To the Fellows of the Alabama State Medical Association: The Essay on the fc Unity of Disease," which the undersigned had the honor to read before the Association, December last, and which was pub- lished in the " Proceedings," is so obscured, by errors, partly original, partly typographical, as to be scarcely intelligible. In justice to himself, and subject, he has attempted, and he trusts, succeeded, in correcting nu- merous errors; and by additional illustrations, rendered it more complete and intelligible. As this will not interfere with the continuation of the subject, by appointment, at the next meeting of the Association, it is hoped that this re-publication will be acceptable to those to whom it is addressed. H. BACKUS. Selma, Ala.. April, 1853, £9 The fundamental condition requisite to the developement, growth, and maintenance of an organised body exhibiting the phenomenon of life, is a constantly circulated supply of f he materials of which it is composed. The truth of this proposition appears in the fact, that all bo- dies, organic and inorganic, are built up by molecular con- densation, aggregation, or arrangement. To condense, ag- gregate, or arrange these molecules into forms or bodies, in- volves motion, circulation. Again, every phenomenon exhib- ited by living beings, is at the expense of a disintegration of a portion of the tissue or organ exhibiting such phenomenon. Somatic life is at the expense of molecular death. We live by*dying. Hence a necessity of a constantly circulatelsup- ply of materials for reproduction, maintenance. Molecular motion, then, is the type, the antecedent, the base of all forms, all motion or phenomenon, since molecular motion builds up, sustains, disintegrates or pulls down. To observation, the conditions of form, of phenomenon, are media of different densities acting upon each other, represented in air, water, and the earth. There must be resistance to motion, as a ful- crum for motion. This is no more paradoxical than that death is the condition or type of life, or that the invisible is the condition or type of the visible. It is the action, resis- tance, pressure of these different media upon each other, that exhibits form, phenomenon. Organic bodies,being speciali- zations of inorganic bodies, the same conditions # of form, of phenomenon, obtain in them as in their type, viz: Media of dif- ferent densities acting upon each other, represented in their solids, liquids, and fluids, or air in respiration. These condi- tions are universal;—they obtain wherever there is form or phenomenon ; whether involving molecules or masses; wheth- * It does not follow, that because, organic and inorganic bodies have certain conditions in common, that they do not differ from each other, and among them- selves. All bodies have certain common properties, and it is with these, that we have at present to do. The principles or doctrines of medicine, are not so firmly established as to suppress all farther inquiry, and it is more in the light of suggestion, than positive assertion, that these views are offered: adopting the language of that admirable Philosopher and Physiologist, Dr. Carpenter, as ex- pressed in his General and Comparative Physiology, p. 36. "In the considera- tion of this or any other Theory of Life, it is very important to keep constantly in view, that it has relation only to the agencies concerned in the formation and conservation of the material organism. The phenomena of mind belong to a category altogether distinct, and cannot be considered as bearing any neces- sary relation to tne former. It seems also necessary to point out, that in speak- ing ot forces as possessing an absolute existence, it is not intended on the one hand to imply that they are any thing else than " affections of matter " * nor on the other to regard them in any other light, than as the direct operation of the primal all-sustaining Cause." * S'ee Grove on the " Correla tion of Physical Forces," p. 7. 3 er applied to absorption or circulation, voluntary or involun- tary motion ; the organic or inorganic world. They are the instruments, so to speak, in the hands of the Creator for the accomplishment of his great designs; they form the funda- mental subtratum; the common condition, the unity of plan, lying at the foundation of all things; and equally the diver- sity of form, or phenomenon every where exhibited. Absorp- tion of nutritive materials from the surrounding media^ is the type of circulation, respiration. This being a general princi- ple, its most simple and most complex specialization must rest upon it, these specializations being adaptive in char- acter. The surrounding media, then, in furnishing the materials or conditions of absorption, furnish the materi- als or conditions of circulation. In other words, acquisition of materials is circulation, absorption being the type. Blood, i. e. water and other materials in suspension or solution, is an internal reflection, extension of its type, the external surroun- ding media. The vascular apparatus is an internal reflec- tion, extension of its type, the external absorbing surface.