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A SYNOPSIS, 
 
 OR 
 
 GENERAL VIEW 
 
 OF THE PRINCIPAL 
 
 THEORIES OR DOCTRINES 
 
 OF 
 
 DISEASES, 
 
 WHICH HATE PREVAILED OR BEEN TAUGHT AT 
 DIFFERENT PERIODS 
 
 TO THE PRESENT TIME. 
 
 BY WILLIAM "CURRIE, 
 
 FELLOW OF THE COLLEGE OF PHYSICIANS OF PHILADELPHIA, 
 MEMBER OF THE PHILOSOPHICAL SOCIETY, &c. &c. 
 
 " Nothing extenuate, 
 
 " Nor aught set down in malice " 
 
 PHILADELPHIA 
 
 PUBLISHED BY EDWARD PARKER, If 8, MARKET STREETS 
 
 W. Brown, Printer, Church Alley. 
 
 1815. 
 
bLoo 
 
 CONTENTS 
 
 Page 
 \n Abstract of the Theory of 
 
 Hippocrates ------ 10 
 
 Galen 15 
 
 Willis 29 
 
 Sydenham ------ 30 
 
 Stahl - - - - - - 35 
 
 Hoffman 36 
 
 Boerhaave - -- - - -41 
 
 Sauvages, Vogel, Gaubius, M'Bride, Tode, 
 
 Burserus, and Screta - 43—47 
 
 Cullen 50 
 
 Brown - 63 
 
 Darwin - - - - - - - 87 
 
 Wilson 113 
 
 Rush 119 
 
 Gregory - - - - - - 167 
 
PREFACE. 
 
 THE Author of the following Synopsis, 
 or general view of the theories or doctrines 
 of diseases, that have prevailed or been taught 
 at different periods, (compiled from the most 
 authentic sources) has been induced to pub- 
 lish it, from a conviction that a correct know- 
 ledge of the nature and proximate causes of 
 diseases, or that condition of the system on 
 which the symptoms of diseases depend, 
 would be of incalculable benefit in conduct- 
 ing to safe, and successful practice. And as, 
 next to 'peace of mind, reflection upon an in- 
 nocent and useful course of life, and a soul 
 aspiring after perfection, there is nothing in 
 this world more to be desired than health of 
 body, and a knowledge of the means best 
 adapted to remedy or alleviate the various ills 
 of life, he hopes, as he has " nothing exten- 
 uated, nor aught set down in malice ;" but 
 has reviewed each theory with freedom and 
 impartiality, and has endeavoured to the best 
 
IV PREFACE. 
 
 of his abilities to point out the merits as well 
 as the defects of each, that the publication 
 taken in the aggregate, will not only contri- 
 bute to the entertainment of those that are 
 engaged in medical studies, but aid them in 
 separating truth from the almost infinitude of 
 error with which it is blended. 
 
 The diseases to which the human body is 
 liable, are so various, and frequently so com- 
 plicated, that it requires great judgment to dis- 
 tinguish them with accuracy, as well as a per- 
 feet knowledge of the philosophy or laws of 
 the animal economy in health and disease, to 
 treat them with safety and propriety. A con- 
 stant and diligent attendance on the sick may 
 instruct us in the external aspect of diseases, 
 and enable us with some degree of cerfaiuty 
 to prognosticate their issue, but without a 
 knowledge of their proximate cause or that 
 condition of the system from which the symp- 
 toms proceed, such knowledge can never fur- 
 nish us with any other than the mere fortuitous 
 means of removing them. How blind and dan- 
 gerous would be all attempts to cure the dis- 
 orders of the eye without a knowledge of its 
 
PREFACE, V 
 
 m 
 
 structure, and an acquaintance with the the- 
 ory of vision ? The empiric, or one who con- 
 fines himself entirely to experience and obser- 
 vation, regardless of the causes of diseases, 
 is ignorant of both. Suppose him consulted 
 in a case of gutta serena. No external de- 
 fect appears, no pain is complained of, and 
 the patient's health in other respects does not 
 appear to be impaired. By what symptoms 
 will the empirical occulist be able to ascertain 
 the seat and immediate cause of the disease, 
 or upon what principles will he proceed in 
 the treatment of it ? Uncertainty, and conse- 
 quently confusion and danger, must necessa- 
 rily attend his random practice. By the laws 
 of the animal economy, a certain sympathy 
 subsists between different parts of the body, 
 bv which the disordered state of one or^an 
 impairs the functions of another. The head 
 and stomach, for instance, have an almost 
 universal consent with the rest of the system, 
 and of course are subject to various and some- 
 times opposite kinds of indisposition; each 
 indicating a different and peculiar mode of 
 cure. Thus, watching, flatulency, indiges- 
 tion, rheumatism, or inflammation, may pro- 
 
 a 2 
 
VI PREFACE, 
 
 duee the head-ache; and sickness or vomiting 
 may arise from surfeiting, from a load of mu- 
 cus, or an influx of bile, # or from an affection 
 of the kidneys or bladder, and from other 
 sources* In all these cases the empiric, or 
 mere matter of fact physician, if he acts con- 
 sistently with his professions, will attend only 
 to the leading symptom, and will indiscrimi- 
 nately apply his stomachic cordials, or ce- 
 phalic plaster, without any regard to the ori- 
 gin, nature, or proximate cause of the disor- 
 der. May w r e not, therefore, conclude, that 
 mere experience, whether derived from books 
 or acquired by observing the rise and pro- 
 gress of diseases and the effects of the re- 
 medies prescribed, is insufficient of itself to 
 qualify us for judicious and successful prac- 
 titioners ; and that the theorist, or physician 
 who is acquainted w 7 ith the nature and proxi- 
 mate cause of diseases, has the same advan- 
 tage that the empirical practitioner can boast 
 of, from reading, observation, and practice : 
 with the additional advantage, of knowing 
 on what circumstances the disorder and its 
 symptoms depend. 
 
PREFACE. Vll 
 
 Notwithstanding the necessary conclusion 
 from these facts, and although deductions 
 from unequivocal facts and self-evident pro- 
 positions are the only certain method of im- 
 proving any art or science, and though Rea- 
 son is the most exalted faculty of man, and 
 the source of that high rank which he holds 
 above all other animals of the terrestrial globe, 
 there are a set of grovelling spirits who vilify 
 the powers of the understanding, and with a 
 sagacity adequate to the rank of beings to 
 which, by their rejection of the aid of reason, 
 they degrade themselves, pronounce all theo- 
 ry or reasoning on the nature and causes of 
 diseases, and the modus operandi of medi- 
 cines, useless and unavailing. 
 
 The reader will perceive by the following 
 abstract of the theories of fever which have 
 been taught at different times, that no theory 
 of fever that has hitherto been proposed, is 
 true, or in all respects perfect, though some 
 of the more modern ones approach near to 
 perfection. The failure in this instance ap- 
 pears to be owing to the unaccountable inat- 
 tention to the rules of inductive philosophy^ 
 
Vlll PREFACE. 
 
 by which Newton discovered the laws of the 
 planetary system, and to the misapplication 
 of the erroneous philosophy of former times, 
 and to the unfortunate circumstance of phy- 
 sicians of eminence in their profession mis- 
 taking effects for causes, assuming imaginary 
 for the real laws of the animal economy, and 
 to their not being acquainted till very lately 
 with the want of connection between the 
 heart and bfain, and with the important ef- 
 fects produced on the condition and properties 
 of the blood by the atmospheric air through 
 the medium of the lungs. The author there- 
 fore hopes that the observations contained in 
 the following pages, will contribute towards 
 leading the way to the establishment of a 
 more improved theory, and consequently to 
 a more rational and efficacious mode of prac- 
 tice in the different varieties of fever, than has 
 heretofore obtained. 
 
SYNOPSIS, &c. 
 
 x HE most ancient treatise of physic worthy 
 of notice, that has escaped the ravages of 
 time, and the more destructive hands of bar- 
 barians, was compiled between four and five 
 hundred years before the sera of Christianity, 
 by Hippocrates, a native of the renowned re- 
 public of Greece, and a descendant of the 
 once celebrated Esculapius, who it is said, 
 performed such extraordinary and miraculous 
 cures, that his countrymen paid him divine 
 honours. 
 
 Before the time of Hippocrates, it appears 
 from ancient history, that the healing art con- 
 sisted of little else than the most absurd su- 
 perstition and quackery, and that remedies 
 composed of the most discordant materials, 
 in conjunction with amulets, charms, and 
 magic spells, or mysterious and magical and 
 absurd ceremonies, were employed for the 
 
10 
 
 cure of diseases, by artful, designing, and 
 unprincipled impostors, who pretended " to 
 hold converse with the airy tenants of the 
 world unknown." 
 
 According to the doctrine or theory of dis- 
 eases contained in the works of Hippocrates, 
 (whom posterity has honoured with the title 
 of Father of Physic, and Prince of Physi- 
 cians), the generality of diseases are occa- 
 sioned either by a disproportion in the usual 
 quantity or a depraved change in the quality 
 of the phlegm and of the bile, or of either of 
 these excreted humours mixing with the 
 blood; and these, in conjunction with too 
 great a proportion of atmospheric air contain- 
 ed in or introduced into the blood, is the 
 cause of the cold fit which precedes a fever. 
 
 We may judge of the correctness of the 
 pathology and the qualifications of this " Fa- 
 ther of Physic," for explaining the causes of 
 the symptoms of diseases, from his explana- 
 tion of the rigor and yawning which accom- 
 pany the cold fit of an intermittent fever. 
 
