those leading from the bones, skin, and other parts which are not nerves of motion but of sensation, as are also many leading from the muscles, and they all appear so similar that it is impossible to separate them after they have united, and their fibres are so minute that as yet it has been impossible to trace them, for often they unite with the spinal cord, so that it is yet uncertain whether any or all of them do really connect with the brain. The different kinds of nervous apparatus are so interwoven, that in this part of our course it is better to describe the whole nervous system together, and conjecture the use of its parts as we best may. That the nervous system, though at first view apparently a whole, is composed of a congeries of apparatus adapted to different purposes, and each of DIV. II.] 293 NERVOUS SYSTEM. which, to a certain degree, does act independently of the rest, is shown, 1st. By the simple state in which it is found in some ( of the lower animals, additions being made to it as additional functions must be performed by the nervous system. (See Fig. 172.) 2d. By the action of the muscles in groups, the muscles being associated apparently with particular centres. 3d. The mind can be as it were disconnected from parts of the nervous apparatus, while its communication with the rest is perfect. When I have taken ether by way of experiment, incapability of feeling has been first produced, but the will has had perfect control over the motor apparatus, in a few seconds that also has been lost, and the apparatus which excites the emotions and allows their exhibition has had full play, though the will was perfectly decided against it. The will seemed to be put " out of gear " with certain parts of the brain, and though the thinking processes occurred in the most orderly manner, there was no way of showing it to others.* Often when slightly attacked by paralysis, and after fainting, consciousness has remained perfect, but no controlling power over the motor apparatus. The same effort of the will is made, and the same mental sensation, as usual, is connected with the effort, but there is no result. A person may then speak, and is surprised to hear some other words uttered than those he willed. 4th. The distinct locality of some of the nervous centres, and the distinct character of some of the nerves, is strong proof that there are several nervous systems blended in that which is now called the nervous system. 480. There may be two grand divisions of the nervous system:—1st. The cerebro-spinal system, which belongs to the apparatus of relation. 2d. The sympathetic, external gan- * One occasion, which I distinctly remember, was very peculiar; the senses were completely locked up in a few moments, and there was no consciousness of the presense of any external object, nor with the strongest effort of will could the least motion be exhibited. The mind was only conscious of its own existence, and memory with the swiftness of a thousand lightnings, spread out the entire panorama of my life, and passed it before me many a time; in not more than two minutes, every book was re-perused and every face of my boyhood was painted as with a daguerreotype. Then came disturbance of the mental action, and it seemed as if I was rising through spiral circles, hundreds and thousands of years in circuit. This was before I had ever heard of the circles of those who have been in trances. All seemed a reality; and if, when again restored to consciousness, I had not been sure it was all owing to the disturbance of the nervous system, I should have believed that what I experienced was a reality. Though a digression, it may be here said, that in case of such disturbance of the nervous system, the sensations frequently caused, suggest the idea of circles, spirals, &c. Are the different parts of the nervous system isolated from each other ? What proves that the nervous system is a congeries of parts ? What is mentioned as the result of taking ether ? SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 294 glionic, or organic nervous system, which is supposed to belong to the apparatus of organic life; each will be treated upon under its appropriate head. They are intimately united with each other, and by different authors have been thought to spring from each other. .There is no doubt, I think, but that the sympathetic exists lower down in the scale of animal life than the cerebro-spinal; and perhaps, when its functions are unfolded, a minute description of it will be deemed one of the important duties of the physiologist; but at present, little can be said of it which would interest or profit the general student. 481. The cerebro-spinal nervous system may be discussed under three heads—the nerves, the spinal cord, the brains. CHAPTER L. The Nerves. Meaning — Nerves exhibit extremities, a course, roots, ganglia, and a course of action, which are to be considered — Nerves may be classed anatomically or physiologically — Nerves grouped, as, 1st, cerebral; 2d, spinal—Nerves described in their anatomical order — Nerves grouped according to their uses — Special, sensory, motory, and mixed — Utility of grouping the nerves. 482. Nerve is the name properly given to those cords which connect with the nervous centres, and all divisions of these should be called branches ; but in common use the term nerve is applied to the trunk or branches indiscriminately, and specific names are given, according to the situation of a branch or the part which it connects with the centres. Thus we have the cerebral, the spinal, and the sympathetic, the sensory, the motory, the respiratory, the white, the gray, the centripetal, the centrifugal, the reflex, the direct, the auditory, optic, cutaneous, the pneumogastric, the cardiac, the splanchnic, the crural, the sciatic nerves, &c. By some they are all thought to What two grand divisions of the nervous system may be made ? Which belongs to the apparatus of relation ? Which exists in the lowest part of the scale of animal life ? To what is the term nerve properly applied ? How is it commonly applied ? DIV. II.] 295 NERVOUS SYSTEM. Fig. 171. be parts of one whole, or of a single system, while others think that they might be included under the heads of several systems which are only indirectly connected with each other. There is no doubt but that they are all internuncial in their office, and it is not only not improbable, but probable, that some are used for one special purpose, and some for another, and that they therefore properly belong to those parts between which they extend. General Characters of Nerves. 1st. Extremities. 2d. Their course. 3d. Plexuses. 4th. Roots and ganglia. 5th. Mode of action and being acted upon. Two suppositions exist in regard to the external ends of nerves—one that they are looped as represented in Fig. 112, representing a very highly magnified portion of the thumb ; another, that from these loops minute fibres branch out and terminate in points. As, however, the sensation caused through a nerve is referred to a definite point, and the muscular tissue acted upon in a definite and cir- Fig. 171 represents a front view of the dura mater covering the spinal cord and the lower front part of the brain. 1. the part attached to the crista galli. 2, covers the anterior fossa of the cranium. 6, eye. 6, over the sphenoid bono. 7, over the cella turcica. 8, covers the basilar gutter. 9, place of foramen magnum. 10, over the foramen lacerum. 12, below the cavernous sinus. 13, carotid artery. 14, temporal fossa. 15, sides of cranium. 20, place of jugular vein. 24, coccyx. 25, front face of spinal dura mater.—3, the small sheaths of the olfactory nerves, or 1st pair. 4, sheath of optic nerves, or 2d pair. 11, the motores oculorum, or 3d pair—pathetic!, trochleares, or 4th pair, and abducentes, or 6th pair. 16,17,18, three branches of the trifacial, trigemini, or 5th pair. 19, the facial (portio dura) or 7th pair, and the auditory (portio mollis), sometimes reckoned as part of the 7th and sometimes as the 8th pair. 21, glossopharyngeal, sometimes counted as part of an 8tb, and sometimes as the 9th pair; pneumogastric (vagus or par vagum), sometimes counted as part of an 8th, and sometimes as the 10th pair; and the spinal accessory, sometimes called part of an 8th, and sometimes the 11th pair. 22, hypoglossal, sometimes reckoned as the 9th, and sometimes as the 12th pair. 23, sheaths of the 81 pairs of spinal nerves. How are the nerves specifically named? What general characteristics of nerves are to be examined ? What suppositions exist in regard to terminations of nerves ? 296 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. cumscribed manner, it will be proper to speak of that part of the nerve where the action naturally begins or ends, as the extremity of the nerve. Two suppositions also exist in respect to the inner extremities of the Fig. 172. nerves; one, that the nerves are looped; another, that they connect with the ganglionic cells. They are so small and delicate, that their course or connections in the centres have not yet been traced in many cases. Wherever their action ceases, or wherever they are first acted on naturally, may be called their extremity. The course of the nerve between its extremities is as short and direct as the nature of the case permits,—each fibre being isolated throughout its entire extent. The general appearance of the nerves is therefore that of radiation from the cerebro spinal axis towards the periphery of the body. (See fig. 6.) The length of different nerves vary from imperceptibly short to several feet. Plexuses are formed whenever it is desirable to have filaments of different nerves take new and similar directions, as represented Fig. 178. by fig. 173. Though the nerves lose their identity, the filaments do not. Roots are names given to the different parts or nerves of any nerve which is formed near the cerebro spinal axis, and each of which is of course smaller than the nerve formed, in the same manner as the nerve is called a trunk in respect to the smaller branches into which it divides. The roots are always toward the centre—the branches away from it. External Ganglia are collections of grayish cellular and intercellular substance found about nerves, and usually distinguishing the roots of sensory nerves, as seen at D, fig. 174, which represents the two roots of a spinal nerve with the ganglia upon the sensory root. What may be called the extremity of a nerve ? Describe fig. 172. What is the course of nerves between parts ? What are plexuses ? What are the roots of nerves ? What are external ganglia? Why are they so called ? DIV. II. J NERVOUS SYSTEM NERVES. 297 The mode in which the nerves act or are acted upon at either extremity, or throughout their course, it is yet desirable to learn. Some suppose that there is an exceedingly delicate layer of vesicular matter covering the outer extremities of the nerves, and through which they are acted on; but a prick or almost any cause will affect them in any part of their course and cause a sensation. The property by which they cause sensations must, therefore, reside in the nerve itself; which is also proved by the fact, that different causes produce similar sensations through the same nerves, and the same cause different sensations through different nerves—e. g., Pricking a cutaneous nerve causes pain, while the same thing, done to the optic nerve, causes a sensation of light; while electricity and pressure cause a sensation of light through the optic, but pain through the cutaneous nerves. It is curious to observe that ordinary temperatures do not cause sensations, except acting on the extremities of nerves, e. g., The nerves extending from the feet are acted upon by many different temperatures between the feet and the nervous centres, but no sensations are caused except by the temperatures of the feet. A temperature of 96 at the sciatic nerve produces no discomfort; but let it act at the extremity of the same nerves, in the feet, and very unpleasant sensations will be experienced. The nerves of motion produce no effects upon any muscles through which they extend—only upon those in which they terminate, and then only to a very limited distance from their extremities, as the contraction of the muscle can be restricted to a very small portion. The nerves conduct, therefore, an influence entirely different from electricity, which they cannot isolate. Heat and various causes can excite the nervous influence, and will stimulate the muscular contractility ; but electricity is no more nervous influence, than nervous influence is muscular contractility. In what mode do nerves act ? In what portion of thenervesdoes the property by which they cause sensation reside ? On what muscles do the motory nerves produco effects f Does electricity cause muscles to contract ? B. 3.—13* 298 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 483. Nerves may be classed either anatomically or physiologically. Anatomically they are counted in pairs, from above downward, as follows; see also Fig. 171 : — 1st. Olfactory. 2d. Optic. 8d. Motores oculorum 4th. Pathetici (trochleares). 5th. Trifacial (trigemini). 6th. Abducentes. ORAM A I, - , 7th Facja , (portif> dura) lla - | 8th. Auditory (portio mollis). i 9th. Glosso-pharyngeal. 8th. < 10th. Pneumogastric (vagus, par vagum). j 11th. Spinal accessory. 9th. 12th Hypoglossal (lingual). Cervical, 8 pairs. o_„., Dorsal, 12 pairs. spinal ¦ Lumbar, 5 pairs. Sacral, 6 pairs. 1T5. The cranial are classed in 9 or 12 pairs, according to the judgment of authors. I prefer the number 12, and shall speak of the cranial nerves accordingly. They are represented by the preceding partially ideal figure in their natural order: How may nerves be classed ? How many cranial nerves ? How many spinal f In how many parts are the cranial nerves classed in this work ? Describe the 1st, 2d. etc DIV. II.J NERVOUS SYSTEM. 299 Description of Nerves. Ut Pair. What is usually called the olfactory nerve is, in fact, a portion of the brain, and in some animals, the largest part of it. It lies above the ethmoid bone, and from it the proper olfactory nerves extend through the small holes of the ethmoid, and terminate in the upper two-thirds of the nasal lining. 2d Pair. The optic nerve arises by two roots from the lower and inner part of the brain, and extends to the eyes, one half to each; the optic extremities form what is called tho retina. Where the halves cross to the eye of the opposite side, what is called a commissure is formed, and it is said that filaments from one half the brain pass round by the commissure to the other half, and also that filaments connect between the eyes in a similar manner, as shown by the figure 176. Therefore, the commissure is formed of six kinds of filaments, two passing direct from the brain to each eye, two crossing from the brain to each eye, one connecting the eyes, and one connecting the halves of the brain. 8a! Pair. The motores oculorum arise from the lower part of the brain, and terminates by five branches in the superior, interior, and inferior recti, the inferior oblique, and the levator palpabrs? muscles of the oye. 4th Pair. The pathetici arise from the lower parts of the brain, and extend by one branch to the tentorium, by another branch it is associated with the ophthalmic, but the chief part terminates in the superior oblique musclo of the eye. 5th Pair. The trifacial nerve arises from the lower part of the brain by two roots; on the larger a ganglion exists, near which the nerve exhibits three branches, (see fig. 178) called tho Fig. 176. ophthalmic, the superior and inferior maxillary nerves. They terminate in the skin covering the face, except the parotid region, and in the lining of its passages, in its muscles, and in the teeth, by which means all these parts cause sensations, and the nervous filaments connecting them with the brain are thought to form the sensitive root of the 5th. The filaments of the motor root are supposed to terminate exclusively in the muscles of mastication. One branch, called the lingual, has been thought by some to be a nerve of taste. 6th Pair. The abducentes arises by two roots, and connects by a few filaments with the upper cervical ganglion, by a few others with the ophthalmic branch of the fifth, but the greater portion of them terminate in the external rectus muscle. 1th Pair. The facial is a motor nerve arising from the lower part of the brain, or upper part of the spinal cord, and terminating in all the muscles of the face, except those of mastication. It has therefore been called the nerve of expression. 8th Pair. The auditory Is the nerve of hearing, arises near the 7th and. terminates in the labyrinth of the ear. 9th Pair. The glossopharyngeal nerve arises from the upper part of the spinal cord, and terminates In the lining of the back part of the mouth,of the pharynx, and of the Eustachian tube, etc. It is therefore a sensory nerve. 10th Pair. The pneumogastric arises near the 9th, and terminates in, 1st, the mucous membrane and muscles of the pharynx and eesophagus; 2d, the mucous membrane and muscles of the larynx and trachea; 8d, in the heart and large arteries; 4th, in the lungs; 5th, in the stomach, so that from Its terminations aud numerous associa- 300 SPECIAL ANATOMY, ETC. APP. OP RELATION. [B. I. tions it is probable that a part of its filaments are motor, part sensory, and part organic in their character. 11th Pair. The spinal accessory arises between the roots of the npper cervical nerves, and extends up till it is found by the side of the 10th, and by one branch terminates in the stcrnoclydomastoid and trapezius muscles, while the rest of its filaments are so intimately associated with the 10th, that some have supposed the motor filaments of the 10th were derived from the 11th. 11th Pair. The hypoglossal arises from the upper part of the spinal cord, and terminates in the muscles which act upon the hyoid bone, and those in particular between it and the tongue. The spinal nerves are divided into the posterior and anterior branches immediately after they appear outside the spinal column. The posterior branches are short, and terminate in the muscles and skin of the back part of the head, neck, dorsal, lumbar, and sacral regions. The upper four cervical anterior branches form the cervical plexus, from which nerves lead to some of the muscles of the shoulder and Fig. 177* the neck, to the skin of the cervical and parotid regions. From this plexus the phrenic or diaphragmatic nerve, which is chiefly formed from the fourth cervical, with some filaments from the 3d and 5th, extends to and terminates in the diaphragm. The anterior branches of the lower four cervical and 1st dorsal form tho brachial plexus, the nerves from which load to the muscles of the upper extremity. The anterior brandies of the dorsal nerves lead along between the ribs and terminate in the muscles and skin of the thoracic and abdominal walls. The anterior branches of the lumbar nerves incline downward, and form the lumbar plexus, from which nerves continue to the muscles and skin of the lower part of the abdomen, of the pelvis, and of the upper and back part of the thigh, while a number of branches from the pelvis form the large crural nerve, which terminates in the muscles and skin of the front part of the thigh. The anterior brandies of the sacral nerves form the sacral plexus, from which some nerves lead to the muscles of the lower part of the pelvis, while the greater part of the filaments unite to form the great sciatic nerve, which extends down the tnigh just back of and within the femur, and terminates in the numerous parts of the leg and foot. * Fig. 177 represents the termination of some of the branches of the facial nerve and cervical plexus. 1. Facial nerve. 2. Posterior auricular branch. 8. Temporal branches. 4. Frontal nerve. 6. Infra orbital nerve. 8. Mental nerve. 9. Cervical branches. 10. Superficialls colli nerve. 12. Auricularis magnus nerve. 18. Occipitalis minor. 14. Superficial and deep descending branches of the cervical plexus. 15. Spinal accessory extending by one branch to the trapezius muscle. 16. Occipitalis major nerve. DIV. II.] 301 NERVOUS SYSTEM. 484. Physiologically, the nerves may be both classed and grouped. They may be classed as the special sensory, special motory, and mixed. 485. The special sensory are also called nerves of special sensation, and embrace the olfactory, the optic, and the auditory. 486. The special motory nerves are adapted to produce motion only, and embrace the 3d, 4th, 6th, 7th, 8th, 9th, 10th, and 11th. 487. The mixed nerves are adapted to produce both sensation and motion, and embrace the 5th pair, and all the spinal neryes. Upon close examination, it is found that the mixed nerves are composed of two distinct nerves; one a motory, and the other a sensory, inclosed in one sheath. For, when a spinal nerve is traced within the spinal canal, it is found to be composed of two roots, one of which is, in fact, a motory, and the other a sensory nerve, with its ganglion, as shown by fig. 174. So also the fifth pair is found to be composed of two nerves, one of each kind, as shown by fig. 178. The nervous filaments are not, therefore, ever of a mixed character, but each has its specific office, and there are, in fact, but two kinds of nerves. Fig. 118. — 1. Small root of fifth nerve. 2. Large root with its ganglion. 3. Ophthalmic branch. 4. Upper maxillary branch. 5. Lower maxillary branch, a, submaxillary gland, b, sublingual gland. 488. The sensory portion of the mixed nerves is called nerves Fig. 178. SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 302 of common sensation, because they are common to so many parts of the body, extending between the bones, the muscles, the skin, and the viscera generally, and the centres. There are, therefore, many different kinds of nerves, as it respects their connections, and the sensations caused, composing the nerves of common sensation. It is not probable, therefore, that they are similar to each other in structure and other conditions, but they are so blended that the differences, if any exist, cannot as yet be distinguished. It is, however, important, that the student keep in mind, that though they are embraced under one name, there are many different kinds of the nerves of common sensation, which is not a perfectly proper name. 489. The nerves of sensation may be grouped : t st, as those of special; 2d, as those of common sensation, which may be more fully discussed when the organs of sense are described. 