I1 Hi* W:-- «io nv am i -s ivn o ii v n kiiii 1,'nOiiiN 3 N I 3 I Q 3 I /\/ I ■MlIBRARY OF MEDICINE NATIONAL LIBRARY OF MEDICINE NATION ■!^ ifl miio iivaaii ivnoiivn 3Ni3iaaw jo ahvhbii ivnoiivn inoio f ■ s .* c o"N. - ri IIBIARY OF MEDICINE NATIONAL LIBRARY OF MEDICINE NATION t -" z1^ t *^r , ^w-±®r \ "*-■ $ ^/ ®@a@ » ILLUSTRATED BY •RACTTCAL PROOFS AND EXAMPLES. By SIR GILBERT BLANE, BART. "ELLOW OF THE ROYAL SOCIETIES OF LONDON, EDINBURGH, AND GOTTINGEN; MEMBFR OF THE IMPERIAL ACADEMY OF SCIENCESIQJ^*E!a9HSak^ijlIRGH; AND LIBRARY WITH ADDITIONS AND CORRECTIONS. HARTFORD: HUNTINGTON AND HOPKINS. 1822. DISTRICT OF CONNECTICUT, s». BE IT REMEMBERED, That on the eleventh seal, day of May, in the forty sixth year of the Inde- pendence of the United States of America, Huntington & Hopkins of the said District, have deposi- ted in this Office the title of a Book, the right whereof they claim as Proprietors in the words following—to wit:." Ele- " ments of Medical Logic, illustrated by practical proofs " and examples, by Sir Gilbert Blane, Bart, fellow of the "royal societies of London, Edinburgh, and Gottingen; " member of the imperial academy of sciences of St. Pe- tersburg; and physician to the King. The first Ameri- " can from the second London edition. With additions " and corrections" In conformity to the Act of the Con- gress of the UNITED STATES, entitled "An Act for the encouragement of learning, by securing the copies of Maps, Charts, and Books, to the Authors and Proprietors of such copies, during the times therein mentioned." CHAS. A. INGERSOLL, Clerk of the District of Connecticut. A true copy of Record, examined and sealed by me, CHAS. A. INGERSOLL, Clerk of the Districtof Connecticut. Goods ell & Wells,—Printers, Hartford. 24898 i Sire, e | Suffer me to lay at your Majesty's feet I the fruits of more than fifty year's medita- i tion and experience, the greater part of which has been employed in the service of the State, and in that of your Majesty's Person and Family. In the exercise of my professional Du- ties, it has fallen to my lot to be present in some of the most brilliant and impor- tant events which grace the British An- nals ; and if my humble labours have in the least contributed to the welfare of any 4 DEDICATION. class of your Majesty's subjects, or of the world in general, they have met with more than their due meed in the counte- nance and approbation of your Majesty, under whose auspices, the civilized world has been rescued from degradation and ruin ; and the British Empire raised to an unexampled height of Grandeur and Renown. Deign, Sire, to accept this tribute of the homage and attachment of Your Majesty's most faithful, most devoted, and dutiful Subject and Servant, GILBERT BLANE. London, 16th June, 1821. ABTlBTOMIimiOT* The reception of the first edition of this Work, which appeared in the year 1819, having exceeded whatever the Author's most sanguine expectations could antici- pate, he has felt himself bound by gratitude, as well as duty, to use his best endeavours to render the Impres* sion now called for, more worthy of the acceptance of his too partial and indulgent readers. He has there- fore bestowed considerable time and thought in correc- tions and additions, particularly in what is important— the practical applications and inferences. He has, however, greatly abridged that part which relates to the question, regarding the contagious nature of the Yellow Fever, or more properly, that species of it in which a morbid poison generated by the living human body, is superadded to the other causes, and therefore called the Typhus Icterodes, to which, on account of its vital im- 6 ADVERTISEMENT. portance, he had allotted a larger space than was due to it as a mere illustration. But having learnt that the fatal delusion regarding it, had been so far done away, parti- cularly in the sea-ports of Europe and America, as to have led to a general system of preventive regulations, which had been attended with the most salutary effects, he does not now deem it necessary to enter so largely and anxiously into this subject. ADVERTISEMENT TO THE AMERICAN EDITION. Several pages were annexed to the last London edition of this work, designating errors and embracing additions. In this edition, the former have been cor- rected—the latter incorporated with the work, and the index somewhat enlarged.—This volume, the favourite production of the " most learned and classical phy- sician of the age," has no ordinary claims to the atten- tion of the Medical reader. CONTENTS, Page. Introduction, 7 SECTION I. Preliminary Observations, 25 Enumeration of the Elementary Principles of Life, 41 1. The Generative, 43 2. The Conservative, 47 3. The Temperative, 53 4. The Assimilative, 69 5. The Formative, ... 84 6. The Restorative, 96 7. The Motive, 110 8. The Sensitive, 136 9. The Appetitive, 140 10. The Sympathetic, 142 SECTION II. The general Principles of Truth and Error, in the Cultivation of Medicine, 151 Enumeration of the Sources of Error, 156 SECTION III. 1st Source of Error—the Fallacy and Danger of Hypothetical and Theoretical reasoning, 159 Examples and Illustrations from the Works of Aristotle, Bacon, Hippocrates, Galen, Sy- denham, Boerhaave, and Pitcairn, 160 o CONTENTS. Bge Misapplication of Natural Philosophy, - 166 Fallacy of the Humoral Pathology, - - 174 The Utility of Anatomy and Physiology, ques- tioned and vindicated, - - - 180 Dogmatism and Empiricism compared, - 193 SECTION IV. 2d Source of Error—the Diversity of Constitu- tions, - - - 201 SECTION V. 3d Source of Error—the Difficulty of apprecia- ting the salutary Efforts of Nature, and of discriminating them from the Operations of Art, - - 221 SECTION VI. 4th Source of Error—Superstition, - 235 SECTION VII. 5th Source of Error—the ambiguity of Language, 243 Examples of its pernicious Effects in Sea- scurvy, - 244 ———— in Yellow Fever, - 246 --------in Dropsy, - - 267 SECTION VIII. 6th Source of Error—the Fallacy of Testimony, 271 CONCLUSION. Some Remarks on pre-conceived Opinions, and the excessive Deference to Authority and Fash- ion, - - - 291 ELEMENTS OP MEDICAL LOGIC, &c. INTRODUCTION. As medicine has for its object the preservation and restoration of health, it comes under the de- finition of an Art, a term, the import of which consists in the adaptation of means to ends. These means must be derived from the previ- ous knowledge of the changes producible by them, whether as corporeal agents constituting physical causes, or as affections of the mind con- stituting moral causes. The most precise criterion that can be fixed upon for distinguishing rational beings from 10 ELEMENTS OF brutes, is the faculty of adapting means to ends ; and there is perhaps no attribute purely intellec- tual, to which the term reason is so appropriate- ly applicable. It is the first line of distinction between man and the inferior animals : it is this which characterizes his intellectual nature, as that moral agency which renders him an account- able being, characterizes his moral nature, both together forming that insuperable line of demar- cation which separates him from the brute crea- tion. To contemplate an end, and to devise the means of attaining it, in other words, Art or De- sign, is a faculty which does not belong to mere animals, but to a more pre-eminent being, sanc- lius his animal et mentis capacius altos. Lan- guage has very commonly been assigned as the distinctive faculty of rational nature ; but it re- quires little reflection to perceive, that, under this definition of art, language itself is an art, for it consists in the contrivance and employment of the means, articulate sounds, for accomplishing the end, the interchange of thought between one intellectual being and another ; and the logical MEDICAL LOGIC. 11 process of thought, by which children first catch the import of words, is an example of the same sort of induction, by which cause and effect are ascertained. The same principle explains the improvable capacities of man as .contrasted with brute animals. It follows from this, that as it is physical influ- ences with which we have chiefly to do in medi- cine, the main and ultimate object in cultivating this art, must consist in ascertaining the agency of external objects, whether salutary or noxious, on the living body, and in applying or avoiding them so as to obtain the desired result, either of preventing the occurrence of disease, or in con- verting the state of disease into that of health. It is in the extent and correctness of our knowl- edge of these agencies, that the perfection of the art of physic must consist. This knowledge has to some persons of a scep- tical turn of mind, appeared so unattainable, as not to be worth prosecuting, insomuch that they have raised the previous question, an datur ars 12 ELEMENTS Of ?nedicinf males. Hufeland, a German Physician and Naturalist, has been at great pains to collect the relative numbers of the two sexes in all parts of the world, and has found them every where the same.t It seems still more singular, and at the same time most admira- * See D. I. F. Blumenbach, Abhandlung uber die Nut- ritionskraft. St. Petersburgh, 1780; and de Nisu For- mativo Gottingen, 1787. jSee Journal des Pratische Heilkunst, January 1,1820, Berlin. The proportion is that of 21 males to 20 females. MEDICAL LOGIC. 45 ble in the institutions of nature, that this rela- tive number of the sexes should be maintained, though the primordial germs are mixed in differ- ent proportions in the ovaria of different females; for it is well known that many females produce such a number of children in succession of the same sex, as is utterly irreconciliablc with the laws of blind chance, another word for mathe- matical necessity.* What commands attention in this is, that, nothwithstanding, this inequality and irregularity in the procreative function of * This might be more familiarly illustrated by stating, that the succession of the births of the two sexes, does not follow the rule which takes place in drawing a lottery. When, for instance, an equal number of black and white balls are shaken together in the same bag or box, it would be contrary to the laws of chance (for chance is subject to mathematical laws) that six, eight, or ten, or more of the same colour, can be drawn successively, as we not unfre- quently witness with regard to children of the same sex in particular families.—The final cause of the small plu- rality of males seem to be, that more male children are still born or die in infancy than females, so that at the age if 11, both sexen are equal. 46 ELEMENTS OF individuals, the relative number of the sexes is maintained with the greatest and most universal exactness with regard to the whole species. Not only the great curiosity, but deep impor- tance of this fact, seems hitherto to have escaped the notice of physiologists, philosophers, and theologians. Does it not prove that the arrange- ments of nature are utterly irreconcileable with atheism, either absolute, or that form of it called naturalism ? for it must be obvious to every re- fleeting person, that what has been just stated, cannot be accounted for without admitting the existence of design, an attribute which can only be predicated of that conscious intelligence which constitutes mind. Innumerable questions in this and every other department of nature might be raised equally unsolvable on any other principle,* equally impenetrable to finite under * See a remark illustrative of the same principle in the Edinburgh Review of 1807, Vol. XI. in the article Mec- anique Celeste, well known to have been written by that accomplished mathematician, philosopher, scholar, and gentleman, the kte Professor Playfair, of Edinburgh. medical logic 47 standings, equally commanding our admiration and devotion, being equally demonstrative of the existence of a supreme contriver. The morbid deviations of the generative en- ergy, consisting in mal-conformations, monstros- ities, extra-uterine, and abdominal* foetations, can hardly be regarded as objects of practice ; and it need merely be remarked that the health, happiness, and virtue of the parent, and the perfection of the offspring, can only be main- tained by the temperate exercise of it. 2. The Conservative Principle.—By this is meant that power by which the living body is prevented from running into putrefaction. Ac- cording to the experiments of Dr. Alexander,! the range of temperature most favourable to the putrefaction of dead animal matter, being be- tween 86° and 100° Fahrenheit, includes the * See Med. Chirug. Tr. Vol. viii. Article 8. t See Experimental Enquiry on the Causes of putrid Diseases, London, 1771. ** 4tf SLEMENTS OF usual standard of human heat. There must therefore be some powerful energy in life itself, which counteracts this tendency to spontaneous decomposition. It was alleged by Dr. Alexan- der, and some of the other physiologists of that day, that putrefaction is averted by constant mo- tion of the fluids and solids during life, together with perpetual removal of effete matter, and the fresh supplies from food. These are evidently quite inadequate to account for this striking phenomenon: and that there is an antiseptic power in life independent of motion, and of the change of matter is proved, by the same princi- pie of self-preservation being found in the qui- escent state ; for instance, in impregnated eggs and torpid animals. This subject was first set in that clear and interesting view which is due to it, by Mr. John Hunter. (See Observations on certain Parts of the animal Economy, Lond. 1786; also Treatise on the Blood, 1794.) These works are rare and valuable specimens of true inductive research ; and for logical pre- cision and vigorous originality of mind have medical logic. 49 never been surpassed, nor perhaps equalled, in the history of physiology; and it is not easy to be accounted for, that in the present times, nei- ther the import of his doctrines is clearly under- stood, nor their importance duly appreciated. We meet with works on physiology, some of them even professing to be complete systems, in which the fundamental law of life is not once adverted to ! It pervades also the living organ- ic bodies of a lower order, as is manifest in ve- getable substances, which though not endowed with the same degree of heat as animals, are yet in such a state of succulence, as would lead to immediate destruction, unless they were sus- tained by this principle. This conservative principle was considered by Mr. Hunter as so important an element in the existence of all or- ganized beings, that he deemed it the most es- sential constituent of what he called emphati- cally, the Living Principle. This principle main- tains a constant and arduous struggle against the sceptic tendency incident to the matter in which it is inherent, and it is more or less equal to this 5 50 ELEMENTS OF struggle, according to the constitution of indi- viduals, and the operation of morbid causes. The circumstances in which it shews itself in a state too low to maintain life, are in those lo- cal affections in which gangrene takes place, and in those affections of the system in which the whole constitution sinks under them, as in acute disorders, generally produced by a morbid poi- son, such as small pox, typhus fever, and plague., The propriety of calling these disorders putrid has been questioned, because they do not produce actual putridity before death. This is certainly true, for actual putridity is incompatible with life ; but the rapidity with which the dead bodies 'I of those who perish by those disorders rush into putrefaction, is so much greater than that of those in whom life had been extinguished by other diseases, or by external injury, that there can be no doubt, that the conservative principle had been maintaining, before death, an unequal combat with the principle of spontaneous de- composition. The flaccidity of the muscular MEDICAL LOGIC. 51 fibres, and the fluidity of the blood after deathj are also indications of impaired or lost vigour in this principle; and these circumstances are ob- servable in the bodies of those who die of cer- tain diseases, or of certain poisons ; also in cer- tain forms of violent death, as from lightning; and in all such cases putrefaction is observed to come earlier than where no such circumstances have taken place. This principle is very strong in the blood, for if the flow of it into any mem- ber is obstructed, gangrene ensues. As there is a comparative deficiency of this conservative energy in some constitutions, so there is an exuberance of it in others. The proofs of this consist in the resistance which some individuals oppose to the causes of gan- grene and putrid fevers, either by maintaining an exemption from them, or by restoring them- selves more readily than others, when under their action. The superior prevalence of this principle is probably also one of the main causes of the longevity of some individuals. 52 ELEMENTS OF The difference in the vigour and duration of this principle in different individuals, depends most essentially on the primordial stamina, but somewhat also on the habits of life. The spon- taneous local gangrenes in extreme old age, par- ticularly in the lower extremities, is an indication of a decay of this principle from time alone. And we may here take occasion to remark, that the various forms in which dissolution approach- es, are owing to the relative vigour of the differ- ent principles on which life depends. In a sub- ject, for instance, in whom there is an incurable disorganization of the lungs, or any other vital part, the struggle will be longer or shorter, ac- cording to the power of this conservative prin- ciple : or of the digestive, which maintains life against the decayed state of the vital organs; and the cause of one individual suffering longer, or more intensely, than another in the extremity of life, is owing to one constituent of life being more vivacious than another, which preVents, as it were, the springs and wheels of life from run- ning down in concert, so that easy death or en- MEDICAL LOGIC 53 thanasia consists in the simultaneous extinction of these energies. 3. The Temperative Principle.-—By this is meant that steady degree of heat with which all animals are endowed, and which, in the mamma- lia and birds is higher than that of the atmos- phere in any climate or season in the ordinary course of nature. It is extremely uniform in the same species, and in man it is found at 98° of Fahrenheit, with less deviation in different indi- viduals, than in most other points of the animal economy. There is a considerable latitude in the variety of the stature, features, and form of individual men, and in the natural frequency of their pulse and though there is a great variety in individuals with regard to their sensibility to heat and cold, there is hardly any in the healthy standard of their temperature. This seems a presumption of its being an essential constituent of life, and combined with the conservative en- ergy, may be deemed the main basis, or stamina of simple vital existence. 54 ELEMENTS OF The standard of heat is very different in differ- ent species of animals. In the amphibia and fish- es, it is very little above that of the surrounding' medium. But the resistance which these animals give both to heat and cold, by maintaining the^ specific temperature, in spite of the application of higher or lower degrees of it, contrary to the law of communication in inanimate bodies, is a proof that temperature is both raised and depres-1 sed by some power essentially inherent in life. ' This is most observable in birds ; for in those even of the smallest size the natural heat is ten or twelve degrees above the human. When it is considered how immeasurably greater the ab- stracting power of the atmosphere is in these small bodies, in consequence of the ratio of their . surface being as the square of their mass, it is utterly impossible to account for this on chemi- cal principles, and must depend on a specific gen- erating power, furnished in various degrees to the respective species of animals; and it must i be astonishingly great in small animals, to enable 1 them to resist the strong power of abstraction medical logic 55 in the external medium. This argument is ren- dered still more strong by what is found to take place with regard to some insects. Let the bulb of a thermometer be thrust into a swarm of bees, the heat indicated will be 97° or 98°, that is as high as that of the living human body. The chief facts in favour of the chemical ori- gin of animal heat, are those in proof of the ne- cessity of the application of oxygen, by means of respiration. This is extremely plausible, when it is considered that the specific temperature of different orders of animals, holds a striking pro- portion to their intercourse with the atmosphere, as is obvious in the gradations of mammalia, am- phibia, and fishes.* But on the other hand, a de- gree of heat above the external medium remains in torpid animals during their hybernation, though they do not breathe. It is a fact incontroverti- bly attested by Portal and other writers, that af- * The arterial blood was also found to be warmer than the venous, by Dr. Davy. 56 elements of ter death from apoplexy, the temperature of the body is maintained, even above the natural stan- dard, to a period beyond that in which it would be totally abstracted from the like mass of inani- mate matter. Dr. Badenoch, in a work on the diseases of India, ascertained by repeated and ac- curate experiments, that the heat of those who die by a coup de soleil, or insolation, continue* for a considerable time, several degrees higher than the natural standard. In one case, twenty: hours after death, the heat felt to his hand as if it had been five or six degrees higher than in life and health. If the heat of the body depended on respiration alone, any one might by a volunta- ry effort of quick, deep, and prolonged respira- tion, increase the temperature of his body at„ will. I myself, as well as others, have tri-* ed this without effect. However, therefore, the introduction of oxygen may be the occasional means of exciting or supplying heat, it cannot possibly be the exclusive and constituent cause j in all cases. medical logtc 57 That principle by which the powers of life re- sist both heat and cold, was proved in the most satisfactory manner, first by the experiments of Dr. Cullen,* and then of Mr. John Hunter,! but most strikingly with regard to heat, by the ingen- ious and elaborate experiment planned by Dr. George Fordyce, and the account of it which was drawn up by Dr. Blagden.J It was found that the living human body maintained its natu- ral heat, under the influence of an external heat, raised to a degree between 211° and 212° of Fahrenheit's thermometer. But without recur- ring to these and other similar experiments, it is obvious on the least reflection, that a uniform * The scientific world is much in3ebted to Dr. Cullen for some of the most important doctrines on the subject of heat. His experiments on the cooling power of evapora- tion, published in the Physical and Literary Essays of Edinburgh, 1755, is ingenious and original; and he was the first who suggested and illustrated the power of the liv- ing principle in producing heat and cold. See an Inaugu- ral Dissertation of his Son, A. Cullen, de Frigore, 1780. t See Phil. Trans. 1768. * Phil. Trans. 1775. 58 elements op temperature of the body, such as actually takes place in nature, could not be maintained under the ordinary vicissitudes of the atmosphere, with- out this regulating principle. The effect of the. emotions of the mind also, in generating both heat and cold, is proof sufficient of temperature depending on a vital and not on a chemical cause, such as mixture, fermentation ; or a mechanical one, such as attrition. The affections of the nervous system do with- out doubt influence temperature,* both by excii^ ting and depressing it. But it does not follow that these affections, any more than oxygen, con- stitute this power ; for heat is known to exist, independently of its propagation by external, bodies, not only in cases where there is neither consciousness nor sensation, but where there is no nervous system, and even where there is no * See experiments of Mr. Brodie, Phil. Trans. 1811; and Mr. Earl, in the Medico-Chirurgical Transactions, j Vol. viii. 4 medical logic 59 organization, as in the fluids. Dr. Wilson Phil- lip* has proved also that galvanism excites heat, not only in the living solids, but in fresh drawn blood ; but it is to be regarded like the nervous system and oxygen, as an exciting, not a con- stituent cause. Farther, Mr. Hunter has clear- ly demonstrated that there is in living vegetables a power of generating heat. It is by this power that their juices maintain their fluidity in frost; and when through the intensity of cold they are killed, they then freeze, and by their expansion split the tree with a loud noise. There is a cu- rious proof of the increase of temperature by vegetation, in the American Philosophical Regis- ter for 1814. It is there recorded by Dr. Brown, 3f Lexington, that the roots of wheat having shot ft nto ice, thawed it. Is not the heat found to take )lace in the operation of malting, generated by "he powerful germination which goes on ? f Oil The experiments of Dr. Crawford, in proof of to he chemical origin of animal heat, are generally * See his Enquiry, p. 243, London, 1820. 60 ELEMENTS OF admitted to have been of so delicate and fallible a nature, as not to afford any solid ground for de- cidingthis question ; not to mention the assump- tion of the exploded principle of phlogiston which enters into his reasonings. The basis of this the- ory consists in the supposed extrication of sensi- ble heat from oxygen, which possessing an extra- ordinary capacity for heat, parts with a large por- tion of it upon entering into combination with other bodies. Though some heat may be pro- duced in this way, it is quite inadequate to ac- count for the quantity necessary for steadily maintaining, and equally distributing it through the body, which is chiefly done by the action ofl the vascular system ; and it will still less ac- count for that power, by which both heat and cold are resisted. Though oxygen may contri- bute somewhat to the generation of heat, fo chief action is that of serving as a stimulus to the living power in generating it ; for it plays an in- teresting and active part as an exciting power throughout all nature, both animate and inani- mate, being a main constituent in water and at- MEDICAL LOGIC. 61 mospheric air, and indispensible to combustion; and no animal can exist without more or less of its influence, either by respiration or otherwise. Moreover, one of the main purposes of respira- tion evidently is to invigorate and refresh the vi- tal powers, merely by checking the generating power of heat, as the most familiar experience evinces, and when the air is not sufficiently coo) to produce this effect, the utmost distress arises from the accumulation of heat. The author has deemed it necessary to enter into these details, in order to justify himself in inserting the temperative energy in the list of powers peculiar to life, essentially and fundamen- tally inherent in every form and degree of life, whether animal or vegetable, solid or fluid- As the heat of the human body is above that of the atmosphere in almost every season and climate in the world, the generating power, in order to maintain this pitch, must be in perpet- ual requisition, and must be excitable in various 62 ELEMENTS OF degrees, in order to supply the consumption of what is carried off by the fluctuating temperature of the external air, and must also accommodate itself to what is retained in unequal degrees by the unequal quantity and quality of clothing. The requisite exertions of this animal energy, be- comes therefore a main element of health and disease, of pleasure and pain. Should the tern- perature of the atmosphere be far below that of j the body (98° Fahr.) the disagreeable sensation of cold is excited. When it is carried to such an extreme as to master the resisting power of the generating principle, it extinguishes this vital action, and either destroys life, or produces local gangrene. It is a fact well ascertained that at very low degrees, that is below zero, cold is not proportionabiy distressing to the sensations: a happy circumstance, and encouragement to those who navigate the arctic seas. On the oth- er hand, should the heat of the atmosphere rise so as to approach the heat of the body, it be- comes disagreeable, and still more so should it equal or exceed it; there must therefore be MEDICAL LOGIC 63 some point at which the temperature is most agreeable and salutary ; and this is found to be about 62° in the human constitution. These views of the subject, which have hith- erto been little attended to by physiologists and pathologists, seem to explain some important points regarding the effects of atmospheric tem- perature on the human body. For is it not evi- dent, that it is the sudden check which this gene- rating power of heat meets with in the bodies of those who pass suddenly from a cold or tempe- rate to a tropical climate, that produces lan- guor, debility, and various diseases to which the natives, who are habituated to it, are strangers ? The application of external heat in an undue degree, therefore, lowers the powers of life. As heat is a powerful stimulant, the contrary effect might be expected; and the actual effects can only be accounted for by conceiving the genera- ting power to be repressed, and thereby con- strained in its exertions; and the invigorating effects of cold within certain limits is, in like IJ4 ELEMENTS OF^ manner, accounted for by this power being al- lowed to put forth a stronger exertion, the ex- cess, defect, and salutary medium depend on the state of actual excitement; a view of the subject which seems conformable to the system of Brown; and according to the same system, what is called direct debility, consists in the want of actual excitement, the excitability remaining un- impaired, and morbidly accumulating. The desirable medium has been stated to be near 62°, at which limit the vigor and alacrity of mind and body may be said to be at their maximum.* This being a fundamental and highly impor- tant principle in the economy of life, the devia- tion from it must naturally constitute some of the chief elements of disease ; and as the powers of art have considerable control over tempera- ture, some of the principal resources of medi- cine will consist in the management of it. It is * I am the more anxious so be explicit on this point, for being a new idea, it has been misconceived in'the foreign Translations of the first edition. MEDICAL LOGIC. 65 manifest that this salutary and grateful warmth consists in such a temperature as excites the gen- erating power in maintaining its genial standard, and that the exertion of this power is in such cir- cumstances invigorating and refreshing; but when the external heat is such as to repress this degree of exertion, it becomes oppressive and debilitating. The morbid excess in the generating power of heat is chiefly exemplified in the system, by this being one of the most prominent characters of fever, and from which the name of fever is de- rived in all languages ; and in local affections, by the cognate term inflammation. The highest degree to which the heat rises in fever is 110° or 112°. It has been alleged that morbid tem- perature can be carried even to combustion. Narratives of such cases occur not unfrequently in the annals of medicine, and Plouquet* enu- * See his Literatura Medica, Article Combustion Tu- bingen. 