— We have said that the conditions of absorption are, the ac- tion, resistance, pressure of media of different densities upon each other. Chemistry of Plants, by Dr. Draper, page 28, "From these simple principles we deduce the following im- portant law—important because it gives us at once a clear explanation of the rise of sap in trees, and a beautiful expo- sition of the true cause of the circulation of blood; when two different liquids are brought in contact in a porous solid, which is wetted by both, but by them unequally, that one which has the greatest affinity for the solid, or which wets it most perfectly, wiU pass most rapidly through it, and may even drive the other before it." Page 40, " It is well known to physicians, from the phenomena of asphyxia, that when- ever the admission of Oxygen into the air cells of the lungs is prevented, the circulation through them simultaneously stops; but it may be renewed again on the re-admission of that gas, provided it is within a short space of time, and re- covery may and often does take place under these circum- stances. What, now, is the cause of that asphyxiated condi- tion ? Why does the blood cease to flow ? The chemical theory of the circulation through the lungs which I have just given, points to the oxydation of that blood as the very cause of its movement. It is the pressure of the deoxydised upon the oxydised blood that drives the latter along the pulmonary veins to the heart. But should any thing intervene to pre- vent that oxydation taking place, no pressure, and, therelore, no movement can ensue." It is the pressure of these media of different densities upor. each other, then, that is the cause of the movement or circu- 4 lation of blood. Absorption being the type of circulation, and the conditions of absorption being pressure of media of differ- ent densities upon each other, it follows that the conditions of circulation are the same, represented in the pressure of the heart upon the blood. The pressure of the surrounding me- dia, together with that exerted by air in respiration, food'and water, i. e. blood, their internal reflections, is the type, the ante- cedent, the fulcrum of the returning pressure of their conden- sation, specialization into tissues upon them. Air, blood, and the solids of the body may be said, severally, to form one third of a heart ;'the same action, resistance, pressure of these different media that circulates the molecules, air and blood, circulates the solids, or the mass; the molecular circulation being the antecedent, the base of the circulation of the mass. Was it not for the antecedent molecular motion or circula- tion of air, our bodies, like the earth, would be impaled as it were in a heaven of brass. Was it not for the antecedent molecular motion or circulation of blood, our muscles would be as rigid as iron. The pressure of the air is to the circu- lation in general what the pressure of the bandage is to the circulation through a varicose limb. The bandage does not increase the pressure of the heart, but the influence of both be- ing that oi pressure, it is an additional heart, or as a heart itself to the circulation through that limb. This may be seen by placing a limb in an exhausting receiver, and unloosing, re- moving these molecular bandages or hearts of air. The cup- ping-glass is a familiar local illustration. How admirably adapted to support the delicate vessels of the lungs, to circulate the blood through those vessels, are these elastic bandages of air. The blood may be said to cir- culate through its type, tubes of air, and by its type, hearts of air. What a union of types; acquisition of materials, Oxy- gen, here as elsewhere, is circulation; absorption being the type. The increased pressure of water over air, is a bandage or counter heart to the body of the fish, the foetus. When the firm fulcrum of the surrounding media is removed from the smaU heart of the foetus in birth, its large respiratory heart is evolved in its stead, the first to beat, literally throbbing and beating on and through its type, air. This may be seen in our efforts to revive the still born. All our efforts are directed to excite the pulsation of its respirato- ry heart,' all other means failing, we artificially dilate it with air, its permanent fulcrum of motion; the returning pressure of its parieties alternating its movements. The increased density or pressure of the earth over water, is a bandage which the God of Nature binds around the roots >f the tree; absorption, its own movements in extension, its it waving leaves, branches, and trunk, in the winds or banda- ges of heaven, these are its hearts. The influence of a dense medium in the circulation of li- quids may be seen in the arteries, capillaries, and veins ; in the experiments of Dr. Williams with rigid and membranous tubes; or^vhen we make our foot-steps on the yielding sand. The only influence of the heart in the circulation of blood, is that of mechanical pressure. It contracts upon its contents, i. e. it returns upon its type, the antecedent pressure of blood, its molecular surrounding media. Carpenters General and Comparative Physiology, page 6U6. Note.