490. The motor nerves may be grouped according to their uses, discovered by experiment or conjectured by their connections. The sacral, and part of the lumbar nerves, extend between the lower extremities and lower part of the spinal cord ; they are very properly grouped as the nerves of locomotion. Part of the lumbar, dorsal, and cervical nerves connect the middle and upper parts of the spinal cord with those muscles which stay and move the trunk and head; those nerves, very properly, may form a group. Some of the cervical and dorsal nerves connect the spinal cord with the muscles of the upper extremities, and they may be associated in a group; and as all the muscles mentioned act together sometimes, and as the spinal cord is a continuity of parts, if not one whole, all the groups of nerves mentioned may, with propriety, form one grand group, called the spinal group. The middle of the upper part of the sides of the spinal cord is called the respiratory tract, and between this and the muscles of respiration, speech, and expression, certain nerves connect, which are very properly grouped and called by Bell the respiratory. They are cranial, viz., How are the nerves classed physiologically ? What are special sensory f Motory ? Mixed ? Of what are the mixed nerves composed f Describe fig. 178. What are nerves of common sensation ? How may nerves of sensation be grouped ? DIV. II.] 303 NERVOUS SYSTEM NERVES. {4th. PATHETIC!, Yth. FACIAL, 9th. GLOSSO-PHARYNGEAL, 10th. PNEUMOGASTRIC, 11th. SPINAL ACCESSORY. The motor part of the 5th connects the nervous centre with the muscles of mastication. The hypoglossal connects it with muscles which act upon the tongue, and, as 1 believe, harmonizes its action in the process of mastication, and those two nerves may therefore be grouped. The remaining three nerves connect some of the muscles of the eye with the nervous centre, and therefore may be grouped. 491. This grouping of the nerves according to their use, should impress the mind favorably in respect to the practicability of exercising the muscles in groups, as they would naturally be used, and shows that nature has designed that certain parts should be used together, e. g., that the tone of the voice, the expression of the face, and the movement of the eye, should harmonize. This view also shows, that if we wish to use skilfully the muscles of different groups, and rapidly combine their action, the task will be more difficult, and require longer practice, than when the muscles to be used belong to the same group. 492. Sub-grouping, and a common origin of many nerves, which connect minor parts with the nervous centres, might be exhibited if space permitted. The practical lesson just given would then be repeated. 493. As the nerves are channels of communication, it would be natural to suppose, that frequent use would improve their condition—also, that pressure, or inflammation, or any disease would prevent their action, and that disuse would enfeeble it. Illus. When sitting uncomfortably the sciatic nerve is compressed, the foot becomes numb. What nerves are respiratory according to Bell ? What muscles are influenced by the motor 5th ? What nerve may be grouped with it f Of what use is this grouping of the nerves ? How might the nerves be sub-grouped ? 304 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. 494. Our ideas of the mode in which the nerves fulfil their duty, are so indefinite, that any particular course to be pursued for their benefit, cannot be pointed out. CHAPTER II. Spinal Cord. Analysis— Spinal cord defined — General characters of the cord — Its protections—Structure—Its uses — Its necessities — How it is preserved in health. 495. Spinal cord, is the name given to what appears externally to be a large nerve, formed by the uniting together of all those which enter the spinal canal. But upon closer examination, it is found to be composed of vesicular matter as well as fibres, and from not gradually increasing in size from below upwards, it is supposed to be something more than a bundle of nerves. It is thought, and without doubt correctly, to be constituted of both nervous centres and nerves, which are partially isolated from, and partially dependent upon, the brain and mind. Its color and consistence, and general properties, as well as situation, have obtained for it the common name of spinal marrow. In size it is about five-eighths of an inch in diameter, exhibiting three enlargements where many nerves are connected with it; viz., at its summit, where it is denominated the medulla oblongata, at the lower part of the cervical and dorsal regions. Three constrictions are also seen in the middle cervical, and dorsal, and at the lowest part. It extends from the brain to the second lumbar vertebra, where it terminates in several large nerves which collectively have received the name of cauda equina, and occupy the remainder of the spinal canal. The position of the lower point of the cord is slightly changed in stooping. The surface of the cord is very smooth. It exhibits two grooves in its central front and back part, which indicate a division of the cord into the right and left halves, while two superficial furrows upon the sides mark the anterior, middle, and posterior columns. What will probably improve the state of the nerves ? Give an analysis of Chapter II. What is the spinal cord ? Why is it called spinal marrow ? Where is the position of the lower point of the cord? Describe the surface of the cord. DIV. II.J 305 NERVOUS SYSTEM SPINAL CORD. Protections of the Cord.—Fig. 179 represents the spinal canal open, and that, 5, the spinal'cord, does not fill the spinal canal, but is enveloped by several strata of parts. 1st. It is immediately surrounded by a fibrous sheath, 4, called the pia-mater; the outer surface of this is continuous with a thick layer of areolar tissue, 3; the areola? of which are large and distended with serous fluid. At the surface of this the fibres again become condensed into a thin fibrous membrane covered with a Fig. 179. basement membrane and cells, which compound membrane, 2, is denominated arachnoid membrane; it also lines the dura-mater, 1, which is a thick fibrous membrane lining the canal, but adhering rather loosely by areolar tissue to the bones. The two free surfaces of the arachnoid move upon each other without appreciable friction ; while the fluid, by pressure, keeps the cord in place, and at the same time allows it motion. The same general ideas are exhibited by Fig. Fig. 131. 180, which represents Fig. 180. a horizontal section of the cord on a line with the centre of a pair of nerves—1 is the duramater lining the canal and covering the nerve at 2; 3, is the arachnoid lining 1, just below and above the nerve it passes entirely around the canal, but at the nerve it becomes continuous with 5, which adheres to the areolar tissue 4. A space apparently exists between 3 and 5, but they in fact touch, but do not adhere. 6 is the delicate but strong pia-mater. The areolar tissue is seen to be thicker at the back than the front part of cord ; 7 is the cord in the centre of which the gray part is seen, one of its horns reaching to the surface at 10, where the posterior root of the nerve connects; 8 is the posterior and 9 the anterior fissure partially dividing the cord; "What is the dura mater of tho spinal canal ? The pia mater ? Where, in the canal, is the cord situated ? Describe figs. 179, 180,181. How do the spinal column and its membranes and fluids protect the cord? 306 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. L 13 is the posterior root on which the ganglion is seen; 14 is a process of the pia-mater which separates the roots for a short space, called the lateral ligament, and which, extending to the dura-mater above and below the nerves, forms the ligamenta dentata, as seen by Fig. 181, where 1 represents the spinal cord ; 2 the pia-mater; 3 the lateral ligaments ; and 4 the dentata. The cord is also retained in the centre of the canal by the fibrous covering of the nerves, which continues from the pia-mater to the dura-mater; and, by the process of the piamater, which between the nerves upon each side extends to the duramater, as represented by 1.1., Fig. 182, where 3 represents the spinal cord; 2, the pia-mater; and, 4, the duramater. These processes collectively form the ligamenta dentata of the spinal canal. 496. A longitudinal and transverse section of the spinal cord shows that it is composed of two classes of fibres, and of vesicular matter, which occupies its centre. One class of fibres are called longitudinal, and the other commissural. The longitudinal appear Fig. 182. cora > % tne pia-mater; and, 4, the dura- to be of two kinds—one are evidently the fibres of nerves, which, as they unite with the cord, incline upward in all the lower parts of the cord, and can be traced for a considerable distance before they are lost in the cord. At the upper cervical portions, the nerves unite almost horizontally, while above that point they incline downward. This arrangement seems to indicate a central point. Some of the longitudinal fibres seem to be for the purpose of connecting together various parts of the cord, and might be classed as commissural. The commissural fibres pass across from one part of the cord to another, and seem to weave the whole into an inextricable confusion; but this is only apparent. Without doubt, the most pleasing, and useful, and orderly relation of parts is established by these means, which will appear simple enough when they are clearly studied out. Of what parts is the spinal column composed ? What are the transverse fibres called ? Docs confusion really exist among the parts of the cord ? D1V. II.] 307 NERVOUS SYSTEM SPINAL CORD. Fig. 183. Fig. 188 represents a transverse section of the spinal cord very much magnified; a, anterior; p, posterior Assure dividing the halves; L. L., the longitudinal fibrous portion the vesicular portion : b, anterior; c, posterior roots of a spinal nerve; f, commissure between the two halves, d, vesicular matter. 497. The wses of the spinal cord seem to be twofold. 1st. It seems to be composed of several nervous centres to a great degree independent of the brain and mind. They are called automatic. The meaning of this is, that through nerves these centres are acted upon, and then immediately and necessarily from them certain influences are involun- Describe fig. 183. How many offices has the spinal cord ? Of what does it seem to be composed ? What is the meaning of automatic ? 308 SPECIAL ANATOMY, ETC. APP. OP RELATION. [B. I. tarily exerted, which by a natural law produce certain results. Illus. a. When a person swallows food, his voluntary act only passes the food into the throat, when it is swallowed by the automatic or reflex action of the nervous system. Mus. b. When a person inhales tobacco dust, and sneezes, the whole action is beyond his control. So there are a thousand acts which are automatic or reflex. 498. The 2d. use of the cord is to serve as a conductor to and from the brain. It is supposed by some that a portion of the spinal nerve filaments terminate in the cord, while another portion extends to the brain. Thus there would be found as many centres as there are distinct termini of the nerves. It is also supposed that a constant influence is exerted from the cord upon the muscles, whereby their tonic state is preserved. However limited the offices of the cord may be, its great importance is abundantly proved by its connections, the quantity of blood with which it is supplied, and the results of disease, accidents, and experiments. 499. The perfect action of the cord requires a liberal supply of blood containing the qualities which are nutritious to the nervous tissues. Muscular exercise and a thorough rubbing of the system, the respiration of pure air, and perfect health of the digestive organs, will act in the most favorable manner on the spinal cord. 500. The clothing worn upon the spinal column should be such as will conduce to a healthy circulation of blood about the cord. In many instances, especially in case of females and children, the upper portions of the column are too thinly clad, while the lower portion of the column is so thickly covered, that great inequalities of temperature are experienced by the cord, which necessarily tend to produce or aggravate disease in it. What causes the food to be swallowed from the throat ? What is the second use of the cord ? What does the perfect action of the cord require ? How can blood be furnished to the cord ? DIV. II.] 309 NERVOUS SYSTEM BRAIN. CHAPTER III. Encephalon. Analysis.— Encephalon not a single organ, out constructed of several, which are grouped according to their situation, and described — The medulla oblongata, including the pyramids, olivary bodies, restifbrm bodies, and central and round tracts — Their functions — The pons Varolii — The cerebellum — The cerebrum, including the corpora geniculata and quadrigemina, the thalami, the corpora striata, the inteltectory ganglia, and their commissures — Membranes of the brain, and its protections — Uses of cerebrum — Functions of encephalon — Effect of its action upon itself, the mind, the body, and the world at large — Causes of its activity. 501. The encephalon includes four parts,—the medulla oblongata, pons varolii or mesocephalon, the cerebellum, and the cerebrum. 502. The medulla oblongata, as its name signifies, is a prolongation of the spinal cord, with which it has many characters in common. It is that part of the enlarged spinal cord which is found in the cranium. It is composed of fibres and gray substance, the latter being more conspicuous than in the cord. On each side are marked an anterior pyramid, an olivary body, a lateral tract, a restiform body, a posterior pyramid, and a round tract. 503. The anterior pyramids seem to be mostly composed of the fibres of the anterior column of the cord; and it is especially worthy of notice, that most of the fibres of each pyramid cross over to the opposite side, a part also extending backward, so as to be associated with those of the lateral columns in forming a portion of the cerebrum above. From these pyramids arise the motor 3d and 6th nerves. 504. The olivary bodies are produced by gray substance embedded in the fibres of the posterior part of the anterior columns of the cord. Their fibres extend up to form part of Give an analysis of Chapter IIL What parts are called the encephalon ? What is the medulla oblongata ? What are the anterior pyramids ? What nerves arise from them, motor or sensitive ? In what muscles do they terminate ? 310 SPECIAL ANATOMY, ETC. APP. OP RELATION. [B. L the cerebrum. From a groove between the pyramids and olivary bodies the motor 12th arises. 505. The lateral tracts, are narrow columns of fibres, sometimes called a part of the olivary bodies, but they curve back to form part of the cerebellum. From these the motor 7th arises. 506. The restiform body is a large column of fibres, continuous below with the posterior column of the cord; and above they curve back to form part of the cerebellum. From the front part of it the sensory, glosso-pharyngeal, and pneumogastric nerves arise. 507. The posterior pyramids are small columns, continuous below with the posterior fibres of the posterior column. Above, they extend across and assist to form the opposite side of the cerebrum. 508. The round tracts are situated more deeply than the pyramids, which must be spread apart to exhibit clearly the round tracts, which are small, rounded bundles of fibres. From these arise the 4th pair of nerves. 509. The functions of all these parts seem to correspond with those of the cord, except that some of them are of a higher order. The medulla oblongata contains both nervous centres and conducting fibres. It seems, both by experiment and connections, to be the nervous centre by which the movements of swallowing and respiration are induced, and, of course, sneezing, coughing, &c. Inf. —The connections of this centre show why dashing cold water on the face in particular, is likely to excite respiration in many cases when it has not been too long suspended, and also shows that a little will be sufficient. What are the olivary bodies ? The lateral tracts 1 The restiform bodies ? Posterior pyramids ? Bound tracts ? The functions of all these parts ? DIV. II.] 311 NERVOUS SYSTEM BRAIN. Great care should be taken not to use so much as to reduce the temperature below what is desirable. 510. The pons varolii is mostly composed of transverse fibres which connect the halves of the cerebellum. They do not pass directly from one half to the other, but curve round some distance, and include the fibres of the medulla oblongata, before described, which are interlaced with the transverse. It is therefore composed of, 1st. the transverse fibres; 2d, those fibres which connect the cerebrum with the medulla; 3d, those which connect the cerebellum with the medulla j. 4th, a notable quantity of gray substance which fills the interstices of the fibres. From the pons the 5 th pair of nerves arise, and a small root of the 6th. 511. The uses of the pons are apparently those of conductors and nervous centres, of which it seems to be one of the higher orders, and is perhaps the first one of the brain with which the mind is associated. 512. The cerebellum exhibits externally a gray and white striated appearance. In size, it is about one-twelfth that of the whole encephalon. The form is exhibited by the annexed figure, and figs. 185 and 188. The surface is quite Fig. 184 smooth and convex, except where a shallow furrow indicates a division into halves at the bottom of this furrow ; ,at the upper surface is a slight eminence called the vermiform process. It is rtn^h^ill the P° ns , ? 0f how man y klnds of flbres composed? What are Its uses? Describe the external appearance of the cerebellu m. 312 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. composed of fibres and gray matter. The fibres are prolongations of what are called the crura cerebelli. These are bundles of fibres obtained from three sources : 1st. The restiform fibres of the spinal cord, called the inferior crus. 2d. The transverse fibres of the pons, called the middle crus. 3d. The fibres which connect the cerebrum with the cerebellum, and called the superior crus. The gray matter is embedded in layers between these fibres, and envelopes the ends of them in such a manner as to present a dentated appearance when the cerebellum is cut across, as seen in fig. 188. 513. Two opinions prevail in respect to the uses of the cerebellum. Flourens and his followers believe it is a nervous centre, which harmonizes the action of all the muscles in the body. Foville holds that the cerebellum is the organ through which the mind is able to perceive the state of the muscles, viz., that it is an organ of muscular sensation. Either opinion will account for the singular phenomena exhibited by experiments. If the cerebellum be cut the animal exhibits no signs of pain, but his movements become irregular, and like those of a drunken person. If one half the cerebellum be removed, the animal begins to turn on its horizontal axis, and sometimes as often (says Majendie,) as sixty times per minute, which shows that in some way control over the muscles of one half the body is wanting, while those of the other act for want of opposition. The connection of the cerebellum with the posterior columns of the cord, favors the idea of Foville. It seems unfortunate that the higher we progress in our examinations of the cerebro spinal system, and the more interesting the subject becomes, the less connection can we perceive between the structure and the functions of the parts we examine, and the more involved in mystery is the mode of action, and the more difficult to make dear is the structure of the organs. 514. The cerebrum forms by far the largest part of the encephalon. It is connected with the medulla by two crura Describe the fibres of the cerebellum. Where is the gray matter found ? What is Flourens's opinion of the use of the cerebellum? What Fovilla's? What is the effect of cutting the cerebellum ? DIV. II.] NERVOUS SYSTEM BRAIN. 313 B. 3.—14. or peduncles, which are mostly composed of fibres continuous with those of the anterior pyramids and olivary bodies, Fig. 185. Fig. 185, represents the interior appearance of the meso-cephalon with the origin of the cranial nerves, except the first pair, h, the spinal cord; s, part of the olivary body or ganglion sliced off and turned down to show the origin of k, the 12th nerve; (by Dr. F. G. Smith it is, and with great propriety, called the 11th, as the spinal accessory arises below it, though it apparently leaves the medulla above. See Fig. 175). t,10th pair, and i, 9th nerve arising from the restiform ganglion; w, restiform tract, Where is the cerebrum situated ? 314 {B. L SPECIAL ANATOMY, ETC. APP. OF RELATION. which together form the inferior crus, and the fibres of the round and posterior pyramids, forming the superior crus. It is connected with the cerebellum by the superior crura of Fig. ISO. also called Inferior cms cerebelli; it terminates in e. the cerebellum; h, 8th or auditory nerve with two roots about the restiform body; o 4, olivary tract, extending up to the thalamus opticus k; g, 7th nerve, arising by one root from the olivary tract, and by the other from the lateral tract which extends to the cerebellum; /, 6th nerve, arising from the pyramidal tract which p, t, extends through the pons x to the thalamus and corpus striatum above i; c, the superior crus cerebelli; e, sensory root of 5th nerve; em, its motor root; d, 4th nerve; «, 3d nerve arising by one root from tho locus riiger, and by another from tho continuation of the pyramidal tract; b, optic nerve, arising by four roots; 1st, from the thalamus; 2d, the geniculatum; 3d, tho anterior, and"4th, the posterior, tubercula quadrigemina. Fig. 1S6, is an ideal diagram of the chief encephalic centres shown by a perpendicular section ; a, cerebrum ; b, cerebellum; olf, olfactory ganglion; c «, corpus striatum ; thai, thalamus; opt, tubercula quadrigemina, or optic ganglion; and, auditory ganglion; c, sensori-motor tract; n, medulla oblongata; a, olfactory, b, optic, c, auditory, d, pneumogastrie, e, hypoglossal, and / spinal nerves. The lines in the central part of the cerebrum, denote the connections between its ganglionic surface, and the sensori-motor centres. Which parts of fig. 185 connect with the cerebellum ? Which with the cerebrum ? Where is the pons situated 1 What are the peduncles of the cerebrum ? What Ideas are suggested by viewing the numerous parts and communications of fig. 185 f DIV. «.] 315 NERVOUS SYSTEM BRAIN. that organ. The cerebrum and cerebellum may be considered as continuations of the spinal cord, on which the cerebellum, a very simple development, is placed, while the cerebrum is composed of larger and more numerous structures. 515. The crura are essentially conducting fibres, but among them will be found a quantity of gray substance containing black pigment cells, which give to the part the name of locus niger; they must therefore be centres. The third pair of nerves arises from this part. 516. If the fibres of the crura be traced upward into the cerebum, they will be found connected with several ganglia, called the corpora geniculata, the corpora quadrigemina, the optic thalami, and the corpora striata; when being greatly increased in number, they radiate outward, and terminate in loops as some think, and in nerve cells according to others, and uncertainly, according to most. Gray substance is embedded among them, and their extremities are so overlaid by it as to give the surface of the cerebrum a very uneven appearance, like that of a peach-stone; the prominences being called convolutions, and their interstices anfractuosities. "What has been described is double, and the ganglia of each side are connected by white fibres called commissures, the largest of which is from its firmness called corpus callosum. Fibres also extend between different parts of the same side of the cerebrum, interweaving the various parts, and associating them as it would seem, inextricably. 