1808. 6* 66 ELEMENTS OF merates twenty-eight of them. The greater^ number, if not the whole of these cases, have been aged females addicted to intoxication by means of spirituous liquors. I believe none of them have been witnessed in the act of combus- tion, so that doubts still remain whether they have not been caused by accident. It is by rules founded on this principle, that the regulation of heat and cold, as remedies, is to be studied. Dr. Currie observes justly, that a high degree of morbid heat cannot fail to aggra- vate the disorder in which it exists, by its nox- ious stimulus, and that it ought to be abstracted by the application of cold water to the surface. In following out this, however, a nice exercise of judgment in the selection of cases, and in the mode of administration, is required; for when the powers of life are strong, as in the case of ac- tive inflammation, whether general or local, the application of cold may excite to excess the gen- erating power of heat by reaction ; and when they are languid, it may produce sueh a chill as MEDICAL LOGIC 67 to extinguish arterial action, or cause a determi- nation on some vital part.* The excitability of Dr. John Brown, if the author understands it rightly, seems nearly the same as our principle of simple life, being expressive of the combined result of the conservative and temperative energies. The doctrines of this author ted to such destructive practice, that they are now generally and deservedly exploded. The argument of a reductio ab adsurdum, may be legitimately employed in physical, as well as mathematical, reasoning; so that whenever a doctrine terminates in a conclusion, which is false in fact, we may rest assured, that it is itself false; and, as it is certainly false in fact, that * This is well expressed by Cicero in one of his rhetori- cal similes. " Ut s«pe homines aegri morbo gravi cum sestu febrique jactantur, si aquam frigidam biberint primo relivari videntur, deinde multo gravius vehementiusque afiectantur." Orat. I. in Catil. This may be received as a proof of the professional opinion of the ancients on this .nbject. 68 ELEMENTS OF- depletory remedies are, almost in every case, that is, ninety-seven cases in one hundred, ac- cording to Brown's own calculation, pernicious; and that stimulating remedies are, almost in ev- ery case, salutary, insomuch that it has been proposed by some of the partisans of this sys- tem to destroy lancets, and throw away all purg- ative remedies, no further refutation need be sought for. The errors of this ingenious person, seem to have consisted in his having erected his system on the narrow foundation of only one or two of the principles of the animal economy, and in pushing that principle to an extreme. Had he referred a larger class of disease to over-ex- citement, which his system seems to admit of, his doctrines would have been more tenable, and would probably have lived longer. It is doubtful, however, whether they would have spread so far, and been so enthusiastically em- braced ; for something strikingly new, and even absurd, seems indispensible for giving a popular prevalence to medical, as well as religious sects. There seems, nevertheless, to be in the doctrines MEDICAL LOGIC. 69 of Brown, as far as their narrow principle will admit, and when received under a fair and tem- perate interpretation of their import and merits, some suggestions not undeserving the attention and imitation of a sober and candid practitioner. 4th. The Assimilative Principle. This pow- er consists in processes peculiar to life, effecting certain combinations and decompositions, also peculiar to life, and manifesting itself in those operations which are carried on in digestion, san- guification, and secretion, as subsidiary to the growth and repair of the individual, and the per- petuation of the species. When we consider the nature of the changes produced on the ali- ment in the living stomach and duodenum,* and the shortness of time in which it is effected there will appear sufficient proof, even in this * I have said duodenum, in consequence of some well deduced remarks on the function of this organ by Dr. Yeats, in an article in the 6th vol. of the Transactions of the College of Physicians. London 1820. 70 ELEMENTS OF stage of assimilation, that there are agents at work, totally different from those of inanimate matter.* The familiar fact of the shortness of time in which the aliment becomes acid in de- praved digestion, is also expressive of the sin- gular powers of animal chemistry, a change be- ing produced in an hour or less, which, out of the body, could not be produced in several days. But this difference becomes still more striking, when we contemplate the ultimate results of these processes, and that by virtue of the living" powers, the aliment, whether vegetable, animal, or mixed, is converted into matter of the same chemical character, as existing in the flesh and bones of every animal indiscriminately. The flesh and bones, for instance, of an ox, an ani- mal subsisting on pure vegetable food ; a lion, an animal subsisting on pure animal food ; and a hog, an animal subsisting on mixt food, though differing in some of their sensible qualities, are * See Examination of Chyme, by Dr. Marcet, Medico- Chirurgical Transactions, Vol. IV. p. 626. MEDICAL LOGIC. 71 identical, considered as chemical compounds, and exhibit changes totally different from, and utterly* inimitable by any chemical processes, of which dead matter is susceptible. It is one of the curious and inexplicable questions on this subject, how it comes about that azote enters as much into the composition of the flesh of grami- nivorous and herbivorous animal, in whose food no azote is found, as it does into the flesh of carnivorous animals, in which this principle abounds. As there is none in the food of the former, and as it appears by the very accurate experiments of Mr. Allen and Mr. Pepys, that none is absorbed from the respired air, nay that more is expired, than what is inspired, it would appear that it is elaborated in the assimilating processes of life ; the like may be said of the carbonic acid, with which the breath is so much impregnated. The new, important, and very- interesting discovery of the application of vol- taic electricity for effecting chemical changes, apparently bears some analogy to animal pro- 72 KLEMENTS OF cesses.* The changes accomplished by the actions of life, may be conceived to be effected through the agency of some imponderable fluid; such as electricity, light, or magnetism. We can conceive, for instance, that each gland may be furnished with a sort of voltaic apparatus,! for effecting its specific change. That the accu- mulation and presence of such fluids are not for- eign to the animal functions, may be illustrate^. by the electrical battery of the torpedo an4 ' The idea of the identity, or rather analogy, of the pro- cesses of the voltaic battery, with the processes of animal assimilation, was first broached in 1806, by Berzelius, in his Animal Chemistry; in 1808, by Professor Brandis, of Kiel, in Holstein, in a work, entitled Pathologie oder Lehre von den Affecten des lebendigen Organismus. (See Hufeland's Bibliotek der practischen Heilkunde, 1809, Book I. p. 38, et seq.); and the next year, by Dr. Wollas- ton, in an article in Tilloch's Magazine. See also a paper in the Philosophical Transactions, by Sir E. Home, with experiments by Sir Humphrey Davy and Mr. W. T. Brande. t See this illustrated farther in Dr. Young's Medical Literature, p. 110, Lond. 1813. MEDICAL LOGIC. 73 electrical eel, the flashes of light from the eyes of some animals of the feline genus, and from the glow-worm and fire-fly. Some physiologists* seem disposed to refer the assimilating process entirely to nervous power; but the like assimila- tions take place in animals without nerves, and in vegetables ; and the nerves, though they may by lateral influence act as stimulants, vehicles, modifiers, or even disturbers of action, are not to be regarded as the organs, in which the ini- tial action originates. Nervous action is found in some instances even to retard and disturb the assimilating process ; for it is matter of observa- tion, that in many cases of hemiplegia, where the nervous power is withdrawn or impaired, digestion goes on better than in ordinary health. This is further illustrated by an ingenious and conclusive experiment described in the Quar- * See Experiments by Mr. Brodie, Philosophical Trans- actions, 1814; and Enquiry into the Laws of Life, by Dr. Wilson Philip, London, 1818. ?4 ELEMENTS OP terly Journal,* where, though the nerve, of the stomach were divided, digestion and all the pro- cesses of cbylification went on as before. The main source of physiological controver- S1es, particularly in what regards the nervous system, seems to be the want of discriminating j the actuating from the influential, lateral, tervening agencies of the several organs. The author's meaning will be best illustrated, by an example borrowed from mechanism. In all complicated machines, the purpose or ultimate result, is effected by a number of springs, wheels,* &c. accelerating, retarding, or giving new di- rection to the main action, but every one of them indispensible, or sine qua non to the pro- duction of the proposed effect, which is the di- agonal as it were of these compound forces. Thus by means of the balance-wheel and spring of a watch, the power of the main spring can not only be arrested, but the motion of the * See Quarterly Journal of Science an,\ the Arts, So- 13, page 165. MEDICAL LOGIC 75 whole machine can be accelerated or retarded at pleasure. Here the main spring is the actu- ating power, the balance-spring the influential a^ent, which though it modifies, it contributes nothing to the power which puts the whole in motion. In like manner, the efficient, or prima- ry power, in the process of digestion, is inherent in the stomach : but this process may be promo- ted, impeded, or variously controled and modi- fied, by the influential power of the nervous sys- tem. - As a farther proof that the nervous power is not indispensable to the creation of cither the fluids or solids of organic being, we may adduce not only the fact of the placenta, and the curious case of the monster without brain and nerves, described by Dr. John Clarke,* but that, as above stated, whole classes of animals are with- out these organs, not to mention the whole ve- getable kingdom, in which the formation of solids * See Philosophical Transactions, 1799. 76 ELEMENTS OF and fluids is equally an act of vital energy as in animals. The like reasoning will apply to the expert- ments and arguments of those, who wish to prove that galvanic is identical with the nervous pow- er. And besides, when we reflect that in the changes brought about by voltaic electricity in inanimate matter, there is a limited number ofl the combinations of pre-existing principle*™ whereas those of living organic bodies, present t countless varieties of newly created qualities in the solids and fluids of every species of animal) and vegetable beings; it must be confessed, that, though these newly discovered processes assist our conceptions and abstract our imaginations a from the gross ideas of the humoral pathology^ for it is deducible from what has been said, that all the modifications of animal and vegetables, matter must originate in the solids,) they are quite inadequate to account for the transmutsj tions taking place in living organic bodies, and that a gulf is still left between the actions of 24!?98 MEDICAL LOGIC. 77 living and dead matter, which will probably nev- er be passed. In the sense which I have affixed to the term assimilation, it is applicable only to matter in a fluid form, whether the product of digestion, chylification, sanguification, or secretion. When these portions of matter pass into a solid form, there is, strictly speaking, an assimilative pro- cess ; but as new properties of matter take place by virtue of a distinct operation of life, I have distinguished this by the name of formative. But in none of the stages of this series of change, is there the least resemblance to any of the changes which are produced on inanimate mat- ter by chemical action. They are all brought about by the action or contact of solid organs,* * One of tb.3 most conclusive proofs of the power of the mere contact of a surface is, that the gizzard of a fowl which is lined with a horny, unsecreting surface, does, nev- ertheless, pio.luce a sensible change on the quality of the contained food ; and that when there are secretions, such as the gastric juice, they produce no change resembling 7 * 78 ELEMENTS OF in the form of glands, or follicles, or of mem- branous surfaces, indued with the power of ani- malising the alimentary matter, and giving it those in innumerable properties required for the growth and repair of the body. It is of the highest moment in physiology and pathology, that correct notions on this subject should be entertained ; for there has not been t more abundant source of errors, whether theo*;, ^retical or practical, than that of conceiving that the various changes above enumerated, are ei- ther identical with, or allied to, the chemical{ changes belonging to inanimate matter. We ought constantly to bear in mind, that all effects produced on the living body, whether in its solid or fluid parts, are referable to principles pecul- iar to life, and that most if not all the means proposed for controlling their actions, or alter- digestion when mixt with food out of the stomach. See Experiments by Englefield Smith, M. D. European Mag- azine, June 1797. MEDICAL LOGIC. 79 ing their qualities, must be addressed to the prop- erties of vital, and not of inanimate matter. It ought also to be constantly borne in mind, that the fluids of living animals are endowed with life as well as the solids. One of the most obvious and plausible objections made to this doctrine, when first broached by Mr. Hunter, was, that the attributes of life could only belong to organic structure, which implies that degree of cohesion in which solidity consists. To ob- viate this objection, it is necessary to define in what sense this life of the blood and other fluids is to be understood. And here we find the ad- vantage of having made an enumeration of those elements in which life consists. Some of these elementary properties are as congenial with the nature of fluids, as of solids. Such are the conservative and temperative ; and it is in 4he possession of these that the life of the fluids of living animals is made to consist. There are other elements of life, such as the Generative, the Formative, and others, which are incompat- ible with fluidity, inasmuch as they imply the 80 ELEMENTS OF action of organs; and organic structure can be- long only to solid parts. But the resistance to putrefaction, the resistance also to external heat and cold, are as conceivable qualities in fluids ever so quiescent, as in the solids. The fact of blood passing spontaneously into the form of vascular texture, was also employed by Mr. Hunter as one of his proofs of its life. And it is rather surprising, that a fact so obvious and. , striking as the seminal liquor acquiring organi- zation, should have escaped him as a proof of the same principle. But as fluids are incapable of assuming an or- ganized structure, while they retain that form,;! and therefore incapable either of initiating or giving direction to motion, all the initial actionsj of life, as well as its ulterior processes, must be referred to the solids ; and it follows, that the virtues of medicine should be directed to thoseil attributes that belong to solids; that is, excitabil-| ity, sensibility, and contractibility. MEDICAL LOGIC. 81 It has been questioned whether there are any medicines whatever which operate on principles purely chemical. The destruction of a morbid ;icid in the stomach by means of an absorbent, is unquestionably a chemical action ; but in those recesses not within the immediate reach of de- glutition, the changes seem all to depend on vi- tal action. The action of mere chemical power, may also be maintained with plausibility with regard to the remedies for urinary concretions. There can be no doubt of the relief obtained in these cases by the use of remedies sometimes acid, sometimes alkaline, according to the indi- cations derived from the nature of the concre- tions. But it may be alleged, that this relief is referable to the alteration and improvement of the digestion, and not to the neutralization of the acid and alkaline bodies, which in such remote mazes of the circulation, seem hardly accessible to remedies thus applied. It is in favour of this that there are remedies of the sedative kind, hav- ing a sensibly good effect on gravel, of which the operation can only be referred to vital action ; 82 ELEMENT.? OF of this kind are opium and hemlock ; and I can say, that in my own practice I have found the most striking benefit in such cases, from combi- ning these with the chemical remedies; and there is nothing I am better convinced of, than that the cure is rendered by this treatment more certain, more expeditious, and more permanent,^ than where the chemical remedies alone arc em- ployed.. ' Beside the main purpose of the assimilating process that of creating and maintaining a due quantity and quality of the several fluids neces^ sary for growth and repair, there are some secon- dary purposes of these fluids too important ty be overlooked. By their specific stimulus in the various cavities in which they are prepares fhey serve as a stimulus to the healthy action ot these organs, namely, the stomach, intestines * See an article in the 3rd volume of Transactions of tht Society for the Improvement of Medical and Chirurgieal Knowledge, London, by Sir G. Blane, 1812. MEDICAL LOGIC. 83 and blood-vessels. The mechanical distention also which they give by their bulk, is not less ne- cessary in supporting their action, and even life itself, as will be more fully explained in another part of this work. The importance of these is no where more conspicuous than in the stomach, the first stage of assimilation ; and, as it is the only organ which converts foreign and dead mat- ter into living animal matter, its energy must be regarded as peculiar and eminently powerful. By its universal sympathy, it exercises a strong influence over every other organ and function. A blow upon it is more certainly fatal than upon any other part of the body. Its aberrations, therefore, form some of the most copious sources of disease ; and for this reason, as well as from its situation, it is the first stage for all internal appliances, to whatever quarter they may be di- rected. There seems, therefore, to be rational grounds for the present fashionable pathological doctrine of referring all diseases to the stomach, and of curing them all through it. To this doc- trine, there is only that objection to which all 84 ELEMENTS OF matters of fashion are liable—that of pushing it to an extreme, by following it out to the exclu- sion of every thing else. 5th. The Formative Principle.—This may be called also the organizing or plastic. It has not usually been stated as a principle dis- tinct from the last. In so far as the simple change of matter is concerned, an act of assimila^ tion does indeed take place in the the formation, of organs: but this is the smallest part of the Formative process, the essence of which con- sists in the construction of the various organs, < and differs from the Assimilative, as an edifice does from the materials of which it is construc- ted ; nay, more so, for the fluid particles, in as- suming solidity, undergo a change in their chem- ical nature, none of the forms of the matter composing the solid parts having any pre-exis-. tence in the fluids. It may be said of the solids, in their relation to the animalised fluids, what has been said at page 77 of these fluids, in rela-j tion to alimentary matter, namely, that they are MEDICAL LOGIC 85 created by the animal process. This cannot be better illustrated than by the example of calcareous earth; for are there not such im- mense strata, and mountains of it, composed of the remains of testaceous animals, the existence of which can no otherwise be accounted for ? The creation and application of these materials to the rearing of the wonderful fabric of the living body, is one of the most astonishing phe- nomena which the human mind can contemplate. It is stated by the ingenious and profound Blu- menbach, as a continuance of the Generative energy. And it is certainly not less mysterious ; for what can be more incomprehensible in the whole compass of nature, than the act by which that conversion and accretion of elementary particles is effected, by virtue of which, bone, cartilage, muscle, membrane, and every other form of organized animal substance is created, at the very point of time and space, in which this conversion and accretion is called for, and there and then moulded into the form of the respective organs which they constitute; that 8 86 elements of these organs should be precisely adapted to the ends of nature, the growth of each keeping pace with all the others : and that these un- ceasing processes of growth and repair should go on with such harmony on both sides of the body, as to produce that correspondence and symmetry which we behold! This is a subject, the nature of which eludes the keenest research, and overwhelms the mind of man with astonish- ment and despair, from which it can find no re- fuge, but in resting on it as an ultimate fact, and referring the whole to Supreme intelligence. Should any one attempt to scan it farther, by ascending higher in the scale of natural causes, he will either find himself baffled, or will be in hazard of falling into some extravagance; such as that of Van Helmont, who held that there is in living beings an intelligent principle, which he called Archaeus, presiding over and directing the secret movements of the animal machine ; or of Stahl, who referred it to the rational soul. In that early stage of science, these were not un- natural notions to spring up, on a subject so dark MEDICAL LOGIC. 87 and unfathomable, in ingenious and contempla- tive minds, endowed at the same time with a warm imagination ; and they are notions certain- ly not less venial, nor less abhorrent to reason, than the theory of the sun and planets, conceiv- ed by their cotemporary and countryman, Kep- ler, to whom the palm of high genius and intel- lectual excellence will not be denied. This very celebrated mathematician and astronomer, who first ascertained that the ratio of the mean distance of the planets to their periodical times of revolution, was as the cubes of the former to the squares of the latter, and solved other im- portant and abstruse problems in physical astron- omy, conceived that the sun and planets were animated beings, that the rocks were to be con- sidered as the bones of the earth, the seas and rivers as her blood, the metalic veins as absces- ses, and that she performed her daily and yearly revolutionary journey in the ecliptic, by an act of her will, in concert with that of the sun. 28 ELEMENTS OP The proper function of the formative faculty, is growth and repair. The long and universally received mode of conceiving the progress of growth, was that of a constant accession of or- ganic matter, giving additional length and breadth to the parts nourished. But it is evident, that this mode of accretion would render the pre- servation of shape utterly incompatible with the enlargement of dimension; and it was first clear- ly demonstrated by Mr. John Hunter, that the only process by which the growth of solid parts, particularly bones, could be carried on, was by a constant removal and replacement of particles. The effete substances, the ramenta1 or detritus as it were of the living body, after being detached by absorption, and set afloat in the circulation, are conveyed through the mass of blood, and eliminated by the excretory glands and emunctory outlets, such as the kidneys, in- testinal glands and salivary glands, and the ex- halants of the skin and lungs. MEDICAL LOGIC. 89 The absorption and replacement of solid parts goes on in the adult, as in the adolescent state; for the actions of life making an inces- sant consumption of the solids, as well as of the fluids, require an incessant repair by new sup- plies of aliment. One of the most curious problems that could be proposed in animal science, would be to ascertain how much of the identical matter of which the body is composed at birth, remains at any given period of future life. This question, besides being too difficult for me to grapple with, seems more curious than useful; and 1 shall leave its solution to those who have more ability and leisure. But some Other remarks on this absorption of solid parts will not be out of place here, being closely con- nected with the subject, and throwing light on some of the most important parts of physiology, and pathology. The matter of which the urine is composed seems to be the effete parts, not only of the fluids, but of the solids; for the solid substances 9O ELEMENTS OF found upon evaporating this excrementitous fluid, seem to contain not only those particles de- tached from the various organs in the processes of health, but also the morbid concretions so in- cident to it, and which probably form a part of that detrius of these organs, which are removed in order to make room for fresh accretions. The salivary glands are also one of the outlets for the ramenta of the bones ; for the phosphate of lime, with a small excess of lime, the mate- rials of bone are found in analysing the saliva ; and it concretes on the teeth, and sometimes on the salivary ducts, in the form of what is called tartar. Does not this, in some measure, ac- count for these glands being the parts upon which determination is made by the operation of mercury, which consists in exciting an active absorption of solid parts, as I have elsewhere observed.* It may here also be remarked, that * Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, vol. iii. page 119, London, 181?. MEDICAL LOGIC. 91 one of the active effects of mercury is to alter the natural sensibility of the lacteals, which un- der its influence absorb feculent matter, as is dis- covered by the smell of the breath; the fetid particles being carried into the circulation, and thrown off in the halitus of the lungs, or by the salivary glands, in consequence of the mouths of the lacteals losing that selecting tact, whereby, in their sound state, they reject whatever is of- fered to them except the chyle. Were this the time and place for pursuing this research farther, many similar illustrations might be adduced. I shall conclude with only one more. It is evident that the incessant friction in the play of the joints would very soon wear out these organs, were there not a copious supply and active transformation of matter by the For- mative process, to compensate for what is abra- ded by such strong attrition. And were it not for the same operation of this process, the superficial parts of the body would be exposed to rapid de- struction, as may be familiarly illustrated by the 92 ELEMENTS OF shortness of time in which dead skin, in the form of a glove is worn out; whereas the natural in- teguments of the hands are so constituted and re- paired as to last for life. It is also conceivable that these solid particles when set afloat in the blood, in order to be elimi- nated by their respective emunctories, may be detained, or by an error loci, may be determined on a wrong outlet, thereby proving a sonrce of disease. May not urinary concretions, and va- rious cutaneous disorders be produced by such a cause ? There seems to be a like error loci in diabetes* and dropsy ; for certain portions of the blood, destined for the repair of the frame, are blended with the recrementitious matter, and * Error loci alone seems not adequately to account for it, for there is no saccharine matter created by the natural and healthy power of assimilation. This power itself, therefore, seems depraved in its action, MEDICAL LOGIC. 93 eliminated along with them. In dropsy,* the in- terstitial fluid is thereby both increased in quanti- ty and endowed with a preternatural quality ;- and in consequence of the latter circumstance, the absorbents being deprived of their specific stimulus, become inert. Were I to form any conjecture regarding the proximate cause of the sea-scurvy, I should say that it is owing to an in- terruption of that salutary renewal of the organ- ic parts, so necessary for maintaining their re- spective functions in their natural vigour. How- ever this may be, there can be no doubt that the disease called Mollities Ossium, and emaciation, are owing to a deficiency in the formative energy, as tumors, exostosis, and obesity are examples of its excess. The operation of healing, also, by the creation of new parts in cicatrization, and the formation of callus, for the repair of injuries, is another * See Medico-Chirurgical Transactions, v. 11. Article 30, by Dr. Marcet. 94 ELEMENTS OF manifestation of the same energy by which these organs were originally formed and moulded. In- flammation therefore, in so far as it is necessary for producing vascular texture, adhesions, and other new organic parts, is an act of the same en- ergy, and is to be deemed morbid only when ex- cessive, or misplaced. As human life advances into old age, the same quantity of matter required to replace that which is removed, becomes less and less necessary ; for that decay which limits the duration of life, con- sists greatly in the vessels becoming more and more rigid, and from minute ramifications being obliterated altogether; both absorption and ac- cretion become more slow and languid. There is therefore, less demand for the assimilated fluids which furnish the materials of growth and repair; consequently, a redundancy of blood is extremely common in old age, when the assimila- tive powers remain unimpaired, as is frequently the case, and is most likely to happen in those constitutions calculated for longevity. It is con- MEDICAL L0GK-. 95 formable to my own observations, as well as that of others with whom I have conversed on this subject, that, in consequence of the plethora produced from the cause above-mentioned, aged people are frequently subject to spontaneous haemorrhages, which are not only innoxious, but salutary. I was lately called to a lady aged 82, emaciated and weak, labouring under a profuse haemorrhage from the nose, by which nearly a quart of blood was lost. It was followed nei- ther by faintness nor weakness, but by an im- provement in health, in point of vigour and alac- rity, evidently proving that there was a redun- dancy of blood, the removal of which gave re- lief. Other similar cases have not unfrequently occurred to me. Lately, I had occasion to know of a female, aged 100, who, in an attack of pneumonia, had been freely and successfully bled in the arm. Sydenham gives very strict cau- tions against bleeding aged people, without as- signing any reasons, and without any exceptions or qualifications, resting, no doubt, on the plau- sible notion, that old age being a state of exhaus- 96 ELEMENTS OP tion and debility, a loss of blood, must always be detrimental. This is perhaps true in a majority of cases ; but I am well convinced that practi- tioners will fall into frequent and fatal errors>by adhering to it as an invariable rule. 6. The Restorative Principle.