—To use the lan- guage of Dr. Grant, "It is the restless activity of the Worm and of the Insect, that makes every fibre of their body as it were a heart to circulate their blood, and propel their fluids. They require no complicated apparatus to accelerate the ever ac- tive current of their blood, and hence the imperfect develope- ment of the great centre of their vascular system. Indeed it has been shown by Ehrenberg and by Nordmann, that in the simplest of these animals, the trematoid Entozoa, the blood' flows through the system by the mere motions of the body, without the least motion or impulse of the vessels which contain it." Reflect this extract upon man, the highest spe- cialization of organised bodies, and it is equally true of him, that every fibre of his body is a heart to circulate his blood, his own heart being in the condition of the worm, circulating its own blood by its oion movement. So with all moveable parts, and the immovable parts, the solid frame-work of his body, affords by its resistance, like the earth to his feet, a firm fulcrum or counter heart to the moveable parts. This may be seen in the paralysed limb; it becomes atrophied from loss of its general heart, its own movements ; restore this gen- eral heart through artificial exercise, and its nutrition is restored. The nervous mass introduces no element of force not found in its molecular surrounding media, heat, light, electricity, or some modification of molecular motion not differing more from those than they do from each other. Dr. Carpenter, in his great work on General and Comparative Physiology, says, that physical and vital forces are correlated; that the germ cannot develope itself into the cell, all other conditions being present in the absence of heat,' that heat acting through organised matter becomes itself the formative force,' and that the vital force is itself dependent upon the preceding nutritive operations. Now, if nutritive operations precede the vital force, and these nutritive operations cannot take place in the absence of heat, it is not necessary to assume the existence of such a force, if it differs from heat. Heat, light, and electri- city are quite as mysterious in themselves as the vital force, supposing it to be something different. 6 Sensation, common or special, is elicited by pressure, mo- lecular touch, motion How delicate, how refined is the mo- lecular touch of summers gentle breeze; of light, of sound, of taste, of smell; how admirably adapted-are the nervous mo- lecules to appreciate, distinguish this attenuated touch. Sensation may be said to be elicited solely by the pressure of the surrounding media. Since the pressure of blood, which is but an internal reflection of that surrounding media, elicits the sensations ascribed to internal causes, pleasurable or painful, according to degree. Man, then, may be said to mirror the external world? to be an internal reflection of the surrounding media, returning upon themselves to themselves; the physical Universe in mi- nature, with all its conditions of form, of phenomenon, the illimitable heavens twinkling in thought, a type of his mind. Disease is obstructed circulation, a disturbance of the fun- damental condition laid down in our first proposition, a loss of equilibrium in the action, resistance, pressure, of the dif- ferent parts, solids and fluids upon each other and the sur- rounding media, illustrated in disease of the heart. The positions which we shall attempt to establish in illus- tration and confirmation of the truth of our general proposi- tion, that disease is a unit, obstructed circulation, are, 1st, that prostration is the antecedent, the fulcrum of reaction; 2d, that * this state of prostration is the only essential condition in dis- ease; and, 3d, that whatever reaction contributes to disease, is the same in kind with its antecedent. It will be observed that we are not attempting to prove uni- ty in names, or in what are called exciting causes, nor of lo- cality, in disease. We attempt to go deeper into the nature of the subject than mere names frequently import. We affirm. that wherever there is disease, there is a common state or condi-* tion, differing only in degree; rejecting in toto the doctrine of plurality of causes or conditions producing the same results. It is said that many causes produce motion, sensation, heat, death, &c. We have.»said that the conditions of motion, whether of molecules or masses, were media of different den- sities acting upon each other; that molecular motion was the type, the antecedent, the base of the motion of the mass ; that these conditions were common, not only wherever there was motion, but form, or phenomenon, as heat; that sensation com- * mon or special, was elicited solely by pressure, molecular touch; that disease or death was obstructed circulation. The different causes of death, as they are called, all produce one common state antecedent. To illustrate, the circulation may be arrested through the system or a part, by the applica- tion of a cotton, silk, flax, leather, or wire ligature to the ves- * sels. These ligatures, like the exciting causes of disease or 7 death, may, and do differ from each other, or among them- selves, but they are notdifferent causes oi the arrested circulation; they obstruct the circulation by virtue of one common element, viz: pressure. Anemia and Plethora, two opposite condi- tions, as they are called, produce the same result, convulsions for instance. Now, although a plethoric man may have more flesh and blood than an anemic one, though one may have a strong, and the other a feeble pulse, and though they may both have convulsions, it does not follow that the conditions