517. In the formation of these ganglia certain cavities are formed, called ventricles, the. sides of which touch each other, but do not adhere. Their utility is not apparent, and they seem to be accidental. What is the difference between the cerebrum and cerebellum ? Where is the locus niger? With what are the fibres of the crura cerebri connected? Describe the surface of the cerebrum. What are the cerebral commissures ? 316 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 518. An external view of the cerebrum exhibits first, a deep fissure at its front, upper, and posterior central line, indicating its division into two halves or hemispheres. Viewing the hemisphere on its side, it appears hemispherical above, but below it is irregular, and by indentations is marked into three lobes, called the anterior, middle, and posterior. The under surface of the cerebrum is very irregular, and the back part somewhat concave, being situated upon the tentorium, and directly above the convex cerebellum. The in- Fig. 187.* side of each hemisphere is nearly perpendicular, three-fourths or four-fifths of that surface being free, the rest being occupied by the commissures of the halves. The whole surface of the cerebrum is convoluted, the size of the convolutions differing in different parts of the cerebrum, in different people, and at different ages. 519. The brain is immediately covered by a very delicate membrane, called the pia-mater. At the upper part and sides of the brain it is constructed of little more than bloodvessels, but towards the base of the brain the fibres are numerous. Next to this -membrane, and adhering to it, upon the convolutions, a basement membrane covered with * Perpendicular surface of the 1. Cerebrum. 2. Section of cerebellum. 8. Cord. 17. Medulla. 16. Crus cerebelli. What is the external appearance of the brain? Describe membranes upon brain. DIV. U.] 317 NERVOUS SYSTEM BRAIN. cells is found, and called arachnoid membrane. Its cellular surface is free, and moistened with a serous fluid. The arachnoid, existing for the purpose of lubrication, need not pass down into the anfractuosities, as the blood-vessels ought, so it passes across from one convolution to another, while what is called the pia mater follows the surface of the brain. The arachnoid and pia mater together form a serous membrane, which is here analyzed into its components of fibrous and secretory membranes. Near the base of the Fig. 188. brain, as said, the fibres of the pia mater become numerous, and also a layer of areolar tissue is formed between the pia mater and arachnoid, constituting what is called the sub-arachnoidean areolar tissue; it connects with the similar structure about the cord, and the areolae are filled with fluid, so that the brain rests upon a hydrostatic bed, supported by a column of fluid—the most admirable protection against the effect of jars with which the brain could be furnished. 520. Upon the other side, the cranium is lined by a very thick coat of fibres, called the dura mater, and this is lined by basement membrane, with cells upon its inner surface. These two are called the arachnoid of the dura mater. From the cen- Fig. 189. a represents somewhat rudely the areolar tissue beneath the bram and around the cord. Describe flgs. 18T. 188. Can the brain move in the skull? 318 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. L tral line of the front, upper, and back part of the inner surface of the cranium, the dura mater extends down between the hemispheres of the cerebrum as far as to the surface of the corpus callosum, whence it extends back again to the skull, and Fig, 190. Fig. 189. lines it as before. This partition is called the falx. Its form is seen by fig. 189. The arrangement of the dura mater is shown by fig. 190, by which it is seen that there are 12 simple membranes between one half of the cerebrum and the other when the falx is in its place; or, as the two fibrous strata of the falx are blended, there will be 11. Falx. Fibrous. Basement. Cellular. Cellular. Basement Fibrous. Basement. Cellular. Cellular. Basement. Fibrous. Left Cerebrum. Right cerebrum. Fig. 189. Side view of the falx stretched between the halves of the cerebrum, and supporting thorn when the head is turned to either side. 1, anterior part and commencement of veins. 4,6, called sinuses. 5, 6, 7, 8,9, veins. Fig. 190. Rude view of a section of the falx and skull, p. Periosteum, s, Skull. / Fibrous. 6, Basement c, Cellular membrane. F, Falx, at the upper part of which the triangular sinus is seen. DIV. II.] 319 NERVOUS SYSTEM BRAIN. 521. From the inner occipital ridge the dura mater extends forward, forming a kind of shelf upon which the posterior part of the cerehrum rests, and by which the cerebellum is covered. The same number of simple membranes exist here as in the falx. As, therefore, the cellular surfaces, which are free and moistened, extend around all parts of the brain except where obstructed by the commissures, nerves, or blood-vessels of the brain, it can move with great freedom in its bony case, which it completely fills, but to which it does not adhere. 522. If a slice of the brain be removed, a contrast of color between its gray external layer and its chiefly white internal fibrous part is conspicuously exhibited, and the inequalities of the surface are seen to depend on those of the white part. If a deeper slice be removed, the ventricles are presented to view, and the corpora striata, quadrigemina, and geniculata, and the thalami opticorum j with their connecting commissures. These ganglia collectively are called the sensorium, though it is by no means 191. certain that their Of- Section of the head; s, skull; d, dura mater; a, n . ..i anterior, p, posterior Assure; g, g, grey substance; IlCe IS entirely Sensory. D. fibrous substance, v, ventricle. Where is the falx situated? Describe figs. 189. 190. How many simple membranes between the halves of the cerebrum ? Where is the tentorium situated ? What is exposed by slicing off the brain ? 320 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. Indeed, it would be equally correct to call them the motorium. The rest of the cerebrum is called the cerebral hemispheres, or intellectual ganglia. Some minor parts of the brain have not been described, because nothing could be said about them which would be satisfactory. 523. Uses of the Cerebrum. —It is not possible, in the present state of science, to determine with accuracy the particular uses of the various parts of the cerebrum. The prevailing idea at present is, that the thalami are the ganglia through which sensations are chiefly produced on the mind, and that the corpora striata are those ganglia through which the will acts to cause motions. But whether the thalami act upon the mind directly, or through the cerebral ganglia, is a debated question; as it is also whether the mind directly acts upon the striata, or through the medium of the cerebral hemispheres. There seems to be evidence, as has been shown, that there are ganglia peculiar to each kind of sensory nerve ; and I believe there are. The best conclusions at which I can arrive in regard to the whole matter are the following. The spinal cord and medulla contain nervous centres, the office of which is, to receive and exert influences which are altogether unfelt and involuntary. The parts between the medulla and the cerebral hemispheres can act upon the mind, causing sensations; and, on the other hand, the mind can act upon them, and cause voluntary and orderly movements. From all the muscles of the body, influences are exerted through the inferior crus upon the cerebellum, which then, through the superior crus, exerts harmonizing influences upon the cerebral centres, from which they are exerted upon the various parts of the body. These centres, in the vicinity "What parts are called the sensorium 1 Through what part does the will act in causing motion ? What is the office of tho centres of the medulla and cord ? How is it probable that the contraction of the muscles is harmonized ? 321 DIV. II. J NERVOUS SYSTEM BRAIN. of the pons, are also so connected and associated, that, after frequent repetition of mental, in connection with physical influences, at last the physical is sufficient to alone cause the accustomed action. Mus. —When the mind has often associated the action of certain muscles in playing a piece of music, the physical effect of each note excites the action of the muscles which will produce the next. It is thus that habit enables a person to do many things without especial mental attention, and leaves the mind free for other duties. 524. The centres now under consideration also have an office in exciting the emotions, and their close connection, or identity in part, with the sensory ganglia, is worthy of observation. Thus the emotions may easily and involuntarily be excited, and act either upward upon the cerebral ganglia, or downward upon the muscles, and manifest themselves outwardly; or the mind, by recalling experienced sensations involuntarily, excites the emotions previously connected with them. The cerebral ganglia are adapted for the use of the mind in all its higher operations, which are usually called intellectual and volitional. But whether the mind has its seat in the gray peripheral portion of these ganglia, or in the central ganglion, is altogether conjectural, as is also the mode in which the mind uses these ganglia. 525. The functions of the entire encephalon are fivefold— sensory, emotory, intellectory, motory, and sanatory. However great the uncertainty may be in regard to the functions of specific parts of the brain, there can be no doubt in regard to it as a whole. 526. The accomplishment of these functions affects— 1st. The encephalon itself. 2d. The mind. 3d. The body. 4th. The world at large. What Is the effect of repeated action of the pons and its neighboring parts ? What parts of the nervous system are concerned in producing the emotions ? Where in the brain is the seat of the mind ? What are the functions of the entire encephalon ? 3. b.—14* 322 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. 527. The action of the brain is constantly and necessarily attended with change of its suhstance. Inf. —The action of the brain should never be greater than in accordance with its nutrition. 528. The activity of branial changes and nutrition will depend upon natural constitution, age, manner in which they are produced, and upon the quantity and quality.of hlood flowing to the hrain. a. The constitutions of different persons differ very much in respect to cerebral activity; and though this may be modified a great deal by education, especially in early life, the constitutional tendency can seldom be entirely eradicated. Those whose nervous systems are sluggish should be placed in circumstances of an exciting character. A city life stimulates such to a natural degreo of action, and they appear cool and collected where ordinary men are carried away by too hasty action. An excitable nervous system will dislike quietude, but it should frequently be sought, surrounded by those circumstances which will tend to circulate the blood through other parts of the body more than through the brain. b. That age affects branial activity is too evident to need remark. That kind of activity should be encouraged which is adapted to the age. Muscular inactivity is not best for the child, while it is for old age. The studies and duties of life should be adapted to that development of the brain which nature has intended should be produced. Let it be remembered also, that this development takes place step by step, and therefore every moment of life must be profitably employed in order to prepare us for the next. And every moment of the waking hours may be profitably and actively employed, in exercise of the sensory, emotory, intellectory, or motory functions. c. The manner in which the branial changes are produced is of great consequence. There is a natural order of things—a natural mode of action, both of the mind and of the world around; and there is, no doubt, an adaptation of the brain to these modes of action. Shakspeare is the most illustrious example of the application of this idea. He first acts through the ear by the delightful influences of music; then through the eye by beautiful or wild scenery ; he then addresses the emotions, and thus, approaches the What effect attends the action of the brain? Upon what does tho activity of branial clanges depend? What kind of life excites branial changes? What effect does age have upon the rapidity of cerebral changes? DIV. il.] 323 NERVOUS SYSTEM BRAIN. intellect. Now, there is no channel through which the nervous system can be aroused, or the circulation to it increased so quickly, as through the ear; the emotions can thus be very quickly stirred; the fife and drum make boy or man step more martially; angry tones soon stir angry feelings, &c.; and the near relation of the sensory to the emotory ganglia shows the reason for this. It is also noticeable, that if one emotion is excited another can easily be. If a man will laugh, he can easily be made to cry, and vice versa. The emotions act through their commissures upon the intellectory ganglia, and also cause that increased flow of blood which reaches to the parts above. In early life, especially, and in case of all those who have not by habit acquired a facility in the use of the intellectual ganglia, *I believe the sensory and emotory ganglia should be used freely, either in attempting to give instruction, or to persuade. When the music and scenery of Shakspeare cannot be had, let another expedient of his be used; paint to the imagination what is not presented to the eye, or call up the scenes of youth, or stir the emotions of patriotism or sympathy, or let something mirthful excite to action those parts of the nervous system which" so favorably affect those other parts which it is so desirable to reach. Here is the secret of part of the success of some orators endowed with extraordinary and impressive voices, of illustrated works, and those which are highly imaginative. But there is a natural mode of action of the intellectory parts of the nervous system. Demosthenes, Webster, and all such men, looked at things in a natural order of cause and sequence. Hence the advantage of reading the ancient authors in their own tongue, and the works of men who have thought rightly. It habituates the mind not only, but the brain, to a natural mode of action, so far as those persons were right, though it is equally bad where they were wrong. Hence the advantages of mathematical studies. A long course of study is also necessary in order that the intellectory ganglia may be properly active without the assistance of the sensory or emotory. This state is partly produced naturally as age advances. d. The quantity of blood flowing to the brain is partly dependent upon the action of the brain itself, but is increased by proper muscular activity. It is not, therefore, a waste of time for the student to take muscular exercise, more than it is for him to cultivate and gratify the emotions. On the other hand, it is one of the means which he must take for mental improvement both direct and indirect. The necessity of muscular exercise, or its ad- How does Shakspeare act on the mind ? What relations have the emotions to each other ? What is the physical advantage of reading those languages and the writings of those men in widen ideas are naturally expressed ? 324 [B. L SPECIAL ANATOMY, ETC. —APP. OP RELATION. vantage in respect to the nervous system, does not seem to exist after mature age and nervous action has arrived. The temperature of the skin also affects the quantity of blood in the brain, as, on the other hand, the circulation in the brain is apt to lower the temperature of the skin. The student should therefore be warmly clad. The digestive process requires blood in large quantity, and therefore, when it should be active, the brain should not be, for, if it is, indigestion is likely to ensue. The quality of the blood is affected by the air, the food, the water taken, and by the action of the respiratory, digestive, and eliminatory apparatus. The air must be pure, and as the respiratory action does not seem to be especially affected by> the nervous activity, it is very important that the student breathe cool air; whereas, on the other hand, not clothing themselves sufficiently, they are apt to feel cold, and to endeavor to remedy the evil by elevating the temperatures of their rooms. The chest must also be free and extensively movable. The food taken should correspond in quantity and quality with the degree of nervous activity. In ordinary food but a small proportion of nutriment for the nervous system exists, and a liberal allowance of it will be required. It should be well prepared, and the health of the digestive organs must therefore be carefully preserved. The quantity of water taken by students is usually greater than is needed. When in too large quantity, it distends the vessels, and thus produces oppression, while it also prevents the brain from receiving nutriment as rapidly as is desirable. The action of the eliminating apparatus is very important. Excretory substance should never be allowed to circulate through the brain, it has a peculiarly deadening effect upon it. Carbonic acid soon causes a stupor, and the influence of all the other excretions are more or less unhealthy. Hence bathing and attention to the eliminating organs, are matters of vital consequence to the student. 529. The action of the encephalon upon the mind produces sensations either pleasant or unpleasant, while inactivity of the brain causes unpleasant sensations. Most parts of the brain do not cause pain when they are cut, but yet it is productive of the most exquisite sensations, either Wha_t affects the quality of blood i Why is it important to the brain that the air be pure ? What should be the character of food for tho use of the brain ? What quantity of drink should tho student take f What is the effect of bathing f DIV. II.] 325 NERVOUS SYSTEM BRAIN. pleasurable or painful, not only when it is excited to action by other parts of the body, but when itself alone is active. It has been constructed for activity, and its activity is essential to its own health and the well-being of the entire man. The sensations it causes correspond. Some suppose that the sensations experienced when the emotions or intellectual faculties are active, are owing to the mind's action alone ; but the emotory sensations are precisely similar to those produced when the emotory action is not caused by the mind; and I believe that all these sensations are produced by the action of the brain upon the mind. It matters not, the practical conclusions are the same; the activity of all those emotions and faculties which tend to a man's own good, or that of society, which in fact is the same thing, produce pleasant sensations, while every emotion, passion, or mental act which is injurious, is productive of unpleasant sensations. Too active or prolonged exercise of the nervous system is injurious, and causes sensations of discomfort, perplexity and exhaustion. Intense application of the mind should not therefore be indulged too long; but should be intermitted, by a new direction of mental action. Inactivity of the nervous sj'stem is productive of sensations of ennui almost insupportable. One great reason for the uneasiness, dissatisfaction and restlessness that persons manifest is, that their minds have not been educated nor their nervous systems exercised properly. All parts of the brain require action, and a person cannot enjoy life without he produce the proper activity. 530. The action of the encephalon upon the body is exhibited in two ways. First, it exerts a constant influence upon all parts, conducing to their health, or the reverse, as the case may be. It exerts a constant influence upon the muscles, till after a time they exhibit the usual state of the brain. Nothing is more certain than that the action of the brain tends to produce, prevent, or remove indigestion; while the healthy action of the skin is superintended by influences derived from the same source. The health of the parts not only, but the beauty of expression and loveliness of complexion is dependent upon the brain. Second, all the voluntary movements of the body are produced through the brain. What sensations are produced by activity of the brain f What emotions have a healthful influence upon the brain ?' What is the effect of allowing the brain to be inactive ? 326 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. 531. The action of the hrain upon the world is entirely dependent upon its action on the muscular apparatus of the body, the complexion, etc. 532. The action of the brain is caused by the nerves, the mind, and the blood, and its own constitution. 533. Through the nerves two kinds of influences are exerted, one from without the body, and one from within. The influences of external objects on the brain are not sufficiently appreciated; they are constantly acting and producing effects. They ought therefore to be such as will produce favorable effects upon the changes of the brain, and through it upon the mind. Nature has produced a thousand beautiful objects, and they ought to be allowed to educate the mind. Pleasant tones of voice, music, and beautiful flowers, all tend to develope the emotions and store the intellect. Such riches may be had without money and without price. The nerves extending from all parts of the body also exert influences upon the brain. Indigestion causes unfavorable effects upon the brain. Loading the stomach with too much food, or eating that which is unwholesome, is prejudicial to the brain. The usual action of the muscles as well as their transient, exert influences upon the brain; e. g., let a person place his muscles in the attitude of any particular emotion, and soon it will be excited. Let the muscles of expression imitate any expression of feeling, and they will tend to produce the feeling. Thus frequently by imitating the usual expression of any person, his character can be appreciated, e. g., if a person wishes to feel stingy, let him imitate the face of the miser. 534. The action of the mind upon the brain is the great cause of its activity, and entirely so of its controlled action. Hence, as the mind is, so will be the action of the hrain upon the body and world. The eye has well been called the window of the soul; not only through it does the mind look out, but through it also another can look in. Not only, then, for the health of the bfain, should the mind be cultivated and refined, but for the health of the whole body as well, and not less, for the sake of personal appearances. 535. The action of an intelligent mind with a cultivat- How does the brain act upon the world? What are the causes of encephalic action ? What influences are exerted through the nerves? What are the proofs that the body influences the mind ? What is the cause of the controlled action of the brain ? DIV. II.] 327 NERVOUS SYSTEM BRAIN. ed, actively amiable disposition, is essential to the perfect health of the brain, and through it to the perfect health of the body, its beauty of complexion, attractiveness of expression, grace of motion, or melody of voice. 