—It is well remarked by Dr. Gregory,* that the animal ma- chine differs from all others in this, that it carries in itself the means of repairing the injuries and disorders incident to it. A species of restoration, consisting in the repair of solids and fluids, ren- dered necessary by their perpetual waste and depravation, has just been mentioned. This has reference to the support of the material fa- brick of the body ; but what is further meant here to be designated, consists of laws belonging, and indispensible, to the principle of life itself. The first is, " Nature's sweet restorer," sleep. The state of excitement, of sensation, thought, and voluntary motion, by which all living beings ■* See Conspectus Medecinae Theoretics, V. i. p. 5 medical logic 97 subsist in their ordinary existence, cannot, by the constitution of nature, be maintained, with- out a daily suspension of several hours. It is evident from this, that vital power is a quantity exhaustible by the exercise of its own energies. Sleep being one of the universal and indispensa- ble wants of nature, is highly important, and one of the most prominent features in the natural his- tory of life; and being indispensable, nature, with her usual wisdom and kindness, has provi- ded great powers of accommodation, suited to the emergencies of human life. With a view to this, it is observable, that the refreshment of sleep is not in the simple ratio of its duration, the principal share of this act of restoration be- ing found to take place in the beginning of it. If a person be at any time deprived of one half, or more of his usual portion of it, the inconvenience experienced is by no means in proportion to this privation : and habit will bring persons, whose affairs require it, to subsist in health and vigour with a small allowance of sleep. General Pich- 9 98 ELEMENTS OP egru* informed me, in the course of my profes- sional attendance on him, that, in the career of his active campaigns, he had for a whole year, not more than one hour of sleep at an average in twenty-four hours. According to my own expe- rience, I find, that when I have been called- out * The singular exertions and alertness of this leader of the revolutionary armies of France, need not excite sur- prise, when we reflect that he performed what I believe is not to be met within the ancient or modern annals of Eu- rope. In a climate, in which, during all former wars, it was deemed impracticable to carry on the operations of a campaign through the winter, he kept the field for two suc- cessive winters, that is, from the time at which he stormed the lines of Weissemberg in the end of 1793, and drove the Duke of Brunswick across the Rhine, till he over-ran Holland in January and February 1795. He informed me, that in all that time his armies had no camp equipage, and that their only substitute for tents, was an occasional light hutting of turf and boughs which could be erected in a few hours. On enquiring respecting the health of his armies, he answered, that sickness never prevailed among them, except in a detachment which he sent against Sluys, in Dutch Flanders, which suffered severely by the intermit- ting fever incident to that marshy district. MEDICAL LOGIC 99 of bed, after an hour's sleep or less, I feel a very great difference in my feelings next day, from what I have felt when I have had no sleep at all. The powers of the sensorium seem to be wound up, as it were, at the most rapid rate in the first period of sleep; and great part of the refresh- ment in the later hours, seems more imputable to the simple repose of the organs, than to the recruiting power peculiar to sleep.* There are some persons, to whom more or less sleep has become habitually necessary in the course of the day, particularly after dinner; and they find that a few minutes of it satisfy nature. But the most striking illustration of this principle, which I have met with, is what I learnt from a gentleman of great observation and intelligence, who had been long in China, and had an opportunity of seeing * It is perhaps an obscure perception of this that has giv- en rise to the old English Apothegm, " one hour's sleep be- fore midnight is worth two after," and is an example of that popular sagacity and just observation discernible in proverbs. 100 ELEMENTS OF the habits of the Missionaries. These pious and conscientious persons felt themselves bound to abstract as little time as possible from their du- ties, and took the following method of abridging the period of that sleep which habit had made necessary to them, in the middle of the day. They threw themselves on a couch, with a brass ball in the hand, and under it a brass bason. The moment they dropped asleep, the ball drop- ped from their hand, and ringing on the bason, waked them. This they found afforded all the recruit which nature required.* This principle admits of a valuable practical application; for in the business of human life, * Since the first edition of this work, the Author has met with a somewhat similar remark in Q. Curtius, regarding the private habits of Alexander the Great, Somni natura parcissimus, etiam vigilantiam adjuvabot si quid occurris- set quod seria meditatione dignum videretur ; comprehensa pila argentea, brachium extra lectum porrigebat, ut in sub- jectam pelvim illapsa, exicato sonitu torporem in somnum deficientis discuteret. MEDICAL LOGIC. 101 particularly in circumstances of fatigue and long continued exertion, short intervals offer which are well worth being taken advantage of for the purpose of refreshing nature. Persons so cir- cumstanced may, for want of knowing this, think, it not worth while to compose themselves to rest for so short a time, only to be disturbed when their pleasing oblivion had just begun. The on- ly other remark which occurs to the Author to make on this subject is, that there are many per- sons so constituted by Nature as seldom to enjoy an undisturbed night's rest in their best health, but who nevertheless find all the refreshment they could wish for in the practice of their daily duties. And it must have occurred to every practitioner, even of moderate experience, to have observed occasionally that persons labour- ing under indisposition, feel sometimes more re- freshed in their powers and spirits after a restless night, than after one which had been passed in profound sleep. It would appear, therefore, on the whole, that the wisdom and beneficence of the Creator have been displayed in so constitiit 9* 102 ELEMENTS OF ting animal existence, that such a latitude is al- lowed with regard to this Restorative principle, as is compatible with the unavoidable calls and indispensible duties of life. There is reason to believe that sleep is neces- sary to the existence, not only of every species of animal, but of vegetable. The periodical diurnal collapse in the leaves of plants, is referred by Linnaeus, and other naturalists to sleep.* The other branch of the restorative element which has been stated, is the spontaneous cure of diseases and accidents, or what is commonly understood by the vis medicatrix natural. It may at first sight seem not natural to class this with sleep; but as the epithet restorative, applies strictly and literally to both, and as both * See an article in the Hamburgh Magazine of 1759, by Professor Zin, of Gottingen, entitled, Von dem Schlafe der Pflanzen. MEDICAL LOGIC. 103 are attributes exclusively applicable to vital ex- istence, they come under one head when con- sidered under this aspect. Fatigue may in some sense indeed be reckoned a disease or injury, of which the means of restoration is sleep. The main difference consists in this, that the one is as indispensible as food towards the daily sup- port of life, whereas the other is so only contin- gently and occasionally. The energy of nature displayed in combating and subduing diseases and wounds, are so unde- niable, and so obvious to the most cursory ob- servation and reflection, as to need no proof. A cut finger affords sufficient evidence of it. Artificial remedies can seldom be considered in any other light, than that of auxiliaries to the spontaneous principle of restoration : and if such a principle did not exist, the human species would long ago have been extinct. It is manifest that in the diseases excited by morbid poisons, such as the plague and small 104 ELEMENTS OF pox, there is brought about in the course of the disease, an insensibilily of the whole system to the action of the poison, for convalescence com- mences at a period when the poisonous matter is accumulated to the utmost; and the event, in- stead of proving fatal in a certain proportion of cases, would necessarily terminate fatally in eve- ry case, unless provision had been made against it by this insensibility, which arises in the course of its action. And what is farther remarkable is, that in the case of specific poisons, such as the small pox and measles, this insensibility to the virulent impression of the infectious matter continues, with very few exceptions, through the remainder of life. In the case of those morbid poisons, the na- ture of which is not to excite febrile commotion in the system, such as the virus of the syphilis and itch, this insensibility to future attack does not take place. It would appear from this, that fever is a salutary process, by which a spontane- ous cure is effected, by bringing the system into MEDICAL LOGIC 105 for many of the phenomena of disease seem to consist in the struggles of this self-healing ener- gy ; and it is one of the 'greatest difficulties of medical philosophy so to interpret nature, as to ascertain and determine what symptoms and suffering are referable to positive disease, and what to the warfare of the restorative with the noxious principle. It might plausibly be main- tained, for instance, that all the leading phenom- ena of fever, consisting in a regular series of movements, producing crisis and types, is the campaign which nature carries on with various success in waging war against the hostile inva- sion of disease. This has been properly enough 106 ELEMENTS OF called the re-action of the system ; but this re- action, though in its nature salutary, may exist, either in excess or defect. For instance—if one of the morbid poisons exciting fever, should as- sail life by attacking one of its fundamental prin- ciples, the generating power of heat, this prin- ciple may re-act with such violence, as to make it one of the main objects of practice to repress it, either by internal remedies, or by the exter- nal application of cold ; and the converse of this will happen, should the re-action be too fee- ble. This however probable, is not to be con- sidered as an adopted theory ; but merely as a matter af hypothetical illustration. With regard to the spontaneous cure of wounds, it may be viewed, as has been already remarked (page 78.) as one of the manifestations of the pre-existing or sustaining powers of nature ; for what is the spontaneous cure of a wound, but an example of the same assimilative and formative processes, upon which nutrition and growth de- MEDICAL LOGIC. 107 pend; and what are these but a continuation or emanation of the generative energy ? Tn all solutions of continuity by violence, there is a spontaneous tendency to what is called un- ion by the first intention, in cases where parts can immediately be brought into contact. This power remains even for some time after the parts have been separated, as has been proved by some late examples of small members adher- ing after a considerable interval of separation.* When this resource has either not been practi- cable or has been neglected, there is a resource provided through the medium of inflammation and suppuration. Union by the first intention, seems to have been much overlooked by the earlier improvers of surgery, and they preferred the method of throwing the injured parts into large suppurating surfaces, whereby cures were rendered both more painful and more tedious. * See Medical and Surgical Journal of Edinburgh 1014, p. 421, and the same work for the year 1815, p. 4 jQg ELEMENTS OF Modem surgery pays more regard to the method by the first intention: and we have in th..an example of the praeheal advantage of entertam- ing eorreet physieal ideas, and true eoneepfions of the resources of nature. It may be further remarked, that it is on the operations of the sanguiferous system, and the changes producible on it by art, that this restor- ative faculty, practically considered, chiefly de- pends. It is the unremitted motion of the blood which sustains life from the first moments of con- ception, as discoverable in the punctum saliens, till the last moments of vital existence; and whenever it is stopped but for an instant, sensa- tion, consciousness, and all the active functioa of life are suspended, as is clearly exemplified in syncope. And it not only sustains life, but is the instrument of restoring all lesions and as- saults made on its integrity, from a cut-finger to the most dangerous accidents, and the most for- midable operations of surgery. It also supports in an eminent degree the Conservative and MEDICAL LOGIC 109 Temperative energies ; for if the circulation is stopped in a limb, it loses its heat and passes into gangrene. The artificial means of relief also consist chiefly in such agents as have a tendency to incite its action if too languid, or to restrain it if too impetuous. I shall conclude with one remark more on this subject. As artificial means of restoration, are called for, only while nature is in a state of disorder from disease or accident, in order to as- sist her in converting the morbid into the sound state, these remedial agents must be pernicious in a state of health ; for as every thing in a state of health is already as it ought to be, any change, such as every active remedy must cause, cannot fail to be for the worse. And it follows on the same principle, that the virtues of med- icines cannot be fairly nor beneficially ascertain- ed by trying their effects on sound subjects ; be- cause the particular morbid condition which they are calculated to remove, does not exist. 10 110 ELEMENTS OF 7. The Motive Principle.—By this is meant muscular action, in its most extensive sense. The motions taking place in the living animal body, for carrying on its various functions and actions, are strikingly distinguished from those of the external world, inasmuch as they are not referable to gravitation, chemical attraction, mechanical impulse, nor any of the other causes by which the particles of inanimate matter are put in motion. All the attempts that have been made to explain muscular motion, by referring it to any of these principles, have been ground- } ed on gratuitous hypothesis, and have therefore terminated in abortive speculations. It is stated here among the ultimate and inexplicable attri- butes of animal nature. The living motions are manifested in the ac- tion of the voluntary and involuntary muscles of the vascular system. The voluntary muscles are excited to action by the will: the involunta- ry muscular organs, consisting chiefly of the heart, the circulating and absorbent vessels, and MEDICAL LOGIC 111 the intestines, are excited by their contents, which partly by their bulk act mechanically in distending their containing tubes and cavities, partly by the peculiar qualities of their contents acting as specific stimuli. A certain degree of mechanical tension is indispensible also to the action of all muscles. No muscle, whether vol- untary or involuntary, can act unless the fibres are previously in such a state, that if divided they would shrink by their resiliency, leaving an interval between the cut extremities. The Bame may be said of the vascular system in all ramifications, in order to give play to their con- traction in grasping and propelling their contain- ed fluids. This state of permanent tension is indeed necessary for the existence of life itself, as is exemplified in the fatal effect of profuse haemorrhage, particularly if it is sudden so as not to give time for contraction. In short, no mus- cle can otherwise make that contractile exertion necessary for the performance of its function, excepting the sphincters and the orifices of the cxhalants, for the essence of the functions of 112 elements of these consists in such a state of permanent con- traction as to obstruct their orifices. In short, there is perhaps no character of life more ex- pressive of its nature than the universal state of tension of every fibre, and that state of pressure in which every particle of living matter, wheth- er solid or fluid, must consequently be found in every living being ; nor is there any more cer- tain token of the extinction of life than the ab- sence of all tone and pressure. The mere sur- face of the body is an exception to this. It is pressed indeed by the whole weight of the at- mosphere, but purely mechanically, and not by any thing peculiar to life. If this state of tension in the arterial system were to cease suddenly from any other cause beside haemorrhage, such as the operations of a poison, life would equally be extinguished ; and it is conceivable and not improbable, that such is the operation of some of those poisons which produce a momentary effect in destroying life. This may be farther illustrated by the effect of MEDICAL LOGIC 113 the lessened pressure of the atmosphere on the surface of the body in ascending high mountains. This is accurately stated, and well reasoned upon by M. de Saussure,* who describes the sort of distress arising from a very light atmos- phere, as producing a species of muscular de- bility and syncope, quite different from that which occurs either from fatigue or from the de- fect of oxygen, but resembling exactly that which is felt from profuse haemorrhage, the vessels being so relaxed as not to be able duly to grasp their contents : nor is this to be wondered at, when it is considered that the pressure on the surface of the body at the level of the sea was 220331b. 12 oz. the barometer standing about 29.9 inches, while it stood at the summit of the mountain at 16 inches, so that the pressure was little more than one half of what it usually is. From these physiological facts regarding the influence of tension and pressure, some impor- * See Voyage dans les Alpes. Vol. 1. p. 486. 10* 1 14 ELEMENTS OP tant practical inferences are deducible. It is upon this principle that a certain degree of vigour is produced by swarthing and lacing where de- bility occurs from relaxation of the fibres wheth- er in the trunk or extremities of the body. The support afforded to persons who have been tap- ped for the dropsy, and to weak and exhausted females immediately after child-birth, who would otherwise fall into syncope, or expire, is ac- counted for in the same manner. It is on the like principle, that that most excellent method of treating ulcers by strapping, first introduced by Mr. Bainton, produces its beneficial effects. The effect of tension is also very remarkable on the stomach. Nature has wisely provided, that along with the pure nutritious matter of the food, there should be a certain admixture of unassai- lable matter, in order to give it more bulk, and thereby more tonic energy to the stomach. The most invigorating articles of food, accordingly, are such as are introduced into the stomach in a solid form; and not only devoid of fluidity, but possessing a certain degree of hardnes and tenaci- MEDICAL LOGIC 115 ty, so as to excite the powers of the containing viscus to stronger action. It is found, therefore. in the human species, that plain solid food, com- bined with a certain proportion of unassimilable matter, is infinitely more efficient for the purpos- es of health and strength, than that which con- sists of pure alimentary matter, whether gelati- nous, albuminous, oily, or saccharine. And with regard to animals, it is a well ascertained fact, in horses, that their strength is much better sus- tained by hay than by grass ; for the stomach being an organ of universal sympathy, does, by the exertions on which it is put in digesting hard food, confer vigour on the whole frame. But the most obvious and common, as well as the most fatal effects, observable by the re- moval of tension from the cavities of living ani- mals, are those which arise from the abstraction of the circulating fluids, more especially by the sudden depletion of the vascular system by hae- morrhage, as already observed. Haemorrhages are either spontaneous, in which case they are 116 ELEMENTS OF generally salutary efforts of nature to relieve re- pletion, or they arise from violence, as in wounds. Spontaneous haemorrhage is very seldom fatal, and if left to itself, so as to induce syncope, the progress of it is stopped by the suspension of the circulation ; and leave being given for a thombus to form, it does not return on the revival of the person so affected. The case is different with regard to haemorrhage from external injury, for this is not brought on like the other, as the means of relief to excessive repletion. In loss of blood, therefore, by external accidents, not only com- pression and ligature are required, but in extreme cases, the aid of stimulant cordials, and of opiates. It is well ascertained by surgeons, whose duty it has been to attend to recent wounds in battles by sea or land, that the most successful method of saving life endangered by profuse haemorrhage, is by the free use of brandy or laudanum, or of both. But great discrimination seems required here.,* and in order to establish a principle by which MEDICAL LOGIC. • H7 the judgment is to be guided in these important points, it is necessary that we should be aware of the distinction between active and passive haemor- rhage. In the former, the discharge of blood is, I apprehend, to be referred to the elastic tone of the vessels, in the latter, to their relaxed state. It is evident, therefore, that in an haemorrhage, while the vessels are under the strong action of their tonic contractility, there could not be worse practice than to administer stimulants and opi- ates. But when the discharge has advanced so far as to exhaust the powers of life, and even to subdue the arterial tone itself, it is, then, that these remedies are imperiously called for. There is a very interesting class of cases in which haemorrhage constitutes the most alarming symptom, and in which there has existed conside- rable ambiguity, with regard to the treatment. Perhaps a candid attention to the principles here adverted to, and a fair application of them, may afford the grounds of settling the difference of opinion which has arisen on this subject. The 118 ELEMENTS OF cases alluded to are those of flooding, particularly after child-birth, and frequently attended with syncope and convulsions. When convulsions oc- cur before or during labour, they are attended with lethargy, and other symptoms of pressure on the brain, which clearly indicate the necessity o[ depletion ; and there can be no doubt of the propriety of blood-letting, local or general, even though there should be syncope and haemorrhage, the latter being, under such circumstances, of the active kind. But the case to which the au- thor alludes, and to which he has occasionally been called as a general physician, are where great alarm arises from the occurrence of these symptoms immediately after labor. His experi- ence is certainly limited ; but he finds five cases in his notes of this description. One died from pure exhaustion and depletion : no active means were taken to save her. In the four oth- ers he was induced, from the fatal event of the former case, and by the success which he had heard of, in a similar one, from the use of strong cordials, to make trial of this treatment in the MEDICAL LOGIC. 1 19 subsequent cases, which he did with the most satisfactory results. Such cases are undeniably of the passive kind above described, for they occur after the strength has been exhausted by the severe throes of labor, by the loss of blood, beyond that which takes place in the course of nature, from the contraction of the uterus, and by the sudden removal of tension from the ex- pulsion of the child; besides the alarm and agi- tation of mind at such perilous and painful mo- ments. The vigor acquired by cordials at this crisis, may also be naturally supposed to assist the uterus in the expulsion of the placenta and se- cundines, of which the adhesion, bulk, and irrita- tion, are the most common causes of haemorr- hage. One of the cases which the author al- ludes to, was that of a young lady in her first la- bor, whom he found in a state, apparently, of ex- tremity. She was recovered by a quantity of brandy, which it was computed would have intox- icated three or four men ; yet she felt no such effect from it, nor any inconvenience whatever, the stimulus being merely sufficient to restore and 120 ELEMENTS OF s sustain life. In another case of very profuse flooding, the patient took two hundred drops of laudnum, and half that quantity, several times at the intervals of four hours. The author has been induced to state these cases from his hav- ing found by the language of respectable practi- tioners and authors, that the practice in such cases is held to be very ambiguous, with a reluc* tance among some of them to admit that there are any cases whatever which admit of such treatment. It would be presumption in the au^ thor, from his limited experience, to deny that there may not be cases even after labor, which require to be treated like active haemorrhages. But if he is correct in what he has stated, his observations will be deemed of some utility, not only in this particular branch of practice, but (what is more suitable to the scope of this work,) it will serve as an exemplification of a point of medical reasoning, whichhe has already adverts to at page 66, and which he will again have occa- sion to elucidate, namely, the great danger in the practice of physic of laying down rules so rigor- MEDICAL LOGIC. 121 ous, as to admit of no qualification and excep- tion.* One of the most difficult and important points in this part of our subject, and in the whole com- pass of physiology, is to determine what is the value and extent of that connection which sub- lists between the muscular and nervous system. That motions peculiar to life can exist without the acompaniment of brain and nerves, is proved by the existence of those animals which are des- titute of them ; and by the phenomena of fetal life, particularly by the absence of nerves in the placenta; also by those monstrous produc- * Some judicious remarks on this subject are to be met with in a Treatise on Uterine Haemorrhage, by Duncan Stewart, M. D. Lond. 1816. There is an Article on the same subject by the same author, in theMedico-Chirurgical Transactions, vol. ii.; also Observations on the Prevention of Abortion, by Suppositories of Opium, in the same work, vol. v. It may be added, that cool air, and the local appli- cation of ice, have been highly beneficial in uterine hae- morrhage. i22 ELEMENTS OF lions* without brain, spinal marrow or nerves. The economy of vegetable life furnishes a far- ther proof of the same principle. The actions taking place in growth, the impulse given to the sap, from the extreme roots of a tree to its sum- mit, and the clasping of tendrils may be instanc- ed as motions not referrable to any of the causes of motion in inanimate bodies, and as examples of vital energy, as genuine as those which take place in animal life. In the complex animals the densorium and the system of nerves are indispen- sable for the purposes of sensation and voluntary motion, and are never wanting except in cases of montrosity, in which life cannot subsist beyond the fetal state. With regard to the influence of nervous energy on the involuntary motions in general, some ad- ditional light has been thrown on it by the recent * See Dr. Clarke's case above quoted; also cases in Pbil. Trans, vol. xix. and xxi. MEDICAL LOGIC 123 experiments of Dr. Wilson Philip,* confirmatory of my opinions delivered in the Croonian Lec- ture^ read before the Royal Society, in the year 1788, and published separately the follow- ing year. Upon the whole, it appears, that the irritability and excitability of muscular action are not constituted, created, or imparted by nervous energy, but that this energy incites, restrains, and regulates these'organs, and connects them with each other, and with the organs of sense in carrying on the purposes of life. Mr. Hunter, by a happy turn of expression, calls the function of the nervous system internuncial. The pur- pose of nerves, therefore being that of acting a- stimuli to contractile fibres,]: there are no * See Experimental Enquiry into the Laws of the Vital Functions, &c. by Wilson Philip, .M. D. London, L817. t This tract has been long out of print, but the substance of it will be found in the Encyclopaedia Britannica, under the article Muscle. f See lecture on Muscular Motion, page 26. 