 "The former (he says) is occasioned by 
 air finding its way into the blood, by which 
 it is refrigerated and condensed, in propor- 
 
11 
 
 tion to the quantity and degree of coldness 
 of the air which has gained admission into 
 the blood; and a shaking or shivering takes 
 place, because nature (which he says is 
 something divine, that preserves order in the 
 animal ecqpomy in health and restores regu- 
 larity to it when disordered,) being alarmed by 
 the sense of cold, causes the blood to take re- 
 fuge towards the internal and warmer parts of 
 the body. Its leapings and boundings make 
 the whole body shake or tremble; the places 
 which it has deserted shaking for want of it 
 to keep them steady, a-nd those to which it 
 has run trembling frpjjoD being over distended 
 by its quantity, and the force of its influx." 
 "The yawning (he imagined,) was occa- 
 sioned by the pent up pir, rushing at once 
 towards the mouth, and forcing it open, to 
 find a passage out." 
 
 Unluckily for the credit of this doctrine, 
 it happens, that no experiments have dis- 
 covered the existence of atmospheric air in 
 the blood vessels; and in the act of yawn- 
 ing, the air passes in, instead of out of the 
 mouth. 
 
2 
 
 This doctrine of critical days, Celsus, who 
 lived in the reign of Tiberius Caesar, thinks 
 he invented from a superstitious or implicit 
 attachment to the doctrine of Pythagoras, 
 relative to harmonic numbers. 
 
 Hippocrates who appears to have been the 
 first founder or promulgator of the doctrine 
 that morbific matter, generated in or intro- 
 duced from abroad into the circulating fluids, 
 was the immediate or proximate cause of all 
 febrile diseases; presuming that what he 
 calls nature never separates crude matter in 
 the beginning of fevers, or while it is blend- 
 ed with good juices, he prescribed very few 
 remedies, but waited to see what evacuations 
 would make their appearance on the days 
 that he supposed the disease would come to 
 a crisis, (namely, on the 4th, 7th, 11th, 14th, 
 17th, and 21st,) but after removing the con- 
 tents of the stomach and bowels, by a gentle 
 emetic and cathartic, and prescribing rules 
 for the regimen to be observed, which he di- 
 rected to be of a mild and liquid kind, he 
 trusted the management of the disease al- 
 most entirely to the economy of nature, and 
 waited patiently for a crisis or change for 
 
13 
 
 ..belter or worse ; as appears from bis book 
 •De diceta in morbis aeutis." 
 
 The theory or medical philosophy of this 
 eminent physician of the ancients, though its 
 errors and fallacies are almost self-evident, 
 became remarkably popular, and continued to 
 bear sway among the most eminent of the 
 Greek and Roman physicians for nearly 
 three hundred years after the decease of its 
 distinguished author, though its merits were 
 called in question at different times within 
 that period, by the chiefs of two sects or so- 
 cieties of physicians known by the names of 
 dogmatists and methodists; and in the reigu 
 of Tiberius Csesar, Themison, a distinguish- 
 ed physician of the methodic sect, ridiculed 
 Hippocrates's doctrine of critical days, and 
 because he advised physicians to wait and 
 observe the way that nature took to relieve 
 the suffering constitution from the effects of 
 fever, on certain days before they interfered 
 with their remedies, which he supposed did 
 more harm than good if administered before 
 the morbific matter was concocted or ripen- 
 ed, so as to be fit to be separated and expel* 
 
 B 
 
14 
 
 led; he called his practice " A meditation 
 upon death. " 
 
 The methodic sect, and Themison in par- 
 ticular, reprobated the tedious method of stu- 
 dying the symptoms of every individual dis- 
 ease, and the effects of every remedy which 
 had been sanctioned by time and experience, 
 and invented a more easy method of shorten- 
 ing the study of medicine. With this view, 
 lie divided all diseases into two distinct 
 classes, according as the symptoms indicated 
 too rigid and tense or too soft and relaxed a 
 state of the solids, or an unequal combination 
 of these two conditions. 
 
 In the early part of the second century of 
 the christian ssra, Galen, who has been much 
 celebrated in medical history, and was at the 
 head of his profession in the city of Rome, 
 undertook to reform medicine, and restored 
 dogmatism, (which had been superseded by 
 the doctrine of the methodic sect,) though 
 the doctrine of the dogmatists consisted of 
 scarcely any thing but visionary hypotheses 
 or fanciful conjectures, without reference to 
 experiments or any alliance with the laws of 
 the animal economy, and were involved in 
 
13 
 
 an impenetrable labyrinth of error and con- 
 fusion. He also wrote numerous commenla* 
 ries on the aphorisms of Hippocrates, and 
 composed several voluminous works of his 
 own. 
 
 The theoretical opinions of Galen, in gene- 
 ral, agree with those of Hippocrates, but he 
 differs from him in extending the noxious 
 qualities of the different humours, and in di- 
 viding the disordered pulse- into minute and 
 almost endless distinctions, which instead of 
 instructing only serves to mislead and per- 
 plex the student. 
 
 He fancied that the reason why more or 
 less feverish heat constantly succeeds an 
 ague or chilly fit, is because, the blood after 
 some agitation, brings to its own degree of 
 heat the liquors or humours that have mixed 
 themselves with it, and being thus increased 
 in quantity must necessarily produce more 
 heat in the body by the friction produced be- 
 tween the solids and the fluids." The phleg 
 matic and bilious portions of the fluids, rari- 
 fied and attenuated by the feverish heat, in 
 his opinion, separate themselves from the 
 
16 
 
 mass, and are expelled on the critical days 
 by the efforts of the animal economy." 
 
 Galen and his followers, as well as all the 
 physicians of the ancients, appear to have 
 believed that animal heat depended entirely 
 upon the reciprocal friction of the solids and 
 fluids, independent of any chemical change 
 produced through the medium of respiration, 
 
 In conformity with his doctrine, the chief 
 object of Galen and his followers was to pre- 
 vent the heat from being increased by the 
 friction, and the blood vessels from being 
 ruptured by the rarifaction of the blood; for 
 which reason their chief dependahce was on 
 copious blood-letting, and the liberal use of 
 cold water inwardly. They also favoured 
 
 such evacuations as occurred on the sup- 
 
 «. 
 
 posed critical days, but restrained them 
 when they occurred on the intermediate days 
 as an erroneous or mistaken propensity and 
 effort of nature. 
 
 Galen supposed the lungs were intended 
 for ventilators to the heart, that the animal 
 heat might thereby be prevented from rising 
 to excess. He imagined that air mixing with 
 the blood generated the animal and vital 
 
4 *-* 
 
 spirits. The chyle he supposed was con- 
 veyed from the stomach to the liver and 
 there manufactured into blood by a species 
 of fermentation not understood. But to the 
 nerves he assigned their true function, as in- 
 struments of sense and motion. He was en- 
 tirely ignorant of the laws and principles of 
 chemistry, nor did he observe that close 
 cautious method of investigating the causes 
 of diseases or the effects of medicines which 
 has since been recommended by Sir F. Ba- 
 con, from facts and experiments, but too 
 often contented himself with substituting 
 plausible but fallacious conjectures; hence; 
 his pompous and chimerical doctrines have 
 vanished before a more enlightened philoso- 
 phy, "like the baseless fabric of a vision. " 
 
 Notwithstanding the prolixity, incongrui- 
 ties, and inconsistencies of Galen's doctrine 
 of diseases, it took the lead and kept domi- 
 nion over all others, till the Roman empire 
 was subverted by the Goths and Vandals in 
 the 5th century, which event put almost an en- 
 tire stop to the cultivation of literature of every 
 description in Europe. From that time the 
 study of the arts and sciences was entirely ne=, 
 
 b 2 
 
18 
 
 glected, and the only knowledge which had 
 any relation to medicine that was cultivated, 
 till after the revival of literature, which be- 
 gan to dawn hi the 11th, but made little pro- 
 gress till after the invention of printing in the 
 15th century, was judicial astrology or the 
 art of predicting future events by certain 
 signs supposed to be legible in the stars. 
 During that period, many physicians united 
 with their profession the occupation of a sor- 
 cerer, conjurer, or fortune-teller, and pre- 
 tending that they knew the nature of every 
 disease from the mere inspection of the urine, 
 without seeing the patient, and that they 
 knew how to prescribe the most efficacious 
 remedies from an examination of the signs 
 of the zodiac, they took advantage of the 
 credulity of the illiterate, and sported with 
 the lives of their fellow creatures for the 
 sake of a little filthy lucre, to enable them 
 to live in idleness and ease; and by unde- 
 tected or tolerated frauds frequently gained 
 a palace, when their only title was a gal- 
 lows. 
 
 During those dark ages of ignorance and 
 credulity, the understandings of many ap- 
 
19 
 
 pear to have been so much under the domi- 
 nion of a misguided or deluded imagination, 
 that they believed diseases of particular or- 
 gans could be infallibly cured by particular 
 vegetables, for no other reason than that 
 there was a resemblance between the figure 
 of the remedy and the diseased organ, 
 
 Th<* physicians of those ages having ac- 
 quired a superficial and incorrect knowledge 
 of astronomy, supposed that every mortal was 
 under the influence of the particular planet 
 that was visible in the horizon at the time of 
 his birth, and that his constitution and tem- 
 perament partook of the qualities and tem- 
 perament of that planet; of course, when 
 disordered, medicines of a quality different 
 from the temperament of such planet were 
 to be employed. They also examined and 
 consulted the different signs of the zodiac to 
 know when it would be the most proper time 
 to perform the common operations of surgery, 
 to open a vein, pare a corn, or wean a child, 
 
 A remnant of the same absurd and ridicu- 
 lous credulity, the offspring of ignorance and 
 want of reflection, I am sorry to say, still 
 continues to hold dominion over the minds o£ 
 
m 
 
 the illiterate and vulgar part of the commu- 
 nity in this as well as in other countries. 
 