upon which the convulsions depend are different. In the anemic case, or where the pulse is feeble, the convulsion de- pends upon retrograde pressure oi venous blood, while in the other case, there is added to this retrogade pressure of venous blood, the arterial vis-a-tergo or pressure of re-action. This is frequently illustrated, especially in children, in ague and fever. We sometimes see convulsions in the cold stage, or stage of prostration, from this retrograde pressure of venous blood. This pressure not being sufficient in certain cases, we have the convulsions in the stage of re-action. In fact, the involuntary tremor in ague, is as pure convulsion, as the most terrific that goes by the name, having the same cause, and differing only in degree. This will be more clearly illus- trated when we consider disease of the heart. In order to > establish the truth of our first position, it is not necessary that every case should sink into extreme prostration, preceding re-action. There are degrees here as elsewhere. As this posi- tion is admitted in general, it falls upon those who hold that there are exceptions to its universal application, to bring for- ward a case, in which they have witnessed every step of the transition from a state of perfect health to that of disease, fe- ver, or inflamation, where this state of prostration was absent. Jhe testimony of the patient, of his friends, or the imperfect observations of a physician, cannot be admitted against the general admissions, upon this point, of the profession. The terms prostration, debility, collapse, shock to the nervous sys- tem, want of power, depression, dilatation, congestion and ob- struction, are here used as synonymous; different terms mere- ly for the same state, or differing only in degree. The first argument adduced in support of our first position, is founded upon the term re-action. w Re-action,implies a state of previous prostration to re-act from, and this, whether involving the smallest surface in lo- cal inflammation, or spread over the system in fever. Cyclope- dia Pract. Medicine, Vol. 1. p. 454. " Caloric, or heat as it is commonly called, acts as a stimu- lant when applied to the animal body, its effects being local or general according to the extent and degree of its applica- tion; it increases, like most other stimulants, the action of 8 the heart and blood-vessels; but as is also the case generally with stimulants, a secondary effect occurs, which consists in a collapse, or in an action lower than that which is natural, after the excitement has subsided; effects exactly the reverse of these take place from the abstraction of caloric, or, to use the common phrase from the application of cold. Heat is therefore a stimulant and cold asedative. Page 456, "But the injury sustained from exposure to cold is not always de- pendent on its direct sedative action, for it may produce (ag- gravate) disease and even cause death, by that secondary ef- fect which is denominated re-action; this re-action after de- pression consists in the return of the action of the vascular system; if moderate it may go little beyond the natural de- gree. But when the re-action is great, the vascular excite- ment is so increased beyond due bounds, as to constitute fe- ver; and perhaps there maybe in reality no difference in this state of the body and fever from other causes. The symp- toms are often the same and sometimes last as long. Fever is not the only consequence to be feared from re-action after exposure to cold; local inflammations may follow this general reaction and any of the internal membranes or organs may become the seat of inflammation." These extracts illustrate this important point—that these agents, stimulants and seda- tives, produce a common condition, viz: a state of collapse, or an action below the natural standard, secondarily in the case of stimulants and primarily in the case of sedatives, which common condition we define to be disease. Williams principles of medicine, page 152, u Malaria, and the influences which produce continued and exanthematous fevers, seem to have the same effect as external cold, but it is not so easy to explain how they operate. The cold stage of these diseases exhibits in a high degree the marks of intropulsive conge* tion, and it is well known that in ague, the congestive en- largement of the liver and spleen are among its most remark- able phenomena. The congestions remaining during the fe- brile stages of fevers, «eem to be the chief causes of their in- flammatory complications." Cyclopedia Pract. Med., Vol. 3, page 556, "We have stated that absolute plethora was the parent of pure inflammation. Previously to the occurrence of febrile or inflammatory action there is always a sensible inter- val of disease marked by diminished power in the arterial sys- tem, the oppressed and irregular actions of which evince its inadequacy to carry on the circulation with its wonted vigor. The pulse, if examined, will be found low, oppressed, irregu- lar, which state passes progressively into one of increased ac- tion or fever. Multiplied observations have satisfied us both that the stage of disease here mentioned precedes that of fe- brile action, and that the morbid actions indicated by the j 9 pulse succeed each other in the order here mentioned, the first being that of