124 ELEMENTS OF grounds, but rather the contrary from this to infer, that they have any thing more in common in their nature with these fibres, than any other stimulus, however foreign, whether chemical-or mechanical. There is no more difficulty in conceiving the nervous power to be distinct from that by which muscular contraction, secretion, and heat, are effected, than in distinguishing be- tween the power of the helm which guides the vessel, from the power of the wind which impels it; and in following out the parallel, it may be affirmed, that if a ship were never to steer but one course, with a wind of the same power and direction, the helm would be useless, just as a nervous system would be useless in a simple animal. It is accordingly found only in complex animals. In considering the matter in a view still more abstract and comprehensive, it seems absolutely necessary, than in complex and sensitive animals, there should be a minute, universal, reciprocal, and prompt connection and intercourre establish- MEDICAL LOGIC 125 cd between every part and every other part; and the anxiety of nature to do this, is sufficient- ly manifested by the intricate intertexture of the nervous ramifications in the various ganglions, plexuses, and innumerable communications, like the anastomosis of vessels running between one branch and another in every spot. Is it not by virtue of this universal, accurate, and close con- nexion and instantaneous intercourse that the consciousness of individuality and personal iden- tity is created and kept up ? Let the integrity of this system, and the reciprocal intercourse of its parts be broken down, as in the case of hemiple- gia, the members of the affected side are felt as something foreign to the rest of the body. The hallucinations in some species of delirium* and mania, by the person referring his own sensations and actions to another person, also seem to de- pend on a like disjunction of the free intercourse between the several parts of the nervous system. There is this important inference therefore to be gathered from the great difficulties of unravelling * Diseases of Seamen, 3rd edition, page 343- 11 * 126 ELEMENTS OF and interpreting the influences of the nervous system with the other functions, and the inter- minable controversies, to which it has given oc- casion, namely, that nature in establishing their intricate and intimate connexion, has shewn how necessary the reciprocal influence of every part of the system on every other are, in carrying on the purposes of life as a whole. This contro- versial contention of physiologists may therefore be viewed as a physiological fact in itself. There is a function which seems to belong to this regulating and internuncial influence of the nervous system on the motive organs of complex animals, which appears not to have been duly appreciated and attended to by physiologists and pathologists. I mean that by which fluids of a particular quantity and quality are distributed or determined to particular parts in health and dis- ease. This may be excited even by a thought in the mind, as in blushing, and the occasional afflux to the organs subservient to the appetites and to the Mammoa: The blood contains not MEDICAL LOGIC 127 only the alimentary matter necessary for the support of the various organs, and for the supply of the several secretions, but for the conveying of heat, and for supporting the tension required for maintaining the activity and even existence of the different functions, as is strikingly exem- plified when the circulation is suspended in the brain. It is indispensible to health, therefore, that a fair portion of blood should be distributed to each member of the body according to its exi- gency ; and it is evident, that either an excess or defect of this must produce disorder. But this is not all. There is a provision evi- dently made by nature for conveying specific portions of the fluids to corresponding glands. It is not meant to apply this to the secretions in general, as if the secreted matter pre-existed in the mass of blood, and were not generated in the gland itself. The observation here stated ap- plies only to the effete, extraneous, or acrid mat- ters which are to be expelled by the emuncto- rics, as noxious or redundant, such as the urine, 128 ELEMENTS OF and matter of perspiration. In no other manner can the rapid transmission of fluids from the sto- mach to the kidney be accounted for. It seems to be for want of this selecting power, whereby the useful and recrementitious fluids are kept se- parate, and transmitted to their respective desti- nations, combined with a vitious assimilation and depressed state of the powers of life, that dropsy arises. It is curious to contemplate with what precision fluids are transmitted through the com- mon mass of blood in health, and conveyed to their respective glands or outlets. As a farther proof of the useful and recrementitious fluids be- ing blended in dropsy, it is observable that albu- men is found in the urine of hydropic patients. There is, therefore, a selecting and conveying power peculiar to life, not less unaccountable than the operations of the Formative process already adverted to, as an ultimate and inscruta- ble attribute of vitality. It is a common manner of speaking to say, that the matter of a secretiop is produced in greater or less quantities, by the greater or less energy of the respective glandular MEDICAL LOGIC 129 organ. It seems clear, however, that no exer- tion of these organs could augment their pro- duct without a co-operation, a secret under- standing or concert as it were, with the general store-house, the mass of blood, which alone could supply the additional afflux necessary for the in- creased secretion: as well might a mill produce meal without a continued and adequate supply from the hopper. Fluids of a particular character seem to make their way through the general mass of fluids to their appropriate glands, as an acid does, even through a solution of alkali, from one extremity to the other of the Galvanic wire. It is not meant to say, this is an exemplification of the Bame process in nature, but only, as before men- tioned at page 76, to state a comparison or par- allel between the operations of life, and those of the chemistry of inanimate matter, in order to assist our conceptions of the vital energies. It is sufficiently conceivable, that by virtue of that constant pressure which must take place in 130 ELEMENTS OF the sanguiferous system, considered as one great cavity bounded by the sides of a vessel in a con- stant state of tension, that glands might be sup- plied from the general mass in proportion to their wants and discharges ; but this will not ac- count for the supply of the selected fluids. These processes of specific determination open new views in pathology, agreeably to what has been said at page 89 ; for as there are cer- tain glands and exhalant vessels of which the proper function is to eliminate the effete solid parts that have been absorbed, or such noxious and acrid fluids as may be floating in the mass of blood, an excess or defect of these, or a wrong determination of them, will be productive of disease, as was exemplified with regard to the urinary concretions and cutaneous defeda- tions. A redundant determination of the blood ' itself to certain organs, is also one of the fre- quent constituents of disease ; but we cannot MfcDICAL LOGIC 131 concede to a late pathological writer,* that all diseases whatever, with a few exceptions, are referable to this cause, there being so many oth- er ways enumerated in this work by which devia- tions may be made from the sound state. When this circumstance in the animal econo- my first attracted my attention, I was about to enlist it as a distinct head in the catalogue of vital energies, under the title of Determina- tive ; but on further consideration, it appeared to me to be one of the manifestations of that universal influence, concert, or sympathy estab- lished between all the organs and functions through the instrumentality of the motive power. The morbid actions incident to the voluntary muscles, to the heart, and the muscular part of the stomach and intestines, consist chiefly in con- vulsive and spasmodic contractions. The most * See Elements of Pathology and Therapeutics, by C. H. Parry, M. D. J32 ELEMENTS OF ordinary morbid condition of the motive part of the vascular system consists in inflammatory af- fections, and in excess or defect of tone, alter- ing its capacity beyond or within the healthy standard. The want of the habitual exercise of these powers, is also a source of disease extremely important to be attended to. There is no insti- tution of nature more evident than the necessity of the actual exercise of all the organs and func- tions of animal as well as rational existence for improving them, and for maintaining them in a healthy state. A due degree of labour strength- ens, and even multiplies, muscular fibres; and the want of it produces various chronic diseases not only of the muscles themselves, but of every organ and function of the animal frame. The healthy and vigorous action of the muscular fibres of one organ communicates firmness and strength to another. The action of the stomach required to subdue hard articles of nourishment, as already observed, communicates firmness and MEDICAL logic. 133 strength to the voluntary muscles, which the same alimentary matter in a soft or fluid form does not give. The indulgence in indolent hab- its and excess of sleep in which those ranks of life who do not depend on bodily labour are en- abled to indulge, contribute no doubt to create those diseases, particularly the gout, which are peculiarly incident to the affluent. During the twelve years in which I was Physician to one of the largest hospitals in London, not one case of gout occurred in several thousands which came under my care, an irrefragable proof that as labour (I ought to say habitual and unremitting labour) with simple diet infallibly prevents gout, so its remote cause must be sought for in the re- verse of these. Of the manner in which this was brought about, that is, the proximate cause,, I have never seen any rational conjecture, nor am I able to form one myself: but such is the fact. The share which excess of sleep has in creating chronic disease, has probably not been sufficiently attended to, unless we are to except the common popular observation that, all long 12 134 ELEMENTS OF livers have been early risers. Ought not a su- perfluous share of sleep to be deemed a de- bauchery, as much as an excess of food and drink ? If the proximate cause of gout and hy- pochondria should ever be discovered, it will probably be found in the relation in which de- fect of muscular motion and excess of sleep, combined with a redundancy of aliment and the habitual stimulation of vinous liquors, stand with regard to the symptoms which characterize these maladies. Let it never be forgotten, then, that the per- fection and health of all the organs of motion, can be promoted and maintained by that exer- cise alone, which Providence has ordained as indispensable to the practical duties of life. The painful and dangerous diseases decreed as the sanction annexed to the violation of this law of Nature, furnish proof enough that such violation cannot be committed with impunity. MEDICAL LOGIC. 135 But here, as in all human affairs, whether natural or moral, extremes on either side are pernicious. Fatigue, that is the over-exercise of the motive powers, is also a cause of disease. Excessive labour strains and wears out the pow- ers of Nature, and tends to shorten life, partic- ularly if combined with privations, that is, an insufficiency of wholesome food, clothing, and fuel. The following practical remark arises out of these observations. It occurred to me in a great number of instances, particularly in the early part of my practice, before 1 was suffi- ciently aware of what I am going to mention, that when 1 had occasion to recommend air and exercise, I found that the patient, from misap- prehension, in almost every instance injured himself by fatigue and exposure. Let me there- fore admonish young practitioners always to subjoin the appropriate cautions in the like cases. 136 ELEMENTS OF 8. The Sensitive Principle.—Sensation be- ing a simple idea, does not admit of definition; but its import may be understood by a reference to some of its descriptive attributes, such as pleasure and pain, and to the several percep- lions conveyed through the organs of sense adap- ted for receiving the impression of their exter- nal objects. To these might be added con- sciousness and volition ; but as the elements of the intellectual operations and mental emotions, they belong to man as a rational and moral be- ing, and they are foreign to the present subject, which professes to embrace only his animal na- ture. It belongs to this place, however, to ad- vert to this aspect of the human character, in as far as it exercises an influence over the cor- poreal frame, thereby adding to that complexity of agents, that obscurity of effect, and that dif- ticulty of analysis, which it is the purpose of this rapid sketch of the animal powers of man to elucidate. medical logic. 137 Sensation and voluntary motion, also appetite, in so far as it is referable to sensitive beings, in the language [of M. Bichat, a modern French physiologist of considerable fame and great in- dustry, compose (if I understand it aright) what he calls Animal life. The other faculties, by which must be meant the Generative, Conserva- tive, Temperative, Assimilative, Formative, Re- storative, and Sympathetic, as enumerated and defined in this work, none of which imply sen- sation, volition, or consciousness, he terms Or- ganic life. By the latter is meant (if I mistake not) what some other physiologists term Auto- matick life. It is deducible from what has been said, that all the elements of life as enumerated at page 41, are independent of the Sensorial or Nervous System, except the Sensitive, that part of the Motive which is subject to volition, and that part of the Appetitive, which implies sensation and voluntary action ; for though they are all influenced, and more or less guided by the brain 12* 138 elements of and nerves, they possess an independent exis- tence, as is exemplified in the lower animals, and in vegetables. It has already been remarked, that all the senses carry a reference to the material world, each having a corresponding object in external nature, to which its structure is adapted. Were it not for the great familiarity of the subject, the adaptation of the eye and ear to the properties of light and air, would strike us with the most in- tense delight and astonishment. The same may be said of the other senses, and of the conforma- tion of the hand, and of the whole body in its stature, and the relative position of its limbs and viscera, as adapted to the laws of gravitation, and the mechanical properties of matter. The perfection of the sensitive principle there- fore will consist in its fidelity to nature, and this fidelity will consist in the uniform identity of the sensations excited in each individual. This iden- tity is not necessary in separate individuals ; for MEDICAL LOGIC. 139 though the same corporeal affection of matter which excites a red color in the eye of one per- son, were to excite that of yellow in another, all the purposes of intelligible intercourse would still be answered, provided this continued con- stant in the individuals respectively : nor could the one ever discover that his sensation was dif- ferent from that of the other. It would appear from some recorded and well authenticated cases, that there is some subtle 6ub-division and distribution of the nervous fila- ments, whereby those of sensation are rendered distinct from those of motion.* It has also been remarked, how essential it is that the human mind should likewise be physical- * See a case related by Dr. Yelloly, Med. Chirurg. Transactions, vol. iii., another by Dr. Brown, in the American Repository, and a third by Lamark in his Zoolo- ' gie Philosophique, in all which, there was a total loss of sensation, while the muscular powers and circulation re- mained perfect. __ 140 ELEMENTS OF ly adapted to the constancy of nature. It is on this constancy that all our experience and judg- ments are founded, whether in operating upon matter, or in our intercourse with our fellow- creatures, the one having relation to that reli- ance which we have in the invariable course of nature in the physical world, and the other in the moral world. It follows, that the morbid state of the senses will consist not merely in simple excess and defect, constituting over-acuteness or hebetude, in the corporeal frame, but in those false references in what may be called the ration- al and moral frame, in which depraved judgment delirium and mania consist. 9. The Appetitive Principle.—Under this is comprehended not only that attribute of adult man, by which the species is propagated and per- petuated, and that by which the individual is sus- tained by aliment; but those instinctive proper- ties of mere animals, and of the human species in the infant state, by which alone their existence can be maintained. To the same principle be- MEDICAL LOGIC. 141 long also those instincts, if they may be so called, pertaining to vegetable life, by which they bend and extend themselves towards air, light, and heat, and that most astonishing instance of what may be called autpmatick appetency, by which their roots extend themselves under ground through incredible obstacles to that quarter where alone the water necessary for their suste- nance is to be found. And to the same principle belongs also that faculty by which the seeds of vegetables, when buried in the ground, feel or judge as it were, whether their germinating or- gans can reach the surface in seeking light and air, and when they are at a depth at which this is unattainable, they do not attempt to germinate, but retain the power of doing so for ages, pos- sessing an excitability which can be roused into action in case there should ever occur the requi- site proximity of light, air and heat.* * See an article on this subject in the first volume of the Transactions of the Royal Society of Edinburgh. 142 ELEMENTS OF With regard to the morbid state of'the animal appetites, medically considered, much more is to be feared from their excess, than their defect; for their inordinate indulgence is one of the most fertile sources of disease in the human subject: and, morally considered as the subjects of self- control, the author must leave to moralists, the due enforcement of this, as one of the main con- stituents of virtue, dignity, and happiness. 10. The Sympathetic Principle.—This is the last in the catalogue of those cardinal attributes which have been stated as peculiar to life. The term sympathy has been much objected to, but as I apprehend, rather fastidiously and unreasonably. It is like most other terms be- longing to the science of life, figurative, being a metaphor taken from an affection of the mind. The import of the words, according to the most correct and received rules of philology and rhet- orick, is not at all to be deduced from etymology, but either to be assumed conventionally accord- MEDICAL LUGIc. 143 ing to a definition, or to be adhered to in the sense affixed to it by established usage. By ani- mal sympathy, is not meant the intelligent prin- ciple ofStahl's hypothesis, but that mutual influ- ence of distant parts, so subtle and rapid as in some instances to be compared to thought or to lightning : in other instances, it is an action more tardy and habitual. - If this term is to be reject- ed, some other must be invented to express what actually takes place in those operations of the living body, by which, without the transmission of ponderable matter, or the intervention of any of its properties, the most indispensable functions are carried on in health ; and some of the most striking phenomena of diseases, such as their translation and conversion, can no otherwise be explained. It sometimes consists in the trans- mission of mere sensation, without any perceiva- ble change of the sympathising part. Such is the pain which is felt in the shoulder in hepatitis and that which is referred to the fore part of the thigh in the inflammation of the hip joint. The medium of this communication is probably some 144 ELEMENTS OF imponderable fluid; but it would here be out ol place to discuss this, since we have only to do with a fact referrable to an ultimate and inexpli- cable law of life. It is through this energy, that all the preceding faculties act and re-act upon each other, in carry- ing on that harmonious play of the animal sys- tem, in which its sound state, and its perfection as a whole, consists. The most descriptive char- acter of a healthy state, being the quietness and imperceptibleness of the operation of the various functions and organs, this intercourse by sympa- thy is but little observable in health, and is only manifested in morbid actions, or in the operation of medicines. Every such action must there- fore carry a reference to a corresponding action, or previously existing habititude in the healthy state. The connection of the stomach with the head, the heart, the surface of the body and the kidnies, and the reciprocal action of all the func- tions and organs of the skin, may be adduced as MEDICAL LOGIC. 14,3 gome of the most striking and important exam- ples of sympathy.* Sympathy seems in general to be carried on by the instrumentality of the nerves; but to this there are important exceptions. The species of sympathy, called by Mr. Hunter the contiguous takes place not only in the relations of mere proximity and continuity, but by the influence of the containing on the contained parts, as that of the integuments on the subjacent viscera, in none of which does there seem to be any reference to the distribution of nerves. This may be exem- plified by the relief afforded to the lungs and in- testines, by bleeding, blistering, or fomenting the nearest external surface. We find in some old anatomical books, an attempt to trace sympathies * See Observations on the Diseases of Seamen, by G. Blane, M. D. page 565, 3d Edit. London, 1798; also Dr. Webster's work, entitled Facts tending to shew the Con- nexion of the Stomach with Health, Disease, and Reco- very. 13 146 ELEMENTS OF to the ramifications proceeding from the common trunk of a nerve ; but better observation has proved, that sympathies have little or no depend- ance on the connection and distribution of nerves. There are also evident indications of sympathy in vegetable life ; for, not to mention the effect of the irritation of a single leaflet* of the sensi- tive plant, in making the whole leaf and its foot- stalk contract, there is undeniable proof of it in * My friend Dr. John Sims, so well known for his excel- lent taste and great knowledge of botany, was so kind as to communicate to me, the following interesting and hitherto unpublished experiment of his own. A leaflet of the sensi- tive plant being irritated, and the greatest pains being tak- en to avoid moving any other part of the leaf, the whole of it nevertheless contracted, and the foot-stalk dropped. But in order to be sure that mechanical motion, communi- cated by this irritation, had no share in this contraction, he threw a sunbeam concentrated by a glass lens on one of the leaflets ; the whole leaf contracted, and the foot-stalk drop- ped. MEDICAL LOGIC 147 the excitement of the roots of trees, in sending up the sap in consequence of an influence from the trunk, branches, and leaves, on the return of the vernal warmth. The temperature of the earth, at eight feet deep, is lower in April when the sap is ascending, than in January, accord- ing to experiments related in the 59th Number of the Edinburgh Review, p. 6 and 7, in an article of which Professor Leslie is said to be the author. And if in the winter time the branch of a vine be introduced into a hot house, it will produce a luxuriant crop of leaves, blossoms, and fruit, the materials of which could only be derived from the excitement of the roots propagated by sympathy with the parts in contact with warm air. This fact is stated on the authority of that eminent professor of Botany, in Edinburgh, Dr. John Hope, whose Lectures the Author attended in the year 1771, at the Botanical garden in Leith Walk. This will take place even during a frost, in which situation, these roots would have been in a torpid state, had it not been for the sympa- thetic influence of the parts above ground, 148 ELEMENTS OF brought into action by warmth. The action of the roots, therefore, must be excited from what Mr. Knight, in treating on the same subject, calls " a vehicle of irritation, arising from an intrin- sic power of producing motion in vegetable life."* It is evident how much processes of health must be deranged from an excess, defect, or to- tal suppression of the sympathetic faculty; and this opens a wide scope to the speculation of those who search deeply into the proximate causes of disease, the operation of remedies, and the sources of error from the false reference of the seat of disorders.t * See a series of ingenious Papers on Subjects of Ve- getable Physiology, in the Phil. Transactions, from 1801 to 1806, by T. Andrew Knight, Esq. ' t Though remarks on moral subjects are here not quite in place, yet the reader will perhaps forgive the fol- lowing one, as it is closely connected with the subject of sympathy. There is a maxim to be met with in the works MEDICAL LOGIC. 149 of one of the Greek sages, but more cogently laid down in the Christian doctrine, namely, the reasonableness of our doing to others as we wish others to do by ourselves, a maxim, which of all others, comprises in the fewest words, the largest portion of practical morality, and depends on that sympathy with the feelings of others by which we put ourselves as it were in their place; a habit the most to be cultivated and fostered of all the moral duties. See Smith's Theory of Moral Sentiments. 13* SECTION II. On the General Principles of Truth and Error in the Cultivation of Medicine.—Enumeration of the Sources of Error. The Author has endeavoured in the preced- ing Section to enumerate and define the prima- ry elements, or ultimate facts, which belong ex- clusively to animated nature, and are as it were the alphabet of physiology. In an attempt which is new, on a subject of which he has taken a view peculiar to himself, he does not dare to think that he has attained any thing like perfec- tion. It is evident, however, that it is only by following out an analytical scheme of this kind, 152 ELEMENTS OF that a foundation can be laid for the genuine principles of theoretical medicine ; for the ele- ments of disease can only be expounded by a thorough knowledge of the elements of life and health. But it is not his intention now to apply it synthetically by building upon it a formal sys- tem of nosology, physiology, or pathology; far less to bewilder himself, or his reader, by agita- ting the mechanical question, whether life con- sists in the play of these principles, or whether it is something superinduced on them. His main object in this analysis, is to convey an ad- equate conception of the great difficulties which those have to encounter, who would found prac- tical medicine on a knowledge of the animal economy, and to bespeak a liberal indulgence for the errors of those, who, in attempting this, have had to grope and wander in more dark and intricate mazes, than what has fallen to the lot of any other class of inquirers into the various departments of nature. We have seen that the animal nature of man, besides being subject to the mechanical laws of inanimate matter, and MEDICAL LOGIC. 153 to the influence of the passions, consists of a number of principles, which must all act in har- mony in a state of health, and that the disorders will be multiplied according to the number of combinations of which these requisites of health admit. It is not from physiologists not being aware of these difficulties, and from their not clearly perceiving that animal processes are quite inexplicable on mechanical and chemical prin- ciples, that the abuses and errors of theory have been engendered and accumulated in this de- partment of knowledge above any other, de- forming and discrediting medicine as a science, obstructing and retarding its advancement as an useful art ? I shall accordingly place the abuse of theory, foremost in the enumeration which I am going to make, of the causes which have corrupted and impeded the art of medicine. It is only by addressing ourselves to these prin- ciples of life, that rational physic can be cultiva- ted and practised. Under this aspect of the hu- man frame, the various morbid conditions of the 154 ELEMENTS OF body might be classed; 1st, as they consist in the simple excess or defect of these several prin- ciples ; 2dly, as discordant states of the recip- rocal influence which they exert upon each oth- er j 3dly, by a depraved action* of some of these principles ; 4thly, by the want of that due exer- cise which preserves all the organs and faculties in their natural perfection and soundness. We have also endeavoured to demonstrate that the fundamentnl laws of life are essentially dis- tinct from those of inanimate matter. In the beginning of last century, almost all medi- cines were conceived to operate either chemi- cally or mechanically. Those who are conver- sant with the works of Boerhaave and Mead, must be well aware of this. But except in so far as some of the circumstances of digestion are concerned, such as that of the morbid excess of acid, and perhaps in what relates to the secretion * This may be exemplified in the false reference of the Sensitive Principles alluded to at page 121. MKDICAL LOGIC 155 of urine, and the cure of urinary concretions, there is no fact either in physiology, pathology, or practice, but what is referable to the vital processes. An accurate and comprehensive knowledge of the principles upon which the diversified springs of animal agency hinge, has also a tendency to obviate one of the most common sources of me- dical error,—that of laying an exclusive or undue stress on one or more of those principles or ele- ments, which have been enumerated. Some of these have been already alluded to : such as the narrow views which form the basis of the doc- trines of Dr. J. Brown, embracing only the Con- servative and Temperative elements of life; the theory by which almost all diseases, and their cure, are referred to the stomach, embracing on- ly one of the elements of life, the Assimilative ; also the theory adopted by a late eminent pathol- ogist, referring the proximate causes of almost all diseases to an undue determination of blood to the respective seats of disease. 156 ELEMENTS OF The comprehensive view which is here taken of the constituents of life, will, it is humbly pre- sumed, when they have been carried to their ut- most extent by abler hands than those of the au- thor, lead to a clearer view of many branches of the animal economy, and of the history and treat- ment of diseases. We now proceed to the proper object of this work, which is to enumerate and elucidate the various causes which have most materially ob- structed the improvement of medicine. The order in which it is proposed to consider them, is as follows: 1. The fallacy and danger of hypothetical or theoretical reasoning. 2. The diversity of constitutions. 3. The difficulty of appreciating the efforts of nature, and of discriminating them from the ope- rations of art. 4. Superstition. MEDICAL LOGIC 157 5. The ambiguity of language. 6. The fallacy of testimony: with some re- marks on the excessive deference to authority and fashion. 14 SECTION UK 1st. Source of Error. The Fallacy and Danger of Hypothetical and Theoretical Reasoning. Examples and Illustrations from the Works of Aristotle, Bacon, Hippocrates, Galen, Syden- ham, Boerhaave, and Pitcairn. Empiricism and Dogmatism compared and appreciated. Pra<, j it al medicine seems more indebted to the sagacity of those who, in a rude state of soci- ety, discovered active and useful medicines, than to the early labours of the learned. From what we know of Democritus, and his followers, of whom Hippocrates was the most eminent, it ap- pears, that the cultivation of science in the early ages of Grecian philosophy, was undertaken on 160 ELEMENTS OF the soundest principles, namely, the observation of nature, and the collection of facts. Aristotle himself, was a most diligent observer of nature, and collector of facts ; but unfortunately, his lo- gical and metaphysical writings, caught prefera- bly the notice and taste of the learned world, and engrosed its attention for many ages, to the ex- clusion of all other useful and liberal knowledge. For more than a thousand years, the syllogistic logic of Aristotle usurped the place of all literary and scientific pursuits. In those dark times, however, it was better than no knowledge at all; and I am one of those who arc of opinion, that this logic, though it affords little or no assist- ance in the discovery of practical truths, and the interpretation of nature, is yet an excellent dis- cipline of the understanding, tending to give precision to language and thought, and to induce habits of close attention, and patient application of mind ; and that some knowledge of it can hardly be dispensed with in a liberal education. I am thankful, therefore, that it made part of the academical education which I received. The MEDICAL LOGIC. 