 If any reliance can be placed on historical 
 facts, the physicians of Europe became en- 
 tirely ignorant of the nature and causes of 
 diseases as well as of the laws of the animal 
 economy after the subversion of the Roman 
 government in Italy, till in consequence of 
 the invention of printing in the 15th century, 
 the remains of the literary and scientific trea- 
 sures of ancient Greece and Home became 
 more generally diffused and sent abroad. 
 
 In consequence of these events, the works 
 of Hippocrates and Galen again gained the 
 ascendency over the medical world, and their 
 rules and precepts once more became the 
 standard of legitimate practice. To these 
 as to the oracles of reason, every one appeal- 
 ed, and these it was the study of every one 
 to imitate. 
 
 But after the art of chemistry became cul- 
 tivated, and medicines prepared by chemical 
 processes were introduced into practice about 
 the middle of the 16th century, by Paracel- 
 sus, who was born in Switzerland A. D. 
 1531, a few physicians of more cultivated 
 
21 
 
 understandings, began to entertain doubts of 
 of the infallibility of those authorities, as 
 others did soon after of those who had as- 
 sumed the privilege of regulating the faith 
 of the christian world, and called in question 
 the propriety of paying implicit homage to 
 their precepts. 
 
 About the close of the sixteenth century, 
 in the reign of Queen Elizabeth, arose that 
 great luminary of science, Sir Francis Ba- 
 con, afterwards created Lord Verulam, who 
 by means of experimental philosophy and in- 
 ductive reasoning, invented or discovered the 
 only method of acquiring certain knowledge 
 in the arts and sciences. 
 
 While the other branches of science Were 
 daily improving, id consequence of the adop- 
 tion of the plan proposed by the sagacious 
 Bacon, Dr. W; Harvey, physician to King 
 Charles the First, of England, followed the 
 same plan in his anatomical researches, and 
 rendered his name immortal by his discovery 
 of the circulation of the blood. A discovery 
 of infinite service to the art of surgery, in par- 
 ticular, and of very great importance to the 
 healing art in general. The true kuowledge 
 
of the circulation had eluded the researches 
 and dissections of all Dr. Harvey's prede- 
 cessors-, though Michael Servetus, a native of 
 Geneva, who afterwards suffered martyrdom 
 through the resentment and religious zeal of 
 Calvin, on account of his religious opinions, 
 appears from his account of the circulation 
 of the blood through the lungs, published in 
 the year 1533, to have niade very near ap- 
 proaches to it.* 
 
 In consequence of this discovery of Dr. 
 Harvey, which was first made public in the 
 year 1628, the doctrines of the ancients, and 
 particularly that of Galen, which had been on 
 the decline from the time that chemistry be- 
 gan to be cultivated, were renounced by the 
 generality of physicians of that period, though 
 too many, still governed by habit and the 
 prejudices of an imperfect education, prosti- 
 tuted their reason to blind authority. 
 
 The knowledge of the circulation of the 
 blood, however, did not for a considerable 
 time, contribute to advance one of the essen- 
 tial objects of medicine, the knowledge of the 
 
 * For an account of the opinions of Servetus, the reader is 
 referred to Dr. Priestly's church history* vol. v. p. 454. 
 
S3 
 
 nature and proximate causes of diseases, so 
 much as might have been expected, owing in 
 a great measure, to physiologists and physi- 
 cians adopting and applying the principles of 
 mechanical philosophy to explain the motions 
 and operations of the living body; for, it is 
 a discovery of a more recent date, that the 
 laws which govern passive and inanimate 
 matter, are by no means similar to those 
 which govern living bodies, and that maxims 
 which are true and just when applied to in- 
 sensible tubes and inanimate substances, are 
 erroneous, and lead to false conclusions, 
 when applied to those that are sensible or ir- 
 ritable, and are every instant changing their 
 areas. The principal defect of the mechani- 
 cal doctrine consists in overlooking the great 
 influence of the vital principle in every part 
 of the animal economy. 
 
 For a number of years after the discovery 
 that the blood, passing from the heart w 7 as 
 carried by the arteries to all parts of the liv- 
 ing system, and that from thence it returned 
 to the heart through the veins, the human 
 body was considered as a hydraulic machine, 
 the good state and preservation of which de- 
 
m 
 
 pended on the liberty that the blood had to 
 pass through all the tubes with which it is 
 supplied. The principle of life and health 
 being thus founded in error, the loss of the 
 equilibrium between the solids and fluids 
 and a disordered circulation were looked 
 upon as the chief causes of diseases ; the at- 
 tention of physicians was therefore directed 
 to the too lax or too rigid state of the fibres, 
 and to the fluids being in too large or too 
 small a quantity for the capacity of the ves- 
 sels. In a word, the physicians of that pe- 
 riod considered the living body to be a mere 
 hydraulic machine, provided with mechani- 
 cal instruments, including pullies, levers, 
 pumps, suckers, bellows, strainers, &c. ; and 
 they imagined that the fluids of the human 
 body ascended and descended by the power 
 of gravitation, as well as by a vis a tergo 
 and contractile power of the heart and arte- 
 ries. They were acquainted with no argu- 
 ments but numbers, and with no proofs but 
 algebraical calculations. Thus, by applying 
 the laws of mechanics to explain the motions 
 and operations of the animal economy, the 
 discovery of the circulation for a time, in- 
 
25 
 
 .stead oT leading to correct views, became the 
 source of dangerous errors in the theory and 
 treatment of diseases. 
 
 This, among others, is a strong evidence 
 of the injurious practice which must necessa- 
 rily be the consequence of adopting an erro- 
 neous theory, and of the great importance of 
 acquiring a competent knowledge of the na- 
 ture and proximate causes of different dis- 
 eases. 
 
 Other professors, about the same time, 
 joining chemistry to mechanics, taught among 
 other errors, that all fevers were occasioned 
 by certain minute substances with rough or 
 angulated surfaces or sharp points, in the 
 shape of triangles, introduced into or gene- 
 rated in the blood, in consequence of the ope- 
 ration of certain remote causes suppressing 
 or obstructing some of the natural and cus- 
 tomary secretions, or occasioning a retention 
 of the substances which ought to be secreted, 
 and that the fulness, heat, or acrimony, 
 jointly or severally, proved direct stimulants 
 to the heart in the course of the circulation; 
 and for the cure of the diseases, they pre- 
 scribed such medicines as they fancied were 
 
 c 
 
adapted to -soften, obtund, and render these 
 little wedges and sharp pointed substances 
 soft and globular, and thus fit them to be ex- 
 pelled from the circulating mass by what 
 they called an effort of nature. 
 
 For some time after the introduction of me- 
 dicines prepared in the laboratory of the che- 
 mists, which were brought into practice by the 
 .enthusiastic Paracelsus, about the year 1547? 
 who appears to have been fanciful and enthu- 
 siastic in his theories, bold in his practice, 
 and rashly confident in his means : the profes- 
 sors, who, agreeably to the fashion of the 
 day, devoted much of their time to the study 
 of chemistry, to the exclusion of the other 
 branches of medical knowledge ; and particu- 
 larly, after the improvements made by the 
 noted Vanhelmont, several years later, came 
 to be publicly known, appear to have been 
 sq much under the influence of a chemical 
 jnania as to consider the human body similar 
 to an alembic; and fancying febrile diseases 
 to be owing to an excess of fermentation, 
 among the particles of which the fluids of 
 the human body are composed, they had re~ 
 £Qurse to such remedies as they had observed 
 

 to bate the effect of subliming or precipi- 
 tating portions of different compositions in 
 their retorts J and mistaking the coagulable 
 lymph or gelatinous substance which covers 
 the crassa men turn of the blood in diseases 
 depending on inflammatory affections, for 
 crude and indigested morbific matter, they 
 took great pains to prevent the febrile heat 
 from being reduced so low as the usual tern- 
 peratu re in health, lest its fermentation and 
 maturation should be prevented or retarded, 
 Riverius, physician to King Henry the 
 Fourth of France, and cotemporary with Sir 
 Theodore Mayerne, who was afterwards 
 physician to King Charles the First of Eng- 
 land, w as so much influenced by the hypo- 
 thesis or false philosophy of the time iri 
 which he lived, that in cases of small pox, 
 he advised the air to be excluded from the 
 chamber of the patients, and (heir beds to 
 be covered with red cloth, •'• because thatco- 
 r bv some affinity with the red and boil- 
 log blood, attracts it to the external parts.** 
 He says ''-'it is also cu-iomary to keep a 
 sheep in the chamber, or on the bed near the 
 patient, because these creatures are easily 
 
28 
 
 infected, and draw the venom to themselves 
 by which means relief is given to the sick." 
 The prescriptions of both the physicians 
 above mentioned, in general, contain such a 
 number of heterogeneous and discordant ma- 
 terials, that they have more resemblance to 
 the compositions of the witches in Macbeth 
 than to the prescriptions of rational and re* 
 gularly bred physicians. 
 