536. By the action of the mind habitually the ordinary action of other influences than its own, can be controlled to a certain and very great degree. The mind can either withdraw itself from certain parts of the brain, or shut off their action; or, by calling into intense action other parts, draw away the blood to them, so that undesirable influences cannot be produced. On the other hand, it can give attention to parts, and cause them to become very active, and produce very powerful effects from slight causes. Thus it can refine its taste and appreciation of objects which are good, or it can allow the slightest causes to produce irritability, moroseness, and all the characteristics of ill temper. 537. The circulation of the blood produces changes in the brain, and of course excites its activity. The rapidity and character of the changes depend much upon the quality of the blood. When some persons are burdened by ennui, or disturbed by unpleasant thoughts, they endeavor to change their sensations by the use of poisons, viz., those things which produce an unnatural and unhealthy influence upon the brain. They use alcohol, opium, or tobacco. Either through the nerves or blood, these things produce effects upon the brain, modifying its changes and activities, and of course the sensations it produces. Inf. One way to promote temperance, will be to make happy homes, and to furnish young people with agreeable society; for either of which purposes it is necessary that all persons should be well educated. Then will their brains be active in a healthful manner, and the sensations caused will be such, that they will not be inclined to seek the delirium which is more evanescent than the passing cloud, and always leaves a bitterness; for the brain excited unnaturally, will always in a short time produce most unpleasant feelings of depression. What kind of mental action is essential to the health of the brain? What is the effect of habitual aotion of the mind? What effect has the circulating blood on the brain ? How may temperance and good society be promoted ? 328 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. CHAP. IIL Sympathetic Nervous System. Analysis.— Reasons for the names of the Sympathetic System — Composition of Ganglia and, Nerves — Their fimations; their number and arrangement—View of living nervous system. 538. The name Sympathetic was given to a portion of the great nervous system, at a period when it was believed to be the means of establishing what were called sympathies between different parts of the body. As branches of this portion of the nervous system extend to the parts of the head and trunk, some of which receive no other nerves, it was called the organic nervous system, and as it is composed in part of many ganglia, it is called the ganglionic system. 539. It is composed of ganglia and nerves. The ganglia are small in size, and composed of nerves which extend through them, and those which commence in them, of nerve cells connected with the nerves, and of others embedded between them. They are directly enveloped with a delicate fibrous capsule and surrounded with areolar tissue. 540. The function of the nerves of this system is that of conductors, without doubt, while the function of the ganglia is to receive and produce influences, and also to transmit them. It is supposed that the influences they receive and produce have reference to the involuntary motions of the viscera and to nutrition and secretion. It is supposed that usually the parts with which the sympathetic nerves are connected, exert influences no further than the ganglia; but when the cause of action is intense the influence is extended Give the analysis of Chapter III. What are the names of the sympathetic nervous system, and why is it so called ? Of what is it constituted 1 What are the supposed functions of this nerve f DIV. II.] 329 NERVOUS SYSTEM SYMPATHETIC. to the spinal cord and brain, through which the mind is acted on, and pain caused. Six pairs of ganglia are situated in the head, four of them being particularly associated with the 5th pair—see figure 1*78. These may be said to be one class, and by some are grouped with those of the spinal nerves. Three pairs exist in the cervical, 12 in the dorsal, 4 in the lumbar, and 4 or 5 in the sacral regions, nearly corresponding to the intervertebral foramina. They are connected by nerves which, with the ganglia, form a chain or gangliated cord upon each side of the bodies of the spinal column. The ganglia are also connected with the neighboring spinal nerves— as shown by figure 192, where s represents the sympathetic, connected by e a gray and white nerve, with the spinal nerve, which by a, its Fig. 92. anterior, and p, its posterior root is connected with c, the spinal cord. Nerves also communicate between the ganglia of the opposite sides, and those from different ganglia by uniting with each other, form larger nerves, which extend to the viscera of the chest and abdomen. For the most part, the nerves of this system follow the course of the arteries, and form plexuses about them. In the course of these nerves or branches of nerves more ganglia are formed. Review and View of Living Nervous System. If we notice the living nervous system, many nervous centres or ganglia are seen with internuncial nerves connecting them with How many pairs of ganglia in the head r How many in the neck ? How many in the remainder of the chain ? 330 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. all parts of the body. The largest ganglia of all fill the upper, middle, and back part of the cranium. Its gray or vesicular matter forms its entire surface, between different parts of which, and between it and the ganglia found in the central lower part of the cranium, commissural fibres connect. In the central ganglia the gray matter and the white fibres are very much blended, while below, throughout the length of the spinal cord, the gray matter occupies a central position. All these centres and nervous collections are carefully encased and protected. Again, we observe a great number of small ganglia, upon the front aspect of the cranium and spinal column, connected with the large ganglia within, with each other, and with the organs of the face, neck, chest, abdomen and pelvis —and perhaps following the arteries into every part of the extremities. If the action of all these parts be observed, it will be noticed, that with the speed of lightning, influences are constantly being exerted between the centres and the various parts with which their nerves connect, modifying the action of all parts of the body, and causing very active changes of the nervous centres to be necessary. The blood will be seen flowing to, through and from them, without intermission, and undergoing rapid changes as it gives nutriment and receives excreted substance from the parts it visits. But as the encephalon is regarded, it will be seen that the mind must also be taken into consideration, for it both modifies the brain and is modified by it. Every external influence, which acts on any part of the body, and every condition of the body, can be traced till its termination is found at the mind, while on the other hand, every state of the mind diffuses an influence spreading wider, and wider, till it operates on every part of the body. Whoever sees this clearly, will appreciate that a person with a cultivated and exercised ear, eye, muscles, and every other part through which the world acts, and a body healthy naturally, and preserved so by exercise and the use of proper food, drink, air, and clothing, and a mind with cultivated intellectual and emotional powers, is a person possessed of inalienable wealth —and able not only to enjoy, but daily enjoying all the happiness that the world can bestow — not dependent on nominal possessions, but on his own capabilities— not dependent on the non-possession of others, but on the fact that it is the heritage of all men who will exercise their bodies and properly educate their minds. On the other hand it will be appreciated that the scholar cannot study, nor the teacher teach most profitably in badly ventilated, In noticing the living nervous system, what parts are observed to occupy the head ? What the spinal column ? What to be situated in front of the cranium and spinal column ? What is the effoct of action of all these part* ? DIV. III.] 331 ORGANS OP SENSE. cold, or highly heated school rooms. Legislators, judges, jurors, or lawyers cannot do their duty well in similar circumstances: The doctor cannot advise best when fatigued by over duty, and above all no legislator, judge, juror, lawyer, docter. or other person, can do his best when his blood is poisoned with alcohol or anything else. While most important of all no mans brain can operate to the best advantage, without a man is in every sense of the term, a noble minded and good man. If therefore we wish due, responsible services of a man, we should among the first questions ask, is he a good man—does he expose his brain to the action of poisons—is he fatigued, &c. DIVISION III. Organs of Sense. Analysis.— Sensation is produced by action of the brain upon the minil. First cause fourfold: the brain, the nerves, the parts in which the nerves commence, the objects which surround the body. These act through site classes of organs of sense. Four classes of objects act through the skin — Their mode or action — lis structure — Nerves of touch. Savory objects act through parts of the mouth — Its structure as an organ of sense and mode of action — Its nerves. Odorous particles act through the nose — Its structure and mode of action — Its nerves. Three kinds of light emitted, transmitted, and reflected, or absorbed by objects, which determines their color. The eye needed that their direction may be determined — Its protections, structure, use, and mode of action — The optic nerves. Waves of air act through the ear — Its structure, use, and mode of action. The contraction of muscles being resisted, sensations are caused by which the mind determines the solidity of bodies. Sensations in General. Sensation is the name of any effect produced by the brain on the mind, and of which it is conscious. So far as we know, the brain is the only part by which the mind is acted upon. The sensations frequently seem to be in other parts of the body, but they are not. After the arm is removed, pains seem to be felt in the hand, and do not seem to be in the brain, where they are produced. The fact is, we are so constituted as to refer the sensations to various parts for the purpose of directing attention to them. The brain, then, is the part which in all cases is the direct cause of the sensation. In other words, the brain is associated with the mind, and any state of the brain produces an effect on the mind which is pleasant or unpleasant, as the necessity of the case requires. It Give the analysis of Division III. What is a sensation ? To what parts do we refer sensations felt? What is the immediate cause of sensations? Do dissimilar causes always produce like results ? 332 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. L matters not what cause produces any particular state of the brain, the sensation it produces is the same; the cause may be the mind, or disease, or the blood, or an influence exerted through the nerves, the resulting sensations will be similar, provided these dissimilar causes produce similar states of the brain. The same is true of the nerves; their effects upon the brain will be similar, provided similar states are produced in them, even by dissimilar causes. Inf. —The cause of a sensation cannot always at once be determined, nor where the cause is acting. 541. The causes of sensations may correctly enough be counted as fourfold: 1st. The brain; 2d. The nerve; 3d. The part in which the nerve commences; 4th. The external object which acts upon the body. 542. The action of the brain itself, independent of any cause except the mind, produces the most intense sensations the mind experiences. The health and perfection of mind and body is dependent to a great degree upon cerebral activity, which has, therefore, when proper, been made correspondingly pleasurable, as a reward and inducement, while inactivity, or improper activity, is attended with discomfort, both as a punishment and an inducement. The exercise of those parts of the brain associated with the affections and social faculties, and all the benevolent emotions, is particularly delightful ; and if honest industry will count up the delights of" life which he cannot obtain, he will find them very few. Can riches buy for him the wealth of his gratified affections 1 In his wife, his children, his parents, his brethren, and his neighbors, has he not a store which is inexhaustible ? How much could he add to happiness with money ? He might gratify vanity, love of ostentation, and show contempt for his fellow-men; but does not the exercise of his brain, under such influences, produce unhappiness 1 He might gratify his benevolence, true, and this would add to his happiness ; he might more highly cultivate his mind, and this would be for his good; but after all, let him fairly make a computation, and see if he have not within his reach the greatest portion of happiness that mortal can enjoy, and if his unhappiness do not spring from the cultivation of envy, jealousy, pride, &c. I call If sensations are similar, is it certain that their causes are? How many general causes of sensations are there ? What effect does activity of the brain havo upon the production of sensations ? 333 DIV. III.] ORGANS OF SENSE. no man poor who has the rich sources of gratification which an affectionate family affords. 543. The diseased brain frequently produces sensations similar to those usually caused through the nerves. Overaction of the brain causes it to produce pain, and diseases of other parts of the body cause it to produce intense pain. Mus. —Derangement of the digestive organs frequently cause headaches. Indeed, they are generally to be attributed to the improper use of food; though not eating food, or not enough of the proper quality, causes headaches. 544. Some diseases of the nerves cause the most excruciating pain, and as the pain usually seems to be at the outer extremities of the nerves, the real seat of the disease is overlooked. 545. The nerves commence in all parts of the body, except, perhaps, the cartilages, and any state of the part affects the nerve, producing what is called an impression upon it, then through the nerve an effect is produced upon the brain, then upon the mind, and a sensation results. 546. If the various parts of the body be healthy, pleasant sensations, if unhealthy, unpleasant sensations are caused. The unpleasant sensations vary very much, as, hunger, thirst, weariness, fatigue, lassitude, cold, heat, etc. The kinds of pain are almost innumerable, and by them alone a skilful person can sometimes determine what part is diseased, and in what way. 547. Pain is evidently for the purpose of calling the attention of the mind and causing relief to be given. While pleasant sesations are for the purpose of inducing a continuance of the state. This is not, however, always a safe rule, for pleasant sensations are sometimes produced by poisons. Man has not been endowed What sensations does the diseased brain frequently produce f How do diseased or deranged states of the body produce sensations ? What sensations do some diseases of the nerves produce, and to what part are they referred f 334 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I, with ever-protecting instincts, but with reason, judgment, and a natural desire to acquire knowledge, all of which must be cultivated. 548. All those sensations which have their cause in the body, may be called internal or subjective, while those which have their cause outside the body, may be called external or objective. , CHAPTER I. Sensation of Touch—Its objects and organs. 549. There are four classes of objects that act through the skin, to produce sensations of touch. 1st. Those which merely come in contact with the skin. 2d. Those which change its temperature. 3d. Those which compress the skin. 4th. Those which disorganize it. 550. How those objects, which merely come in contact with the skin, produce effects on the nerves, is uncertain. It does not always seem to be by pressure, for this may be so gentle as hardly or not at all to exist. It may be by electrical influence. 551. The use of the effect produced by touch, is merely to inform the mind of the presence of objects, and their position in respect to the body. Inf. As the presence of these merely in contact with the skin is neither harmful nor beneficial to health, the sensation is neither pleasant nor disagreeable, but neutral. To some persons, however, certain objects of touch only, are pleasant or disagreeable, especially when a smooth or rough object is moved over the skin. 552. Objects which change the temperature of the skin, act directly on the nerves, and indirectly by affecting the blood-vessels. How many classes of objects act through the skin to cause sensations ? How do objects touching the skin act on the nerves? What is the use of sensationa of touch ? DIV. III.] ORGANS OF SENSE TOUCH. 335 These objects act not, therefore, by virtue of touching the surface of the skin, but by acting upon it deeply, or causing it thus to be acted on. It matters not, therefore, what temperatures exist ever so near to the skin, if the skin is not affected. But if objects are in contact with the skin they will affect it. They must therefore be warded off by clothing. The most healthful temperatures of the skin are caused by heat produced within the body and preserved in the skin. But to produce heat most rapidly, cool air to breathe is necessary. To keep the skin of a proper temperature, therefore, cool air near to the skin must be permitted, but it must be prevented by proper clothing from acting on the skin. Inf. As the temperatures of the skin are of the greatest impor. tance to health they ought to be productive of the moat intense sensations. There are no sensations more pleasant than those produced by healthful temperatures, or more annoying than those caused by unhealthful temperatures. This ought to teach to correct the evil. But people will frequently allow the skin to produce sensations of chilliness without correcting the evil, or if they attempt to do it, it is by elevating the temperatures which act on the skin, and thus in the end bring on themselves a second evil. Thus people allow their feet to become and remain wet and cold; ladies in particular, wear too little clothing, or expose themselves in cool evening air, or stormy weather, with no more clothing than usual, and that so tight that heat cannot be abundantly produced, and then complain of cold hands and feet. Children are clad with short-sleeved and low-necked dresses, and thus are caused to almost constantly suffer from sensations of chilliness, which tend to render their dispositions fretful. Oftentimes people unawares sleep with too little clothing beneath or above them, and not then feeling any unpleasant sensation, they find upon waking that they have taken a severe cold. 553. Continued pressure prevents the circulation of blood. Inf. a. —It ought to cause unpleasant sensations. Inf. b. —Seats of every kind should be comfortable, and positions frequently changed. Inf. c. —Tight dress ought to produce unpleasant sensations—and Why should the skin be protected by clothing ? Are the sensations produced by the temperatures of the skin easily perceived ? Are they ploasant or disagrceablo? When and how do people suffer from sensations of chilliness? 336 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. of course to tend to cause irritability—which is very far from rendering a lady attractive. Inf. d. —Tight shoes cause unpleasant sensations in three ways: by direct pressure on the nerves, by preventing the circulation of the blood, and causing too low temperatures for health. 554. All objects wbicb disorganize or divide the skin, are of course injurious, and should produce unpleasant sensations ; the use of which is, to call the attention of the mind to the dangers to which the body is exposed. 555. The Skin is called the organ of touch. It is composed of three membranes, a thick external cellular membrane, the external cells of which are dried into the state of horny scales—and serve as a protection to the delicate parts below. This layer is kept soft and flexible, by an oily fluid constantly poured out upon its surface. Part of the deeper cells of this layer contain a pigment, which in part gives color to the complexion. The perfection of this layer depends upon a free circulation of blood in its immediate vicinity, and upon its surface being kept clean, both that excreted substance, and the dry oil may be removed, and that the air and light may perfect its pigment. Inf. —The skin must be kept of a healthful temperature, frequently and thoroughly rubbed; muscular exercise must be taken, and mental action must also be favorable. The second layer of the skin, is the exceedingly delicate basement membrane. Beneath, is found the fibrous membrane, containing the vessels and nerves. The whole constituting what is called the true skin or dermis. The surface of this which is next the basement membrane is uneven, and presents prominences called papilla?, and these again, especially on the hand, are arranged in rows. 556. The nerves of touch commence in the papillae of the skin, very near to the basement membrane, in the form of loops, as it is usually supposed, one particular point of which may be looked upon as the extremity of the nerve. 557. For the healthy action of the nerves, there must be What is the effect of continued pressure upon the body ? Illustrate. What is the organ of touch ? How is it constituted ? How should it be preserved in a good condition? Where do the nerves of touch commence ? PIV. III.] 337 ORGANS OF SENSE TASTE. a free circulation of blood through the dermis, which is very abundantly supplied with blood-vessels. Whether this is in order that nutritious substance may be supplied to the nerves, or that they may be preserved of a proper temperature, or both, is uncertain. The importance of the active circulation is positive. Inf. —Rubbing the skin and muscular exercise, must tend to improve the sense of touch. 558. These nerves soon become associated with those of the muscles, bones, and other parts, and extend with them to join the cerebro-spinal centres. It is probable, however, that all the cutaneous nerves are associated with only two common ganglia, which might be called the cutaneous ganglia. CHAPTER II. Sensation of Taste, and its Organs. 559. Taste is the name given, to the sensation ordinarily caused by objects taken into the mouth. 