161 error has been in suffering that to obtain a predo- minant rank, which ought to hold a subordinate one, and in substituting the means for the end, that which was only one of the organs of know- ledge, being exalted to the station of its main and almost sole constituent. It is" to Bacon that the world is chiefly in- debted for dissipating the clouds of false philo- sophy, and for pointing out the road which led to solid learning and the discovery of interesting truths. He himself, however, affords a proof how necessary it is, that the mind should be sub- jected to a long course of discipline, in order to bring it intocorrect habits of thinking, on matters depending on that inductive principle of observation, in ihe recommending of which his own chief merit consisted; for there are in his works evidences of his being not a little infected with the credulity of the times in which he lived. He did not entirely disbelieve in the virtues of amulets and charms ; and when treating of the interpretation of Nature, he certainly fell into 14* 162 ELEMENTS OF a great error, in excluding the consideration of1 final causes, as one of the keys for unlocking her secrets. Bacon, with that exhuberance of imagination, with which he was so richly gifted, and not with- out some savor of the quaintness of the age in which he lived, says, that final causes, like the vestal virgins, are devoted to the service of the Divinity; but like them too, are unfruitful, the consideration of them not leading to scientific improvement and natural discoveries. Nothing is more certain, however, than that we are en- tirely indebted to the consideration of final causes for the discovery of the circulation of the blood, for it was a clpse attention to the use of the valves of the veins which led to it. Is it im- possible, that the discouragement thrown out to the consideration of nature under this aspect, in which Bacon perhaps was not singular, may have retarded this discovery ? If the anatomists, who lived prior to this era, had contemplated the structure of the heart, with reference to final MEDICAL LOGIC. 163 cause, they could hardly have failed to have made out the circulation. It is a principle fully recognized by modern anatomists and physiolo- gists, as may be seen in Sir E. Home's late arti- cles on the digestive organs, in the Philosophical Transactions ; and the Germans have invented a word, Zweckmassigheit, expressive of that pro- perty of organs by which they are adapted to their ends, which cannot be translated but by circumlo- cution, into any language with which I am ac- quainted. If a modern anatomist were to find in a new animal of uncommon structure, just brought from New-Holland, a large muscular or- gan, the function of which was not obvious, he would not merely conjecture, but decide with the most confident certainty, that it performed some important function requiring powerful mechani- cal action, and would not rest till he found out to what purpose it was destined. A moment's se- rious reflection on the materials and structure of the heart, ought, in like manner, to have reveal- ed the circulation to physiologists, many ages before it was detected by Harvey. Upon the 164 ELEMENTS OF whole, if the subject of final causes, as an index of the operations of nature, be duly consider- ed, it will no longer be deemed unphilosophical to avail ourselves of them, as a clue for tracing some of the most secret operations of nature. Philosophers of the present age, infinitely in- ferior to Bacon, are in no danger of falling into the like error ; for there is a certain maturity of the human mind, acquired from generation to generation in the mass, as there is in the differ- ent stages of life in the individual man, in which respect the ancients are the young, and we are the old, as is justly remarked by the author in question : so that he who in these times so clear- ly sees the defects of Bacon, and well knows how to improve and extend his views, may be compa- red to the dwarf on the giant's shoulders, who sees further than the giant himself. Hippocrates too, though one of the most chaste and accurate observers of nature, and collector of facts, was by no means exempt from that spirit of system, originating in the innate propensity of mankind MEDICAL LOGIC. 165 to assign causes, however lightly and hastily, manifesting itself in hypothetical and gratuitous assumptions of general principles. And there cannot be a more flagrant exemplification of this, than in this great man referring all diseases to excess, defect, or vitiation of the four humours, blood, phlegm, black bile, and yellow bile. Equally absurd and gratuitous, equally disavowed by nature and observation, is the theory of Galen, grounded on the cardinal qualities of heat and cold, moisture and dryness. Nor can we quite acquit Sydenham of a like aberration from rea- son, in ascribing the different species of fever to the respective humours; and that the principle of cure consisted in expelling these humours; not indeed, in what he calls their crude state,b\it after they had been elaborated and prepared lor expulsion by coction. These ideas are per- fectly visionary or gratuitous, and in the present state of knowledge it would be held unworthy of a schoolboy to entertain them, unless indeed they were to be considered as a sort of metaphor- ical or allegorical terms, expressive of that pro- 166 ELEMENTS OF cess through which the animal economy must march in its road to health; and if it is hereby meant that nature ought not to be hurried noi put out of her way, by the over-officiousness of art, but to be left to the operation of time and the self working of nature like boiling and fermen- tation, a useful rule of practice is deducible from this theory. We derive from these aberrations the benefit of an example, at least, for they serve as a beacon and safeguard against that premature generalization of facts, which, in our times, is considered as one of the most sure criterions of an inferior capacity, or untutored mind. After the revival of genuine philosophy in the 17th century, it might naturally be expected, that medical science would immediately avail itself of its light, and partake of its benefit; but this was so far from being the case, that, in the first instance, it proved a new source of error, and threw fresh impediments in the road which was supposed to be thrown open to the improve- ment of rational medicine. The discovery of medical logic 167 the circulation of the blood, may indeed be con- sidered as one of the first fruits of the enquiries into nature begun in that age. But though this is a fundamental element in the economy of the living body, it throws little or no light on the principles peculiar to life, being purely of a me- chanical nature ; and abstractly considered, hard- ly admits of any application to the practice of medicine. On the contrary, this discovery, by its perverted application, tended to corrupt and mislead, by a loose adoption of the principles of mechanical philosophy, so well laid down in that age, by Galileo, and others. Borelli, in Investi- gating the force of the heart by experiment, es- timated it at 180,000 pounds; Hales, at 51 pounds ; Keil, at 1 pound. The mechanical powers of the stomach were, about the same time, subjected to experimental research, by Pitcairn, who gravely gave out, that he found this viscus in the human subject exerted a force equal to 12,900 pounds, in compressing food in the pro- cess of digestion. Others conceiving that chem- ical power had the chief share in this function, 168 ELEMENTS OF endeavoured to evince, that the change in the food was brought about by means of heat and fermentation. Sounder principles have referred these changes to powers, which have nothing in common with the mechanical and chemical powers which characterize inanimate nature.* But the most singular, the most celebrated, and 1 will add, pace tanti viri, the most mischiev- ous abuse and misapplication of the principles * Dr. William Hunter, whose peculiar sagacity and pre- cision of mind, detected at a glance the hollowness of such delusive hypothesis, and saw the danger which theorists run in trusting themselves on such slippery ground, was heard by the Author to express himself on this subject, in his public lectures, with that solidity of judgment, com- bined with facetiousness, which rendered him unparallel- led as a public teacher, in the following terms, as nearly as his memory serves him : " Some physiologists, Gen- tlemen, will have it, that the stomach is a mill; others, that it is a fermenting vat; others again, that it is a stew- pan : but, in my view of the matter, it is neither a mill, a fermenting vat, nor a stew-pan: -but—a stomach, Gentle- men, a stomach !M MEDICAL LOGIC 169 of natural science to the animal economy, are to be found in the works of Dr. Boerhaave. Towards the end of the 17th and beginning i* of the 18th century physiologists had begun to • perceive, that life was regulated by laws pecu- liar to itself, and that some other principles x than those of mechanism and chemistry, ought to be resorted to in explaining the operations, N whether of health or disease. The humoral pathojogy was that which prevailed in all anti- quity, except in the Methodic sect, founded about a hundred years before the Christian era by Themison, who introduced the principle of contraction and relaxation, attributes of the solids, as the causes of diseases. Glisson and Willis, in England, Baglivi, in Italy, and Hoff- man, in Germany, led the way in-this reforma- ation, in modern times, and there was a fair prospect of a more legitimate system of reason- ing being established. This was checked and retarded by the appearance of Boerhaave, in the beginning of the 18th century. He was a 170 ELEMENTS O* man of uncommon capacity, great erudition, and indefatigable industry, and a zealous and honest searcher after what he conceived to be truth. But probably, from the habitual application to his favourite study, chemistry, he suffered him- self to be deluded into what is now viewed as a most fallacious train of reasoning. This he de- livered in language so imposing, that his doc- trines prevailed universally for about fifty years in the Bchools of physic, and among the practi- tioners of all Europe : and it is equally astonish- ing and humiliating to contemplate, how the as- sent of an enlightened age, could have been won over to a body of doctrine, so puerile and shal- low.* * As a general efficiency of the art, to say the least, must have been more or less the effect of the prevalence of doctrines so fundamentally erroneous, is it to be wonder- ed at, that in that age there should have been a disposition in extra professional authors to ridicule and disparage the profession of physic ? This was observable not only in France, but in England; (vide the Spectator passim) and other works, particularly the Dramatic. MEDICAL LOGIC 171 So heavy a censure ought not to be brought lightly againit a person so celebrated in his day, who possessed many truly estimable quali- ties, and to whom science is much indebted for the improvement and diffusion of rational chem- istry, and for being the first who brought the thermometer into general use and notice. In proof of our allegations, let his theory of in- flammation, therefore, being one of his most im- portant and peculiar doctrines, be tried by can- did criticism and discussion. He held that the proximate cause of inflam- mation, was a morbid viscidity of the blood, ob- structing the course of circulation in the small vessels. The main fact brought in proof of this, was, the coriaceous crust formed on the surface of blood, .drawn from a patient labouring under an inflammatory affection. This is disproved by considerations so obvious, that it is truly unac- countable that they should not have occurred to this eminent physician and his followers. For, in the first place, it does not appear in blood 172 ELEMENTS OF taken away at the beginning of inflammation, as it certainly would, if the alleged, viscidity were the cause of the disorder.—Secondly, The same crust appears on blood, taken from a person la- bouring under inflammation from a mechanical injury, such as a fractured bone : a sure proof that it must be an effect, and not a cause.— Thirdly, This crust is merely the separated coa- gulable lymph of the blood, at all times present in it, and an essential constituent of it; and when it separates itself on the surface, it is from its fluidity being increased, and from continuing longer in a fluid state while in the act of cool- ing, so far is this appearance from arguing vis- cidity.—Fourthly, It is found usually in blood taken from pregnant women. This doctrine of Boerhaave, had an universal currency in the be- ginning of last century, and materially influenc- ced practice, as appears by the terms attenuant, diluent, &c. applied to medicines, and introduc- ed in conformity to the theory of thelentorof the blood, being one of the principle causes of disease. MEDICAL LOGIC 173 The like judgment may be passed on this au- thor's chemical principles of pathology, by which he referred the cause of a large class of diseas- es, to certain acrimonious conditions of the flu- ids. That morbid acrimony, in various forms, does exist, that its effects are considerable in producing and aggravating disease, that the elim- ination of vitiated and redundant matter, con- stitutes some of the most valuable resources of practical medicine, cannot be denied ; but it is equally manifest, that, as the fluids owe their re- spective healthy condition to a specific organic action, their morbid changes must be brought about by the same means; that is, in almost every instance, by means entirely foreign to the processes of chemistry in inanimate matter.* The only exception to these, are those already * It was in the School of Edinburgh, jwder Dr. Cullen, that the doctrines of Boerhaave received their chief over- throw. Culleo was the first who clearly marked, and de- fined the principles of life, as-^distinguished from those of dead matter. 15* 174 ELEMENTS OF mentioned at page 80, in regard to digestion, and the urinary secretion and concretions. The whole of the humoral pathology rested on a fallacious and shallow, though specious foundation. Boerhaave and his followers, in their principles and practice, assumed, that all alkaline bodies promoted putrefaction in the liv- ing body, and were therefore pernicious in a large class of diseases. No experiments are alleged in proof of this, and the doctrine was probably taken up on a slender and inconclusive analogy founded on the supposed tendency of chemical ferments ; particularly with regard to the vola- tile alkali (ammonia) which is one of the products evolved in the putrefactive decomposition of an- imal substances. But it has been ascertained by the experiments of Pringle, that alkaline sub- stances produce no septic effect on dead animal matter. Even if they did, it would not follow that they exercise any such power over living matter. MEDICAL LOGIC 175 What is called morbific matter by Sydenham, and other theorists, consisting of vitiated secre- tions ought to be regarded as the effect, and not the cause of disease. A due regard to them in practice is, however, of the highest importance ; for one of the principal means of relief and cure in many diseases, consists in the elimination of acrid and vitiated secretions. But morbific mat- ter, properly so called, that is, the matter of in- fection or contagion, produces its effects in quan- tities incredibly minute, and having excited by its specific stimulus a certain series of movements and changes in the solids, as happens in plague, small pox, or typhous fever, it is no longer trace- able, but vanishes and is lost sight of; so that there can be no practical question about effecting a cure by the elimination of it, the only question then being how to regulate the excited state of the solids. In the progress of this excitement, the same morbific matter comes to be generated and multiplied; but neither then is the object of practice to expel it; for, not to mention the im- practicability of this, the cure is effected by a 176 ELEMENTS OF provision of nature at the moment when the mor- bid poison is multiplied to the utmost, and when it might naturally enough be supposed to be most deadly. This act of nature consists in her then rendering the subject of the disease insensible to any farther impression of the morbid poison, as is so strikingly exemplified in the cases which re- cover from small pox ; and it is plain that if this, did not happen, every case whatever must prove fatal. We have seen melancholy proofs of the ex- treme errors in which physiologists have been be- trayed, by a false and perverted application of science, in the instances quoted from Pitcairn and Borelli. But, though the principles belong- ing to inanimate matter, were to be applied with the utmost precision of correct induction, they would go a very short way in ascertaining causes, I or guiding practice. It is only by touching the springs of life, that the actions of life can be reg- ulated. The early physiologists, in all their reasonings, have almost entirely overlooked all MEDICAL LOGIC 177 those energies peculiar to life which have been enumerated ; namely, the Generative, the Con- servative, the Temperative, the Assimilative, the Formative, the Restorative, the Motive, the Sensitive, the Appetitive, and the Sympathetic, not to mention the affections of the mind. And it is evident, that, as the actions of life must depend on the compound operation, and reciprocal influence of all these powers, those who propose to found practical medicine on their knowledge of the laws of life, must encounter such difficulties in estimating and ascertaining the result of them, as must appal the boldest the- orist. For, as in an algebraical problem, if any one element of the calculation should be omitted, or mis-stated, the result must be erroneous; so, if in taking our measures in medicine, due weight is not assigned to each of these influences, our practical inferences must be illusory. These sentiments are admirably expressed by Bacon in the following passage : Subjectum illud medicines (corpus nimirum humanum) ex omnibus qua natu- 178 ELEMENTS OF ra procreavit maxime est capax remedii; sed vicissim Mud remedium maxime est obnoxium er- rori. Eadem namque subjecti subtilitas et varie- tas, ut magnam medendi facultatem pmbet, sic maxime etiam aberrandi facilitatem. The circulation of the blood, the distribution of the blood-vessels and nerves, the relative posi- tion and co-aptation of the muscles, bones, and viscera, were well known before the middle of the last century ; but the existence of the lym- phatic system, as co-extended with the whole body, being unknown till that period, and as this knowledge was necessary for understanding the animal machine, professional men were in no de- gree qualified to account for its structure and diseased action. And who will affirm, that in the present improved state of knowledge, or even in the utmost attainable degree of it, he would be sufficiently confident that his measure of science was such that he could purely a prio- ri, act upon it with practical effect ? Could any one, though he had reached the very summit of MEDICAL LOGIC 179 anatomical and physiological knowledge, ven- ture, without the utmost risk of error, to predict or control the results of actions into which there falls to be considered, not only the properties of inanimate matter, but the variously combined operations of all those properties peculiar to life, which have just been enumerated, and the influ- ence of mental affections. And when it is fur- ther considered, what a mass of credulity and error has actually accumulated in medicine, from the presumptuous attempt to grasp at such ob- jects, and to make hasty and dangerous applica- tion of them to practice : when we cast our eyes upon our shelves, loaded with volumes, few of which contain any genuine profitable knowledge, the greater part of them composed chiefly of matter, either nugatory, erroneous, inapplicable, or mischievous, in which the dear bought grain is to be sought in the bushel of chaff, may it not be questioned, whether such researches have not tended more to retard and corrupt, than to ad- vance and improve practical medicine ? 180 ELEMENTS OF Those who are disposed to depreciate the practical value of anatomy, might allege that there are several of the most important functions upon which the knowledge of the structure of the dead body, though ever so minute and perfect, could throw little or no light ; nay, that there are some morbid circumstances and indications in the living body, ascertained by empirical ob- servation, in which mere anatomy is more apt to mislead than instruct. For example, it is known from experience, that impressions made on the external surface of the body, have a decided ef- fect upon the subjacent viscera, though there sub- sists no anatomical relation between them: thus cold applied to the external surface of the thorax or abdomen, will more readily excite inflamma- tion or spasm in the lungs or bowels, than in oth- er parts. And in curing inflammation of these viscera, the abstraction of blood from the adja- cent surfaces, will, as we learn from experience, have much more effect than a bleeding from the system, though there is no anatomical connexion between these parts, that portion of the circular MEDICAL LOGIC 181 tion which is in the skin, being as remote from that of the subjacent lungs and intestines, anato- mically considered, as any other part of the body. It has also been alleged, by the disparagers of anatomy, that even for the purpose of detecting the seat of diseases after death, the information obtained is extremely limited, or altogether falla- cious ; for whether it be from the morbid affec- tion existing in one organ, and the sensations from sympathy being in another; or that the symptoms of disease are different in constitu- tions, or from its not being possible to decide what morbid appearance has been the cause, and what the effect of the disorder, it so happens that those even who are most practised in morbid anatomy, are in numberless instances deceived as to the pre-conceived nature and seat of the disease, as investigated by dissection; so that often little other instruction is acquired, than a lesson of modesty and of distrust in ourselves. Are we then to admit, that the greater part of what we have been taught at the schools of phy- 16 182 ELEMENTS OF sic, and of what we have read, or may read, in books, is in no wise conducive to our practical improvement ?•—Far from it, for 1st. Though anatomy, physiology, and pathol- ogy, should be proved to be of little or no avail, nay of pernicious tendency in the practice of physic, the acquisition of these branches of edu- cation is nevertheless indispensable, in order to appreciate their value, and in order to be armed with antidotes against the influence of fallacious theories, and to obtain the guidance of true bea- cons, instead of false lights. There is nothing better known to those, who are conversant in medical practice, than that the most ignorant and shallow, those of the least learning, nay those of no learning at all, are the most addicted to hypo- J thetical reasoning, the most infected with pre- sumption and self-conceit. The only means, | therefore, of guarding ourselves from being mis- led by false theories, or by the misapplication of j those that are true, is to gain a thorough acquaint- ance with both. I say thorough, for the philo- | MEDICAL LOGIC 183 Bophic poet in stating the beneficial influence of a liberal education on the practice of life, does not say simply didicisse,* but fideliter didicisse; that is thoroughly, and in good earnest. In a word we should strive to attain that only crite- rion of substantial and profound knowledge, that of knowing how little we know. 2dly. The knowledge of Nature, in all its branches, is an indispensible requisite in the cul- tivation of the mind. It is highly useful, were it only as a palastra or gymnastic exercise of the understanding, by that salutary discipline of the mental faculties, implied in the acquisition of hab- its of attention, and the practice of the reasoning powers. Besides, all arts and sciences have a bearing on each other; and the history and phi- losophy of animal life, is surely as necessary an accomplishment to a physician, as any other branch of science or literature ; and we should Ingenuas didicisse fideliter artes, Emollit mores nee sinit esse feros. Ovid. 184 ELEMENTS OF be tempted to think, from this sense of the word physician, being peculiar to our language, that this notion especially prevailed in England. The study of nature is surely the most salutary of all intellectual exercises in the practical arts, particularly that of medicine, inasmuch as it comprises the knowledge of the mutual agencies, about which it is conversant. Mathematical ac- quirements are here comparatively but little ap- plicable ; for, the relations of quantity, about which the exact sciences are conversant, do not apply to the laws of organic beings, and is a pro- cess of thought quite distinct from that which is termed inductive, employed in the investigation of nature.* It is, in creating habits of self-con- trol, of steady and protracted attention, in which I conceive the main practical utility of mathe« matical studies in natural and moral sciences consists. '* See an Essay on this subject in the Philosophical Transactions, vol xlv., page 505, by Dr. Reid, of Glasgow. MEDICAL LOGIC. 185 3dly. The habitual meditation on natural cau- ses, tends to banish superstition, and to abolish the frivolous practices riveted in ordinary minds by early impressions and imposing authorities, or sanctified by immemorial usage and tradition. These illusions are found to prevail not only in rude ages, but in those of considerable civiliza- tion ; for, besides amulets, incantations, and va- rious other supernatural influences, certain prac- tices, hardly referable to any ascertainable agen- cy, either natural or preternatural, have prevail- ed in all ages. We find it, for instance, stated in very good Latin, by authors who flourished about 150 years ago, on the fanciful principle of what is called signatures, that turmerick is good for the jaundice, because it is of a yellow colour; that fox's lungs are good for the asthma, because that animal has strong powers of respiration, as is proved, by the long and hard run he makes when hunted ; that the testicles of the wild boar, reduced to powder, are good against barrenness, and kidney beans against diseases of the blad- 16* 186 ELEMENTS OF der ; and that the root of the ochis,* was indi- cated by its shape, to be a promoter of procrea- tion. And have we not seen in our times, per- sons of liberal education, of both sexes, who could persuade themselves that certain unmeaning mo- tions of the hand, called magnetising, could ex- ert sensible and salutary influences upon persons however distant ? But these need no longer blush for themselves," when they are told that some of our early instructors in the laws of na- ture, were nearly as absurd. Bacon did not dis- believe in amulets, sorcery, and magic; and Boyle seriously recommends the thigh-bone of * This doctrine of signatures was avowed by Dioscorides and Pliny, among the ancients, and after the restoration of learning, not only by that maniac Paracelsus, but by later writers, who maintained that it was conformable to princi- ples of reason and religion, that remedies should be stamp- ed as it were by the seal of the Almighty, as visible indica- tions of their virtues. It is hardly necessary, in answer to this to say, that it is equally untrue in fact, as it is at vari- ance with the ordinary administrations of Providence and the analogy of Nature. MEDICAL LOGIC. 187 an executed criminal, prepared in a prescribed manner, as a remedy in certain disorders. Nor can it be doubted, that practitioners would still be liable to fall into the like weaknesses, were they not, as they now are, habituated to the con- templation of the genuine agencies of Nature. The effect of the study of nature, in thus coun- teracting superstition, is no where, that I know of, so well expressed as in these lines of Virgil : Felix qui potuit rerum cognoscere causas, Atque metus omnes et inexorabile fatum, Subjecit pedibus sterpitumque Acherontis avari. Men of great capacity, and high mental attain- ments of a different class, also men of dignified stations, the heads of the law and the church, but who had not given their minds to such pur- suits, have been known to become converts to the most grovelling imposture, and dupes of the vilest quackery. When to these considerations it is added, that the fair exercise of judgment is impeded by the inordinate love of life, and fear 188 ELEMENTS OF of death, among those in the full possession of their faculties ; that it is not only impeded, but impaired in those who are under the influence of sickness; and when it is farther considered, that great allowance is to be made for those who become impatient from protracted sufferings un- relieved, and perhaps unrelievable by human skill, we shall be at no loss to frame an apology, nor find it difficult to account for persons of the best understanding, being occasionally betrayed by their own credulity, or that of their importu- nate and well-meaning friends, into the most ir- rational practices. In short, when we reflect how deeply interesting life and health are, par- ticularly to the affluent, and that they engage the hopes and fears of mankind so anxiously, as to pervert the judgment of the most enlightened, the popular mis-conceptions on this subject, ought rather to be a matter of pity and regret, than of surprise^ indignation, or derision. 4thly. Though physiological and pathological researches, even the most correct have had little .MEDICAL LOGIC 189 share in suggesting active and useful remedies, the greater part of these having been discover- ed in dark ages by fortuitous incidents, or in more enlightened ages by analogical reasoning, yet theories, though ever so visionary, afford useful suggestions. It is also very remarkable, that theories, though widely different, do often wonderfully coincide in matters of practice with each other, and with well established empirical usages, each bending and conforming, in order to do homage to truth and experience. It has been remarked, that Boerhaave, inro 11 owing out his fanciful and erroneous views of the animal econ- omy, stumbled upon some practices, the utility of which were sanctioned by experience. For example, he dissuaded from the use of sudowfics, and strong purgatives in pleurisy, from the con- sideration of their carrying off the most liquid part of the blood, leaving the remainder in that state of spissitude, in which he conceived the proximate cause of inflammation to consist. This is sound practice, however exceptionable the theory may be. He believed that the blood 190 ELEMENTS OF owed its red colour to iron, a doctrine found, by future chymists,* to be erroneous ; and with this in view, he strongly recommends the inter- nal use of this metal in chlorosis, and other ca- ses of chronic debility, in which there is an evi- dent deficiency of red globules. Though this remedy does not act on the principle which sug- gested it, it has nevertheless, been found to be a most efficacious plan of treatment in these disor- ders. Some of Sydenham's theories, such as those of fermentation and coction, have appear- ed so fanciful, so abhorrent to nature and sound philosophy, that it has been said, that if any one were to utter nonsense for a wager, he could hardly surpass what this eminent physician has delivered on these subjects. Nevertheless, as his expressions may be received as metaphors or allegories, fermentation and coction being ob- scure conceptions of those processes, types, and crises, which actually exist in nature, they are not so foreign to truth as they appear to be in * Brande and Vauqueliu. MEDICAL LOGIC. 191 their literal acceptation, and admit of an applica- tion practically useful, as has been already re- marked. Such suggestions as those of Boer- haave are at lest preferable to trials made at ran- dom, and are fairly admissible, if duly tested by experience. 