 Such was the astonishing credulity in 
 those times, even of men who devoted much 
 of their time to the arts and sciences, and 
 such has ever been the rage for the marvel- 
 lous with the illiterate, that a belief was pre- 
 valent that the mere application of the hand 
 of a king or queen (to which superstition had 
 assigned divine power,) to scrofulous tu- 
 mours, would effectually disperse them: and 
 that touching warts, corns, and other excres- 
 cencies with a dead man's hand, or a piece 
 of the flesh of an animal recently killed, and 
 afterwards buried, would produce a si- 
 milar effect. This was supposed to be 
 owing to some sympathizing or subtile oc- 
 cult connecting principle, existing between 
 the decaying substance and those excv 
 
9 
 
 pencies with which it had been iu contact, — • 
 in consequence as the one decayed the otket 
 followed its example. 
 
 A remnant of the same credulity, super* 
 stilion, and propensity to the marvellous still 
 continues to exist at the time of my writing 
 this; especially among those whose minds 
 have not been enlightened by scientific cul- 
 ture, of which we have had recent examples 
 in Mesmer's Animal Magnetism, and Per- 
 kins's Metallic Tractors.* 
 
 Some of the professors of that age, and 
 among others, Doctor Thomas Willis, co- 
 temporary with Sydenham, and a professor 
 of considerable celebrity in the university of' 
 Oxford, where students are still taught "by 
 rule to stray/? (an English translation of 
 whose works were published in the year 
 1684.) was of opinion that febrile heat was 
 occasioned by a collision of nitre (which he 
 
 * In May }682, notice was given in a London Gazette, that 
 as the weather was" growing warm, his Majesty would not ; 
 touah any more for the king's evil, till after Michaelmas ; and 
 in- 1687, an indigent citizen of New Hampshire, having tried 
 t\Qvy other means without effect, petitioned the Legislature 
 for aid to transport him to England for that efficacious rerrce-" 
 dy, Massachusetts Medical Communications, vol 
 
30 
 
 supposed was contained in and separated 
 from the atmosphere by the lungs,) and sul- 
 phur, which -he supposed was one of the ele- 
 ments or constituent principles of blood. 
 
 The sagacious and highly celebrated Dr. 
 Thomas Sydenham, who published his ob- 
 servations on diseases in the year 1685, 
 which are chiefly valuable on account of the 
 accurate description which he has given of 
 the symptoms of those diseases that occurred 
 in his own practice, influenced by the opi- 
 nion of the ancients, and particularly by that 
 of Hippocrates, though he disclaims all in- 
 struction or assistance from the works of 
 others, adopted the doctrine, that morbific 
 matter is the immediate or proximate cause 
 of every form of fever unconnected with lo- 
 cal inflammation. The remote or generating 
 causes he supposed were indigestible or un- 
 wholesome food, impure water, the suppres- 
 sion of perspiration from cold and moist air, 
 and the subsequent operation of unusual heat, 
 and particularly, some supposed, (for he kas 
 offered nothing in proof of his opinion) mys- 
 terious and occult change in the constitution 
 of the atmosphere, by some inexplicable ope- 
 
31 
 
 ration of certain planets, comets, or the erup- 
 tion of \ ol anoes, &c. 
 
 According to his theory, when any foreign 
 and ftoxious matter was introduced into or 
 was generated in the blood, for want of re- 
 gularity in the secreting vessels and the ex- 
 cretory ducts, it occasioned a fermentation si- 
 milar to that of vegetable juices in the for- 
 mation of vinous liquors. The preternatural 
 heat he attributed to an effort of nature, or a 
 salutary operation of the animal economy, to 
 ripen and prepare the morbific matter, so as 
 to fit it for separation and expulsion from the 
 circulating fluids. 
 
 The opinion of this worthy but mistaken 
 physician, relative to confining the use of 
 purgatives and diaphoretics to the critical 
 days of Hippocrates, and of restricting bleed- 
 ing in pleurisies and other fevers depending 
 on local inflammation, to the first week of 
 the disease, and with respect to the length 
 of time that the crude morbific matter requires 
 to become ripe and fit for expulsion, and re- 
 lative to intermitting fevers generally ceasing 
 spontaneously, without the aid of art, after 
 the fourteenth paroxysm, must appear ex- 
 

 tremely fanciful, and objectionable to every 
 one acquainted with the more recent improve- 
 ments in meteorology,- and the effects of sea- 
 son, eliniate r soil, and other local circum- 
 stances; as well as ills doctrine relative to 
 certain noxious changes in the constitution 
 of the atmosphere being necessary for the 
 propagation and spreading of contagious dis- 
 eases, as well as of those which depend on 
 season, soil, or local circumstances,— such 
 as intermittent fevers, and dysenteries, du- 
 ring the continuance of which insalubrious 
 change in the constitution of the atmosphere, 
 they would prevail and spread, independent, 
 or without the aid of season, situation, tem- 
 perature, or other sensible qualities of the 
 air; which insalubrious change in the consti- 
 tution of the air, he ascribed to eruptions, 
 and noxious exhalations from the bowels of 
 the earth, or to -the baleful influence? of the* 
 planets. 
 
 The seasons at London have undergone ■ 
 little or no change for many ages, as has 
 been proved from the testimony of medical 
 writers of the seventeenth century, especially 
 of the elegant Claromontius. The same vi- 
 
33 
 
 ciSfeitudes of temperature, and the same seve* 
 rtty of the vernal months, were then as much 
 the topics of complaint as they are at present. 
 Yet we now find that the order of the sea- 
 sons, in respect to the production of diseases 
 is nearly reversed, in consequence of the im- 
 provements which have been made in the 
 structure of the houses, the arrangements of 
 the streets, and in the police of London, al- 
 though the character of the seasons continue 
 the same. Formerly, it was "saluberri- 
 mum ver; autumnus longe periculosissimus ; 
 hut now it is the reverse. The inference 
 from these data, is obvious, by this ; that 
 the constitution of the atmosphere, as to heat 
 and cold, dryness and moisture, which the 
 changes of season occasion, is not the source 
 of epidemic diseases; and that the alteration 
 in the condition of the air, which formerly 
 rendered it the pregnant cause of disease and 
 death, especially in the autumnal months, 
 was not any occult intestine changes in the 
 constitution: not any general contamination 
 brought from afar; not any change from the 
 attraction or repulsion of hostile planets, or 
 noxious impregnations from the eruptions 
 
m 
 
 and exhalations of distant volcanoes; hni 
 an impregnation received upon the spot — a 
 noxious exhalation which that portion of the 
 superincumbent air imbibed from the soil, 
 and the impurities of animal and vegetable 
 substances left upon its surface to putrefy, 
 and to the impurities secreted and excreted 
 from living bodies, suffered to accumulate in 
 unventilatcd situations.^ See Annual Med. 
 Review and Register for the year 1801). 
 
 After the publication of the medical works 
 of Sydenham; and the observations and opi- 
 nions of Baglivi, professor of anatomy and 
 physic at Rome, in the year 1696, a humo- 
 ral; in conjunction with a chemical pathology, 
 continued to he the most prevalent doctrine 
 till about the beginning of the eighteenth 
 century, when Dr. Stahl, professor of the 
 practice of physic in the university of Halle, 
 in Germany, introduced a doctrine of a very 
 different character from any that had pre- 
 ceded that period. 
 
 According- to the system of this professor 
 "the motions and functions of the human 
 body are governed entirely by the rational 
 soulj to many of the motions of which it i* 
 
35 
 
 not conscious, owing (as Dr. Stahl supposed) 
 to a habit of action, and not to the physical 
 mechanism and irritability of the living so- 
 lids. The soul being extended through the 
 medium of the nerves to all parts of the body, 
 perceives every noxious impression or disor- 
 der that occurs in the system, and like a faith- 
 ful guardian calls such powers of the system 
 into action, as are qualified to remove or ob- 
 viate the noxious impressions, and to preserve 
 its salutary operations." 
 
 This fanciful system was not only adopted 
 by the whimsical and unreflecting members 
 of the profession, as is usually the case with 
 every thing that is novel and mysterious, 
 however absurd and unintelligible it may be, 
 but, in part, by several physicians, distin- 
 guished for their erudition, in France and 
 Great Britain, as well as in Germany ; though 
 the mathematical system of pathology, as ex- 
 plained by Bellini, was supported by Simp- 
 son, Perrault, Nichols, and many others. 
 
 Junker defended the system of Stahl, and 
 some traits which favour the same doctrine, 
 may be seen in the works of the late learn- 
 ed Gaubius of Holland. 
 
aS6 
 
 This metaphysical system, however, which 
 favoured an inert practice, and taught to com- 
 mit the cure of all diseases to the care and 
 management of the soul, soon fell into dis- 
 credit with most of the practical physicians, 
 and only continued to maintain its reputation 
 with a few superficial enthusiasts and inex- 
 perienced theorists. 
 
 The next system of any note that attract- 
 ed the attention and admiration of the medi- 
 cal world, was that of Dr. Frederick Hoff- 
 man, professor of physic in the same univer- 
 sity as Dr. Stahl. 
 