560. Food and drink are the ordinary objects which cause taste; but almost any substance allowed to dissolve in the mouth will excite the sensations of taste—how, is uncertain. Usually, the more soluble any substance, the more readily is it tasted. Fluids are, therefore, more active than solids. But as some gases excite taste, and others do not, so is it with fluids. By some, it is supposed that the particles of tasted substance must pass into the mucous membrane, and act directly upon the nerves; while others think that an influence is exerted upon the nerves, but that they are not touched by the substance tasted. According to the former, fluids readily pass into the membrane; according to the latter, they spread over the surface more perfectly than solids. 561. The uses of taste are, to enable a person to distin- What is necessary to a healthy action of the nerves ? With what nerves are those of touch associated? What Is taste? What are the objects of taste? What are the uses of the sense of taste ? 3. b.—15 338 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. guish substances, and to change the duty of eating into a pleasure. The sensations caused by food which is relished, assist not a little in the digestion of the food. Every one can witness to their causing the saliva to flow freely into the mouth. Dr. Beaumont also testifies to their similar influence in causing the juices of the stomach to flow into it. 562. No one of the senses is more susceptible of cultiva tion than that of taste. Inf. —It should be cultivated so as to highly relish wholesome food. There is nothing which tends to increase the pleasures of eating more than a hearty appetite. Inf. —Exercise of the nervous and muscular systems and exposure to the fresh air should be taken, in order to produce a demand for food, and its accompanying appetite. 563. Food should be selected, 1st, which is wholesome; 2d, which is relished; and then cooked so as to be, 1st, wholesome ; 2d, relished. The comfort and attractiveness of a house is not a little increased by a well-set table. The expense is no greater to have whatever food is prepared, well prepared, and neatly set forth. Many a temper has been soured by sour bread. 464. The mouth is termed the organ of the sense of taste. Its cavity receives the substance to be tasted; its muscles and teeth grind it; its salivary glands furnish fluid to dissolve it; and the mucous membrane of the upper surface, and the sides of the back part of the tongue, and the sides of the back part of the mouth, is composed in part of nerves which, when acted upon, excite the sensation of taste. 565. The mucous membrane of the sensory parts of the mouth is formed into papilla, which are easily seen by the Why should the sense of taste be cultivated ? How can an appetite be produced ? Upon what principles should food be selected and cooked ? Describe the month as an organ of sense? What are papilla) of the tongue? DIV. III.] 339 ORGANS OF SENSE SMELL. naked eye; but with a glass, the sides of these are found to be formed into small papillae. In these, just below the basement membrane, the nerves of taste commence. In them also, and in the mucous membrane of the mouth generally, nerves of touch commence, and both kinds soon become associated with the motor nerves of the lingual muscles; and it is not, therefore, certain what large nerve is the nerve of taste. By some, the glosso-pharyngeal is thought to be it; while others think the office devolves upon the lingual branch of the fifth: fibres for taste probably exist in both nerves. The nerves of one side of the mouth and tongue are entirely distinct from those of the other; and, for purposes of taste, there are therefore two tongues, united by the central line. Sometimes the sensations produced through the two sides are not similar. CHAPTER HI. Sensation of Smell, and its Organs. 566. Smell is the name given to the sensations ordinarily caused through the olfactory nerves. 567. The objects of this sense are exceedingly minute particles of matter dissolved in the air. Whether they act by passing into the membrane and touching the nerve, or by merely exerting an influence upon the nerves through the cellular and basement membranes, is uncertain. 568. The utility of this sense in man does not seem to be as great as in case of some animals. It warns of some dangers. It enables him to distinguish objects; it excites the appetite, and increases the relish of food. Its effect upon the mind is, however, much more powerful* either in respect to attraction or repulsiveness than is usually supposed. The freshness of morning, and the sweet fragrance of the flowergarden, charm more than is acknowledged. Judiciously selected perfumes are as advantageous in forming the toilet as personal un- Where do the nerves of taste commence ? How many kinds of nerves commence In the tongue ? Through what organs is the sense of smell produced ? What are the objects of this sense ? What is its utility 1 340 [b. r. SPECIAL ANATOMY, ETC. APP. OF RELATION. cleanliness is disagreeable. This is a sense which can be highly cultivated. But in these days of uncleanly personal habits, badly ventilated rooms, cars, &c., of tobacco using, alcohol drinking, and other infringements of public rights, it is doubtful whether it is not best to do all that is possible to render this sense obtuse. 569. The nose is called the organ of the sense of smell. The upper parts of the nasal cavities are only properly so called. Fig. 193. Fig. 194 The nose is composed of two equal halves, entirely distinct from each other, and which in fact are the organs of smell. Each nasal fossa is partially divided by the turbinated bones into three spaces, called the inferior, middle, and superior meatus. It is lined by mucous membrane, which is rendered very extensive by means of the turbinated bones. It is constantly covered with its own secretion, and still further moistened by the tear fluid, which, however, is poured into the fossa below the sensory part. A lubricated condition of the membrane is necessary, in order that the odorous particles may act upon the nerves, for when in case of a cold the membrane becomes inflamed and dry, the power of smelling is lost. 570. The narrow spaces of the nasal fossa cause the in- Has any person n right to render the air which another must breathe, offensive 1 Wbat part of the body is the organ of the sense of smelly Describe the nose. DIV. III.] 341 ORGANS OF SENSE LIGHT. haled air to be warmed, to act more extensively on the nerves, and to a certain degree serve to detain dust from passing to the lungs. Inf. a. —When the air is so cold as to injure the air passages, or produce coughing, it should be inhaled through a muffler, or something which will warm it. Inf. b. —If a person be situated in a dusty atmosphere, he may guard the air passages by means of a wet sponge tied over the mouth and nose. If the air be very cold when it enters these delicate passages, it sometimes causes inflammation there. The inhalation of dust and its deposit in the nasal cavity irritates its membrane, and causes an unhealthy state of it. 571. The nerves of smell commence in the upper part of the nasal cavities by extremities which are too small to be distinctly seen, even by the assistance of the microscope. They are exceedingly numerous, and as they associate together form a kind of flexus, from which small nerves extend up through the holes in the cribriform plate at the roof of the nose, and connect with the olfactory ganglia, usually called the olfactory nerves. CHAPTER IV. Sensation of Sight, and its Organs. 572. Sight is the name given to the class of sensations, usually produced through the eyes. Its use is to enable a person to distinguish objects, but especially their direction from him. Inf. a. —During waking hours, the use of the eyes is very important, and almost constantly required, and the sensations producr-l through them should be pleasant. Why should the nasal passages be narrow? In which part of the nose do the olfactory nerves commence? To what sensations is the name sight given? Why should they be pleasant ? 342 [B. B SPECIAL ANATOMY, ETC. APP. OP RELATION. Inf. b. —As the use is almost constant, some way must be contrived by which the eye can be rested during its use. This can be, as it is, by having several kinds of light, so that while one is acting, the eye can be in repose in respect to another. It may be. and doubtless is the same in respect to the brain—for the mind must be constantly active during waking hours, and the brain ought not therefore to suffer, and doubtless will not if all the powers and activities of the mind are brought into play. So the eye does not suffer if there is a proper alternation in the action of different kinds of light upon it. 573. Light is the name given to the objects which act through the eye upon the optic nerves. Light is of three simple kinds— Red, Yellow, and Blue. These or their compounds produce all the various and numerous sensations of sight, except the sensation of blackness. This is caused by the action of the nerve alone. In this respect it seems to be different from any of the rest, and constantly active, and when no light is acting upon it, it causes a sensation of black, which is hence called a negative sensation and color. Fig. 195. 574. The proportions in which these act on the eye determine the pleasant or unpleasant character of the sensations experienced. Inf. The art of rendering colors attractive, consists in presenting such a combination of colors before the eye, as shall naturally and necessarily please. The natural proportions of the colors of white or sunlight are 3 Red, 5 Yellow, and 8 Blue, and whenever colors are so combined that these proportions of light are presented to or move across the eye, they must be productive of health and pleasant sensations. Red and green harmonize, and the green should much predominate, as in that most beautiful object in nature, a moss rose bud, because blue and yellow when they act together, produce the sensation of green, and they would together make 13 parts in 16, which represents the white light. Orange and Fig. 195.—A diagram to show how colors are complementary. Those at the angles of a triangle or the diameter of the circle are so. How can the use of the eve be constant, and yet repose be given to Its nerves f How many kinds of simple light are there f DIV. III.] 343 ORGANS OF SENSE LIGHT. blue are likewise beautiful colors in harmony. Orange being produced by red and yellow acting together, blue is the remaining complementary color. It will be seen by Plate 8, that the blending of blue and yellow produce green, while red and yellow produce orange. The more highly compounded the colors are, the more difficult does it become to read the simples of which they are composed. But when they have been obtained, it is very easy to see what color is wanting, and what superabundant. The more the colors are blended, and the greater the variety of shades, the more pleasing as a usual thing the sensations they cause. For the same reason small figures are more pleasing than large, except in the carpet of a large room, when the eye looks over a large surface, and the same result is produced, viz., no one color acts long upon the eye. Flowers are beautiful on account of the delicate blending of their colors. This is especially the case with the budding rose, which from its attractiveness has been chosen as the fit emblem of love, while the bold-faced dahlia can hardly be looked upon as a flower. The beauty of blended colors is still better seen in a tastefully arranged bouquet, than which there is no surer gift to please or win the good feeling of boy or man, girl or woman. The persuasivenesss of its colors, and the eloquence of its perfume, will be more commanding than all the gold of California's mines. 575. The objects which cause light to act through the eye, are of three kinds: I st. Those which produce. 2d. Those which transmit. 3d. Those which reflect light. The sun is the great fountain of light—when we feebly supply the place of his bright rays, it should be with light as nearly similar as possible. There are three respects in which it should be similar. 1st. The proportions of the different kinds of light should be similar. The gas of our cities is very good on this account. Next tt that, lard oil, and spermaceti, stearine, or wax candles, are the best substances with which I am acquainted. Next in order is whale oil. Spirit gas and camphene are both very bad, and in the end unprofitable. 2d. The quantity of light should be considerable. On this account gas is very good, as it produces a brilliant light. A solar lamp for lard, or lard oil, is next in order, both for economy of expense and brilliancy of light. Next in order would be the same lamp used with whale oil. 3d. The direction from whence the light comes should be upward, or a shade should protect the eyes from the direct action of the Why do red and green harmonize ? Why do orange and blue ? What proportion should orange and blue bear to each other? How many kinds of objects cause light to act on the eye ? What will determine the character of the sensations they produce ? 344 SPECIAL ANATOMY, ETC. APP. OF RELATION. [b. I. light. If the shade is about the lamp, the room generally is apt to be darkened, and turning the eye toward it, causes too sudden a change in its state. All these things are not only important for the health of the eye, and for the use of the student, but quite as much so for the lady who wishes to be attractive either by her dress or furniture. Window glass and lamp shades are most frequent illustrations of objects which transmit light, but window blinds and the semitransparent sides of bonnets are quite as important to notice. Where curtains, shades, or blinds, are used, they should be such as transmit the kinds of light which the objects within are adapted to reflect, e. g. If green curtains line the windows, and there is a red carpet on the floor, it will appear sombre. Such curtains are frequently seen at windows, at the sides of, or above doors. Scarcely a young lady in the world has a complexion so florid that she would appear well in the hall, or when at the door. For if the daylight poured in through the open door, only green would pass through the curtain, and too large a proportion of green would therefore be received by and reflected from her complexion, which would appear sallow and ghastly, as any one may see by holding a piece of green paper near to the skin. The kinds of light which will be transmitted through the bonnet, are to be considered when its trimming is selected, and adapted to the complexion. Almost all objects reflect light; as in case of those which produce and transmit it, they are called by the name of the sensation which they produce. Some objects do not reflect any light; these are called black. Some reflect all three kinds in their natural proportions, and are called white objects and good reflectors. Some do not reflect one kind, some do not reflect two kinds, some reflect all three kinds, but not in their natural proportions, which ideas are represented on the left hand side of Plate 8. In arranging dress, goods, furniture, paintings, bouquets, flower-gardens, and every thing the effect of which is dependent on color, all these matters of the production, transmission, reflection and combination of the different kinds of light must be regarded. 576. The distinguishing of these objects and their directions, is dependent upon three things. 1st. Each one causes the light to act from it in every direction in straight lines, till it passes into some object of different density. 2d. The eye is so constituted, that it causes all the light which falls What should be regarded, in producing artificial light? In what modes and in what way is light best produced? What should be regarded, in selecting objects for transmitting light ? What objects reflect light ? DIV. III.] 345 ORGANS OF SENSE SIGHT. upon a certain portion of its surface from any minute point or visual object, to be refracted or bent to the same point, as illustrated by Fig. 2, Plate 8. 3d. Man is so constituted as to instinctively believe when a certain point of the eye is acted on, that the object causing the sensation is in a certain direction. Almost the entire difficulty which has been experienced in understanding optics, arises from a misconception in regard to the objects of vision, and a misapplication of terms. A visual* object is the smallest point or collection of matter which can cause a distinct sensation. (The idea is rudely exhibited by figs. 5 and 6, Plate 8. See description.) This is also a mental object, but usually a mental object is compounded of many such —as a leaf, a limb, a tree, a forest. These are all creations of the mind, from the simple visual objects which have always, one definition. The visual object can course be inverted, for if the blue and the yellow be erased from fig. 2, Plate 8, and the red alone left, it will be seen that there can be no inversion, only one point being left in the eye. If this point be not inverted, any number of others cannot be. The reason why inversion has been so generally supposed to result is shown by fig. 9, Plate 8. (See description.) That the objects may be distinguished, it is necessary that the light passing from them should act on different nerves. This end might be gained by such an arrangement as represented by fig. 1, Plate 8, but in such a case only a few objects could act at once. The effect upon the nerves would not be sufficiently intense, and the precise direction of objects could not be determined. With the arrangement as at fig. 2, millions of objects may act at the same time, each producing its own sensations intensely, and at the same time its precise direction may be perfectly appreciated. If it be above, the point acted upon must be below ; while if the point of the eye acted on be above, the object must be below the axis or horizontal line of the eye. Thus simply, beautifully, and perfectly, is the mind at the same time pleased and stimulated to action, and able to direct the body towards those things which it wishes. 577. The eye is called the organ of the sense of sight. It may be treated upon under the head of its appendages and protections, and the eyeball. By what means is the direction of an object visually distinguished ? What is a visual object ? What is the distinction between a mental and visual object 1 Why is it necessary that light, radiated by different objects, should act on different nerves ? 3 b. —15* 346 [B. I, SPECIAL ANATOMY, ETC. APP. OP RELATION. 578. The protections or tutamina and appendages of the eye, include the sockets, the eyebrows, eyelids, eyelashes, muscles of the lids, the lachrymal glands and ducts, the meibomian glands, the puncta lachrymales, and nasal lachrymal ducts, the fat, and the muscles. The sockets are conoidal cavities, formed by the orbital surfaces of the maxillary, unguis, ethmoid, frontal, sphenoid, and malar bones. The eyebrows require no particular remark; to preserve their health and beauty, they should be rubbed and brushed. The eyelids are composed of the skin, which forms their external and internal surfaces, of the muscles and meibomian glands between the two, and of the cartilages, which exist near the border. It is remarkable that no fat is ever found in this part. The eyelashes are beautifully curved, so that when the lids are shut, they interlock, as shown by the figure following. Fig. 196. The muscles of the lids, are three in number. The orbicularis, Plate 2, the tensor tarsi or Horner's muscle, and the levator palpebrae. The first closes the eye, the second draws inward the edges of the lids, or the tarsal cartilages, the third elevates the upper lid, thus opening the eye. a, Fig. 198. The lachrymal gland is about the size of a sparrow's egg, is situated in the socket near its outer and upper edge; from it several minute tubes or ducts lead down, and open towards the eye, on the under surface of the upper lid. Its use is to form the tears, and pour them down into the eye—this it does slowly most of the time ; but at times the large quantity of fluid it will pour out is surprising. It is especially connected with those parts of the brain concerned in the production of the emotions, and exhibits very clearly their involuntary influence. It is also associated with other centres, which can equally influence it—as is seen sometimes when a person has eaten mustard, and its volatile particles have af- Fig. 197. fected the back part of the nose and upper part of the pharynx. The meibomian glands exist in the upper lid, opening by sevc- DIV. III.] ORGANS OF SENSE —SIGHT 347 ral tubes at the edge of the lid. They are very simple, and form a viscid semi-fluid, which is serviceable in preserving the front part of the lids perfect. The puncta lachrymales, are two minute orifices and tubes, found at the inner part of the lids, and easily seen by turning them out slightly, see fig. 197. They curve round, and open into the nasal duct, which terminates in the inferior meatus of the nose. The upper part of this is called the lachrymal sac. It or the minute puncta sometimes become closed from the effect of colds, and then the tear fluid constantly runs over upon the cheek, subjecting a person to much inconvenience, and the eye at last to inflammation. If when the cold is removed, the tubes are found to be permanently closed, an opening must be made, and a small silver tube inserted, when the whole difficulty will be removed. The cushion of fat which is situated at the bottom of the socket, serves both to keep the eye out in its place, and as a soft bed for it to rest upon ; it prevents jars and allows the eye to turn with perfect ease. It is almost the last of the fat of the body to be used when a person is sick or starved, and hence sunken eyes are signs of great exhaustion. The muscles of the eye are six in number, see title-page and fig. 198. There are four straight, called recti, and one superior, and one inferior oblique. The straight muscles are about as wide and thick as common tape, arise at the bottom, of the socket, and lead out to the upper, lower, outer, and inner parts of the eyeball, to which they are attached about as far back as the white can be seen. The superior oblique arises from the same place, Fig. 19a and extending upward, it terminates in a round tendon, which passes round another short tendon called a pulley or trochlea, situated at the inner edge of the upper and nasal part of the socket. From this pulley it passes back to the upper, outer, and back part of the eye. The inferior oblique arises from near the unguis, and passes back to be attached to the outer, lower, and back part of the eye. The recti muscles move the eye upward, downward, inward, outward, between each of these directions, and of course rotate or roll What are the meibomian glands * The puncta lachrymales ? The lachrymal saes ? Where in the vicinity of the eye is fat found, and where not f Describe the muscles of the eve ? 348 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. the eye. Strange to say, it is not yet agreed what is the use or effect of action of the oblique muscles. They are supposed to hold the eye forward, while the recti muscles direct its axis. The upper is also thought to roll the eye inward, and downward, while the inferior directs the eye upward, and inward. They are also supposed to keep the axis of the eye in the same direction, when the head is turned toward either shoulder. 579. The eye is constructed of three classes of parts. 