5thly. It must be obvious to every reflecting mind, that those who have made themselves ac- quainted with the various organs and functions engaged in the animal economy, must have a great advantage in practice over the unlearned empirick, in discriminating the morbid affections from each other, and in varying accordingly the respective means of relief. For instance a phy- siologist and anatomist, from his knowledge of the intimate nature of morbid affections, the dif- ference of their seat, and other circumstances, is able to distinguish spasmodic from inflammato- ry pains a distinction which would not readily occur to an uncultivated observer, but of the most vital importance in practice, for the reme- dies required for the relief and cure of a spas- 192 ELEMENTS OF modic pain in the stomach and bowels, demands a treatment, not only different, but opposite, to that which proceeds from inflammation. It is only anatomical and physiological science that can exhibit to a practitioner a clear and vivid conception of these and other distinctions essen- tial to the safe and efficient treatment of disea- ses. 6thly. Whatever doubts there may be with regard to the degree in which anatomy is useful in physick, there can be no doubt of it, with re- gard to surgery, in which an accurate knowledge of the relative position and structure of organs is indispensible. Finally, the state of health ought to be fully known, as a standard by which to measure the magnitude, as well as to ascertain the nature of disease, as is well expressed in the following pas- sage of Galen : Cujusque morbi tanta est magni- tude quantum a naturali statu recedit—quantum MEDICAL LOGIC 193 vero recedat is solus novit qui naturalem habitum ad amussim tenuerit. But if the benefits, derivable to medicine from physiological science, are so limited, from what other and better source is improvement to arise ? The answer is, from accurate observa- tion ; in other words, from enlightened empiri- cism. It seems an abuse of words, to restrict the term science to'physiology and pathology, and to withhold it from those processes of the dnderstanding, by which facts are ascertained and accumulated, and useful inferences deduced from them, constituting observation. Shall we dignify with the title of Science, the absurd po- Htions of Pitcairn, the puerile and shallow hy- potheses of Boerhaave,|and Silvius, and deny it to those solid and applicable truths, the fruits of chaste observation and sober experience, ascer- tained by those methods of induction which it was the great aim of Bacon to recommend, and his great glory to introduce, as the only parent of legitimate, substantial, and useful knowledge? 194 ELEMENTS OF On the contrary, the truth seems to be, that a higher order of intellect, a more rare and hap- py genius, a more correct and better tutored un derstanding, is required to elicit practical truths by observation, than to invent theories. By empiricism, is vulgarly understood that knowledge of the virtues of divers medicines, which are supposed to have been ascertained by experience, as applicable to their respective maladies. A few of this description might be named, such as mercury in the venereal disease; fox-glove in a large proportion of cases of hydro- thorax ; the meadow saffron in most cases of ar- ticular gout; and above all, the citric acid, in sea-scurvy. But the exhibition of these, and the like remedies, constitute a very small pro- portion of the whole practice of medicine. The number, variety, and complication of dis- orders, is such, that the most acute exercise of judgment is called for to discriminate cases, to adapt the treatment to the indefinite diversity whichoccurs in actual practice, and to ascertain MEDICAL LOGIC 195 the most advisable methods of cure, all which can only be effected by applying the rules of in- duction, that is, of enlightened empiricism, to- gether with such lights as can be gathered from chaste and sober.theory. We have already more than once adverted to that profound wisdom displayed, in the constitu- tion of our mental faculties, whereby they arc made responsive to the constitution of external nature, in the same manner as our senses, and that this is strikingly exemplified by the suscepti- bility of the human mind to those associations and habits which arise out,of the repetition of events durably connected together by the constancy of the laws of nature. Unless these were indelibly imprinted, or recorded, as it were, in the mind during the early stage of our existence, life could not be maintained ; all those instincts, by which we pursue what is salutary, and eschew what is noxious and dangerous,being founded on this principle. The avoiding of fire, and of pre- cipices, the collision of hard and pointed bodies, 196 ELEMENTS OF may be quoted as examples of this. And what is called sagacity, in the adult stages of life, is a sort of approach to, or imitation of this intui- tive faculty ; but, instead of being the immedi- ate suggestion of nature, is acquired by cultiva- tion ; so that by practice we learn to connect cause and effect, means and end, operations which, in well turned minds, are performed with promptitude and precision, by interpreting fairly the appearances of nature, and stripping them of those adventitious fallacies, which mislead ordi- nary minds. In order to attain this, there are required an appropriate natural capacity, the good fortune of not having been beset with pre- judices in early life, an habitual exercise in the observation of nature, a candid and ingenuous disposition, an ardent love of truth, an exalted *ense of duty, a large store of facts in a correct and tenacious memory, the power of combining, comparing, and discriminating these, by an intu- itive glance, in the moment of applying them to the practical end in view. This is what is un- derstood by the term tact, in English and French, MEDICAL LOGIC. 197 tt>mT«xt«, in Greek, being that faculty by which principal facts are decided on, and is per- formed by an instantaneous, silent, and almost unconscious calculation and induction, to be met with only in minds, at once happily consti- tuted and highly cultivated. From this it will be seen, how vain all acqui- red knowledge is, without practical habits; for in the liberal, as well as in the mechanical arts, expertness can be attained only by frequent and long continued exercise of actual labour: and it is by a happy and appropriate figure, that those who become skilled in languages, painting, elo- quence, physick, or the common business of life, are said in Latin, callere, whence callidus, words derived from callus, that is, a horny substance formed on the hands of mechanical artisans, by- long and unremitting labour. Whatever the at- tainment may be which we aim at, whether men- tal or manual, nothing but practice will make perfect, there being a certain expertness in the exercises of the mind, as there is a slight of hand 198 elements of in mechanical operations, attainable only by long and assiduous application. This same law of nature is finely illustrated in the following passage from Cicero de Officiis : Nee medici, nee imperatores, nee oratores, quamvis, artis pracepta perceperint, quidquam magna laudis dignum, sine usu et excercitatione consequi possunt. Was it not clearly the intention of the author, in pla- cing physicians here in the foremost rank, to in- timate, that, of all professions, the hardest disci- pline of practice and experience, was required in physick ? For it would be presumptuous in us to think, that he meant by placing us first, to concede to us the precedence in dignity over generals and orators. This collocation of words, may be merely for the sake of euphony, or may- be a climax in which he means to assign us the lowest post. Be this as it may, our best thanks are due to this great statesman, orator, and phi- losopher, for admitting us into such good compa- ny on any terms, after what has been said of us, / by Dr. Conyers Middleton, in his dissertation, ' De servili conditione Medicorum apud Romanos. medical logic 199 From all that has been said, we ought to be in some measure qualified to come to a decision on the celebrated question of the comparative merits of the empirick and dogmatic methods of culti- vating physic. It seems pretty evident, that if either method were employed exclusively, or carried to an extreme, the art of physic would suffer, both in its efficiency, and its prospects of future improvement. It has clearly appeared, that, under such a complication of causes, influ- encing the operations of life, it would be utterly hopeless to decide any point purely and strictly a priori, and that it is absolutely necessary, that experience be called in as an aid and a test to the inferences of theory. On the other hand, a blind empiricism would be found deficient, with- out that discriminative judgment, founded on an acquaintance with the laws of life, and without those enlarged and correct views of general na- ture, by which the excess of credulity and scep- ticism is equally repressed. This question was much agitated in antiquity, and is most ingen- iously, eloquently, and judiciously discussed by 200 elements of Celsus, in the preface to his excellent work. He evidently leans to the side of empiricism, which, in the very crude state of anatomy and physiology in that age, certainly argues his good sense ; but he by no means explodes the study of the structure and functions of the body, as of no practical utility, and concludes with the follow- ing recommendation, or rather apology, for dog- matism : " Ista natura rerum contemplatio, quam- " vis non Jaciat medicum, aptiorem tamen medi- M etna reddit." The conclusion therefore upon the whole is, that these two methods ought not to be regarded as adversaries, but as allies; and that good sense will consist in excluding neither, but in fairly ap- preciating what is due to each. This is a com- promise congenial with that which the poet pro- poses between Genius and Study : ——— Ego nee studium 6ine divite vena, Nee rude quid possit video ingenium alterius sic Altera poscit opem res, et conjurat amice. Hon. SECTION IV, id. Source of Error.—Diversity of Constitutions. The second head of causes, which retard and obstruct the progress of medical knowledge, is the Diversity of Constitutions. Practical knowledge in medicine, as in every other art, proceeds on the assumption, that the course of nature is steady, and that what has a given effect on one human subject, will have the like effect upon another. From what has al- ready been said, however, it is manifest, that this holds less strictly in the living human body, than in any other object in nature to which art can be 202 ELEMENTS OF applied. The simplicity of the laws of inani- mate nature, admits of the most certain inferen- ces, whereas the indefinite action and re-action of the numerous faculties peculiar to life, enu- merated in the first section, add greatly to the difficulty and uncertainty of experiment and ob- servation, as already set forth. But this is not all; for constitutions being gifted with various degrees of each of these faculties, an endless va- riety is found to take place among individuals, giving rise to that uncertainty in the results of medicine, which has brought upon it the charac- ter of a conjectural art. This diversity is but little observable in mere animals, and seems referable to the artificial habits belonging to be- ings capable of exercising reason, and analogous to that variety in the stature and form of the body, and in the features of the face, as well as in the tempers, and dispositions, and understanding of individuals, peculiar to the human species. What is here meant, is not exactly synonymous with what is technically termed idiosyncrasy, by MEDICAL LOGIC 203 which is understood, if I mistake not, individual peculiarities, or rare exceptions to the usual con- stitution and habitudes of the human body. The diversity which is here meant, answers more properly to what has been termed Temperaments, when applied to the original constitution of the system, such as scrofula ; and Pre-dispositions, or Diatheses when applied to acquired habits, such as gout and scurvy. They run through large por- tions of mankind, and in some degree, diversify the whole species ; insomuch, that the form and symptoms of the same disorder, and the effects of medicine, are hardly alike in any two persons, and in many are widely different. What, for in- stance, can be more different than the common cases of small pox? In some, the disorder is so slight, as not to interrupt the business of life, even when not communicated by inoculation; while in others, it is as malignant and mortal as the pestilence : and there are all the intermedi- ate shades, diversified to infinity by the number of pustules, the degree and kind of febrile action. There is a like diversity, in some measure, in all 204 ELEMENTS OF diseases. The different degrees of susceptibili- ty to small-pox, and other morbid poisons, may also be adduced as a striking exemplification of this diversity of natural constitution ; for, of per- sons equally exposed to casual infections, num- bers escape altogether. And were it not for this diversity, in point of fatality and susceptibility, in small-pox, plague, and other epidemics, the human species might be extirpated by any one ef them. There could hardly be adduced a more striking example of the unaccountable peculiarity of con- stitutution, than the familiar fact of the diversity of individuals with regard to their various suscep- tibility of sea-sickness. Some are so constituted as never to be at all affected by it; the majority of those who are exposed to its causes become exempted from it by time : but some are so con- stituted, as never to get the better of it, though ever so long at sea. It would be vain, I believe,' to search for any other cause of this, than that primordial and inscrutable peculiarity in which MEDICAL LOGIC. 205 all the other diversities of the human constitution originate. The like diversity is observable in the opera- tion of certain remedies. What can be more dif- ferent, and even opposite, for instance, than the operation of opium on different constitutions ? It is a medicine of such eminent and beneficial ef- fects in the majority of constitutions, by procu- ring sleep and assuaging pain, that the art of me- dicine could hardly be practised without it. Yet there are innumerable individuals so constituted as not to admit of relief from it : some in which it is so far from producing these benignant effects, that it causes great inconvenience and distress, such as sensorial disorder, sickness at stomach, nervous tremors, febrile heat and anxiety : some in which, though it disagrees in ordinary circum- stances, it will procure relief in cases of intense spasmodic pains : some, in which it proves in- 18 206 ELEMENTS OF effectual, or noxious, in every circumstance.* There is more or less diversity, though not so remarkable as here, in the operation of most, if not all medicines, particularly with regard to the dose required, to produce the same effect on dif- ferent subjects. It may farther be remarked with a view to the ascertainment of the correct inferences which sound practice demands, that the effect of medi- cines, and other powers, affecting the human body, are very different in the same individual, at different times and in different circumstances. I have known opium disagree with persons in their early life, and agree with them in more ad- vanced age. This same medicine, though high- ly adverse to some constitutions in ordinary cir- cumstances will, as mentioned above, procure * Professor Kuhn, of Philadelphia, mentions a species of rhus growing in Pennsylvania, the exhalations from which are entirely innocuous to some persons, while they are deadly to others. American Medical and Philosophical Register. MEDICAL L0G1L. 20/ relief under severe spasmodic pains, such as those from gall stones when unaccompanied with inflammation. An example applicable to the same subject, may be taken from the controver- sy regarding the safety or danger of sleeping in damp sheets. A very eminent Physician* has argued, that the opinion of this being dangerous, or even hurtful, is little better than a vulgar er- ror. Others are equally persuaded of the re- verse of this. The truth seems to be, that to those who are in high health, and have a vigorous cir- culation on the surface of the body, this practice is harmless ; but in those who from age, infirmity, or natural constitution, have a languid circulation in the cutaneous vessels and the extremities, the flow of blood to parts so remote from the hearths checked by the cold; and dangerous de- terminations are made on internal parts. * Dr. Heberden. See Transactions of the College of Physicians, vol. ii. page 521. London, 1772. 208 ELEMENTS OF It may be fairly questioned, whether diversity of constitution has had its due weight in the con- templation of medical observers. It is evident, that unless we are fully aware of it, we may ex- pose ourselves to the same fallacy, as those who in the fable made the contradictory report with regard to the colour of the chameleon. This consideration strongly points out the necessity of accurate induction, extensive observation, and the comparison of facts. In a limited observa- tion, to which only one or more cases of the most infrequent effects of a medicine may have occur- red, there is a hazard of erecting an exception into a rule, by mistaking these facts for instan- ces of the universal effects of it. It is only by a sort of arithmetical computation, founded upon large averages, that truth can be ascertained ; and hence the danger of founding a general prac- tice on the experience of a single case, or a few cases. This danger of being misled by excep- tions, is greatly encreased by the publication of single extraordinary cases, which too much abound in the numerous periodical journals of MEDICAL LOGIC. 209 this country, tending more particularly to puzzle and distract young practitioners. This seems to be the chief cause which has retarded the pro- gress of vaccination in England above any other country. The peculiar exuberance of our press brings into notice a few adverse cases, which produce an undue influence on weak minds, not aware that for every such case, there are many thousands of favourable cases which are never heard of. Does not the diversity of constitution also ac- count, in part, for the proverbial discrepancy im- puted to medical opinions, and the deplorable controversies which have too often existed among practitioners and writers ? Were the members of the profession fully aware of this cause of dif- ference, would it not lead them into an amicable endeavour to reconcile and account for the in- consistent reports of their respective modes of practice, instead of engaging in contentious argu- mentation, not always carried on with that dig- 18* 210 ELEMENTS OF nified coolness and candour, which becomes a lib- eral profession. There is nothing in which a young practition- er should be more on his guard, than being mis- led by the sweeping dogmas of schools, and the indiscriminate practices of sects, or of favourite practitioners. This evil may be conceived to grow up in the mind of a tyro, in the following manner. Let him at his outsetting, either at a school of physick, or in witnessing the practice of some private practitioner, meet with one or two impressive and imposing cases, terminating happily under a particular treatment, this will attach him undeviatingly to the like style of practice for the remainder of his life, unless his mind should be duly prepared by the caution here inculcated. In a typhous fever, for in- stance, it may be the lot of one practitioner while serving his novicate, to have witnessed, ei- ther under his own care, or that of some re- spected instructor, one or two striking cures, from an exhibition of strong cordials : another MEDICAL LOGIC 211 has witnessed life saved, as he believed, by well timed and free evacuation from the bowels : to a third, it has occurred to see one or two cases, which being left in a great measure to them- selves, have, by the salutary efforts of kind na- ture, been conducted to a safe termination.— Now, each of these having from his limited op- portunities of observation, imbibed a persuasion, that his own method is universally applicable, is guided by it as the rule of his future practice. Nothing seems more clear to a comprehensive mind, than that they are all four right, in so far as relates to their respective class of cases ; and that they are all wrong in regard to the general principles of practice. The cordial method of the first, is well calculated for those constitu- tions, in which the principles of life are on a re- duced scale, either by original constitution, or by being brought to a low ebb by previous exhaus- tion ; and in some such cases, the cordial prac- tice in its utmost extent is required to save life. The second style of practice, is well calculated for those cases, in which there is a redundant 212 ELEMENTS OF and vitiated secretion of bile, or other humours, in the viscera of the abdomen. It is incredible with what rapidity and abundance vitiated fecu- lent matter will in some cases be generated and accumulated ; insomuch, that one of the main points of practice will consist in a vigilant atten- tion to the state of the bowels, and the adminis- tration of proper purgatives. Such cases occur most frequently in tropical climates, and in the autumns of temperate climates. On the other hand, I have met with continued fevers in which there was no departure from nature in the quali- ty of the alvine discharges.—In the third case, general or local bleeding is not unfrequently in- dicated, by the state of the pulse, or by the heat, pain, tension, or tenderness to the touch, evin- cing sanguineous determination on vital parts.— The last method, that is the negative, or what has been styled the Expectant, is well adapted to those cases which have none of the foremention- ed tendencies, and to which the self-healing powers of nature are all sufficient. There are many cases, in which a mixture of these methods MEDICAL LOGIC. 213 is advisable ; and in most cases the practice re- quires to be varied in different stages of the fe- ver. These remarks will apply also to puerpe- ral fever and scarlet fever; and it is fondly to be hoped, that a due attention to them would put an end to those deplorable controversies, carri- ed on in some instances with much acrimony and illiberality, to the great discredit of the profes- sion and detriment of the—sick. When practi- tioners become fully aware of these varieties, it appears.that no more than an ordinary degree of discrimination and sagacity are requisite to reg- ulate the treatment conformably to them. In a work of Dr. Hamilton's on the utility of purgative medicines, these remedies are recom- mended not only in typhous fever, but in scarlet fever ; and he does not qualify this advice by stating that there are any cases to be expected. I have certainly seen cases of both these sorts of fever, without any perceptible deviation from the healthy state in the secretions of the abdo- men, and in which purging would seem not to be 214 ELEMENTS OF called for, particularly in scarlet fever, in which the employment of purgatives, as a general prac- tice, is considered by the best practitioners in this quarter, as highly pernicious; and there are few symptoms so certainly fatal in this disease, as a spontaneous diarrhoea. Though it is to be wished that the author of this instructive work had expressed himself in a more qualified man- ner, he has by no means merited the severe crit- icism inflicted by a German Journal, where it is said, that " Hamilton's recommendation of pur- " gatives in typhous fever, only proves what " blunders and absurd methods of treatment the " human body can, in certain circumstances " withstand."* Whatever error our author may have committed, these journalists have been guilty of a still greater, by denying the utility of the practice in all cases whatever. And I beg to repeat that great benefit has been derived from Dr. Hamilton's work ; for I remember the time * See Bibliotek der Heilkund H. Band, p. 184, Berlin, 1809. MEDICAL LOGIC 215 when much less attention was paid to the quanti- ty and quality of the alvine discharges, as indi- cations of the diseased state of the bowels, than has been the practice since its appearance. As the present subject of discussion regards the distinctive application of medicine, I shall take the liberty of making one or two more re- marks on this work, which I should not stop to do, if I did not entertain a high respect for its au- thor. One of the diseases, in which he recommends, unqualifiedly, the employment of this treat- ment, is the chorea sancti Viti. The qualified adoption of this practice, I am so far from disputing, that I lately imitated it with success in the case of a young female from the East- Indies, in which the vitiated quality, incredible quantity, and long continuance of alvine sordes, was such as to bid defiance to all the principles of physiology and pathology, to account for. But in a young English female, under my care, 216 ELEMENTS OF about the same time, for the same complaint, nothing preternatural being observed in the al- vine discharges after the first clearance of the intestines, she was successfully treated by the cold bath and metallic tonics, chiefly the sul- phate and oxyde of zinc, and the recovery was effected in a shorter time than in the other case. I found that, in St. Thomas's Hospital, the like success attended the latter treatment of this disease. Opium, hyosciamus, and leeches to the temples, were found good auxiliaries. There is another point, in which I feel myself bound to declare my dissent from this respecta- ble practitioner. He denies that different spe- cies of purgative medicines possess distinct pow- ers over the different species of matter to be evacuated and contemns the notion of chola- gogues, hydragogues, &c. In the course of my experience, there is no practical fact with the truth of which I have been more satisfied, than the specific action of the various species of these remedies in stimulating different organs, in dis- MEDICAL LOGIC 217 lodging and eliminating different species of cor- rupted secretions, and other feculent matter. What, for instance, can be more different than the operation of aloes acting as a mere eccopro- tick on the muscular fibres of the intestines, and only in a particular portion of them, namely, the descending colon and rectum, and expelling only solid faeces, from that of elaterium, of which half a grain, taken three or four times at the interval of half an hour, evacuates im- mense quantities of serous fluid, exhibiting an example of the wonderful power of sympathy : for an impression made on the internal surface of the stomach, by a few particles of matter, conveys by magic, as it were, an impulse to the most remote extremities, rousing their absorb- ents to action; and, in case of cedema there, , awakening the sleeping energies of these vessels, which, like millions of pumps at work, transmit the morbid fluid to the intestines and urinary j passages, effecting a detumescence of the hydro- .. pic limbs in the course of a few hours, and af- , fording a striking illustration of the sympathetic 218 ELEMENTS OF action of medicines, and an instructive example of the operation of those of the sorbefacient class. Again, what can be more different than the operation of neutral salts and calomel, the former exerting but little influence beyond the surface of the intestines, exciting the action only of the serous exhalants, mucous glands and follicles j while the other, by extending its stim- ulus to the biliary ducts and pores, detaches foul congestions, which the other could not reach. Ipecacuanha acts specifically on the stomach, and other medicines on other portions of the intestines and on different glands ; and it is pre- sumable, that no two articles stimulate equally the same organs. It is for this reason that com- pound purges are found more beneficial than simple articles, a* they touch a greater number of the intestinal organs.* The combination * See an Article, by Dr. G. Fordyce, in the second Vol- ume of Transactions of a Society for the Improvement of Medical and Surgical Knowledge, p. 214, London, 1800.— Without reference to this, or any other mode of reasoning'. MLDICAL LOGIC. 21fe found most convenient and efficient, and most employed as a general purgative in the practice of this metropolis, when no specific operation is indicated, is a mixture of purging salts and senna, a combination, but little employed by Dr. Ham- ilton. Dr. Cullen used to say that senna was one of the best purgatives, if it could be divested of its griping quality, which he had in vain at- tempted by manna, and various aromatikcs. It has been found, that the combining of it with salts completely answers this purpose. After the exposition which has been made of the great variety of constitutions, would it be too much to affirm, that all the practical works in existence ought to be re-composed, in order Sydenham (see his Treatise on the Gout) and other prac- titioners have recommended empirically a mixture of medicines of similar virtues. One of these being asked by his patient why he put so many ingredients into his prescription, is said to have answered more facetiously than philosophically, " in order that the disease may take which it likes best." 220 ELEMENTS OF &C. to insert in them, for the benefit of Inankind, and the credit of the profession of physick, the fol- lowing qualifying words. " The practice here recommended will be found to answer in a great majority of cases ; but in imitating it, there are numerous exceptions to it, which it behoves eve- ry judicious and conscientious practitioner to bear in mind." There is a sentiment, similar to (this, in Dr. Anderson's Agricultural Tracts. He says, " the inutility of publications on agri- culture, has chiefly been owing to the authors not specifying clearly the nature of the soil to which the practice recommended applies." SECTION T. id Source of Error—the Difficulty of apprecia- ting the Efforts of Nature, and of discrimina- ting them from the operations of Art. The next obstacle, in the way of our practical judgments, is the difficulty of ascertaining to what degree the efforts of nature operate in the restoration of health, in what cases, and to what point the interposition of art is necessary and sal- utary, and how the operations of nature and of art are to be distinguished from each other. 19* 222* ELEMENTS OF The self-healing powers of nature have al- ready been adverted to, in enumerating the prin- ciples peculiar to life : and that there is such an energy implanted in animal nature, must be ob- vious to the most illiterate and careless observer; for both, in mere animals and in man, not only wounds are cured, but various maladies are re- moved, without any interposition of art. This is effected by virtue of the energies which sus- tain life from the beginning to the end of its ex- istence, in opposition to the noxious and de- structive causes with which it is incessantly as- sailed, and perpetually at war, as it were, and has been designated as one of the fundamental laws of life under the title of the Restorative principle. Such, indeed, is the virtue of this self-preserving and presiding energy, that what- ever deserves the name of cure, is referable to it as the work of nature; for the operations of art consist merely in regulating it, either by exciting it when languid, restraining it when vehement, in changing morbid action, or in obviating pain, or irritation, when they oppose its salutary cour- MEDICAL LOGIC. 