 The theory of this distinguished professor 
 was erected on a very different foundation 
 from those of any of his predecessors. From 
 this system, it appears that Dr. Hoffman was 
 the first who discovered, that the generality 
 of diseases, and that fevers particularly, have 
 their seat in the solids, instead of the fluids 
 of the human body, though according to Dr. 
 Ferriar the opinion had been suggested some- 
 w r hat earlier by Dr. Piens. Professor Hoff- 
 man, however, still admitted the agency of a 
 depraved state of the fluids; and even sup- 
 posed them to be in a state of putrefaction in 
 
37 
 
 some instances. By blending and retaining 
 too much of the mechanical cartesian and che- 
 mical rules of explanation in his system, and 
 allowing them to influence his reasoning and 
 his practice, he has disfigured and rendered 
 it confused and untenable. 
 
 The learned and experienced author, not- 
 withstanding the liberality of his education 
 and the extensiveness of his acquirements, 
 appears to have retained too much of the 
 early impressions of the nursery, and to have 
 suffered himself to be too much influenced by 
 superstitious and vulgar opinions, as is evi- 
 dent from a chapter in his works on diseases 
 occasioned by Witchcraft, or the operation 
 of supernatural agents, for the removal of 
 which he has given very grave and circum- 
 stantial directions. The opinion of superna- 
 tural agency in the production of certain dis- 
 eases, and of those of the convulsive land 
 in particular, was in former ages very uni- 
 versal — the invention of importers, or the 
 suggestions of a disordered and deluded ima- 
 gination; but the error having since been dis- 
 covered, in consequence of more accurate en- 
 quiries and a more improved state of philo- 
 
 D 
 
38 
 
 sophy, it is at present deservedly ridiculed 
 as the phantom of a weak and disordered 
 -mind, or as the base and execrable invention 
 of artful and designing imposters and moun- 
 tebanks to deceive and mislead the ignorant 
 and credulous populace. 
 
 Hoffman, however, was the first that pub- 
 licly dissented from, and exposed the errors 
 of the humoral pathology, or the long esta- 
 blished doctrine of morbific matter, being the 
 proximate cause of fever; and expressly 
 taught that fevers depend upon diminished 
 .power in the nervous system, and of course, 
 led the way to a more correct and rational 
 theory, or one more compatible with obser- 
 vation than any that had been attempted be- 
 fore his time. 
 
 In his opinion, < ; a]l diseases are attended 
 with irregularity of action, or a suspension 
 of all action; and when this irregularity of 
 action is too violent, either spasm or convul- 
 sion is the consequence, and when weaker 
 than natural, atony or weakened contraction 
 of the muscular fibres, is the effect." He 
 also taught that the treatment of diseases 
 was to be improved, not so much by expe- 
 
rience, as by the skilful application of me- 
 chanical principles, and by the sedulous 
 study of their nature and proximate causes. 
 According to his theory, the proximate cause 
 of every form of fever is a spasm or constric- 
 tion of the capillary or minute arteries, at tho 
 surface of the foody, both internal and exter- 
 nal; in consequence of which, he supposed 
 the blood was repelled and conveyed in an 
 unusual quantify to the heart, and that it was 
 thereby distended, and excited to more fre- 
 quent action, till it o'vercame the resisting 
 and irritating cause. He also attempted to 
 account for the symptoms of inflammation on 
 the same principles. Owing, however, to 
 the circumstances already mentioned, he does 
 not appear to have applied his theory in the 
 treatment of diseases with that judgment and 
 effect, for which, if it had been perfectly cor- 
 rect, it was adapted. 
 
 Before the svstem of Hoffman became ze- 
 nerally known, its lustre wa-s not only eclips- 
 ed, but it was almost entirely superseded 
 for a considerable length of time, by the 
 more captivating; and, on a superficial view, 
 the more plausible system of the celebrated 
 
40 
 
 Boerhaave of Leyden, which was afterwards 
 extended and explained in eighteen octavo 
 volumes, by the Baron Yanswieten, physi- 
 cian in chief to the Empress of Germany. 
 
 The, following is the substance of the re- 
 marks of Dr. Cullen on the Doctrine of the 
 last mentioned learned and distinguished 
 professor, viz. "What Dr. Boerhaave has 
 offered on the diseases of the simple solid, 
 has the appearance of being very clear and 
 consistent, and was certainly considered by 
 him as a fundamental doctrine; but in my 
 opinion, it is neither correct, nor extensively 
 applicable. Not to mention the useless and 
 perhaps erroneous notion of the composition 
 of earth and gluten, his mistake respecting 
 (he structure of compound membranes, or his 
 inattention to the state of the cellular texture, 
 all of which render his doctrine imper- 
 fect.™! shall insist that his doctrine is very 
 little applicable towards explaining the phe- 
 nomena of health and disease. The state 
 of the simple solid is upon few occasions 
 either changed or changeable, but the phe~ 
 nomina attributed to that change, do truly 
 depend on the state of the nervous and mus- 
 
cular solids, as has been satisfactorily proved 
 by the experiments and observations of Baron 
 Haller. How much this shews the deficien- 
 cy and imperfection of this system requires 
 no explanation." 
 
 "Having considered the diseases of the 
 solids, Professor Boerhaave proceeds to ex- 
 plain the more simple diseases of the fluids."* 
 
 I need not give a circumstantial detail of * 
 the well known facts and arguments which 
 have been published by Dr. Cullen and 
 others to prove the error of the Boerhaavian 
 doctrine, which assigns a morbid state of the 
 circulating fluids, as the proximate cause of 
 febrile diseases, or to prove the gross error 
 of the humoral pathology, or of inflammation 
 depending upon the escape of globules of 
 blood, and getting as it were by mistake into 
 vessels of a different order, whose diameters 
 are too narrow to allow them a free passage. 
 
 The experiments of the late ingenious Mr, 
 Hewson of London, father of the worthy and 
 much respected Dr. Thomas T. Hewson of 
 Philadelphia, furnish the most convincing 
 proofs that no such lentor or viscidity is con- 
 tained in the blood as described by Boer- 
 
 d 2 
 
haave in cases of fever depending on inflam- 
 mation of any particular viscus, but on the 
 contrary, the blood is in a state of greater te- 
 nuity and fluidity, and the size or gelatinous 
 substance which is observed to cover the 
 crassamentum of blood drawn in such cases, 
 after it has remained in a bowl till cool, is 
 only the natural coagulable lymph, which* 
 being specifically lighter than the red glo- 
 bules, and separated from the rest of the 
 mass by the strong and repeated contraction 
 of the heart and arteries, and the slower 
 coagulation of the blood in such cases, rises 
 to the surface unmixed with the red glo- 
 bules. 
 
 Sauvages, Vogel, Gaubius, and other sys- 
 tematic writers have attempted, in their sys- 
 tems of nosology or methodical arrangement 
 qf diseases, to unite the doctrines of Hoff- 
 man and Boerhaave, in their explanations of 
 the proximate causes of diseases, and have 
 been followed by the late Dr. David M'Bride 
 of Dublin, in his "Introduction to the Theo- 
 ry and Practice of Medicine," and by Dr, 
 John Baptist Burserius De Kanifeld, profes- 
 sor of physic at Milaa in Italy, the last men- 
 
i 
 43 
 
 tioned of whom, published his "Institutions 
 of the practice of Medicine" three or four 
 years after the publication of Dr. Cullen's 
 '•First Lines." 
 
 The doctrine of Professor Boerhaave had 
 gained such dominion over the understand- 
 ings of the generality of physicians in Eu- 
 rope, and particularly in Great Britain, be- 
 fore the time of Dr. Cullen, that not only 
 the experienced Huxham, but even Dr. 
 Mead, the most accomplished scholar of the, 
 last age, so late as the year 1750, was so 
 convinced of the truth of this doctrine, and 
 his judgment was so much perverted by its 
 plausibility, that he fancied, in a case in 
 which the patient speedily recovered after 
 the application of the lungs of a lamb to his 
 head, that the morbific matter issued through 
 the pores of the skin from the part where 
 the lungs were applied.* 
 
 Doctor Tode, a professor in the universi- 
 ty of Copenhagan, the capital of Denmark, 
 who published his opinion in the year 176i>, 
 eight years before the publication of Dr. CuU 
 len's First Lines, considers the proximate 
 
 • See Mead's Medical Works published in 1767. 
 
44/ 
 
 cause of fever to b^ ah increased action or 
 exertion of the sensorium, communicated in 
 different ways to all the other parts of the 
 body, and says " the difference in the phe- 
 nomena or symptoms of fevers, depends upon 
 the greater or less power of the sensorium, or 
 on its greater or less sensibility or susceptibi- 
 lity to the impression of irritating or stimulat- 
 ing agents; the symptoms in the former case 
 being inflammatory, in the latter, nervous or 
 accompanied with symptoms of defective 
 power in the sensorium, and the organs de- 
 pendent on its influence." 
 
 As the accession or cold stage of fever 
 cannot be explained or accounted for on this 
 doctrine, or on the one lately published by Dr. 
 Clutterbuck, who refers all the phenomena 
 of fever to a manifest or latent inflammation 
 of the brain, it would be time misemployed 
 to take any notice of them. The perusal of 
 Dr. Cullen's remarks on the different theo- 
 ries of proximate causes, which had existed 
 before the publication of his works, will 
 satisfy the reader, that all such doctrines as 
 refer the proximate cause of febrile diseases 
 to direct stimuli alone, are erroneous. 
 
43 
 
 The following are a few of the numerous 
 instances of the deplorable effects of the prac- 
 tice to which all the theories of fever led, 
 which prevailed at different periods, pre- 
 vious to the publications of Hoffman and the 
 lectures of Dr. Cullen. 
 