1st. The expansion of the optic nerve, called the retina, which is presented to the action of light, and is the essential part. 2d. The transparent media through which the light reaches the nerve. 3d. The coats which sustain and protect the parts within. 580. The coats of the eye and their appendages, include the Sclerotic, Cornea, Conjunctiva, Choroid, Ciliary Body, Processes, Ligament, and Muscle, Iris, Jacob's Membrane. The sclerotic coat, also called "white of the eye," is a white fibrous box, forming about £ of a hollow sphere. It is about T ' ff of an inch in thickness, and exhibits two openings, one of which is small, posterior, and closed by the optic nerve, the sheath of which becomes continuous with the sclerotic, the other is large and anterior for the admission of light. The use of the sclerotic is for protection and the attachment of muscles. The cornea, sometimes called the window of the eye, is a beautifully transparent, convex externally, and concave internally, lens, about as thick as the finger nail, composed of several layers, and fitted by its circumference to the edge of the anterior opening of the sclerotic, with which it is continuous. It appears like part of a small sphere attached to a larger one. Its use is to transmit and reflect the light which falls upon its surface. The conjunctiva is the skin covering the anterior part of the sclerotic and the cornea, and the back surface of the lids. It is continuous with the lining of the nasal duct and fossa, and for the same reasons that a " cold " affects one it may affect the other, and often for the same reason why disease affects the mucous membrane of the digestive canal, it will affect the conjunctiva. Its inflammation has therefore various causes, and requires different treatment in different cases.* * The washes sold by quacks should be carefully avoided. They may sometimes be harmless, occasionally beneficial; but their use must generally be injurious, and I have known cases where it has shut out the light for ever. Mere water is the safest and best ordinary application, warm or cold, as is most comfortable. DIV. III.] ORGANS OF SENSE —SIGHT. 349 The caruncula is the name given to the small fleshy eminences at the inner corners of the eye. They are apt to grow out upon the cornea, and sometimes affect vision. If they are troublesome, they should be removed. Hairs sometimes grow out from them, and should be extracted. Dust can often be removed from the eye, by simply drawing the upper lid down over the under one. All the above parts are shown by the following figure. The choroid coat is not as thick as the sclerotic, is composed of a few Fig. 199, fibres, a great number of blood-vessels, and very many cells, those near its inner surface containing much pigment, and giving the choroid a beautiful dark brown appearance. It lines the sclerotic as far forward as within an eighth of an inch of the cornea. It adheres closely to the sclerotic at the position where the nerve enters, but by only a few fibres throughout the rest of its extent. Its use is to furnish blood to the eye, and present a dark surface for the absorption of light which has acted on the nerve. The ciliary body is the name given to that portion of the eye which extends from the choroid to the cornea. It is a continuation of the choroid which on one side adheres to the sclerotic, and on the other is formed into numerous folds which extend into the eye, and are called the ciliary processes. From these and the body in part, some grayish fibrous substance, called the ciliary muscle, extends towards the border of the sclerotic, near to which it terminates in a kind of tendon called the ciliary ligament. The iris, or colored part of the eye, can be seen to be chiefly composed of sphincter and radiated fibres. They are muscular in nature. The first contract and the second dilate the pupil, which is the name given to the hole which exists in the centre of the iris. The circumference of the iris is attached to the ciliary ligament, body and processes. The front surface is composed of a serous membrane, which is continuous with that which lines the cornea. The back surface contains black pigment cells, and is called the uvea. See figs. 200 and 201. The use of the iris is to regulate the quantity of light admitted to the nerve. What classes of parts constitute the eye? What do tho coats of the eye, and their appendages include? Describe the sclerotic coat? The cornea. What are the caruncula ? Describe the choroid coat ? What are the ciliary body, processes, ligament, and muscle ? Describe the iris ? What is its use ? 350 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. All the above can be seen in section, in fig 2, Plate 8. Fig. 200 and 201. 581. The transpa- rent Media include the cornea, the aqueous humor, the crystalline lens and the vitre- ous humor, composed of the hyaloid membrane and its con tents. The cornea, already described, is itself composed of three laminae, and covered by the conjunctiva, and lined by a serous membrane, yet they are all as transparent as the most pellucid crystal. Its use is to retain the humors of the eye, and powerfully refract the light, which it does more than any other part of the eye. The aqueous, or water-like humor, fills the space between the iris and cornea, called the anterior chamber of the eye, and passing through the pupil also fills the small space back of the iris, called the posterior chamber. It is apparently secreted by the serous membrane of the cornea and iris. Its density is nearly like that of the cornea, and it affects the rays of light but slightly. The crystalline lens is a double convex lens, the posterior surface being generally the most convex. It is composed of a fibrous transparent capsule, and a body which fills, but does not adhere to the capsule. The body is composed of fibres arranged in concentric layers, like the coats of an onion, the central ones being called the nucleus, and more dense than the outer ones. The light which passes through the central parts of the lens is refracted more than it would be if they were of the same density as the circumference. The lens is situated just back of the iris, sometimes touching it, and forms the back part of the posterior chamber. It varies somewhat in density from the aqueous humor, and of course refracts the light which enters it. The vitreous humor occupies all the back part of the eye. It is composed of the hyaloid membrane and a watery fluid. The hyaloid forms its outer surface, and is in contact with the retina, and sends in processes which intersect each other, and form small spaces or areola? in which the watery fluid exists. This humor is concave in front, and deeply receives the crystalline lens, to the What do tho transparent media include ? What is the use of the transparency of the cornea? Where is the aqueous humor, and what is its use ? Describe the crystalline lens ? Describe the vitreous humor ? div. in.] ORGANS OF SENSE SIGHT. 351 capsule of which it closely adheres. The hyaloid from the front surface of the humor, passes onto the front surface of the capsule of the lens, to which it adheres, leaving however a small space all round the lens at its edge or circumferential border, called the canal of Petit. The front surface of the vitreous humor near the lens, is indented or furrowed, to receive the ciliary processes, which adhere to this part of the hyaloid, which is called the ciliary zone. The use of the vitreous humor is to fill the back part of the eye, support the lens and the retina, transmit, and perhaps modify the light which it receives. 582. The retina is chiefly composed of cells and fibres. The Jibres of the retina are thought to be the axis cylinders only, of the optic nerves, which after extending through the sclerotic,choroid, and Jacob's membrane, expand themselves upon the hyaloid membrane, as far as the choroid extends, presenting a concave, spherical surface to the light entering the eye, which was necessary. Illus. —If a common lens or sun-glass is held before several candles at an equal distance from it, and a piece of paper be placed in the focus of all of them, it must be curved, see fig. 2, PI. 8. How the nerves commence in the retina is not known. Some think it is by loops, some think that the nerves blend into a common expansion, while others, and I believe correctly, think that the nerves commence by points exceedingly fine, which completely occupy the sensitive surface of the retina. As represented by fig. 202, an ideal view of a small portion, and also by figs. 1, 2,3, and 4, PI. 8. I believe this is the arrangement, because, 1st, there are points of exceeding delicacy very near to each other, too near to be distinguished by the naked eye, through which distinct sensations may be caused. 2d. The eye is also constituted, so as to cause light Fig. 202. corning from different visual objects, to act on different points of the retina, from which there must, it would seem, be distinct means of conduction. 3d. In some animals, which have eyes with many facets and tubes accordingly, but no refracting medium of consequence, there is a distinct nerve to each tube. 4th. There is nothing observable in the structure of the retina, as yet observed, which weakens the opinion. But it is not certain. The practical results Of what is the retina composed f Have you tried any experiment with a sun-glass and candles? How do the nerves commence in the retina? What does the author think in respect to this point? 352 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. II are the same as if it were ; therefore the figures have been made, and language used in consonance with the ideas entertained. But it must always be borne in mind, that when the point of a nerve is spoken of, nothing is with certainty meant except an impressible point through which a distinct sensation is caused. The cells of the retina exist on its front surface next the hyaloid, and also compose a considerable portion of its back part, the appearance of many of them is similar to that of those forming the ganglia of the brain. Fig. 203. The retina is very plentifully supplied with blood. An artery called the centralis is situated in the centre of the optic nerve where it enters the eye, and immediately branches out in a beautiful arborescent manner in the retina itself, and connects with millions of capillaries in it. It can be seen by looking steadily at a white object, and moving a light about near to the eye; it will seem to be on the object. 583. The nerve of sight is called the optic or the second pair. Apparently, the nervous filaments from the left halves of the eyes connect with the left brain, and those from the right halves with the right brain. Therefore, those from the inner halves must cross each other, which in part forms the commissure or chiasma of the optic nerves. The reason for this is seen, if it is observed that the light from any visual object acts upon the opposite of the retina from where it is; e g., an object to the right, acts on the left side of the retina, if the object is below, the upper part of the retina, &c* A line drawn from the point of the retina acted on and the visual object, as from r to R, in fig. 2, Plate 8. is called the line of direction of the object. When any object is in the right field of view, the line of direction will reach the left part of the retina, an effect through the nerves will be produced on the left brain, and by the * I have seen it stated that the rays of light from an object crossed each other as they enter the eye, but this is a great mistake. Where they cross, is the focus, and it is an essential thing to correct vision, that they should not cross each other till they reach the retina. Rays from different objects, or from different parts of tho same mental object, do cross, but this has nothing to do with seeing. What in this book is meant by a point of a nerve in the eye ? Have you tried to see the artery of the retina as suggested? How are the filaments of the optic arranged ? What is the line of direction of objects? ])1V. IXI.J 353 ORGANS OF SENSE SIGHT. crossing of the fibres in the medulla, an influence can be exerted upon the right side, when the right hand may be thrown up and the threatened danger warded off. 584. The uses of the eye, are to cause the light received from different visual objects to act intensely on different points of the retina, and produce simple impressions. The office of the eye is very simple, much more so than is usually thought; the sensations are caused by the action of the sensorium, and the idea of the direction of objects, and the corresponding of the sensations, and the knowledge of the qualities of objects gained through the eye, are all dependent upon mental action. When, therefore, pressure on the eye causes a sensation to be produced, the cause not only seems to be light, but it seems to have a certain direction; when, also, the circulation of the blood in the arteria centralis, or any other cause, produces sensations of specks or "wiggles," they seem to be before the eyes. But fig. 204, shows a fact of importance, viz., that with the same lens A, if the object be at a, the light will be brought to a different focus from what i t will be if the object is at b. The eye is curiously constructed, so as to be adapted to seeing objects equally well at Fig. 204. all ordinary distances. But what changes it undergoes, is not yet certain. Some have supposed that the muscles of the eye compressed it, so as to make it longer when near objects are observed. Some have thought the lens was increased in density in such cases. Some have thought that the cornea was distended or flattened. Others have thought that the position of the crystalline is changed forward and backward by the action of the ciliary muscle, which, of all conjectures, is the most probable.* * I have seen it stated that the modification of the eye was produced by a change in the inclination of the lens. The idea is almost too ridiculous to notice; for if the inclination of the lens were in the least changed, it is evident that no perfect focus could be obtained of the light from any two objocts, viz., a person could not see at all. What are the uses of the eye ? Where do all sensations of sight seem to be ? How is tho action of the light coming from objects at different distances represented by fig. 204? 354 GENERAL ANATOMY, PHYSIOLOGY AND HYGIENE. Some eyes never possessed, or have lost, the power of adaptation. If objects can be seen only when they are near, the eye is called near-sighted ; if they can be seen only at a distance, the eye is called long-sighted. But the eye is no more near-sighted in one case, or long-sighted in the other, than any good eyes. The difficulty is, it is not long-sighted in one case, and not short-sighted in the other, while good eyes are both. The reasons for the obscurity of vision are three-fold. Fig. 205 represents a long-sighted eye acted upon by light from a single point, but the light not being brought to a focus, acts over the nerves from b to c. The natural line of direction, when the nerve c is acted on is c B, and if the eye were perfect, and the nerve c were acted upon, an object would be found at B; and if b were acted upon an object would be at 0; and if all the nerves between 6 and c were acted on, there Fig. 205. would be objects at all the points between C and B. But the impressions are made on all the nerves between b and c, and the sensations are naturally, though not intensely produced ; hence it seems to a person with such an eye, that the light occupies all the space between C and B. If the old lady try to snuff the candle, she will perhaps snuff the wick the first time, and perhaps the twentieth time trying. So she attempts to thread her needle all round where its eye really is. Fig. 206 represents the shortsighted eye, the nerves of which are in the same way affected, though from a different cause, and the result is the same; the candle seems to the person to occupy the space between B and 0, the central part of the space being very bright, and the circumference more and more dull. So when the telescope slide is moved out, or in, beyond Fig. 206. the point of distinct vision, similar obscurities are caused. This also shows the simple action of the eye, and the part it takes in What is the defect i n long-sighted eyes ? What is the defect in short-sighted eyes ? Describe figs. 205 and 206. DIV. III.] ORGANS OF SENSE SIGHT. 355 vision, and that the idea of the direction of objects is constitutional, for experience has not corrected the erroneous impression of the old lady about the position of her candle; and the older she grows, the worse it will be. Another cause of obscurity is shown by figs. 3 and 4, Plate 8. The fact is exaggerated to make the idea clearer. It is there seen that the light from different objects acts upon the same nerves, which at once destroys all distinctness of vision, and produces confusion. The cause of this disability of long and short-sighted eyes, as they are improperly called, is not known. Long-sightedness is frequently attributed to a flattening of the cornea as age advances, but a majority of persons who are short-sighted have become so after the age of a dozen years, and usually by study, and neglecting to use the eyes much for long sight; so that it would seem that disuse of some visual power enfeebled it. Short-sightedness may be prevented, and many times remedied, by using the eyes to look at distant objects frequently. How to ward off long-sightedness I know not. It is usually remedied by the use of convex glasses, as short-sightedness is by concave ones. I am, however, acquainted with several persons who are short-sighted, and yet can see distinctly only by wearing convex glasses. I can only account for this, by supposing that their nerves are very sensitive, and therefore the light of near objects is scattered over the adjoining nerves, so that confusion is produced; or there may be undue reflection in their eyes, producing the same result, and the use of convex lenses has the effect to throw the light from objects more intensely upon points of the retina which are also more distant from each other. The effect of microscopes illustrates the same subject, and also shows that the line of direction is judged of instinctively. The effect of the microscope is to cause the light of objects which, in the natural eye, would be received upon the same nerves, to fall at quite a distance from each other on the retina, and the more distant, the farther apart do the visual objects seem to be, and of course the larger does the mental object appear. The distance of objects, when seen, seems to be determined by the judgment based upon experience; e. g., if an object be observed, and while the eye is turned,diminished in size, when viewed again it will appear farther off; as usually a mental object which appears large is near, and vice versa. The reason why objects appear to be single is because, though What is shown by fig. 344, PI. 8. What may be done to prevent or improve shortsightedness ? How does the microscope magnify objects ? How should the eye be treated in order that it may be healthy ? 356 [B. ,, SPECIAL ANATOMY, ETC. APP. OF RELATION. the light from them acts through both eyes, it acts on corresponding points of them, and the apparatus is so constituted, that in this case only a single sensation will be caused. If one eye be pressed on one side, two objects will at once appear where only one appeared before, since the light does not act on corresponding points. Persons who are cross or wall-eyed, see double, except as experience allows them to only pay attention to the sensations caused by one eye. Again, where the nerve enters the eye there is a central point where nerves do not commence, and through it sensations cannot be produced ; e. g., if. with the left eye closed, the adjoining dot be observed with the right eye, and the book moved toward the eye with its lines parallel to the axis of the eyes, the cross will vanish and again appear as the book approaches the eye more nearly, which shows that there is some point of the retina which, when acted upon, does not cause sensation. At all times this point is acted upon by the light from some object, but the sensation produced through the other eye is not less intense than usual, nor is the mind confused in respect to its judgment of the line of direction or distance of that object. The eye is also so constituted as to avoid the effect of chromatic aberration. It will be seen by fig. 7. PI. 8, that blue light is refracted more than yellow or red, and this would be the case in the eye, producing confusion, did not the transparent media of the eye correct the difficulty,—precisely how is yet a an unanswerd question of importance. But the light which passes through the circumference of an ordinary lens is refracted more than that which passes through the central part, producing what is called spherical aberration. This evil is mostly avoided in the eye, partly by the greater density of the central part of the lens, partly by the action of the iris, which prevents light from falling very near the circumference of the lens. 585. To preserve the eye in health it should be actively used and allowed proper repose. It suffers with the general health of the body, and improves with it. It is one of the most pleasure-causing of all the organs of sense, and the healthful influences of light upon it are diffused throughout the body. What is the effect of pressing on the eye 1 Are all points of the retina equally impressible ? Is the eye acromatic ? Do all the rays of light which from one visual object enter a perfect, eye,' act on a single point of the retina ? DIV. III.] 357 ORGANS OF SENSE HEARING. Many persons live in too dark apartments, or with blinds of a single color, and feel too much the influence of only one kind of light. If glasses be worn for weakness of the eyes, those which are gray, and exclude a portion of all kinds of light, will usually be better than those which exclude only one kind and freely admit the others. CHAPTER V. Sensation of Hearing and its Organs. 586. Sound, or the sensation of hearing, is the name given to the sensations usually produced through the auditory nerves. 587. The uses of the sense of hearing are to inform the mind in respect to the direction, distance, and qualities of objects; to startle the mind when danger is impending, to arouse it for the defence of the body, to excite it to relieve distress, and indeed to excite many of the emotions, and to produce mental happiness and physical health. Many sounds are therefore unimportant, and should produce no very decidedly pleasant or unpleasant sensations ; while others should be disagreeable and irritating. It would also be improper to arouse the mind without the body was also put in a state fit for instant use by the mind; while therefore the sensation is caused in the mind, the body is involuntarily acted upon through the organs of this sense. The health of the body as well as that of the mind is powerfully influenced though the ear. The utility of music is doubtless something more than the pleasurable sensations it causes. Indeed, the reason why they are so pleasurable is, probably, because the influence of music is so profitable to the health of the body and mind. 588. The organs of hearing include the auditory parts of the brain, the auditory nerve and the ear. How should the eye be treated, in order that it may remain healthy? What is sound ? What are the uses of the sense of hearing ? Does the state of the nervous system which produces the sensation of hearing, produce any effect on the body ? 