923 ses. This, I apprehend, is so well understood among well educated physicians, that the word cure, as applied to their own merits, is proscribed as presumptuous, and rarely, I believe, escapes the lips of any practitioner, whose mind is duly tinctured with that ingenious modesty which characterizes the liberal and correct members of the profession. It has already been fully argued, in the begin- ning of this Dissertation, that in the human spe- cies at least, the interposition of art is founded in reason, and necessary for the preservation and restoration of health ; and it would be highly de- sirable, if the provinces of nature and art, could be defined by some precise line of demarcation, in order to prevent mutual encroachments; and so to instruct the practitioner, that he shall nei- ther be too sanguine and officious, nor too supine, inert, and despondent. Cases occur in which the perfection of skill consists in abstaining from all active remedies, either because the reitera- tive powers of nature are adequate, or because 224 ELEMENTS OF the disorder is too powerful and untractable to be subdued, as in the irremediable alteration of structure in vital organs. Youth and inexperi- ence can seldom be brought to see cases in this light, and are, therefore, apt to institute an ac- tive and prejudicial treatment, when greater age and proficiency are satisfied either with looking on and consoling, or confining themselves to a palliative practice. No precise definition nor graduated scale of diseases expressive of the de- gree in which they are curable, has been at- tempted in so far as I know ; and it must be con- fessed, that on a subject so vague, little more can be effected than by that approximation which good sense and judgment will suggest, as applicable to individual cases. Nevertheless, the Author submits the following outline as the basis of a more general rule on this subject. It is founded on a classification of diseases as they af- fect the three great vital cavities of the body. Those of the head, such as epilepsy, mania, hem- iplegia, and hydrocephalus, seem to be the least under the control of art, owing probably to the MEDICAL LOGIC. 225 very delicate texture of the brain : those of the abdomen on the other hand, such as inflammation of the bowels, bloody flux, and cholera, afford us proud triumphs of medical efficiency ; for it will be conceded by the most sceptical, that without the intervention of art, a great majority of such cases would prove fatal: those of the thorax, in- termediate to the other two in situation, are also intermediate as to the degree in which they are medicable, the chief of them being inflammation of the lungs, asthma, and consumption ; the two first affording the most unambiguous proofs of life being frequently saved by a vigorous interposi- tion of medical agents, while the last bids defi- ance to all the resources of art.* * By consumption, is here understood that disease in which the parenchymatous structure of the lungs is irrem- ediably injured, the proximate cause being abscesses con- sequent on tubercles. There are cases of a curable na- ture, which, from a similarity of symptoms, are not unfre- quently mistaken for the true phthisis pulmonaris, and of which the proximate cause is a chronic affection of the mucous membrane lining the tracheal and bronchial sur- faces. 226 ELEMENTS OF One of the principal steps to be taken for as- certaining the efficacy of remedies, as distin- guished from the restorative efforts of nature, will consist in obtaining an accurate history of diseases, particularly in circumstances in which little or no artificial means have been employed, Without some such standard of comparison, the utmost ambiguity, with regard to the effects at- tributable to medicine, must prevail: and there is perhaps no subject more exposed than this, to that most common of all fallacies in the general practice of life, the mistaking the post hoc for the propter hoc. Some of the early records of physick are very valuable in this respect. Hip- pocrates, for instance, in his epidemics, gives a number of minutely detailed cases of fever, in which little or no medicine was employed, few having been then discovered. The results are in support of the argument of those who main- tain the opinion in favour of artificial means, for the proportion of mortality being that of twenty-two on forty-five, far exceeds that of any MEDICAL LOGIC 227 modern statement in the like cases.* In the present times, so many remedies are known, that the omitting of them, with a view to ascertain the comparative powers of nature and art, would be deemed an unwarrantable experiment; so that an inquisitive mind, prone neither to scepticism nor credulity, but anxiously and hon- estly intent on observation, finds it nearly impos- sible to institute satisfactory inductions for the regulations of practice. On the other hand, in rude ages, and even in those ages in which science has been in some degree cultivated, there are examples of artifi- cial means being carried to a most pernicious length. It is related by Ambrose Pare, the fa- ther of French surgery, who lived in the middle and end of the 16th century, that it was the cus- *See Medico-Chirurgical Transactions, vol. iv. fpage 128, where this subject is treated more in detail, in an ar- ticle on the proportional prevalence of mortality of disea- ses, by Sir G. Blane. 228 ELEMENTS OF torn to apply boiling oil to recent wounds, and to perform amputations with red hot knives. Being surgeon to the army, he observed, on one occasion after a battle, that from the impossibil- ity of overtaking all the cases by regular dressing, some were apparently neglected, no hot oil be- ing applied; but having remarked that these cases were next day in an incomparably better state than the others, his eyes were opened to the absurdity and barbarity of the old practice. This induced him to suspect the like errors in other points, and he was the first jn France who promulgated rational methods of treating surgi- cal cases.—A similar incident is related of the great father of surgery in our country. John Hunter in early life, was employed as a surgeon at the siege of Belleisle, in the year 1761. Af- ter an action some French soldiers, who had gun shot-wounds, hid themselves in a barn for four days, at the end of which time their wounds were found in a much better state than those whose wounds had, according to the universal method of treatment at that time, been dilated by the MEDICAL LOGIC. 229 knife. This of course proved a lesson for future im- provement. Many casual instances occurred in the late war, tending to the like inferences. It was found after the battle of Waterloo and oth- er battles, that many of the wounded officers and men who were left on the field all the succeed- ing night, or even longer, as at the battle of the Pyrennees, where the ground being woody and full of rocky ravines, the men were not immedi- ately discovered, were found in a much better state than those who had the advantage of warm quarters and alimentary cordials. This was more particularly the case with regard to gun- shot wounds in the thorax. But this observation will not apply to such wounds as consist in se- vere lacerations, and fractures demanding ampu- tation : for it has been established by most cor- rect evidence, that great benefit in such cases is derived from immediate operation,* and much * See Observations by Mr. Copland Hutchison. 20 230 ELEMENTS OF disadvantage from a deferred one.* The bene- fit supposed to be derived from the Royal touch in scrofula, has been ascribed by some author to the like cause ; for this is a disease in which ac- tive practice, particularly the use of the knife, has been proved hurtful; but when, from the confidence in the touch, these practices have been omitted, and nature alone allowed to act, the cure has been effected, not to mention the effect of confident hope in promoting the cure of this and all other disorders. * This is a point of the highest practical importance, and was first stated in a clear light by Mr. A. Copland Hutch- ison, in a work published by him in 1816, entitled, " Some Practical Observations in Surgery," and in another work, by the same Author, in the following ye ar, entitled " Some farther Observations on the proper period for Amputating in Gun-shot Wounds." See also an article in the Transac- tions of the Medical and Chirurgical Society, for 1817, by Dr. Quarrier, Surgeon of His Majesty's ship Leander, in • the action off Algiers, in August 1816. The expediency of this practice seems since to have been admitted, in the ample Treatise on Surgery, by Mr. Guthrie, London, 1821 MEDICAL LOGIC 231 We learn that in the dark ages, it was a com- mon practice to apply salves and bandages, not to the wound itself, but to the weapon by which it was inflicted, the wound being bound up with a simple bandage for seven days, without being inspected or disturbed. This is said to have originated among a sect of absurd mystics, cal- led the Rosicrusians. It is quite conceivable, and indeed conformable to what has been said, that the wound in this situation would make greater progress in healing by the first intention, than when disturbed by daily dressings and ap- plications. And it is not a little curious, that a method founded on the most blind and gross ignorance of nature, should conicide with a method founded on the most enlightened views of nature, while the half-learned were involved in error. It is also difficult to mark where nature ends and art begins ; for, in the rudest state of soci- ety, or in the most destitute circumstances of life in civilized society, though no article of the 232 ELEMENTS OF Materia Medica should be administered, there will be an exercise of judgment called for in the application of heat and cold, of fresh or con- fined air; also of diet and exercise ; and by the injudicious regulation of these, nature may be as much thwarted as by a perverted use of reme- dies. And is not the scope of nature more like- ly to be mistaken by the ignorant and vulgar, than by persons of cultivated minds ? But the warmest advocates for the sufficiency of the ways of nature, ever so wisely interpreted and conducted, will not controvert the evidence in favour of such remedies, as bleeding in pleurisy, or mercury in the venereal disease, and of cer- tain remedies, whether depletory or cordial, in various circumstances of continued fever. It is manifest, therefore, that a large share of medical skill must, at all times, and in all cases, consist in ascertaining to what extent nature may safely and advantageously be entrusted with the cure of disease, so as to supersede the un- seasonable and injurious interposition of art, and MEDICAL LOGIC. 233 in discerning, as far as possible, what is due to the self-healing power of nature, and what to the co-operating resources of skill, which the practitioner is called upon to exert for the pres- ervation of life, and the restoration of health. Without some principle, more or less definite on this subject, he would be continually grop- ing in the dark, and would feel himself full of discouraging hesitations and painful reflec- tions. For if his mind had a bias to scepticism, he might on some occasions be unable to satisfy himself, in case of a fortunate result, whether his patient had recovered by virtue of the means employed, or in spite of them; and in case of a fatal result, his feelings would be still more distressing; for what could be more painful to a conscientious and sensitive mind, than the un- certainty whether the loss of the patient was most imputable to the remedy or to the disease : if on the other hand, he should be prone to cre- dulity, he might be so far blinded as, bona fide, 20* 234 ELEMENTS OF &C. to plume himself, and to congratulate his patient on a great cure, in what may have only been a great escape. SECTION VI. 45 and humanity, he does not judge it necessary to dilate farther on this subject, a circumstance at which he sincerely rejoices, not only for the good will which he bears to mankind, but be- cause it releases him from the painful necessity of differing in such strong language as formerly, from Gentlemen, for whom he in other respects, dical officers of the West Indies; for by official documents just arrived, it appears, that, in consequence of the infatua- ted neglect of police and quarantine regulations, the most tragical events have taken place among the officers and men of the army on that station. In the Island of Tobago, there died last year of this epidemic, more than two-thirds of the troops which had arrived from England—only seven men escaped the attack of the fever, and the like calamity oc- curred in Jamaica. The only consolatory circumstance in these documents is, that at one of the Islands (Barbadoes) where separation was enforced, there was an exemption from this calamity; a circumstance which has at length in- duced the Medical Board of the army to enforce, by posi- tive orders, what they have found it impossible to effect by the more liberal and lenient powers of persuasion and rea- son. 23 266 ELEMENTS OF entertains the most unfeigned regard and es- teem.* * The authorities and argument against the existence of contagion, will be found detailed in a work on this subject by Dr. Bancroft, comprizing all that can be alleged on that side of the question, entitled, " An Essay on the Disease called Yellow Fever,'' Lond. 1811, and a sequel to it in 1817. On the side of contagion, the chief authorities are the travels of Don Antonio Ulloa and Don Jorge Juan,—a tract by Dr. C. Chisholm, entitled "An Essay on the Ma- lignant Pestilential Fever introduced into the West India It- lands from Boulam," Lond. 1795,—the Medical Sketches of Sir James Macgregor, Lond. 1804,—a Treatise on this subject, by Mr. Pym, Inspector of Army Hospitals, Lond. 1818,—an Article in the Medico-chirurgical Transactions, vol. v., by Sir Joseph Gilpin,—numerous articles in the Medical and Philosophical Register of New-York,—articles in the Edinburgh Medical Journal for 1796 and 1805,—sep- arate works by Sir James Fellows and Dr. Caillot, the lat- ter in French,—the Report of the French Commissioner! at Cadiz, in 1804. But perhaps the work the most elabo- rate in point of industry, the most forcible in point of argu- ment, the richest in facts and observation, is one in Spanish, by Dr. Arejula, of Cadiz. MEDICAL LOGIC 2 67 The only oth?r example which shall be addu- ced of a disease, the name of which is in danger of misleading us with regard to its nature, shall be Dropsy. The most common notion that used to be en- tertained of this disease was, that in all cases, it essentially consists in a debility of the powers of life, which in most instances had been exhausted by intemperate living, inducing visceral obstruc- tion. The deficiency of the powers of assimi- lation, a diminished proportion of the red glob- ules and gluten of the blood, a decay of the mus- cular powers, as also of the restorative princi- ples manifested by the proneness of wounded parts to fall into gangrene, the occurrence too of this disease after profuse haemorrhages, and from the circulation being mechanically impeded by organic diseases of the heart,* all militated * See Burns, on Diseases of the Heart.—Two striking cases of this sort occurred to myself; one, that of a young soldier in St. Thomas's Hospital; the other, that of an old 268 ELEMENTS OF in favour of this opinion. On the other hand. there are cases possessing the pathognomic char- acters of Dropsy, that is, the accumulation of colourless fluids in the cellular membrane, and in the great vital cavities, attended with scanty urine, in which none of these debilitating cau- ses exist. It will sometimes arise idiopathically, and without visceral affection, as I have seen it do, even in very early life ; also after scarlet fe- ver, and after sudden exposure to damp and cold, without any other assignable cause. It has been observed, that, in a large proportion of ca- ses, great quantities of albuminous matter, such as belongs to the serum of the blood, is found in the urine. It has been farther observed, that with regard to practice, so far from this disease being treated as one of debility, bleeding and other lowering and febrifuge medicines, as indi- cated by an excess of vascular action, are found Flag Officer, in private practice. Both were dropsical: and in both, the valves of the heart were found ossified; and in neither was there any suspicion of intemperance. MEDICALkLOGIC 269 lo be best adapted to its nature ; and with re- gard to its proximate cause, which the old wri- ters, and others who regarded it as always a dis- ease of debility, were disposed to refer to the defect of absorption; the modern writers allu- ded to, are more inclined to view it as an active and inflammatory affection, depending rather on excess of effusion than defect of absorption. It cannot be denied that this latter view of the disorder was too much overlooked by the earlier writers, and that it has been adverted to with greater precision by later authors and practition- ers, particularly by Dr. Blackall, in one of the most valuable medical works of these days, and so excellent, that all the well wishers to physick, would be glad to see a like compendious and accurate treatise on every other important dis- ease. In drawing the attention, however, to this class of cases, he seems hardly to have al- lowed a due weight to that great majority of ca- ses, which unquestionably depend on a deficien- cy of the vital powers. 23* 270 ELEMENTS OF, &C. The inference intended to be drawn from the whole of this is, that there is a great variety, and even contrast in cases coming under the generic term dropsy, which require a different, and in some measure, an opposite treatment, and that much exercise of judgment is required, in order to avoid indiscriminate practice. SECTION VIII. o iarge, on medical subjects, that all his remedies are excellent preparations or compositions, and under the exercise of discretion, well adapted to the diseases which they professed to cure. Indeed, the injury done to the world by secret medicines in general, is not so much from any thing pernicious and inefficient in their nature, as from their indiscriminate use, and the false confidence they inspire to the exclusion of other, and better remedies. On the contrary, it is presumable, that it must have been from some eminent and ascertained good effects observed from them, that the authors of them were first in- duced to offer them to the public. On the oth- er hand, there are remedies not secret, but en- tirely inert, which attain a high degree of repu- tation, most commonly from the salutary powers of nature being mistaken for the effect of arti- ficial appliances, or from the power of imagina- tion : witness tar water in this country, and gin- national peculiarities, in the same list with boxing, horse- racing, bull-baiting, and cock-fighting, 276 ELEMENTS OF seng among the Chinese, animal magnetism and metallic tractors. Moreover, there are medi- cines of great value, which in consequence of being extolled by sanguine credulity, far beyond what experience justifies, come by cool experi- ence, or perhaps inordinate scepticism, to be run down and stripped of all virtue, so that from be- ing proclaimed good for every thing, they come to be denounced as good for nothing. Cicuta, Digitalis, and Nitric acid may be quoted as ex- amples of this. There is another source of error, arising from the delusions of patients, who without any inten- tion to deceive, suffer themselves to be blinded by extreme anxiety of mind. The deceptions of animal magnetism, by which is meant a pre- tended, subtle influence of one living human body on another, similar to the metallic, or real Magnetism, may serve as an example of these delusions. The fallacy of it has been detected on the clearest evidence, and is exploded in Eng- land and France; but it still maintains its ground MEDICAL LOOK.. 277 in Germany, insomuch, that it is said to be tauglit as a reality at some of their universities. The like deceptions have been practised with the me- tallic tractors, which it was pretended reliev- ed certain pains by mere contract or friction through some obscure influence not referable to any known law of nature. The former of these impostures was detected by a committee of the Academy of Sciences at Paris, in 1783, of which the celebrated Franklin was a member. An equally satisfactory detection of the other, was made and published by Dr. Haygarth, of Bath. These delusions are referable to the credulity and creative imaginations of patients; but medi- cal authors and practitioners themselves are not exempt from the charge of the like weaknesses, and they propounded their doctrines and facts with so much plausibility and unsuspected good faith, as to delude those who are not sufficiently on their guard. . The convictions of their own sanguine minds are, indeed, so irresistible as to betray them into errors against the plainest evi- 24 278 fcLEMENTS' OF dence of the senses. This may be exemplified in Solano's account of the varieties and indica- tions of the pulse ; and we can in no other way account for the effect of remedies, and of cures performed and reported bona fide by different au- thors, which could never be verified by the expe- rience of others. It is indeed impossible to set bounds to the power of self-delusion in creating sensations ex- cited without the presence or operation of any actual corporeal impressions. I have frequently seen simple and ignorant persons, when under the false apprehension of having caught a certain im- pure disorder, tormented with real pains in va- rious parts of their bodies, particularly their loins and noses. I have been assured by those, who have been in circumstances of exposure to the infection of the plague, and in momentary dread of catching it, that they have felt acute pains in the groins and arm-pits, these being the parts known to be most prominently affected in that epidemic. More familiar, though less aggrava- MEDICAL LOGIC 279 ted examples of this, occur among those subject to hypochondria. Enthusiasm, mania, dreaming, night-mares, and delirium, give rise to all the diversified forms and gradations of the same spe- cies of delusion. With regard to that class of delusions which consists in the seeing of apparitions, Dr. Ferriar,* of Manchester, and Dr. Alderson,! of Hull, have very philosophically accounted for them, by proving them to be exemplifications of morbid action, as much as dreams and delirium. There are also some ingenious remarks on the same subject in Mrs. Grant's History of the Popular Superstitions of the Highlands. She mentions that it is part of the creed of those who believe in them, that the visions are perceptible to only * An Essay, towards a Theory of Apparitions, by Dr. John Ferriar. t See the Medical and Chirurgical Journal of Edin- burgh, 1810, p. 287. 280 ELEMENTS OF one person at a time, a circumstance which well accords with the theory of their being morbid af- fections of a single individual, for were it any thing existing in the reality of external objects, they would be equally perceptible to all. The greater number of fantastic illusions are of a gloomy colour, and distressful nature : but some being of a cheerful complexion, it becomes a question whether it would be advisable to cure the patient of these. Horace gives his opinion against the dispelling of pleasing illusions in a world in which there is so large a mixture of bit- ters in the cup of real life, and he illustrates it by the amusing story of a pcr?on of this descrip- tion, who upon beihi; cured of his delightful re- vcries, exclaims, "Pol me oceidi'-ih, Jiaiiei.'1 The English poet expresses himself much to the same purpose in the line, ' If ignorance is bliss, 'tis folly (o be wise.'1 MEDICAL LOGIC 281 The value of that recorded knowledge, which rests on testimony, is also greatly impaired, by the difficulty of ascertaining the exact import of the terms, by which the ancients, and even the earlier writers among the moderns, designate the remedies they employed, whether simple or compound. Of the simples mentioned by the ancients, very few are now recognizable. If we except opium, alloes, and perhaps one or two more, it is doubtful, whether there is a single ar- ticle of the ancient materia medica, which can be satisfactorily ascertained ; and for want of such knowledge, much valuable practical instruction has been lost. This will be best illustrated by an example. A secret medicine, under the ti- tle of Eau medicinale d'Husson, was introduced into this country, one of the first years of this cen- tury, as a remedy for the gout,* and it was * See a clear exposition of the History and virtues of this medicine, in a work entitled " An Account of the remark able Effects of the Eau Medicinale D'Husson, on the Goat." By Edwiu Godden Jones, M. D LcnJon, 1810 24* 282 ELEMENTS OF found peculiarly beneficial in a great number of cases, particularly in that of Sir Joseph Banks, President of the Royal Society. A few years afterwards, it was discovered that a vinous tinct- ure of the colchicum autumnale had the same virtue, and little doubt was entertained of the identity of this, and the secret medicine; and Sir Joseph Banks, among others, has experien- ced exactly the same effects from both. About the same time, a passage was noticed in the works of Alexander Trallian, a physician who practised in Asia Minor, in the 4th century, as- cribing similar effects to a medicine, called her- modactyls. This was naturally supposed to be the same with the colchicum ; but as there was no description of it in any ancient author, this was merely matter of conjecture, till enquiry having been made at Constantinople, it was dis- covered, that there was an herb still bearing that name brought from the Islands of the Archipe- lago, and specimens of it being transmitted to Sir Joseph, it was actually found to be a colchi- cum. Sir Joseph Banks, and others, have used MEDICAL LOGIC 283 a vinous tincture of the root of this herb with the same good effects as the French nostrum, and to these proofs of the identity of their ope- ration, I can add my own experience in a great number of cases of articular gout in which I have prescribed it. Here was a most valuable piece of knowledge, lost to the world for many ages, from the want of a description of the arti- cle, which, on that account could not be recog- nized from one age and country to another. And we see what incalculable advantage must result to medicine in general, from the cultivation of natural knowledge, from this consideration, as well as others already stated ; an advantage pe- culiar to the present age, for never till now, have the various objects of natural history, par- ticularly of botany, been so described, that in all ages to come, however remote, no ambiguity can arise, regarding the identity of the remedies recommended, among the medical practitioners of this, or any future age. 284 ELEMENTS OF From the like consideration, we see a reason for the adoption of the scientific and systematic > terms, in the materia medica and pharmacopoeia, in preference to those loose and trivial names, of which the true import could never be ascertained by our posterity. But, for the like reason, the terms which have been abolished, and which have passed into desuetude, should be kept upon record, with explanations annexed to them ; for there are many of the titles of medicines, espe- cially of those that are compound, which are al- ready so far forgotten, that much of the practi- cal knowledge, contained in the works of the authors of the 16th, 17th, and even in the begin- ning of the 18th century, such as Hoffman,* is nearly lost. Their titles are so obscure and quaint, as to convey no knowledge of their in- gredients, and it is next to impossible, for a com- mon reader, to find a description of them, to serve as a key to the author's meaning. It would * There is a translation into English, of the practical parts of this author, which for want of a glossary for the eomDound medicines, is of little value. MEDICAL LOGIC. 285 add greatly to the Value of pharmacopoeias, if a glossary to these compositions were annexed to them, in place of studiously avoiding all men- tion of obsolete terms, as is the custom in these works. A work explanatory of the old formulas of medicine would be extremely useful, and is a desideratum in medical literature. There is still another circumstance deserving of mention, for which due allowance should be made in the writings of the ancients, as it con- tributes to the uncertainty of the knowledge transmitted to us in their writings : errors of transcriptions arc incident to all subjects ; but more particularly to those that are professional and technical, because being less understood by transcribers than subjects of general knowledge, substitutions and omissions are more likely to occur. On this subject of medical testimony, it is ne- cessary to beware of scepticism, as well as cre- dulity. Thenutnorous instances in which boast- I 286 ELEMENTS OF ed remedies, and plans of cure, proposed by practitioners, are found to fail in the hands of others, produce a fastidiousness, which is occa- sionally carried to excess. It has already been remarked, that from the diversity of constitu- tions, the same remedies will not universally succeed. If a medicine therefore, newly re- commended, on respectable authority, should not be found to answer to its character, on its first trial, it should not be abandoned. I can ex- emplify this in myself. About fifty years ago, the volatile tincture of guaiacum or tinctura gua- iaci ammoniata, in doses of half an ounce, was proposed confidently by Dr. Dawson, on his own experience, as a remedy in acute rheumatism. to be administered after the fever had been low- ered by the use of some evacuating medicines. My first trials of this practice were so discour- aging, that 1 laid it aside for several years, and the more readily, that it did not seem very con- sonant to reason, that a medicine, so stimulant, could be adapted to a disease in which there was so much heat, and excitement; but on re- MKD1CAL Lulili,. 28/ turning to its use, I found that there were cases, in which it succeeded to my utmost wish. It seemed to be best adapted to the habits in which there was scrofula, or a constitution allied to it. The mention of Scrofula, reminds the Author of some remarks which he has omitted to intro- duce in their proper place, in the 4th section of this work ; but as they are of practical impor- tance, he takes leave to subjoin them here. The most distinctive point in the treatment of scrofulous constitutions is, that they not only bear, but require, both medicines and diet of a more stimulating and cordial nature than ordinary sub- jects. He was led to make this remark in his prac- tice particularly with regard to the means of pre- vention, from having under his care, some large families affected with this natural predisposition, for such it may more properly be termed than actual disease, for the morbid manifestations of it may lie latent for life, unless excited by exter- nal circumstances. He observed that, in the families alluded to, certain articles of diet, such 288 ELEMENTS OF as wine, strong malt liquor, and a free use of animal food, which in other children would have excited morbid heat and repletion, was the most salutary system of diet in these scrofulous tem- peraments. The following practical illustration of this in a work on this subject, of the Author's ingenious friend, Mr. James Russel, of Edin- burgh, is so apposite, that he cannot abstain from referring to it. In a large family of chil- dren belonging to scrofulous parents, one half of them in childhood fell under the care of a med- ical attendant, who recommended the use of vegetable and meagre diet and nothing but wa- tery beverages. They became all affected with glandular tumors, and other scrofulous disorders. The other half of the children fell under the care of a practitioner, who advised a diet of an- imal food and a reasonable proportion of fer- mented liquor. They were all exempt from scrofulous affections. There is an analogous remark which the Author himself has made, with regard to adults possessing this tempera- ment, and in such a number of instances, that MEDICAL LOGIC 289 there can be no doubt of its truth. It is that when grown persons of this description addict themselves to intemperance, it produces neither schirrous liver, dropsy, nor even otherwise in- jures health to the same degrees as in other con- stitutions. 