 Dr. Silvius having been misled by the doc- 
 trine that the coagulation of the blood is the 
 proximate cause of fever, banished bleeding 
 and cooling remedies from the cure of fevers, 
 and recommended spirituous and volatile 
 substances to dissolve the supposed coagula- 
 tion. Dr. Gilchrist and other physicians of 
 Great Britain, employed mercury for the 
 same purpose, though its invariable effect is 
 to produce the very circumstance which they 
 employed it to remove. They appear to 
 have fallen into this pernicious error, in con- 
 sequence of a hypothesis engendered in their 
 own minds, from neglecting to ascertain the 
 existence of the fact before they drew their 
 conclusions. 
 
 Sydenham, Baglivi, Boerhaave, and Mead, 
 with a numerous host of servile followers, 
 considered a fever not as a disease, but as 
 the remedy of a disease, called up by nature 
 
46 
 
 almost exclusively for the purpose of throw- 
 ing out peccant or morbific matter, blended 
 with the circulating fluids. For this reason, 
 their chief aim was to regulate the heat, and 
 the excessive or defective motion of the 
 blood, till the morbific matter had time to 
 ripen and become fit for expulsion. For 
 the same reason they were very reserved in 
 the use of the lancet after the first two or 
 three days, even in cases of pleurisy, except- 
 ing when the blood was covered, after stand- 
 ing to cool, with a thick sizey surface, by 
 which they were priucipally guided in the 
 repetition of bleeding, from mistaking an ef- 
 fect for a cause, instead of by the greater or 
 less strength of the heart and arteries as in- 
 dicated by the pulse, heat of the skin, &c. 
 They also prohibited purgatives in the early 
 stage of all fevers, as well as all other' de- 
 pleting remedies, excepting a mild emetic 
 and purgative at the commencement of the 
 disease, to carry off the contents of the primse 
 vise, from a belief derived from their theory 
 that they would prevent or retard the concoc- 
 tion or ripening of the morbific matter; and 
 in cases of inflammation, that they would 
 
47 
 
 only evacuate the thinner or watery portion 
 of the blood, a id leave the remainder 
 thicker. 
 
 Henry Screta, reviving the opinion of Dio- 
 des, derives all fevers from an inflammation 
 of the viscera, and from a supposition that in- 
 flammation is owing to an obstruction of the 
 blood in the small vessels, from its too great 
 viscidity, by which it is hindered from pass- 
 ing through them; he condemns bleeding, 
 purging, and all remedies that diminish the 
 febrile heat, as well as those that carry ofif 
 the thinner parts of the blood, lest it should 
 leave the remainder thicker and more gluti- 
 nous, but proposes to cure them by spirituous 
 volatile alkaline and saponacious remedies, 
 by which means lie expected to dissolve and 
 discuss the thick obstructing portion of the 
 blood, which only existed in his own bewil- 
 dered imagination. 
 
 Some of the over wise gentlemen of the 
 faculty, adopting the cartesian philosophy, 
 imagined that fevers were occasioned by an 
 obstruction of the blood itself, and not of the 
 blood vessels, in consequence of which, the 
 subtile or spirituous matter, which they sup- 
 
48 
 
 posed, was constantly ranging through the 
 blood with great celerity and passed through 
 its pores in straight lines, excited a violent 
 commotion in it, in order to recover its cus- 
 tomary course. 
 
 Consistently with this hopeful theory, their 
 chief remedies consisted in the liheral use of 
 warm water to dilute and dissolve the ob- 
 structing glutinous matter with which they 
 imagined the pores of the blood was plugged 
 up. 
 
 Others imagined that all idiopathic fevers 
 were the effect of more or less putrefaction 
 of the circulating fluids, and being misled 
 from observing that the putrefaction of dead 
 animal substance* is increased by mois- 
 ture, forbid their patients from drinking wa- 
 ter, either cold or warm, for the first three 
 days, lest it should increase the supposed 
 cause of the disease. By this preposterous 
 treatment u the patients frequently suffered 
 more by the doctor than by the disease/' 
 
 If Mr. Malthus, the author of several in- 
 genious tracts on political economy, had 
 been acquainted with the hopeful doctrines 
 and random practice of physicians, general- 
 
*9 
 
 ]y, from the time of the conquest of the Ro 
 man empire in the sixth to the close of the 
 seventeenth century, I fancy he would not 
 have considered the introduction of the small 
 pox into Europe, war, famine, pestilence, 
 and typhus fever, as the only instruments in 
 the appointments of Providence for prevent- 
 ing the population of the world from becom- 
 ing too great for the means of subsistence. 
 
 When Dr. Cullen had exposed the errors 
 and defects of the Boerhaavian doctrine of 
 diseases, and had shewn that the ancient and 
 venerable doctrine of morbific matter, which 
 originated with, or was adopted by Hippo- 
 crates, and which, like a solid body falling 
 from a great height, seemed to acquire addi- 
 tional force as it descended through admir- 
 ing ages, was merely hypothetical or conjec- 
 tural, and had resulted from mistaken facts, 
 and imperfect observations ; and that as it 
 had no alliance with nature or truth, it had 
 a tendency to lead to wrong and dangerous 
 practice, he found it incumbent upon him to 
 compose a new system to supply the place 
 of those which he had exposed and demo- 
 lished, for the instruction, as well as enter- 
 
 E 
 
50 
 
 tainment, of the great number of medical 
 students that attended his lectures in the 
 university of Edinburgh, where he was ap- 
 pointed to the professorship of the theory 
 and practice of physic. 
 
 Such a system he accordingly composed, 
 and afterwards published in the year 1777? 
 under the title of "The First Lines of the 
 Practice of Physic." The substance of his 
 doctrine I shall now proceed to examine. 
 
 Observations on the doctrine of the inge- 
 nious and celebrated Dr. Wm. Cullen. 
 Professor, 8£c. 
 
 Doctor Cullen improving on the hints and 
 opinions of Hoffman, reasonably concluded 
 that we are to look for the origin and seat of 
 diseases, not in the ideal habitations of hu- 
 mours and animal spirits, not in the chemi- 
 cal changes or fermentations of the blood, 
 but in the solids of the human system, and 
 that the true knowledge of the nature and 
 proximate cause of diseases, must be de~ 
 
51 
 
 rived from a knowledge of the causes of the 
 motions and functions of the human body in 
 a state of health, and of the causes of the de- 
 viation or disorder of these motions and 
 functions, when disease exists; and his ob- 
 serving and penetrating mind was soon con- 
 vinced, that the generality of diseases de- 
 pend upon the morbid state of the nervous 
 and muscular portions of the solids, and that 
 the disordered condition of the fluids in the 
 generality of the fevers that occur, is the ef- 
 fect of too strong or of too weak action of 
 thp hpnrt and arteries on the blood, and sel- 
 dom, if ever, the effect of morbific matter in- 
 troduced into it, excepting when occasioned 
 by certain specific contagions, which operate 
 not only in producing too high or too low ex- 
 citement of the sensorium and nerves, but 
 in impairing the vital principle, or principle 
 of excitability in every other part of the sys- 
 tem ; and especially, as observed by Dr. 
 Milman, in the muscular fibres of the heart 
 and arteries. 
 
 Thus we perceive that the fundamental 
 part of this doctrine is, in many respects, 
 
m 
 
 different from all that preceded it, with the 
 exception of that taught by Dr. Hoffman. 
 
 Dr. Cullen's systematic arrangement of 
 diseases into classes, orders, genera, species, 
 and varieties, is perhaps too artificial and 
 complicated, and not so useful as if he had 
 divided all idiopathic, i. e. all diseases in 
 which the whole system is more or less dis- 
 ordered, only into genera and species, or into 
 species and varieties.* 
 
 His histories of diseases are inimitably ex- 
 plicit and correct. He even excels the acute 
 
 and celebrated Sydenham, in his description 
 
 of the diagnostics, or those symptoms by 
 which each form or variety of disease is dis- 
 tinguished from every other. 
 
 The accuracy and comprehensiveness of 
 his definitions are peculiar to himself and 
 stand unrivalled on the records of medicine. 
 The generality of his practical rules are 
 selected from his own extensive experience, 
 
 Dr. Thomas Young, physician to St. George's hospital, has 
 lately published an improved system of nosology, in which he 
 has not only rejected the most exceptionable parts of Dr. Cul- 
 lers nosology, but has added Dr. Wiiian's valuable nosology 
 of the diseases of the skin. 
 
 ., 
 
53 
 
 and the experience of the most judicious and 
 successful of his coteniporaries, and will re- 
 main an invaluable treasure to the medical 
 profession through successive ages. 
 
 Even the theoretical part of Dr. Cullen's 
 system, though by no means faultless or free 
 from imperfections, .must be considered as a 
 prodigy of ingenuity, when the difficulties 
 which he had to encounter are taken into con- 
 sideration. 
 
 Truth, however, constrains me to ac- 
 knowledge, that notwithstanding the judi- 
 cious plan which Dr. Cullen adopted and 
 improved, for investigating the proximate 
 causes of diseases, or that condition of the 
 living system on which the symptoms of dis- 
 ease depend, by collecting and tracing ef- 
 fects to their causes, he has fallen into seve- 
 ral mistakes; and in some instances," in my 
 opinion, very considerable ones. 
 
 Some of these I shall now proceed to enu- 
 merate, that they may serve as beacons, to 
 guard others from falling into the same er- 
 ror. 
 