358 [B. I. SPECIAL ANATOMY, ETC. APP. OF RELATION. 589. The object which acts on the ear, is the air thrown into waves or impulses by the action of various things, which are also called objects causing sound. Almost every object in nature has the property of acting peculiarly upon the air, and producing in it peculiar waves or impulses, which it is the duty of the organs of hearing to distinguish. This influence upon the air may be exerted either by wavy vibrations, or by impulses, or oscillations. Any irregular impulse of the air will cause a noise, while regular impulses cause a musical sound to be produced through the ear, in respect to which three things may be noticed. 1st. The pitch depends on the rapidity with which vibrations are caused. 2d. The intensity or loudness depends on the violence and extent of the impulse which acts on the ear. 3d. The quality is supposed by Herschel to depend on the abruptness of the impulses. Inf. If this be at all correct, it is of great importance, since abruptness can be controlled, or at least qualified by cultivation of the voice and mind. The quality of the sound is not, however, altogether dependent on its degree of abruptness, but upon I know not what. All kinds of impulses move with equal rapidity, since music has the same time at a distance and near by. Waves of air like waves of water, are always partly reflected by any solid body against which they act. The waves thus reflected have a different direction from the original ones, and cause the sound called an echo, which so far as the ear is concerned, is produced in the same manner as any sound. But as waves grow less with the distance they pass through, their effect will be feebler; hence the echo will be feebler than its antecedent. 590. The ear is composed of the external, middle, and internal ear. The external ear is composed of the pavilion and meatus. The pavilion exhibits a rim called the helix, and a lobe below at its circumference. Another rim within, is called the anthelix. A concavity at the upper part is called the scaphoid fossa, and a deep one below is called the concha, in front of which is an eminence called the tragus, and opposite to which is the antitragus. What acts on the ear, when a sound is naturally produced? What is a noise' What is a musical sound? How can the quality of sounds he improved ? What is an echo ? Of what parts is the ear constructed ? DIV. III.] 359 ORGANS OF SENSE HEARING. Three small muscles extend from the pavilion to the skull. Their use is to move the pavilion. Its use is to reflect and transmit Fig. 207* Fig. 208. 207,* represents the labyrinth very much magnified, V, vestibule, O, foramen ovale, R, rotundum, X, Y, Z, semicircular canals, K, cochlea. the vibrations of the air. The auditory canal (8, fig. 208,) leads inward and slightly downward from the concha to its blind extremity. It is partly cartilaginous and partly bony, lined with thin skin, and closed with it at its deepest part. Its sides are furnished with ceruminal glands, which secrete the ear-wax. Sometimes this becomes dry. A little oil dropped in the ear and retained by a plug for a few hours, will soften the wax, when it can be removed by castile soap and warm water.* Fig. 208 represents the ear. It should be remembered that the inner ear, -which is here and elsewhere represented as isolated, is, in fact, in the midst of bone, which is indeed part of it. Here is represented only the more solid portion of the bone which directly forms the ear; 8, auditory canal; 9, membrane of the tympanum; 10, drum containing the bones of the ear; 12, foramen rotundum; 11, promontory; 18, over the opening into the vestibular scala; 14, 15, semicircular canals; 16, ampullae; 17, cochlea; 18, canal by the Eustachian tube for tendon of tensor muscle. * The ear oils etc., sold at the shops as a sure cure for deafness, are, of course, the most barefaced impositions. For any desirable object to be gained by oils, common sweet oil is the best. Ether is sometimes used for the same purpose. Of what is the external ear constructed ? Describe tho auditory canal. Describe figs. 207, 208. What is said of ear oils ? 360 Lb. i. SPECIAL ANATOMY, ETC. —APP. OF RELATION. The auditory canal serves merely as a conductor of vibrations. The middle ear, also called the tympanum or drum, is a cavity about the size and form of a kidney bean. It is situated just at the inner extremity of the auditory canal, being excavated from the petrous portion of the temporal bone. A tube about as large as a straw commences at the lower part of the drum, and leads down, and opens trumpet mouthed into the back part of the nasal fossa. It is called the Eustachian tube (E, fig. 208). It serves the double Fig. 209. Fig. 209, represents the external, internal, and middle ear, in situ; a, pavilion; b, lobe; c, antitragus; d, concha, from which opens the auditory canal; e, f, f, section of the temporal bone; /l, mastoid process; /2, glenoid fossa, in which moves the articulating process of lower jaw; /3, styloid process; /4, extremity of the canal traversed by the internal carotid artery; g, mem- brane external of the tympanum; h, tympanum: i, openings into the mas t o i d cells; j, k. Eustachian tube; I, vestibule; m, semicircular canals; n, cochlea; o, acoustic or auditory nerve. In this representation the bony tissue is seen to increase in density near the parts of the middle and internal ears. The more solid parts being those which aro usually considered to belong to the ear itself. purpose of allowing the air to pass backward and forward, and the mucus, or any substance, to pass down from the drum and openings communicating between the drum and the mastoid cells. In the bony walls of the drum, there are also three other openings ; one leads into the auditory canal, which, as already said, is closed by the skin, within and upon which, a fibrous structure is found, stretching across the opening from the tympanum. It is called the external membrane of the tympanum, or the outer drum- What is the use of the auditory canal ? What is the middle ear? What is the use of the Eustachian tube ? How many openings are there in the walls of the drum ? What is the membrane of the tympanum ? DIV. III.] ORGANS OF SENSE HEARING. 361 head; (9. fig. 208.) Its use is to transmit the vibrations of air which act upon it. At the opposite side of the drum, two holes may be found ; one being round, is called the rotundum; the other being oval, is called the ovale. They are both closed by fibrous structures like the one just described. They are also called the inner heads of the drum. Their office is to transmit the vibratory influences they receive. Across the drum four* bones stretch from the external membrane to the foramen ovale (fig. 208.) The 1st is called the malleus, or hammer; 2d, the incus, or anvil; 3d, the orbicularis, or round bone; 4th, the stapes, or stirrup. These are all jointed, and furnished with cartilages, ligaments, and synovial capsules. The use of these bones is to transmit vibrations. Two delicate muscles also exist in the drum ; one extends from a canal by the side of the upper part of the Eustachian tube to the malleus, and when it contracts by drawing that bone inward, it makes the external membrane tense; hence its name, tensor membrana tympani. The stapedius muscle extends from within a conical eminence called the pyramid, to the stapes, and by contracting assists to make its membrane and the whole chain of bones tense. The other delicate structures, sometimes called muscles, are probably not so. The whole of the Eustachian tube, the drum, and the mastoid cells are lined with mucous membrane, which also covers the bones of the drum. The mucus it forms passes down into the nasal cavity. It is liable to be affected when " colds" are taken, especially the lining of the tube, which causes "hardness" of hearing, or deafness. The internal ear is also called the labyrinth. It is composed of the vertebrae, three semicircular canals, and the cochlea. The vestibule is an irregular cavity, which is in connection with the membrane of the foramen ovale. Out of it open the three semicircular canals by five openings, as two of the canals unite at one extremity. The cochlea has, externally, something the appearance of a snail-shell. Internally, the cochlea is divided by a lamina, partly bone, partly ligament, and partly muscular. The cavities thus formed are called scala; one the vestibular, since it opens from the vestibule, and one the tympani, because it opens against the foramen rotundum of the tympanum. The scalae communicate at the top of the cochlea. The axis of the cochlea is * Some of our best authors make but three bones, the orbicularis being considered as part of the 2d. What is the office of the foramen, rotundum and ovale ? What are the names of the bones of the ear ? What is the use of the bones ? What is the use of the internal muscles of the ear? How can colds affect the ear? Of what parts internal ear composed? b. 3—16 362 SPECIAL ANATOMY, ETC.—APP. OF RELATION. [B. I. called the modiolus and contains many orifices for the nerves. The whole labyrinth is lined with a very delicate serous membrane which secretes a serous fluid called the perilympth. Fig. 210. Fig. 210 represents the membranous labyrinth, and the nerves terminating in it. L, 2, 3. Ampullae. 4, Common canal. o.Utriculus. 6. Sacculus. 7. 7th nerve. 8. Branch of the 8th, leading to 10, ampulla?, and 11, to the otolith es of utriculus. 12. Branch of 8th nerve terminating in 18, the sacculus and its otolithes. 14. Branch extending to the cochlea. The vestibule and semicircular canals contain what is called the membranous labyrinth. It is a membrane forming in the vestibule two communicating sacs, one called the utriculus, the other the sacculus, and extending through the semicircular canals, being of the same general form as the bony parts in which it is, but only a third as large. It connects with the lining of the bony labyrinth only where the nerves enter. It has a free cellular surface both within and without, and is filled with endolymph, and surrounded by the perilymph. The vestibular portion contains a crystalline powder, which proves to be carbonate of lime, and called in this place otolithes. The use of particular parts of the labyrinth is not known ; as a whole, it has the office of transmitting the vibrations of the membranes of the drum to the auditory nerves. The nerve of hearing terminates or commences in the labyrinth, how, is not known. Some think by loops, and some by minute points. They appear to terminate in the sacculus. utriculus, ampullae, and in the lamina spiralis. (See fig. 210.) What is the vestibule ? What are the semicircular canals? What is tho cochlea ? What is the perilymph ? Describe fig. 210. What is the membranous labyrinth ? div. m.] 363 ORGANS OP SENSE —HEARING. Fig. 212. Fig. 211. Fig. 211 represents nerves very much magnified, terminating by loops in the ampullae. Fig. 212, 1, natural size of, 2,- nerves In the modiolus and curving out; to terminate in the lamina?. 8; 4, edge of the bony portion; 5, membranous portion ; 6, bony lamina; 7, cupola. Some of the nerve filaments seem to pass into the sacs, and be - come attached to the otolithes. 591. The essential things for hearing are the nerves and labyrinth, in which their outer extremities are supported Fig. 213. and acted upon. Fig. 213 represents what is seen in some of the lower animals; h, the auditory nerve terminates in b the sacculus; a, g, the utriculus ;f, ampulla?; c, e, d, semicircular canals. Here are the membranous labyrinth and nerves alone, yet hearing is produced. What are the otolithes? How do the nerves of hearing commence ? What things are essential to hearing ? Describe flgs. 211, 212, 218. 364 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. I. Some animals have only a sac, with a few otolithes and nerves connecting with them. Fig. 214. In fig. 214, an ideal representation is given of the human car; I, is the labyrinth in the fluid of which the extremities of the nerve, n, are suspended; o, is the membrane, with which the stapes is connected, while, the malleus is connected with, a, the external membrane of the drum, 6," e, is the Eustachian tube, and h, is the auditory canal. The muscles are not represented. Whatever waves of air act on a, must cause an effect to be produced on the nerves in Ij thus an impression is made on the nerve, and through it a sensation is produced in the mind. 592. The middle and external ear, are only means by which the effects of the vibrations of the air are directed upon the nerves. 593. The sensations of hearing are of a very simple character, and all the knowledge of the directions and distance of objects causing sound, are the result of mental action. Inf. Composed of so many parts, the ear must be liable to many different kinds of disease, which would be difficult to cure, and require very skilful treatment. Colds are the most common cause of deafness; next to that cause, scarlet fever is the most frequent. In case of which, it is usual that the patient has taken cold. What is the simple condition of the ear in some animals? Describe fig. 214. What is the use of the middle and external ear? How do we know the direction whence waves of the air have come ? What is one means of avoiding hardness of bearinsr? DIV. III.] 365 ORGANS OF SENSE HEARING. When obtuseness of hearing has occurred, one of the most judicious things for its removal is to be very careful not to take cold. 594. As in case of all the organs of sense, use, or exercise, improves those of hearing wonderfully. Improper use of them will sometimes derange the nerves or brain, so that " ringing," " singing," and other sounds, will be very unpleasantly felt in the head, though such sensations usually arise from some other cause, there being many which affect the brain, so that noises will be heard. 595. In case of sickness, these organs of hearing have many times a very important effect; the slightest wave of air, or noise as it is called, producing discomfort and aggravating the disease. Inf. Extreme quiet should be preserved. These facts show that the organs of the sense of hearing can exert, by their connections, a very powerful influence both upon the body and mind. CHAPTERS VI. & VII. Muscular and Internal Senses and their Organs. Muscular sensations are names given to those which arise from the action of the muscles, the organs of the muscular sense. Internal sensations have their primary cause in the health, disease or wants of all parts of the body, which are organs of the internal senses. These may be classed as senses of hunger, thirst, suffocation, &c. How the organs of these senses act on their nerves is an enigma. Collections of blood or matter, when confined by fibrous tissue, seem to cause pain by pressure, as in felon, whitlow, boils, etc., which is at once relieved by deeply and thoroughly lancing the part. This cannot be, however, the general mode of action when internal sensations are caused. For the muscles cause most annoying sensations to be produced when the}' are not active at all. The peculiarities and uses of these sensations, may be best treated upon in connection with the parts which cause them. What improves the organs of hearing ? What is necessary in case of sickness if sounds are painful ? What are muscular and internal sensations ? 366 SPECIAL ANATOMY, ETC. APP. OF RELATION. [B. J, REVIEW OF BOOK I. A philosophic view of the grand, apparently complex apparatus of Relation, resolves it into several simple classes, each part of which is most admirably adapted to a particular purpose. A frame-work of light, strong bones, cartilages, ligaments and synovial membranes, present ample surfaces for the attachments of the muscles. A great nervous centre holds communication with the external world, by means of the organs of sensation, and control over the muscles by means of the motor nerves; while it furnishes the means of action for all the mental powers. But while the action of each part is for a particular purpose, the result of their combined action is single, viz., the development of the mind, and however important any action in itself may seem, it will be found to centre at this important focus. Mental requirements are different, at different periods, so is the apparatus of relation adapted to different kinds and degrees of activity, at the different ages. Its life and health consists in activity and change of parts, which to a greater or less degree are constant during life, no change being followed by the same state of things as that which preceded it. These changes are partly inherent in the constitution of the body, and therefore necessary, and partly produced by the mind, and world. An education of every mind must therefore be constantly going on. It is of four kinds; of the senses, emotions, intellect, and motor powers. Education of the senses requires their use. Education of the emotions requires their activity, they are not merely to be read or talked about, but to be felt. Intellect is educated by observing, feeling, reading, conversing, and thinking. The motor powers can be educated only by practice. A complete education embraces an education of each kind in a natural manner, and in proper proportion. The Creator has adorned the world with beauty, that it may act favorably upon the mind, and assist in its refinement. The true happiness of every man is dependent on that of his fellow-men, and the high cultivation of all those emotions and intellectual characteristics which bless mankind by their activity. The child should be early taught to notice and love the exquisite pleasure which converse with nature's works alone can give. "There is a pleasure in the pathless woods, There is a rapture on the lonely shore. There is society where none intrudes." Neatness and comfort should prevail in every dwelling-. Nature should be improved by art, and universal education made to produce an exalted equality among all men. BOOK II. APPARATUS OF ORGANIC LIFE. " My heart is awed within me when I think Of the great miracle that still goes on In silence round me—the perpetual work Of thy creation, finished, yet renewed For ever. Written on thy rocks I read The lesson of thy own eternity. Lo! all grow old and die—but see, again, How on the faltering footsteps of decay Youth presses—ever gay and beautiful youth In all its beautiful forms. These lofty trees Wave not the less proudly that their ancestors Moulder beneath them. Oh, there is not lost One of earth's charms; upon her bosom yet, After the flight of untold centuries, The freshness of her far beginning lies, And yet shall lie. Life mocks the idle hate Of his arch-enemy, Death—yea, seats himself Upon the tyrant's throne—tho sepulchre, And of the triumphs of his ghastly foe Makes his own nourishment."—Bryant. The above beautiful quotation is no more true of the world around than of that within. Asleep or awake, the whole organization of man is experiencing the most rapid changes. Death and life are constantly succeeding each other in every part of the body. The physical man of to-day was not yesterday, and will not be tomorrow, precisely the same. The action of the system requires the preservation of a proper temperature in every part while it is necessarily attended with decay, and repair must succeed, or exhaustion of the system will soon follow. 596. The organic apparatus is the name given to that grand class of apparatus by means of which the body is kept in a proper state for action. It includes the circulatory, the respiratory, the digestive, and the eliminatory apparatus. 368 SPECIAL ANATOMY, ETC. ORGANIC LIFE. [P.. Hi All these parts are grouped by means of nerves, and connected with those centres which cause the action of the members of each group, to be harmonious with the wants of each part, and the whole of the body. DIVISION I. Circulatory Apparatus. Analysis.— General character of circulatory apparatus—Two hearts — Each heart constructed of an auricle and ventricle — Situation of heart. — Uses — Effects of its contraction — Composition and situation of arteries — Two classes, systemic and- pulmonary, their uses — Structure and situation of capillaries—Use—Structure of veins — Three classes, pulmonary, systemic and portal—Use — A single circuit — Its use — Forces which circulate the blood — Lymphatic system, composed of vessels and glands—Two classes, systemic and lacteal — Uses—Closed Glands. 597. The human circulatory apparatus, strictly speaking, consists only of complete tubular circuits, furnished with muscular and elastic tissue, and in addition at proper intervals with valves, the whole of which is admirably adapted to circulate blood with great rapidity through every part of the body. But it may very properly be said to include all vessels in the body through which fluids are moved, and also those parts which are appendages of the bloodvessels only. This division should, therefore, embrace four chapters ; the first should treat upon those parts directly concerned in circulating the blood, viz., the hearts, arteries, capillaries, and veins. The second should consider the blood, and the causes and rapidity of its circulation. The third should describe the lymphatic system. The fourth should discuss the character of the closed or sanguineous glands. CHAPTER I. Hearts, Arteries, Capillaries, and Veins. 598. Heart is the name given to any serous sac, or pouch, surrounded by muscular substance, which by expansion and contraction can assist in circulating any fluid in the body. DIV. I.] CIRCULATORY APPARATUS. 369 It is not essential that the heart have any particular form. This varies in different cases. Sometimes it is simply a tube. Neither is it necessary that its action should be exerted upon blood, for there are lymphatic hearts. 