feebleness, the second of irregularity, and the third of permanently quickened action. Druitt's Surgery, 1st chap. " As the most proper commencement of a systematic treatise on Surgery, we shall begin by describing a state com- monly known as prostration, collapse, or shock to the nervous system, by which terms we signify that general depression of the actions and powers of life, which immediately follows any severe injury. Exciting causes. G'reat and sudden extremes of grief, or joy, or fear, or cold;—large doses of any active poison, such as Arsenic, Sulphuric Acid, or Tobacco; the sudden impression of Miasmata, or of morbid poisons, as the plague ; great loss of blood and mechanical injuries." We have here enumerated almost all the recognised exciting caus- es of disease, and, like the ligatures, they produce a common state, or condition. " The process of recovery from collapse is commonly called re-action, and the manner in which the case may terminate must depend upon the nature and degree of that re-action. Thus, first. If it be healthy and moderate, and especially if the collapse arise from concussion or violent shaking of an organ without actual injury to its structure, it will lead to complete recovery. Secondly, if re-action be ex- cessive, the state of collapse will be gradually succeeded by fe- ver, symptomatic of the local inflammation to which the inju- ry has given origin. Thirdly, if re-action be imperfectly de- veloped, it will be converted into the state oi prostration with excitement, 8rc. Fourthly, if re-action be altogether wanting, the collapse will terminate in deaths It will be seen that while all the extracts we have made from these standard authors fully and amply sustain our first position, they do much more. They are equally to the point, in proof of the unity of fever and inflammation, since both are here seen to have the same antecedents. This is also seen in the argument of Dr. Wood, who takes somewhat different views upon this subject, from those here ad- vocated. Woods' Practice, vol. 1, p. 45. " Hence, consequent- ly, the congestion which is always the first observable change in that series of changes which constitutes the process of in- flammation." Page 79, " The general depression which often * The following quotation from Cullen, first lines, page 37, (which was in- advertently omitted) is so directly in point, that we must introduce it as a Note. " It is therefore evident that there are three states which always take place in fever; a state of debility, a state of cold, and a state of heat; and as these three states regularly and constantly succeed each other in the order we have mention- ed them, it is presumed that they are in the series oi cause and effect with res- pect to one another. This we hold a matter of fact, even although we should not be able to explain in what manner, or by what mechanical means these statei- severally produce each other." His subsequent hypotheses of "spasm of the cap- illaries," whether true or not, does not effect the statement of facts up to that point. 10 ushers in fever, bears to it the same relation as the local de- pression bears to the subsequent inflammation" The symp- toms of inflammation, heat, redness, pain and swelling, are common to fever, but being diffused over a larger surface, may not be so prominent in every part. To complete the analogy, we quote from the Cyclopedia Pract. Med., 2d vol., p. 751, " Inflammation may be continued, remittent or inter- mittent." Fever and inflammation, then, are but different terms for the same state, differing only in extent or degree. Our second position is, that this state of prostration or con- gestion, is the only essential condition in disease. We have seen from Mr. Druitt, that if re-action be altogether wanting the collapse will terminate in death. It is conceded that pros- tration, debility, congestion, or retrograde pressure of venous blood, is the only essential cause of flux, hemorrhage, dropsy, pain, convulsion, coma, ulceration, mortification or death, or may be conceded on reference to dilatation, or valvular dis- ease of the heart. Our third position is, that whatever re-action contributes to disease is the same in kind with its antecedent. This will be illustrated when we consider hypertrophy of the heart.— Dilatation of the heart corresponds to the state of prostration preceding re-action, fever or inflammation. Dilatation is prostration, debility, want of power, congestion or obstruction. Dilatation i. e. prostration, is the antecedent, the fulcrum of hy- pertrophy, i. e. re-action. Hypertrophy is chronic re-action. Re-action is acute hypertrophy. Sometimes we have no hy- pertrophy; sometimes we have no re-action; the cause and the effect, is the same. Sometimes we have a low form of fe- ver, of inflammation, (the state of prostration with excitement spoken of by Mr. Druitt.) This is represented in dilatation with hypertrophy, dilatation predominating. Sometimes we have active fever, inflammation, this is represented in hyper- trophy with dilatation, hypertrophy predominating. With- out resolution of fever, of inflammation, at the point of ob- struction we have degeneration. Valvular disease represent- ing this point, is degeneration. The heart and the capillary reflect their condition in disease, upon each other. The heart