 The first error that occurs in Dr. Cullen's 
 arrangement of diseases is, I conceive, that 
 
 e 2 
 
54 
 
 of classing them according to their symptoms, 
 instead of according to the similarity of their 
 nature and proximate cause. For, it is well 
 known, that diseases the most dissimilar to 
 each other in their nature and proximate 
 causes, have similar symptoms. The inter- 
 mittent fever and the typhus, the proximate 
 cause of the former of which appears, from 
 the symptoms and the effects of the occasion- 
 al cause, to be a certain degree of debility or 
 impaired energy of the nervous, and preter- 
 natural irritability of the arterial system; and 
 in the latter, an impaired state of the muscu- 
 lar fibres of the heart and arteries, in con- 
 junction with nervous debility, he has placed 
 in the same order and genus with fevers ac- 
 companied with, and dependent chiefly on, a 
 local inflammation of one or more of the vis- 
 cera. 
 
 The cyanehe maligna, or putrid and ulce- 
 rous sore throat, he has placed in the same 
 class with the highest of all inflammatory 
 affections, the phrenitis, pneumonia, carditis, 
 ententes, &c. 
 
 The small pox and measles, which are 
 generally attended with strong action and ia* 
 
55 
 
 iiammatory symptoms, during the eruptive fe- 
 ver, are placed in the same order as the pesti- 
 lence, the most debilitating and malignant of 
 all diseases ; because the latter is attended with 
 glandular swellings and carbuncles, or gan- 
 grenous eruptions. The cyanche tonsillaris 
 he has classed with the cyanche maligna, 
 because the tonsils and fauces in both, are 
 affected with swelling and inflammation, 
 though proceeding from different causes, and 
 entirely differing in their nature, and requir- 
 ing remedies of a different kind. 
 
 He has also committed an inconsistency 
 in arranging pyrosis, diarrhoea, and diabetes 
 in the same order (viz. spasmi) with pertus- 
 sis, cholera, asthma, and hydrophobia; and 
 in the same class (neuroses) apoplexy, and 
 hypochondriasis; while menorrhagia, haema- 
 temesis, and hsemorrhois are arranged in the 
 same order with typhus, pneumonia, and 
 dysentery. 
 
 These instances are sufficient ta shew, 
 that attention to symptoms alone, without a 
 competent knowledge of the nature and im- 
 mediate cause of each individual disease, is 
 insufficient, and often tends to lead to false 
 
 ^ 
 
56 
 
 associations, and consequently, to erroneous 
 and hazardous practice; whereas, an ar- 
 rangement according to the nature and proxi- 
 mate causes of diseases, where these can be 
 discovered with certainty, is not liable to 
 such error and confusion ; and it ought to be 
 the object of classification to render the. ac- 
 quisition of knowledge certain, easy, and of 
 practical utility. 
 
 Doctor Cullen has also incorporated with 
 his system, two opinions, one of antiquity, 
 the other of more modern date, both of which, 
 in my opinion, disfigure its harmony and sim- 
 plicity, viz. the doctrine of critical days in 
 continued fever, and that of the vis medica- 
 trix naturce, or what he calls a law of the 
 animal economy, whereby motions are ex- 
 cited to resist and remove noxious or inju- 
 rious impressions ; both of which have been 
 combatted, though not with becoming tem- 
 per, nor in the mild spirit of philosophy, by 
 the late Dr. J. Brown, of Edinburgh, and 
 more recently, with the becoming spirit of a 
 candid and sincere inquirer after truth, by 
 Mr. John Burns, of Glasgow, in the first 
 volume of his dissertations on inflammation. 
 
 
57 
 
 According to the Cullenian doctrine, as ob 
 served by Air. Burns, "fever is not produced 
 directly, by the application of hurtful agents, 
 but by the supposed interference of the vis 
 medicatrix, or healing power of nature." 
 
 That Dr. Cullen has been led into mis- 
 takes by the abstract consideration of symp- 
 toms, appears to me evident, from the proxi- 
 mate cause he has assigned to every variety 
 of fever and inflammation; and from his 
 placing fevers depending on local inflamma- 
 tion, in the same class and order with those 
 
 that arc idiopatliic 7 and that originate frOIX^ 
 
 and depend upon, a different cause. 
 
 The evidences which he adduces in sup- 
 port of his opinion are, that in both the idio- 
 pathic or simple fever, and fever depending 
 on inflammation existing to a certain extent, 
 in some part of the system, there is a dry 
 hot skin, thirst, and a decrease of the seve- 
 ral excretions. 
 
 These symptoms, however, in case of 
 fever accompanied with, and depending on 
 local inflammation, cannot depend on spasm, 
 which unquestionably requires a part to be 
 in a state of debility, in conjunction with 
 
m 
 
 preternatural excitability of the vessels or 
 fibres of the part affected, or acted upon, by 
 stimuli dis proportioned to the morbid state 
 of excitability, but upon preternatural ful- 
 ness and distension, and increased action of 
 the arteries of the affected part, and conse- 
 quent pain and irritation, &c. ; for "the ge- 
 neral operation of all powers productive of 
 inflammatory diathesis, proceeds upon prin- 
 ciples that would remove the atony or defect 
 of power subsisting in the extreme ves- 
 sels, which Dr. Cullen considers as the im- 
 mediate Cause of spasm in eaeps of favar • 
 
 whereas, the remedies employed to remove 
 the arterial tension and inflammation, would 
 necessarily increase and fix a spasm. " 
 
 If the remote causes of fever "produce a 
 sedative or debilitating effect, (as taught by 
 Dr. Cullen,) upon the nervous system," this 
 state of debility, in connection with the usual 
 excitability which exists in the arterial sys- 
 tem at the same time, is sufficient to account 
 for all the appearances of spasm on the ex- 
 treme vessels, at the commencement, and du- 
 ring the course of a simple intermittent fe- 
 ver. 
 
59 
 
 The arteries, which are composed of car- 
 tilage and muscular fibres, have been disco- 
 vered to possess a considerable portion of 
 irritability or excitability, but not of sensibi- 
 lity. 
 
 When the propulsive power of the heart 
 and arteries is so much diminished, in con- 
 sequence of the diminished energy of the 
 brain, (from whatever cause such an effect 
 is produced,) that they cannot propel the 
 blood with sufficient force into the extreme 
 vessels, those vessels must necessarily con- 
 tract, or become diminished in their diame- 
 ters, and shortened in their dimensions, be- 
 cause of their muscular structure, and elas- 
 tic property. But in such a debilitated state 
 of the heart and large arteries, those extreme 
 vessels must also be affected with a corres- 
 ponding state of debility, though their irrita- 
 bility remains unimpaired, or may be, per- 
 haps, preternaturally increased. Hence, it 
 is not probable that they can give preterna- 
 tural resistance to the heart and large arte- 
 ries, and thereby be the indirect cause of the 
 hot stage of the paroxysm in inienuitients, 
 or the protraction of the febrile paroxysm 
 
60 
 
 in fevers of a continued form ; both of which, 
 if that were the case, would readily yield, 
 as soon as the activity of the heart and large 
 arteries was restored, by the employment of 
 strong and diffusible stimulants. 
 
 According to the opinion of Dr. Cullen, 
 every variety of idiopathic fever depends for 
 its existence, and continuance, on an impair- 
 ed state of the energy of the brain, and a 
 consequent spasm of the extreme vessels. 
 That this theory, Dr. James Hamilton, jun. 
 says, is inadequate to the explanation of the 
 phenomena of typhus or continued fever, is 
 presumed from the following circumstances. 
 
 " 1st. Continued fevers are not always 
 preceded by a cold fit, nor by other symp- 
 toms denoting spasm of the extreme vessels ; 
 and 
 
 "%dly. The energy of the brain is not al- 
 ways restored on the cessation of the fever, 
 for imbecility of mind is the frequent conse- 
 quence of that disease. These objections to 
 the spasmodic doctrine of fever are selected 
 as being incontrovertible. Others, founded 
 on the inconsistency of the several parts or 
 
61 
 
 principles which constitute the theory, might 
 be urged." 
 
 How the debility of the functions of the 
 bratin or nervous system, according to Dr. 
 Cullen's theory, proves an indirect stimulus 
 to the sanguiferous system ; how this debi- 
 lity acts in producing the cold stage and 
 spasm of the extreme vessels ; how through 
 the intervention of the debility and spasm of 
 the extreme vessels, the action of the heart 
 and large arteries is increased; how the en- 
 ergy of the brain is restored, and how this 
 energy is extended to the extreme vessels, 
 is not explained by Dr. Cullen. Whatever 
 rests on these points, therefore, is confessed- 
 ly hypothetical, or conjectural and uncer- 
 tain : and if what rests on these is excluded 
 from his theory, all that remains, as is ob- 
 served by Dr. A. P. Wilson, of Edinburgh^ 
 will be found nothing more than a short re- 
 capitulation of the symptoms of fever. 
 
 Many other facts and arguments might be 
 offered to prove that a spasm of the extreme 
 vessels is not a part of the proximate cause of 
 any variety of fever, but is merely a symptom 
 
62 
 
 proceeding from an impaired energy of the 
 sensorium, and a diminished action of the heart 
 and arteries, the effect of the debilitating 
 power of the remote causes; but, in my 
 opinion, what has been already suggested is 
 amply sufficient for that purpose. 
 