599. In the human system heart is the name given to the serous and muscular pouches, by the expansion and contraction of which, the blood is received from the veins and driven into the arteries. It is about the size of a man's fist, and inform corresponds to the hearts of our common animals. Its surface is formed by a serous membrane, upon which a serous fluid is continually poured to lubricate it. In structure externally, it appears to be a unit, but internally it is found both in structure and use, to be a double serous pouch, each of which is surrounded by its own muscular fasciculi—while both are surrounded by an outside coat of fasciculi, which spirally curve from the tip to the base, and the whole is enveloped by the external serous coat. 600. There are, therefore, two human hearts, called the right and the left, or the pulmonic and systemic; each of which is composed of two parts, the upper, called the auricle, and the lower, called the ventricle, between which are valves called the tricuspid, in the pulmonic, and the mitral, in the systemic heart. The auricle is in more than one sense an enlargement of a vein, with muscular substance added between its coats. The amount of it is not great, and the action of the auricle is not strong. The ventricle has thick and strong muscular walls, and exerts corresponding power. The auricles of each heart are very similar, but the systemic ventricle is much the stronger, since it must move the blood so much farther, and through difficult passages. The valves are formed of two layers of the serous coat, with fibrous tissue between them to give strength. Just where the opening from the auricle into the ventricle exists, the serous coat is prolonged and hangs into the ventricle. In the course of a short distance it is divided into three parts in the right, and tWo in the left heart. Each of these is again divided and subdivided, till the border of the valve seems to be composed of many small tendons, which extend across the ventricle, and become continuous with its muscular prominences, called pillars, and which, by contraction and relaxation, keep the b. 3—16* 370 [b. it. SPECIAL ANATOMY, ETC. ORGANIC LIFE. valves precisely where they should be. The use of these valves is to allow the blood to flow from the auricle into the ventricle, but not back again. In the pulmonic heart, however, the valves do not quite close their opening, especially when the heart acts with great power, or if there be some obstruction to the free flow of the blood through the lungs; for then a portion of the blood should flow back into the systemic veins, otherwise the lungs will be overcharged and injured. But the mitral valves close their opening completely, as no blood should be allowed to flow back into the delicate lungs. The muscular filament is mostly of the striped variety, which is an exception to the general rule in respect to involuntary muscles. The heart is surrounded by a heart-case, called the pericardium. It is a serous membrane, continuous with the outer one of the heart about its roots. In one sense it forms a second envelope for the heart. Its surface towards the heart is free, and always lubricated. The other side of the pericardium becomes continuous with the areolar tissue, which at the same time separates and joins it to surrounding parts. The heart is situated a little to the left of the centre of the chest, between the lungs. See 18, fig. 215. The tip of the heart, which is its lower and extreme left point, is situated against the space between the cartilages of the sixth and seventh ribs, and near the sternum. It is neither so low nor so far to the left side as many suppose. The pericardium rests Fig. 215. upon and adheres to the diaphragm. The heart is sustained by the Fig. 215 represents a transverse section of the chest on a level with 18, the heart; 15, 16, 17, lungs which are collapsed, viz., do not fill the chest as when it is closed; 1, 2, 3, external integument; 4, 4, areolar tissue and fat; 5, spinal muscles ; 6, body, 7, canal, 8, spinous process of a vertebra; 10, ribs ; 12, sternum; 13, divisions of Dlood-vessels; 14, division between lobes of the lungs; 20, 21, pulmonary veins ; 22, commencement of aorta; 23, vena cava; 24, 25, divisions of the windpipe"; 26, eesophagus; 27, aorta. DIV. I.] 371 CIRCULATORY APPARATUS HEARTS. ligamentary cords which connect between it and the spinal column. 601. The use of the auricles is to receive the blood, and by gently contracting, to pour it into the expanding ventricle. The use of the ventricle is to receive blood from the contracting auricle, and pour it out into the arteries. Fig. 216. Inf. The contraction and expansions of the two parts of each heart must alternate with each other. The auricles contract together, and so do the ventricles ; but while the former are contracting, the latter are expanding, and vice versa. Three eighths of the time is occupied by the auricles, and four-eighths by the ventricles, in contracting, which allows five-eighths of the time to the auricles, and four-eighths to the ventricles for repose. 602. The rapidity with which the contractions of the heart are produced, vary in different persons, and in the same person at different times. The average in this country is 73, or 74, in men, and 77, or 78, in females per minute. I have known the pulse as low as fifty in youth and health, in one case, and as high as 100, in another. Fig. 216represents the heart between-the lungs, 1 right, 2, left ventricle; 8, right, 4, left auricle; 5,6,7,8, pulmonary artery; 9, aorta; 10, vena cava descendens ; 11, arteria innominata; 12, right subclavian vein ; 18, jugular vein and carotid artery; 17, trachea; 18, bronchi; 19, pulmonary vein; 20, pulmonary artery; 21,upper; 22, middle; 23, lower lobe of right lung. 372 [B. n. SPECIAL ANATOMY, ETC. ORGANIC LIFE. 603. The effects of the contractions of the heart are, 1st, corresponding decomposition of the heart; 2d, sounds very easily perceived, if the ear is applied to the chest; 3d, the throbbing of the heart against the sides of the chest; 4th, the pulsations of the blood in all parts of the body; and 5th, the regulation of the quantity of blood in all parts of the body. 604. The contractions are influenced by every part of the body, and by every state of the mind. Since the heart is a ministering agent to all parts, it must act in accordance with their wants; hence it is intimately associated with all parts by means of the nervous system, and with the mind in particular, that with every rising emotion its action may correspond. There is not, probably, any organ in the body which feels the effects of nervous action so sensitively as the heart; and it is frequently overpowered by the intensity of the action upon it. Arteries. 605. Artery is the name given to any vessel, the sides of which are in part composed of yellow elastic fibres. Their use is to resist to a degree the distensive action of the fluid, forced into them, and by reacting upon it, assist in moving it along. They will, of course, be needed wherever fluid is forced into any vessel —and of course are always found leading out from sanguineous hearts. In the lymphatic vessels which receive the blood from the lymphatic hearts, I believe some elastic fibrous tissue can be detected, and such vessels therefore resemble arteries, but the action of those hearts is so gentle, that the arterial character should not be very decided. 606. Arteries are composed of three coats, —an internal serous, a middle elastic, and an external white fibrous, and are furnished with valves where they are connected with hearts. The internal serous is continuous with the inner coat of the heart. The middle is mostly composed of yellow elastic fibres. The external tunic is composed of white fibres, which blend with the surrounding areolar tissue. The valves are composed of two thicknesses of the serous coat, with fibrous tissue between. They are three in number, and as there is no objection to having all the contents of the heart passed through and retained beyond them, DIV. L] CIRCULATORY APPARATUS. ARTERIES. 373 they perfectly close the opening about which they are situated. They are called semilunar, on account of their form. See fig. 2, Plate 7, and are so arranged, that the side of each overlaps its left neighbor, when they are shut down ; when they are thrown up their edge is not perfectly in contact with the side of the artery, so that the reacting blood will pass behind the valve and close it. These valves are therefore opened and closed by the action of the blood itself. 607. Human arteries are divided corresponding to the hearts, into two classes, one called the pulmonary, the other the systemic. In different animals the number of hearts and classes of arteries vary very much, as the following ideal figures show. Fig. 217. Fig. 218. Fig. 219. Fig. 219. Fig. 217, is an ideal representation of the heart, arteries, and capillaries in man, and the higher classes of animals, as is also tig. 8, PI. 5; d, right or pulmonary ventricle; A, left or systemic ventricle; e, right auricle; g, left auricle; e, pulmonary artery; i, systemic artery ; 6, systemic vein; j, systemic capillaries; /, pulmonary capillaries; a, serous membrane of the heart. Fig. 218, represents the circulation of reptiles, a, ventricle; b, c, auricles; d, pulmonary, e. systemic capillaries. Fig. 219, represents the circulation of fishes, d 2 J vegetables, j ' Lamb, fresh, . . . Broiled, 2 30j Goose Roasted, 2 30; Cake, sponge, . . Baked, 2 30| Cabbage head, . . Raw, 2 30j Beans, pod, . . . Boiled, 2 30 Chicken, full-grown, Fricas'd, 2 45; Custard, .... Baked, 2 45 Apples, sour, hard, Raw, 2 50 Oysters, fresh, . . Raw, 2 55 Bass, striped, fresh, Broiled, 3 Beef, fresh, lean, rare, Roasted, 3 steak, . . . Broiled, 3 Corn cake, . . . Baked, 3 Dumpling, apple, Boiled, 3 -n t u 4 Boiled, 3 Eggs, fresh, . . -j goft) 3 Mutton, fresh, . . Broiled, 3 , .... Boiled, 3 Pork, recently salted, Boiled, 3 Articles. jTirne. h. m. Soup, chicken, . . Boiled, 3 Pork steak, . . . Broiled, 3 15 Pork recently salted, Broiled,; 3 15 Oysters, fresh, . . Roasted, 3 15 Mutton, fresh, . . Roasted, 3 15 Bread, corn, . . Baked, 3 15 Carrot, orange, . . Boiled, 3 15 Beef, with mustard, Boiled, 3 15 Sausage, .... Broiled, 3 15 Beef, fresh, lean, dry, Roasted, 3 30 Bread, wheat, fresh, Baked, 3 30 Butter Melted, 3 30 Catfish Fried, 3 30 Cheese, old, strong, Raw, 3 30 Eggs, fresh, . . j »JJj£ 3 30 , .... Fried, 3 30 Flounder, fresh, . . Fried, 3 30 Oysters, fresh, . Stewed, 3 30 Potatoes, Irish, . . Boiled, 3 30 Soup, mutton, . . Boiled, 3 80 Soup, oyster, . . Boiled, 3 30 Turnips, fiat, . . . Boiled, 3 30 Beef fresh, lean, ) q op .,, i > lioiled, 3 36 with salt only, I ' Corn, green, & beans, Boiled, 3 45 Beets Boiled, 3 45 Beef, fresh, lean, . Fried, 4 Ducks, domesticated, Roasted, 4 Fowl, domestic, . Boiled, 4 , . . Roasted, 4 Salmon, salted, . . Boiled, 4 Soup, beef, vege- ) , 4 tables & bread, J ' Veal, fresh, . . . Broiled, 4 Pork, recently salted, Fried, 4 15 Beef, old hard, salted, Boiled, 4 15 Cabbage, .... Boiled, 4 30 Ducks, wild, . . Roasted, 4 30 Suet, mutton, . . Boiled, 4 30 Veal, fresh, . . Fried, 4 30 Pork, fat and lean, Roasted, 5 15 Suet, beef, fresh, . Boiled, 5 80 DIV. III.] 421 DIGESTIVE APPARATUS' —STOMACH. The appetite, especially of the sick, and" those who actively exercise the nervous system, frequently craves a particular kind of food, and if there is no objection, it is very important sometimes that it be eaten; for different kinds of food serve different purposes, and frequently the best kind is indicated by the organic appetite. Cooking affected the food in two ways: 1st, by changing its character; and 2d, by rendering it more or less difficult for the juices of the mouth and stomach to saturate the food. Inf. As well relished food affects the mind favorably, and badly digested food produces derangement of the stomach, and of course unfavorably affects the mind, causing irritability, d, through, ttofi6ut t I form a mouth). To open into each other. (Used in respect to vessels.) An'eu-rism (&vd, through, cfytW, I dilate). Unnatural dilatation of an artery, producing a pouch, sac, or tumor. An-gi-ol'o-gy (kyytwv, a tubular vessel, \6yos, discourse). The division of anatomy treating upon the blood-vessels and lymphatics. An'gu-li (angulus, an angle). Of the angle. An'nu-lar (annus, a year). Ringshaped. An'ti-cus (L. turning toward the axis). Name of certain muscles. A-ort'a air, rnpiw, I keep). The central arterial trunk. Its name was given when it was thought to contain air. A-pox-EU-Ro'sis (&w6, from, vwpov, nerve). Name given to the expanded fibrous tissue connecting muscles with the parts they act upon. Broad tendon. The ancients called all white, cordy parts nerves. Ai'-pa-ra'tus (apparo, I prepare). A group of organs which contribute to the accomplishment of a function. A-rach'noid (apdxvTi), a spider, ef-8os, like in form). Specific names given to certain mem- 447 GLOSSARY. branes delicate as that of a spider—(spider's web.) Ar'bor-vi'tae (tree of life). Name given to central part of cerebellum. Ar'te-ry (see Aorta). Name of any vessel through which blood flows from a heart. Ar-tio'u-la-ted (articulo, jointed). A-ryt'e-noid (ipvT-fip, a ewer or pitcher, tlSos, like in form). Name of laryngeal cartilage— the two resembling the nose or lip of an ancient pitcher. As-phyx'i-a (a, deprived of, , I throb). Without pulse. Now used to express the condition when the breath is suspended, but life not extinct. As-trag'a-lus (aarpdydKos, ankle bone). At'om (a, not, rifuvw, I cut or divide). Two meanings. 1st. An indivisible particle of matter. 2d. A particle which cannot'be further divided without decom- position. In the last case, atom is a compound, as an atom of water is composed of an atom of hydrogen and an atom of oxygen. Aud'it-o-ry (audio, I hear). Belonging to the hearing apparatus. Au'ri-cle (auris, the ear). The name of the upper portion of each heart. Au-to-mat'io (avTos, self, fidw, I move). Self-moving. Ax-ll'la (L.). Arm-pit. A-zote'(o, without, Qno4\, life). Nitrogen, lifeless air. An element composing about four fifths of the atmosphere. Bi'ceps (bis, double, caput, head). Name of certain muscles with origins or heads. Bi-ous'pids (bis, double, cuspis, a point). Name of the two pointed teeth. Bi-fur-ca'tion (bis, "twice, furca, a fork). Name given to a division of parts forming a fork. Bil 'ia-rv (bilis, bile). Pertaining to bile. Bi-pen'ni-form (bis, double, penna, a pen). Name of muscles in which the fasciculi are arranged on each side of a central tendon like the barbs of a feather on the stem. Brach'i-al (brackium, arm). Pertaining to the arm. Bre'vik*(L.). Short, (-ior) shorter, (-simus) shortest. Bronoh'us (bronchi, bronchia, bronchea, PI.) (fipSyxos from I moisten). The name of any air-tube or portion of the windpipe below the trachea. This name was given when these passages were supposed to be the course of the fluids on their way to the stomach. The singular, when applied strictly, means that part of the air-tubes between the trachea and their next division, the plural being applied to the tubes below. Bron-chi'tis. The termination itis (the first i is pronounced like long e) signifies inflammation; but bronchitis means not inflammation of the entire bronchial tube, but is used to indicate an inflammation of the mucous membrane lining the bronchia, and sometimes of the trachea, larynx, and air-cells. Buc-oi-na'tor (buccina, a trumpet). Name of one of the cheek-mus- cles. Bur'sa (PI. -m) (L. a purse). The name of a small sac or very large cell, containing a variable quantity of serum, situated where parts would otherwise be injured by friction. Ce'ca (L. blind). Names of ap- 448 GLOSSARY. pendagos to the cecum in certain animals. CiB'cuM (L. blind). Name of that part of tho intestinal canal which is below where the ilium opens into the colon. Calx (L. genitive calcis, of the heel). Heel. Cal'ci-um (L.). A simple clement, the basis of lime. CA-PiL'LA-RY(cam/£«s,ahair.) Name of minute tubes. CAi»'suLis(<:ajnsa,an inclosed cavity). A membrane inclosing a cavity. Car'HON (carbo, a coal). A simple element, the chief compound of coal. Car-bon'ic. The termination ic, here signifies that carbon in its highest ratio is compounded with oxygen. Car'di-ac (tcapUla, heart). Pertaining to the heart. Orifice of the stomach beneath the heart. Ca-rot'id (K&p6w, I induce sleep). Name of arteries through which blood flows to the head. Named by the ancients, who believed that through them sleep was caused. Car'pus (L.). Wrist. Car'til-age (cartilago). Gristle. One of the tissues. Cau'da e-qui'na (caudus, a tail, equus, a horse). The name of the terminal extremity of the spinal cord. Cav'a (L.). Hollow. Vena cava, name of a large vein. Cer-e-bel'lum (L.). Small brain. Cer'e-brum (L.). Large brain. Cer-e'bro-spi'nal. Pertaining to both the cerebrum and spine. Cer'vi-cal (cervix, neck). Pertaining to the neck. Chest. The upper part of the trunk. The thorax, Gr. Chlo'rine (x\wp6s, green). A gaseous element. Chor'da, PI. -m (L). A cord. Cho'ei-um (x6ptov, skin, leather). The fibrous membrane of the skin. Cho'roid. Resembling the skin. Chyle juice). The fluid formed in the second stomach. Chy-lif'ic, chy-li-fi-oa'tion (x<5Aos, juice, facio, I make). The name of the process by which chyle is formed. Chyme (xvfj.6s, a thick juice). A semi-fluid or thick, pasty matter, formed in the stomach. Chy-mif'io, chym-i-fi-ca'tion (x«5-juos, thick juice, facio I make). Tho name of the process by which chyme is formed. Cil'ia-ry (cilium, eyelash). Resembling the cilia. Cin-e-ri'tious (cinis, ashes). Resembling ashes (usually in color). Clav'i-cle (clavis, ancient key). Collar bone. Clei'do (k\(Is, a key). Part of the name of a muscle, signifying that it is attached to the clavicle. Co-ag'u-lum (L.). A clot. Coc'cyx (kSkkvI-, a cuckoo). The extremity of the spinal column, shaped like a cuckoo's beak. Coch'le-a (L. a snail-shell). Snailshaped. Co'lon (k5>\ov, a member). The large canal between the caecum and rectum. Co'ma (KtSjua, deep sleep). Lethai'g 'g \ . Com-mu'nis (L.). Common. Com-pres'sor (comprimo, I press together). Name of certain muscles. Con-cus'sion (concutio, I shake together). A shaking of parts among or against each other. Con'dyle (k6vov\os, a knuckle). The name of a bony prominence. Con-ges'tion (congestio, a fulness). An unnatural accumulation of GLOSSARY 449 fluids, generally blood, in any part. Con-juno'ti-va (conjungo, I join together). The name of the skin which lines the eyelids and covers the balls. Con-strict'or (constringo, I bind together). The name of certain muscles. Con-trac-til'i-ty (contralto, I draw together). The name of that property of muscular tissue by virtue of which it is contractiblo. Cor'a-coid (/cJpof, a crow, doos, like in form). Like the shape of a crow's beak. Co'ri-on, co'ri-um (xiptov, skin). Name of fibrous layer of the skin. Cor'ne-a (cornu, a horn). Name of the window of the eye. Cor'o-na-ry (corona, a crown). Encircling like a crown. Cor'pus (L.). A body. Cos'ta (L.). A rib. Cra'ni-um (LA That part of the skull which incloses the en- cephalon. Crib ri-form (cribrum, a sieve). Resembling a sieve. Cri'coid (icplicos, a ring, eiSos). Ring-shaped. Cru'ral (crus, the leg). Belonging to, resembling the leg. Crys'tal-line (KpiaraWos, clear ice). Resembling a crystal in transparency. Cu'bi-tal (cubitum, the elbow and the fore-arm —also the ulna). Pertaining to the ulna. Cu'boid (kv&os, a cube, eTSos, like in form). Cube-shaped. Cu-nei'form (cuneus, a wedge). Wedge-shaped. Cus'pid (cuspis, a point). Onepointed tooth. Cu'ti-cle (cutis, the skin). The external layer of the skin. De-cus'sate (decusso, I cross like an X). Intersection. Deg-lu-ti'tion (deglulio, I swallow). The act of swallowing. Del'toid (A, delta, e75oy, like in form). Delta-shaped. Dent'ai. (dens, a tooth). Pertain ing to a tooth. De-press'or (dcprimo, I depress). Name of certain muscles. Derm'oid (Sep/xa, skin, tltios, like in form). Similar in some respects to the skin. De-8CEn'deN8 (descendo, I descend). Descending. A name applied to parts through which substances descend. Di'a-phragm (Sid, through, , I benumb). The name applied to whatever induces sleep. 453 GLOSSARY. Na'sal (nams, the nose). Pertaining to the nose. Ner'vous (nervus, a nerve). Pertaining to nerves. Neu-ral'gi-a (vevpov, nerve, &\yos, pain). Name of some disease of the nerves in which the pain is very severe. Neu-ri-lem'ma (vevpov, nerve, \4fijuo, sheath). Ni'grum(L.) Black. Ni'tro-gen (vlrpov, nitre, yevvdeo, I produce). Azote. Nu'cle-us (nux, a nut). A centre about which matter is gathered. Nu-tri'tion (nutrio, I nourish). Name of the substance, and also of the processes, by which the body is nourished. Ob-li'quus (L.). Oblique. Ob-tu-ra'tor (olituro, I stop up). Name of certain muscles. Oc-cip-i-tal'is (ob, back, caput, head). Pertaining to the occiput or back part of the head. Oc-u-lo'rum (oculus, eye). Of the eyes. (E-sopii'a-gus (otco, I carry, fi6s, broth). Name of the substance which produces the odor, and to a certain degree the flavor, of cooked meat. Os'se-ous. Pertaining to bones. Os-si-fx-ca'tion (os, bone, facio, I make). Name of the process by which bones are made. Ot'o-lithes (ods, ear, \l6ot, stone). Calcareous substances or powder found in the labyrinth. O-va'le (ovum, an egg). Eggshaped. Ox'ide. A compound of oxygen and some other substance or substances. Ox't-gen (of is, acid, ytvvdw, I generate). The name of one of the simple elements. Pa-la'tum (L.). Palate. Pal'mar (palma, palm). Pertaining to the palm. Pal-pe-bra'rum (palpebra, eyelid). Of the eyelids. Pan-cre-at ic (irdv, all, Kpeas, flesh). Pertaining to the pancreas. Pa-pil'la (L.). A small conical eminence. Pa-ral'y-sis (irapakvw, I palsy). The name of any state of any part of the nervous system in which it is incapable of action. Pa-ren-chy'ma (7rape7X €a, > I pour in by the side). The tissue of a gland. Pa-ri'e-tal (paries, a partition wall). Pertaining to the walls of any part. Name of two bones of the skull. Pa-rot'id (irapd, near, oSs, the ear). Name of one of the sali- vary glands. 454 GLOSSARY. Peo'to-ral (pectus, breast). Pertaining to the front part of the chest. Pe'dis (pes, foot). Of the foot. Pel'yis (L. a basin). That part of the body included by the hip bones. Pen'ni-form (penna, a pen). A name given to muscles in which the fasciculi are arranged on one side of a tendon. Per-i-oar'di-um (irepl, about, KapMa, the heart). Heart-case. Per-i-chon'dri-um (trepi, about, %iv- Spos, cartilage). Membrane about the cartilage. Per-i-cra'ni-um (irepl, about, Kpdvlov, the cranium). Membrane about the cranium. Per-i-os'te-um. Membrane about the bones. Per-i-to-ne'um (wept, about, rov6w, I stretch). Name of the serous membrane lining the abdomen and forming the surface of many of its organs. Per-o'ne-us (vep6vn, a clasp, the fibula). The name of several muscles. Per-spi-ra'tion (per, through, spiro, I breathe). Excretion of the skin. Phal-an'ges (p6s, a gate-keeper). The name of the thick band of muscular fibres about the outlet from the stomach. Pyr-a-mi-dal'is. Name of muscles. Quad-ra'tus. A name of square or oblong muscles. 455 GLOSSARY Ra-chid'i-en (p&xis, the spine). Name of the spinal canal. Ra'di-us (L. a ray). Name of one of the bones in the lower arm. Ram-i-fi-ca'tion (ramus, a branch, facio, I make). The act of branching. Rec'tum (rectus, straight). The last part of the digestive canal. Re-spir'a-to-ry (re, again, spiro, I breathe). Pertaining to respiration. Ret'i-na (rete, a net). The terminations of the optic nerve in the eye. Ro-tun'dum (L.). Round. Ru'ga (L.). A wrinkle; a fold. Sa'cral. Pertaining to the sacrum, or bone situated between the hip bones and supporting the spinal column. Sa'cro-. A term applied to parts connected with the sacrum. San-guif'ic (sanguis, blood, facio, I make). Blood-making. Saph-e'na manifest). Name of veins. Sar-to'ri-us (sartor, a tailor). Name of a muscle. Sca'la (L. an ascending path). Cavity of the cochlea. Sca-le'nus (o-K&\nv6s, unequal). Name of muscles. Scaph'oid (ffK&tpri, a skiff, ttBos, like). Name of a wrist bone. Scap'u-lar (scapula, shoulderblade). Pertaining to shoulderblade. Scarf-skin. Cuticle ; epidermis; outer layer of skin. Schnei-de'ri-an (Schneider, a man's name). The name of the membrane lining the nose; pituitary membrane. Sci-at'io (iVxW, the hip). Name of the large nerve of the hip and thigh. Scle-rot'ic (