25 CONCLUSION. I have thus exhausted the enumeration I made of the various causes which obstruct, or retard, the progress of practical medicine, namely, the errors and abuses arising out of false or misap- plied theory; the great diversity observable in Jthe constitution of individuals ; the difficulty of appreciating the efforts of nature, and of dis- criminating them from those of art: supersti- tion : the ambiguity of language : and the falla- cy of testimony. It will probably not have escaped the intelli- gent reader, that there are two other causes, i32 ELEMENTS OF neither uncommon, nor unimportant, which should not have been omitted in this enumera- tion. These are, the inveterate attachment to pre-conceived opinions, and the excessive devo- tion to authority. The reason for these omis- sions, were, 1st, that the purpose of this discus- sion was to advert only or chiefly, to those causes which are peculiar to medicine. These two are common to all other branches of knowledge, except perhaps mathematics. 2dly, they have already been so fully adverted to, incidentally, as to render it unnecessary any further to en- force, or exemplify them. It may, however, be remarked that, they are both ultimately founded on the same principle of human nature. Man, Irom his earliest infancy, has a strong instinctive propensity to imitate his fellow creatures around him, a faculty on which the acquisition of lan- guage and other attainments depend. The same principle leads him, in early life, to conform to .he example of his parents, instructors, or casual associates, in regard to all his actions and opin- ions ; and these, in a majority of character- MEDICAL LOGIC. 293 become so rivited in their nature, that, let them be ever so erroneous or absurd, they become utterly incorrigible and indefeasible by adult reason. This, combined in some cases with in- dolence, leads us to acquiesce in our own opin- ions and those of others without due examina- tion. This has been pointedly illustrated at page 110 of this work, by an example drawn from the cure of typhous fever ; and the two sources of error above mentioned have been already so strongly adverted to in other passages, that it seems superfluous to treat them separately. What stronger 'example or proof, for instance, could there be adduced, of the pertinacious ad- herence to pre-conceived opinions in the face of evidence, than what has been adduced with re- gard to the contagious nature of one of the forms of the yellow fever ? and what more im- pressive exemplification could be alleged of the blind deference to authority, than what has been narrated at so much length with regard to Boer- haave ? 25 * 294 ELEMENTS OF With regard to this freedom and independence of opinion, we are here called upon to caution youth against falling into the contrary extreme, which consists in self sufficiency, flippancy, and an affectation of singularity. For after all, the excessive deference to authority, is to be consid- ered only as an exception or exaggeration of what is in itself one of the best guides of human conduct, namely, the respect due to the example and accumulated experience of those who have preceded us in the race of mortal existence. Before quitting this subject, there is just one other misleading principle, which ought not en- tirely to escape animadversion: I mean Fash- ion. This exercises its dominion chiefly over persons out of the profession, but is not without its influence on the members of it. It is evi- dently referable to the head of authority; for the devotion blindly paid to it, implies the ac- knowledgment of a certain superiority, to which we are called to sacrifice our own reason and judgment, but which it is the great object of cul MEDICAL LOGIC. 295 tivated reason in independent minds, to resist and cast off with disdain. From the picture that has been exhibited, of the innumerable doubts and difficulties which clog the attainment of medical knowledge, and embarrass the application of it to practical pur- poses, the timid, sceptical, and indolent, may be discouraged from studies apparently so arduous in their prosecution, and so questionable as to the efficiency, and utility of their result. But it is not from characters of this description, that any good can be expected in any of the useful arts of life. If a like despondency were to pervade mankind in general, there would be an end to ;ill that enterprize and energy, which alone can enable them to act up to their destiny, and fol- low up those pursuits, upon which the perfection of their nature depends. As the senses would have lain dormant for ever had there been no external objects to stimulate them, so the facul- ties and virtues, which characterize rational na- ture and civilized life, could never have been de- 296 ELEMENTS OF veloped, but through the excitement of those pains, wants, difficulties, and dangers, insepara- ble from human life. By no other arrangement could our duties, our happiness, our mental and bodily perfections, have been bound together in one harmonious and consistent system. Let us compare the art of medicine, under this aspect, with those of navigation and agriculture. Had man been furnished by the Creator with wings, by which he could have traversed all seas and oceans, so as to supersede the use of ships, where would have been that hardihood of character, and all those ingenious devices, which have called forth the active energies and deep re- searches of the human mind ? If, contrary to the actual institutions of Providence, the life of man had been sustained by the spontaneous pro- ductions of nature, instead of the products of in- dustry, neither the faculties of the mind, nor the powers of the body, could ever have been devel- oped ; man would have been little superior to the brutes; his active and inventive energies would MEDICAL LOGIC. 291 have lain asleep for ever; there would have been no room for the talents exercised in the procuring of food, raiment, and shelter, nor in commercial intercourse : all the mutual and en- dearing ties, and dependences of social and civ- ilized life, all trades, professions, arts, and sci- ences, whether ministering to accommodation or elegance, constituting man's greatest felicity, whether as objects of pursuit or enjoyment, would have been unknown, and untasted. It is obvious, that this reasoning being found- ed on a general law of Nature, must apply equal- ly to Medicine. In a probationary existence, it was necessary that man should be tried, not only by pain and sickness, but by the difficulties of remedying them, as exercises of virtue and in- genuity : Why should the road to medical relief lie through fewer and lighter struggles and dan- gers, than those of navigation and agriculture ?— But the subject is more concisely and emphati- cally illustrated by the philosophical poet, than 298 ELEMENTS OF, &C. by any amplitude of illustration, or farther mul- tiplicity of words which I could employ : .---.----Pater ipse colendi (medendi), Haud facilem esse viam voluit, primusque per artem, Movit agros, (cegros) curis acuens mortalia corda. "1 INDEX. A. Abdomen, the Diseases of it, the most curable of any, 225. Abortion, prevented by suppositories of Opium, 127. Absorption, one of the means of carrying on growth and repair, 88.—The great impor- tance of it towards a theory of diseases, 178. Abuse, the best things most liable to it, 19. Agency, the actuating, to be distinguished from the influential, 74. Agriculture—illustrations borrowed from it, 220, 296. Albumen found in the urine of hydropic patients, 128. Alexander the Great, his method of dispelling sleep, 100. 300 INDEX. Alexander, Dr., his experiments on putrefaction, 48. Animal Life, the most complicated of all the agencies of Nature, and its results the most difficult to be ascertained a priori, 39. Amputation, immediate, to be preferred in most cases, 229. Anatomy, its utility questioned, 180; vindicated, 182. Apologies for the non-contagionists, 259, et seq. Apparitions accounted for as morbid appearan- ces, 279. Appetitive Principle illustrated and explained, 140. Art, definition of it, 9; its interference with Na- ture, is an abuse of it, 19.—Importance of dis- criminating its operations from those of Na- ture, 223. Artificial ills to be corrected by artificial reme- dies, 25. Assimilative Principle, 69 ; not imitable by chemistry, 70.—Its analogy to the Voltaic pro- cess, 71 ; not referable to nervous power, 73 ; creates only fluids, 77. Association and habit founded on the constancy of the laws of Nature, 28.—Necessary to hu- man existence and well-being, 195 ; casual or INDEX. 301 collateral, one of the chief causes of error, by creating false catenations of cause and effect, 37. Aristotle, a great observer of Nature, 160. Atmosphere, the weight of its pressure on the sur- face of the body, 113. Authority, the excessive devotion to it adverted to, 281, et seq ; too little respect for it also to be avoided, 285. Automatick Life, what is meant by it, 137. \zote, elaborated by the processes of life, 71. B. Bacon, Lord, infected with credulity, 23; but the great improver of science, 167; rejected wrongfully, final causes from philosophy, 162. Bainton, Mr., his excellent method of treating ulcers, 114. Banks, Sir Joseph, found colchicum a remedy for gout, 282. Barbadoes, the yellow fever prevented there by separation, 265. Bichat, M. distinguishes life into animal and or- ganic, 137. Blood, its motion sustains life, 108. Blackall, his observations on dropsy, 269. 26 302 INDEX. Blumenbach, his idea of the Formative process, 44 ; that it is a continuation of the Generative, 85. Boerhaave, his doctrines unfounded and detri- mental, 169. Botany, of great advantage in perpetuating the knowledge of medicines, 283. Boyle, his recommendation of a fantastick reme- dy, 186. Brown, Dr. John, his system considered, 67. C. Cadiz, the yellow fever more frequent there, than any where in Europe, 255. Celsus commended, 199. Chemical affinity, the most simple agent in Na- ture, and therefore the most easily, and cer- tainly ascertained, 38.—Changes, the effect of medicines not referable to them, 81. Child-bed, the treatment of haemorrhage occur- ring after it, 117, et seq. Chorea Sancti Viti, various methods of curing it, 215. Cicero, his remark on the cultivation of medi- cine, 198. Cicuta a useful remedy in the cure of gravel, 82. INDEX. 303 Circulation of the blood, the knowledge of it not applicable to practical medicine, 167. Cold affusion in fever, rules for the application of it, 66. Colchicum found to be a specific for the gout, 282. Combustion, spontaneous, of the living human body not fully proved, 66. Conservative Principle explained, 47; first clearly stated by J. Hunter, 48. Constancy of Nature—the frame and functions of the mind and body are adapted to it, 27- 138. Constitutions, their diversity—one of the sources of practical errors, 201 ; have not been duly considered as influencing practice, 208. Consumption, the definition of it, 225. Crawford, Dr., his experiments on the origin of animal heat not satisfactory, 59. Credulity, one of the main causes of errors in medicine, 22 ; the learned as much infected with it as the illiterate, 22-23. Curability, the various degrees of it in different classes of diseases, 225. Cullen, his great merit in the philosophy of heat, 57; in defining the principles of life, as distin- guished from those of dead matter, 173. 304 INDEX. D. Determination of fluids, general and specific, 126; false productive of disease, 130—compared to the Galvanic process, 129. Diabetes, an error loci of the alimentary fluids, 92. Digitalis, a specific in hydrothorax, 194. Dogmatism, compared with empiricism, 199. Dropsy, an error loci of the fluids is one of its causes, 93—remarks on its nature and treat- ment, 267. E. Eau, Medicinale, a remedy in gout, 281. Elaterium, its powers as a hydrogogue and sor- befacient purge, 117. Elementary principles of life enumerated, 41. Empiricism, enlightened, the best guide of prac- tice, 193 ; compared with dogmatism, 199. Erysipelas, some cases of it contagious, 260. Euthanasia, it what it consists, 52. Exceptions, the danger of erecting them into rules, 208. Excitability of Brown explained, 67. Exercise, necessary to the soundness and perfec- 'ions of the vital organs, 132. INDEX. 305 Exotosis, a morbid act of growth, 93. Experimentum crucis, whence that expression derived, 38. Eye, adapted to the properties of light, 30, 138. F. Fashion, the power of it, 294. Fatalism, its pernicious effects, 235. Fever, the heat of, does not exceed, 110° or 112°, 65 ; when excited by a morbid poison, the constitution becomes insensible to it, 104 ; when excited by morbid poisons a salutary process, 105. Final causes—the consideration of them of great use in investigating Nature, 162. Fluids, are indued with life, 79 ; the considera- tion of them not to be neglected in practical medicines, 175. Food, what is solid and plain, more invigorating than what is fluid or concentrated, 114. Formative principle explained, 84. Fox's lungs, a supposed remedy for asthma, 185. 26* 306 INDEX. G. Galen, his absurd theory, 165. Galvanism, not identical with the nervous power, but an exciter of it, 71. Gangrene, produced by a defect of the Conser- vative principle, 49. Generative principle, defined and expounded, 43. Gibraltar, the history of the epidemick which prevailed there, 254. Gout, quite unknown among hard-labouring peo- ple, 133 ; brought on by excess of animal food, fermented liquor, sleep, and exemption from labour, 134; cured by Eau de Husson, and colchicum, 282—et seq. 282. Gravel—opium, a principal remedy in the cure of it, 82. Gravitation—the whole frame of the body adap- ted to it, 28. Grecian philosophy, originally instituted on the soundest principles of observation, 159. Growth, the process of it explained, 88. H. Habit and association necessary to our well-be- ing and existence, 28; the foundation of all useful practical attainments, 197. INDEX. 307 Hamilton, Dr. remarks on his work on purgative medicines, 213. Head, the diseases of it the most incurable of all others, 224. Heat, very little variation in the standard of it in individuals of the same species, 53 ; but differ- ent in different species, 54; very high in birds and insects, 54; arguments in favour ofits chem- ical origin, 55 ; in favour of its depending on a vital generating power, 57, et seq.; remains for several hours after death, from apoplexy and insolation, as high as during life, 56 ; a main element of health and disease, 62; its excess, defect, and salutary medium, consist- ed in its state of actual excitement, 63 ; its generating power in vegetables, 59; a symp- tom of disease, 65. Healing process—grounded on the Formative principle, 93. Haemorrhage, life saved by opium and brandy, in cases of profuse and dangerous, 116; active distinguished from passive, 117; treatment of it after child-birth, 117, et seq. Hermodactyls, proved to be identical with Col- chicum, 282. History of Diseases necessaay for their cure, 119. 308 INDEX. Horses, better nourished by food, hard and dry, than by what is succulent, 115. Hippocrates, his observations on epidemics in- valuable, 126 ; a great observer of Nature, but fell into absurd theories, 164. Hope, Dr. John, his observations on the vine, 141. If ufeland, his account of the relative numbers of male and female births, 44. Hume, his metaphysical doctrines adverted to, 31. Humoral pathology—fallacious, 174. Hunter, John, his great excellence as a physiolo- gist, 48 ; proved that there is a generating power of heat in vegetables, 59 ; the first who explained the process of growth, 88. Hunter, Dr. W., his excellence as a teacher, 168. Hutchinson, Mr. Copland, recommends imme- diate amputation after wounds, 230. I. Inflammation—an emanation of the Formative process, 94.—Boerhaave's theory of it, 171 ; refutation of it, 172. Imitative faculty—its early manifestations neces- sary to human life and conduct, 292. INDEX. 309 Instinct, in what it consists, 32. Intemperance not so hurtful to scrofulous sub- jects, as to others, 286. Involution of embryos an irrational theory, 43. K. Kepler—conceived the earth and heavenly bod- ies to be animated, 87. Knight, Mr. T. A., his papers on vegetable phy- siology, and his observations in proof of the sympathy of their roots and stems, 148. L. Labor, succeeded by haemorrhage, 118. Labour, indispensable to health, 132. Language, comes under the definition of an art, 10 ; its formation implies a very subtle opera- tion of mind even among the most young and illiterate, 35. -------ambiguous, a great source of error, 293. Lemon juice, a certain cure and prevention of sea-scurvy, 194, 244. Life, regulated by laws peculiar to itself, 39,167 *, its elementary principles enumerated, 41. Lisbon, the first place in Europe where the yel- low fever appeared, 253. 310 INDEX. Living bodies, all the changes and motions of them referable to vital action, 77. -------principle of Mr. Hunter stated, 49. Locke—the most valuable part of his work on the Understanding, is that on the abuse of words, 244. Lymphatick system, no sound nor available phy- siology before its discovery, 178. M. Magnetism, Animal, an imposture, 276. Malting generates heat, 59. Matter, the question relating to its existence ad- verted to, 32. Marcet, Dr., his analysis of chyme, 57 ; and of dropsical fluids, 70. Mayerne, Sir Theodore, his fantastical remedies, and his merits, 238. Medicine—embraces the widest range of knowl- edge of any of the liberal arts, 33 ; enumera- tion of the sources of error, in it, 156. Mercury—its operation consists in the absorp- tion of solid parts, 90. Mind, its constitution adapted to the laws of ex- ternal nature, 26 ; particularly to their constan- cy, ibid, et seq. INDEX. 311 Motive principle, 110; inefficient without ten- sion, 111; not to be accounted for on any me- chanical principle, ibid. Mystery, favours false opinions of the virtues of medicines, 243. Muscular action not created by nervous ener- gy, 123. N. Nature, the difficulty of appreciating the effects of, and of discriminating them from those of art, 221 ; knowledge of it banishes supersti- tion, 159 ; is highly useful, 183. Natural History, its great utility in perpetuating the knowledge of medicines, 283. Natural Philosophy, in its first application to medicine hurtful, 166. Navigation, an illustration taken from it, 296. Nervous System, its connection with the muscu- lar system, 121 ; not necessary to life, 122; except where there is sensation and voluntary motion, ibid. O. Observation, distinguished from experiment, 26; what constitutes it, 193. 312 INDEX. Old age very subject to Plethora, rendering bleeding necessary, 94; subject to salutary spontaneous haemorrhage, 95. Opium of essential benefit in the cure of gravel, 82, in haemorrhage, 117, 120; its variety of ef- fects in proof of the diversity of constitutions, 205. Oxygene, plays an interesting part in all the op- erations of Nature, 60. P. Pare, Ambrose, commended, 227. Philadelphia, yellow fever there, 252. Pichegru, General, anecdotes of him, 98 ; hie habits with respect to sleep, 98. Physic, art of, in what it consists, 11; disparage- ment of it, 12 ; vindication of it, 13, et seq. Placenta being without nerves, these cannot be necessary to assimilation and growth,' 75. Poisons, morbid, excite a self-healing fever, 104. The elimination of it not an object of prac- tice, 175. Plague, can exist only under one range of tem- perature, 261. Portal, found the heat of the body unchanged many hours after death from apoplexy, 55. INDEX. 31S Power, from whence we derive the idea of it, 32. Pressure, natural, its beneficial effects, 113. ---------, artificial, its beneficial effect, 114. Privations tend to shorten life, 135. Putrefaction prevented in living organic bodies, by the inherent powers of life, 47, et seq; comes en sooner after death in some circum- stances than in others, 50. Purgative medicines: discrimination necessary in the use of them, 216 ; different species of them, act upon different organs, and evacuate different humours, 217 ; the advantage of mix- ing them, 218. Q. Quackery, accounted for, 185, 273, Quarantine effectually excludes the malignant fever, 257, 264. R. Reason, in what it consists, 10; tends to obliter- ate instinct, 14* Reductio ad absurdum a form of argument appli- cable to physical and moral, as well as mathe- matical subjects, 33, 67. 27 314 INDEX. Remedies, their number co-ordinate with the diversity of disease, 16 ; their virtues cannot be ascertained by experiments on healthy sub- jects, 109. Respiration, its effect on temperature, 60, et seq. on the vital powers, 61. Restorative Principle expounded, 98. Rheumatism, acute, cured by Tinctura Guaiaci Ammoniata, 286 Russell, Mr. James, his excellent observations on scrofula, 288. S. Salivary glands the outlet of the effete matter of the bones, 90. Savages not so long-lived as civilized nations, 13; a great part of their misery consists in the want of artificial remedies, ibid. Sanguiferous system, its great importance to life, •and as the subject of medical action, 108. Scepticism, a disease of the mind, 21 ; the off- spring of superficial knowledge, 13. Scrofula, prevented by generous diet, 286.—In- temperance does not impair the constitution, ibid. INDEX. 313 Scurvy, Sea, its prominent cause, 93.—The fa- tal errors which have arisen from its ambigu- ity, 244, et seq. Sea-sickness, an apt example of the unaccount- able peculiarity of constitutions, 204. Sexes, the successive generation of two does not follow the laws of chance in individuals, yet in a steady ratio on the average of the whole species, 44. Sedatives, their great benefit in the cure of grav- el, 82. Self-delusion, no bounds can-be set to it, 276. Sensation of a member may be lost, while its vol- untary motion and circulation remain, 139 ; can be excited by the imagination, 286. Senses, have all a reference to the external world, 28, 30, 218. Sensitive principle, illustrated, 136—its perfec- tion consists in its fidelity to nature, 138. Sims, Dr. John, his experiment in proof of the sympathetic principle in vegetables, 146. Sleep, a branch of the restorative principles, 96. Indispensable to life, 97—may without injury be shortened by habit, 99—its principal re- freshment is at first falling asleep, 99 ; a prac- tical application of this, 100; incident to veg- 316 fNDEX. etables, 102; excess of it the cause of gout and other chronic disorders, 134. Small Pox, an exemplification of the diversity of constitution, 204. Solano, his account of the pulse imaginary, 278. Solids, all assimilative changes referable to them as a cause, 77 ; they alone are the subjects of medical action, 80; the doctrine of them first taught by Themison among the ancients ; by Glisson, Willis, Hoffman, and Baglivi, among the moderns, 169. Stahl, his theory for accounting ■ for the Forma- tive process, 86. Stewart, Professor Dugald, commended, 32. Stomach, its universal sympathy, strong power, and importance, 83. Its strong action invigo- rates the whole muscular system, 114, 132. Superstition, one of the main sources of error, 235 ; its practices and suggestions should not in all cases be disregarded, 240. Sydenham, his error in dissuading in all cases from venesection in aged people, 95 ; his ab- surd theories, 165. Syllogistic Logic appreciated, 169. Sympathetick principle illustrated, 44. Sympathy—generally, but not always carried on through the nerves, 145 ; exists in vegetable life, 146. INDEX. 317 T. Temperaments, the diversities which constitute them, 203. Temperative principle explained, 53. Tension, a beneficial stimulus, 83 ; necessary to muscular action, 111 ; and to life itself, 112; its effects on the stomach, 114. Testimony, the fallacy of it one of the sources of error, 271. Themison, the first who taught the doctrine of the solids, 169. Theory, the difficulty owing to the number of principles at work in the animal economy, 152; though false, it may be of practical utility, 189. Thorax, observations on its diseases, 95. Tractors, metallic, an imposture, 277. Typhous Fever, an example drawn from it, of the necessity of varying practice, 210. U. Ulcers, cure of them by strapping, 114. Union of wounds by the first intention, 107. Urine, composed of the effete parts of the fluids and solids, 89. Urinary concretions, probable origin of them, 92. 318 VNDEX. V. Van Helmont, his method jof accounting for 'the Formative process, 86. Vegetables possess a generating power of heat, 59; subject to sleep, 102; their vitality as genuine as that of animals, 122; possess an Appetitive principle, 141 ; and Sympathy 146. Vis medicatrix Naturae manifested in the sponta- neous cure of accidents and diseases, 102. Voltaic process, its analogy to the Formative pro- cess, 72-76; the specific determination of fluids analogous to it, 129. W. Witchcraft, the prevalence of the belief in it, and the punishment of it as a crime in England, Scotland, and America, 237. Wounds, their spontaneous cure, 93 ; their cure by the first intention, 106 ; great errors in the treatment of them, 227; gun-shot in the tho- rax, healed best in those who were left all night on the field of battle, 229* INDEX. 319 Y. Yellow Fever, the controversies regarding it, an example of the practical errors arising out of the ambiguity ofianguage, 247, et seq ; three species of fever pass under this name, 248 ; en- umeration of its occurrences in the West-In- dies, 250 ; in America, 252 ; in Europe, 253; the pestilential species incident only once in life, 257, et seq; communicated from ship to ship at sea, 258; prevented at Barbadoes by separation, 265 ; spread at the-other islands from want of separation, 265. THE END. PROPOSALS BY HUNTINGTON & HOPKINS, Hartford ; HOWE & SPALDING, New-Haven ; AND JAMES V. SEAMAN, New-York ; FOR PUBLISHING A NEW PERIODICAL WORK, TO BE ENTITLED, THE AMERICAN MONTHLY JOURNAL OF MEDICINE. CONDUCTED BY AN ASSOCIATION OF PHYSI- CIANS AND SURGEONS. * In soliciting the attention of the medical reader to a Monthly Journal of Medicine, and the collateral branch- es of Science, the editors feel bound to declare with what views it is undertaken, and upon what principles it will be f conducted. On the one hand, we are met by the numerous and re- spectable journals already published in the United States, which would seem to obviate the necessity of the present 2 undertaking—and on the other, we find in the European journals a mass of instruction of great practical value, which has hitherto been but partially diffused throughout our country. The pages of the former are chiefly devoted to the theories which have been embraced, to the practice which has been pursued, and to the observations which have been made or matured on this side of the Atlantic. They furnish intrinsic evidence of the talents by which they are supported, and are happily calculated to prove the obligation of the medical world to American Physi- cians and Surgeons. But " in classical education, and in variety, depth and extent of erudition," the superiority of European physi- cians has been very generally conceded. The armies in which many of them have been trained, and the public infirmaries with which others are associated, furnish op- portunities for the acquisition and improvement of medi- cal knowledge, which far surpass the ordinary range of private practice. Those who are conversant with the Medical literature of the day, knew very well that these opportunities have not fallen into unworthy hands. Ar- dent in the pursuit of professional knowledge, and amply provided with the means of obtaining it, the medical at- tendants of hospitals have given new energy to our rem- edial resources, and shed new light upon the pathology of diseases. Those who were formerly attached to adverse armies, uniting in the cause of humanity and science, have enriched the annals of medicine with the hard earned knowledge reaped on the field of battle, with the detail of many a bold expedient, prompted by necessity, and war- ranted by success. But from whatever source it emanates, periodical journals, and the publications of learned socie- ties, are the ordinary channels, through which medical in- formation is disseminated. To them our attention will be uniformly directed, and we doubt not but the readers of this journal will be gratified with a select republication of those pathological views which appear to be most correct; 3 that practice which has been roost successful, and those observations which merit reiterated perusal. But in directing our attention chiefly to European Med- icine, the labours of our brethren at home will not be over- looked. A concise analysis of cotemporary medical journals published in the United States, will, it is thought prove acceptable to most of our readers—by furnishing those who possess the original works with a general index, and supplying a deficiency in the libraries of those who possess them not. Our object will be to present a comprehensive view of the Medical and Physical Sciences, and by gleaning from foreign journals whatever is valuable, to render our own both useful and instructive. A very limited space will be assigned to those single and extraordinary cases which too much abound in the periodical journals of the day, and, as has been justly remarked, tend more particularly to puzzle and distract the young practitioner; and a more ample range will be given to observations which are the result of long and extensive experience and which have for their object the correction of error, and the elucidation of truth. In conformity with the above plan, and at a very mode- rate expense, the readers of this journal will be furnished with a concentrated record of medical facts, a concise re- view of medical opinions, and a valuable repository of medical improvements. Such a work must be peculiarly useful to those who have not funds to procure, nor leisure to peruse the great mass of publications, which appear at regular intervals to enlighten or amuse the physicians of Europe. It must be peculiarly welcome to those prac- titioners, who, in the discharge of the arduous duties of their profession, have little intercourse with their profes- sional brethren, and find it extremely difficult to keep pace with the progressive improvements of medicine and surgery. To those also, who are anxious to obtain the earliest medical intelligence, the publishers of a Monthly Journal may look with confidence for support. 4 CONDITIONS. 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