and its force, being a condensation of capillaries and their forces, it follows, that the mass, the hearten disease, brings into sensible view, or repeats in a sensible form, the condition in disease of its molecular, capillary type. Hope on the heart, p. 298, " The causes of dilatation, are, 1st, deficient power of the heart, whether congenital or acquired in propor- tion to the system; 2d, in general terms, all obstructions to the circulation, whether situated in the orifices of the heart, or in the Aortic, or pulmonary system." Now, if we consider de- ficient power as itself a mechanical obstruction, and which Dr. 11 Hope has well illustrated, by comparing it to weakness in the main-spring of a watch, retarding its movements, we have but one cause, thereby demonstrating unity in the disease.— This is seen in the following extract, same page, " Dilatation of the heart is a purely mechanical effect of over distension.— Blood accumulated in its cavities exerts a pressure from the centre to the circumference in every direction; and when once it surmounts the resistance (counter pressure) offered by the contractile and elastic power of the parietes, these necessa- rily yield and undergo dilatation" Reflect these extracts upon the capillaries, those molecular hearts, and we have the cause, and its mode of operation, in disease. This state exhibits the list of what are called pas- sive diseases. Page 252, " The reader must here again be reminded that the exciting causes of hypertrophy, are equally those of dilatation; and that supposing no unknown agencies to interfere, as may sometimes possibly happen, it depends on the proportion which the cause (pressure) bears to the re-act- ing energy (pressure) of the cavity exposed to this influence, whether that cavity become affected with hypertrophy, dilata- tion, or a combination of the two." Page 244, " In the same way, whether from mechanical obstruction, or any other cause, blood is inordinately accumulated in the heart, the organ is provoked to extraordinary efforts ; it struggles against the ob- stacle ; it frets and labors to overcome it; the corronary arte- ries are excited, to increased activity; augmented nutrition (hypertrophy) ensues." Reflect these extracts upon the capil- laries, and we have the cause, and its mode of operation, of increased action, re-action, hypertrophy, fever or inflamma- tion. This state, co-operating with its antecedent state of prostration, or dilatation, i. e. retrograde pressure of venous blood, exhibits the list of what are called active diseases. It matters not where the obstruction is situated, whether in the heart, arterial, or pulmonary system. Page 251, " Ob- struction in the right auricle, whether from this (obstruction in the lungs operating in a retrograde course, through the right ventricle) or any other cause (as debility) presents an obstacle to the return of the venous blood, and therefore causes retardation throughout the whole venous system; nor is this all; for the retardation is propagated through the capillaries to the arterial system, and thus at length returns in a circle to the heart. In this way may be explained what at first seems an anomaly; namely: that the left cavities are some- times rendered hypertrophous by an obstruction situated be- hind them in the course of the circulation; as for instance, when the left ventricle is rendered hypertrophous by a con- traction of the mitral orifice." Now as it is the retrograde pressure of venous blood propagated through the capillary v> and arterial systems in a circle to the heart, which is the an- tecedent, the fulcrum of the returning pressure of the heart in re-action or hypertrophy upon it; and as this retrograde pressure is brought into operation in dilatation, i. e. prostra- tion, it is seen how the state of prostration produces re-action, fever, or inflammation. It is also here seen that there may be hypertrophy without any of the recognised mechanical ob- structions, as valvular disease, &c.; thus corresponding with the researches of Dr. Glendinning. Page 254, " M. Bertin has the merit of having been the first to display in a clear light, the essential pathology of hypertro- phy. His distinguished talent for generalization, however, has, I believe it will be allowed carried him a degree too far. He contends that authers are wrong in having assigned to hypertrophy as its symptoms, dyspnea, suffocation, violent in- jection of the face and of the venous capillaries in general, passive hemorrhages, and serious infiltration. He contends that these are the signs, not of hypertrophy, but of a co-exis- tent lesion; viz: a contracted orifice, or any other affection capable of obstructing the circulation; and that pure uncom- plicated hypertrophy is characterised by signs of increased energy of the circulation, instead of by dropsy, and the other signs of its retardation. That this is true in reference to the pure uncomplicated form of the disease, before embarrassment of the capillary circulation has taken place, will not be deni- ed by any one who has had opportunities of verifying the symptoms by dissection. But M. Bertin is not in my opin- ion supported either by sound observation or analogy, when he says that serous infiltration and the whole class of symp- toms bespeaking an obstructed circulation, are totally for- eign and repugnant to hypertrophy. The truth, I believe to be, that the very same energy of the circulation which gives rise, as he admits, to active hemorrhages, apoplexy, &c, pro- duces as its next effect, and in the more advanced stages of the disease, engorgement of the arterial capillary system; the necessary consequence of which is, serous infiltration and more or less of all the symptoms indicative of retardation of the blood." It will be seen that Dr. Hope takes the position, that an hypertrophied heart, can, by its own increased force, so engorge the capillaries, as to give rise to all the symptoms of an obstructed circulation. As this is the pivot on which the whole controversy turns, we give the opinions of others upon this point. Hope on the heart, page 19, "Laennec, and his predecessors have assigned to diseases of the heart a certain series of symptoms, which they believed to be common to the whole; but they had not analysed those symptoms, and as- certained which were peculiar to, and pathognomic of, the several affections taken individually. M. M. Bertin and Bou- 13 illaud, both writers of high talent, made this attempt, and with partial success; but the spirit of generalization (if I am correct in my own views) carried them a grade too far.— What observation leads me to regard as an inaccuracy, con- stitutes the very hinge of their work, the pivot on which turns the principal train of their reasoning; namely, that the symp- toms of a retarded circulation are, under all circumstances, THE RESULT OF A MECHANICAL OBSTACLE TO THE COURSE OF THE blood; that when for instance, they accompany hypertrophy or dilatation, they are not consequences of these affections, but of some co-existent mechanical obstacle, as a contracted valve, an aortic aneurism, &c. I have attempted to show, not only that hypertrophy, dilatation and softening can of themselves, respectively occasion the symptoms in question; but that these symptoms are seldom produced in any very remarka- ble degree of severity by a mechanical obstacle, unless hyper- trophy, dilatation, or softening of the heart is superadded." In differing from Dr. Hope on this particular point, it will be seen that I have strong support. My reasons are first, that ac- cording to his own showing, these several affections of the heart are themselves symptoms or phenomena of an obstructed circu- lation, and, therefore, cannot be the cause of the other symp- toms of an obstructed circulation which occur in their history; that the very existence of hypertrophy, is proof positive of an antecedent dilatation, congestion, or obstruction as its ful- crum; that like its type, re-action, it implies this antecedent state; though when existing, these several affections re-act upon their original, giving prominence to those symptoms.— Second, the molecular or capillary circulation is the antece- dent, the base, of the circulation of the mass, the heart. One more quotation in general illustration and confirma- tion, and I have done. Page 255, "It must be admitted, however, that hypertrophy does not produce serous infiltration so readily and promptly as a direct primaiy obstacle to the return of the venous blood; a fact which admits of a rational and obvious explanation. When there is an obstacle to the return of the venous blood, suppose, for instance, contraction of the tricuspid, pulmonic, or mitral orifice, two causes, con- spire to produce the capillary congestion, namely, the direct pressure of the arterial vis-a-tergo, and the retrograde press- ure of the retarded venous blood. But when the latter press- ure does not exist, when the veins freely receive and transmit their natural proportion of blood, the force of the arterial cir- culation must be very greatly increased before it can so far overcome the elasticity of the capillaries as to give rise to en- gorgement and infiltration." | From all that has been said, it appears that these several N affections of the heart, together with all the symptoms, or con- 14 ditions that arise in their history, must take their places among the phenomena of an obstructed circulation, thereby declar- ing, unity in disease. These several affections of the heart illustrate the great gen- eral truth of unity of plan, with diversity of form; they all be- ing produced on the same general plan, yet exhibiting great diversity of form. If all that has been said be true, man is still quite as mys- terious in himself; exhibits quite as much goodness, wisdom and power in his Creator, as before. Nay more; if it be admitted that man's physical frame is constructed upon purely mechanical principles, and govern- ed by mechanical laws, such wonderful mechanism, such ad- mirable adaptation, such evident design, literally requires, de- mands, demonstrates an Infinitely Wise,Good, and Powerful God, as his Creator. If this paper possesses any value, it is only because it is founded upon the best established principles of Medicine. If it be true, it is only because the present state of Medicine, is ready for generalization. We do not pretend to add to the original materials, nor develope new methods of investigation. How far we have been successful in merely generalizing the facts already known into a comprehensive Science, is left to the respectful consideration of an enlightened Profession. <