 I shall, therefore, conclude my observa- 
 tions on Dr. Cullen's theory with the repe- 
 tition of an old adage, viz. "Urare est hit- 
 manumy' for, though his doctrine is not per- 
 fect nor free from error, it is the best that 
 the state of medical knowledge, at the time 
 he wrote, was calculated to admit ; and it is 
 honourable even to fail in a laudable at- 
 tempt. 
 
 It appears, from a variety of passages in 
 the works of the late Sir John Hunter, the 
 celebrated anatomist and physiologist, that 
 he considered every operation or motion of 
 the human body, as an action of the vital 
 principle, and that "this principle is, as it 
 were, diffused through the blood, as well as 
 through every solid fibre of the body, making a 
 accessary constituent part thereof, and form- 
 ing with them a perfect whole ; giving to both 
 the power of preservation, the susceptibility 
 
63 
 
 of impression, and from their construction, 
 reciprocal actions, and reactions/' "It was 
 also his opinion that diseases are propa- 
 gated from a part, to the whole system, by 
 means of the diffused vitality/' 
 
 This author, who adopted the opinion of 
 Harvey and Willis, that the blood is alive, 
 founded his opinion upon the observation of 
 certain phenomena, and, especially, on the 
 coagulation of the blood. "This living prin- 
 ciple he supposes to be the same with that 
 of the rest of the body, and that something 
 similar to the brain is distributed through the 
 blood, w r hich he calls the diffused matter of 
 life" 
 
 It is probable this doctrine led the way to 
 the doctrine subsequently taught by the noted 
 Dr. John Brown, of Edinburgh, of which 
 the following is an abstract. 
 
 " Our system of solids (says Dr. Brown) 
 is a form of living matter, whose characteris- 
 tics are sensation and motion." 
 
 "The susceptibility of external powers is 
 excitability : the agents, stimuli or exciting 
 powers : The result, excitement." "With- 
 out this property, our bodies would be dead 
 
6* 
 
 and inert matter ;— by this property, they be- 
 come living matter — by this property, called 
 into action by the exciting powers, they be- 
 come living systems." "While the stimuli 
 act on the excitability with a sufficient de- 
 gree of power, then is the pleasant sensation 
 of health : when they raise the excitement 
 above this point, or depress it below it, there 
 is disease. When the stimuli cease to pro- 
 duce excitement, or the system to feel their 
 power, there is death." 
 
 "Excitability is a property or energy of 
 living matter, peculiar and inherent; but it 
 is a property which cannot be subjected to 
 the cognizance of our senses, and it is to be 
 referred to a point of fact. Of this energy, 
 property, or principle, there is assigned a cer- 
 tain portion at the commencement of life ; — 
 but this quantity differs in each individual, 
 and is found to change in the same subject, 
 at different periods of life, and in different 
 situations or circumstances; being, on the 
 one hand, occasionally accumulated, abun- 
 dant, or superfluous, and on the other, ex- 
 hausted, deficient, impaired, or nearly extin- 
 guished" 
 
6;? 
 
 "The stimuli or exciting powers are heat, 
 light, sound, air, and motion; the ingesta, 
 the blood, the secretions, muscular contrac- 
 tion — and liually, the powers of the mind; 
 as perception, passion, and thought, 
 
 "Excitement is life; the natural move- 
 ments of the machine, and the functions re- 
 sulting from these, are sensation, reflection, 
 and voluntary motion; which, as they imme- 
 diately flow from the exciting powers, are 
 vigorous when these are strong; languid 
 when these are weak, and cease when they 
 are taken away entirely." 
 
 Thus we are taught that the actions or 
 motions of our bodies are caused by external 
 agents, and that "life is a forced state;" 
 that our weak frame has an unceasing ten- 
 dency to dissolution, which is opposed only 
 by the incessant application of exciting pow- 
 ers. — That "these powers are the support 
 of life, and that being partially or complete- 
 ly withdrawn, are immediately followed by 
 disease or death. 
 
 "For the better understanding this doc- 
 trine, it is necessary to explain this princi- 
 ple, viz. " That all stimuli in acting on ex- 
 
 F S 
 
66 
 
 eitability, exhaust it; thus, the stimuli of ali- 
 ment, air, motion, passion, thought, have 
 supported the body through the labours 
 of the day; they have supported the func- 
 tions by acting on the excitability; — in the 
 evening it is exhausted (or the whole sys- 
 tem is weakened) by the excitability beings 
 diminished by their continued operation. — 
 They no longer produce the same effect; 
 the functions fail ; we sink into rest, and con- 
 tinue in sleep almost an equal time, unaffect- 
 ed by stimuli; renewing, by sleep, that ex- 
 citability which had been exhausted by the 
 labours or by the exciting agents of the day. 
 — We riser with restored excitability. — We 
 feel a new power of excitement in every ob- 
 ject around us. — We are refreshed in the 
 morning, and feel languid and fatigued at 
 night; and our whole life is an alternation of 
 action and sleep, of apathy and pleasure; of 
 wasting our excitability by day, in labour 
 or enjoyment, and of recruiting it during the 
 night, by sleep and the abstraction of stimu- 
 lating powers." 
 
 The same philosophy extends to the du- 
 ration of life. — "In childhood excitability 
 
67 
 
 is abundant in quantity, as being little ex~ 
 hausted ; but it is low in power, because the 
 tender stamina of that period, and accumu- 
 lated excitability, can neither admit nor sup- 
 port high excitement. The excitability of 
 infants is so abundant, that they are easily 
 supported by weak diet and low exciting 
 powers. In youth, the excitability is yet en- 
 tire, — the stamina are strong, — the powerful 
 stimuli are applied, and high passions are 
 the effect. This is the period of vigour, and 
 of inflammatory disease. In old age, the 
 stamina are worn and impaired, the excita- 
 bility is exhausted, the common stimuli have 
 lost their power, and the system begins to 
 decline ; — we then have weakness of body, 
 imbecility of mind, and chronic diseases, &c. 
 
 "We may last of all, have recourse to 
 more generous diet, and raise the excitement 
 by substituting wine to water, or brandy to 
 wine; perhaps by these means excitement 
 may be a while supported, and life prolong- 
 ed, but in a few years these also lose their 
 effect." 
 
 According to this doctrine, the living ac- 
 tion is never produced but by exciting pow* 
 
68 
 
 ers, as u there is no such thing as a direct 
 sedative in nature, 
 
 "In stimuli there is a gradation which, 
 being relative to the system, deceives our 
 senses; for, since some stimuli are powerful 
 and others weak, a less stimulus, applied af- 
 ter a more powerful one, will stimulate less 
 than the former, and suffer the motions ex- 
 cited by the former to subside, and will on 
 that account be considered as a sedative. 
 
 "Take heat for an example of this ; cold 
 is but an abstraction of heat, yet it has hith- 
 erto been thought to have a positive exis- 
 tence ; and heat has been considered as a sti- 
 mulant power, and cold as a sedative. To 
 detect this deception of our senses, plunge 
 the right hand into water at the heat of 150°, 
 the left into melting snow, withdraw both, 
 and plunge them into water at 100°; this 
 will prove at once stimulant and sedative — 
 cold or sedative to the right hand, and 
 hot or stimulant to the left. — Here we clear- 
 ly see that the effect is not always the same, 
 but is diversified by the state of the excita- 
 bility ; and as cold is an abstraction of heat, 
 so is fear an abstraction of courage — grief of 
 
69 
 
 joy — despair of hope — so is fasting an ab- 
 straction of the usual stimulus of food — bleed- 
 ing of the usual stimulus of blood, &c." 
 
 On this part of the Brunonian theory Dr. 
 Wilson remarks, that "in proportion as the 
 organs on which the animal functions de- 
 pend, have been subjected to the action of 
 stimuli, they become less capable of being 
 excited by them ; and if their application is 
 continued, the strongest fail to rouse the sys- 
 tem to any farther exertion, till a state of 
 sleep, (during which, if it be sound, there 
 is the greatest abstraction of stimuli on those 
 organs,) which is consistent with health, has 
 to a certain degree, renewed its excitability. 
 Such are the laws of the system in health 
 with regard to sleep and watching ; and the 
 doctrine of indirect debility is, for the most 
 part, applicable here. But these are not the 
 laws of the system in disease, as supposed by 
 Dr. Brown ; and his doctrines of direct and 
 indirect debility are totally inapplicable to the 
 other functions of the body, both in health 
 and disease." 
 
 One great error of the Brunonian theory, 
 is the application of the laws which govern 
 
70 
 
 particular functions or portions of the human 
 system, and that only in the healthy state, to 
 the system at large. This error has been 
 attempted to be corrected by Dr. Rush, in 
 his theory of diseases, as well as by Dr. Wil- 
 son in his treatise on febrile diseases. 
 
 Having thus stated the outline of the doc- 
 trine of health ; Dr. Brown goes on to that of 
 disease. 
 
 " Health is the due operation of stimuli on 
 well regulated excitability, producing a mo- 
 derate excitement, and a pleasant sensation ; 
 moving the whole system with a just degree 
 of power, and giving to all the functions their 
 due energy and action. 
 
 "Disease of weakness is the result of the 
 abstraction of stimuli, or the application of 
 stimuli in too low a degree, or of the system 
 less easily excited. 
 
 ff Disease of strength is the result of sti- 
 muli applied in too great a degree, or of a 
 system too susceptible of excitement. 
 
 "The first is depression below the healthy 
 state : it produces languid motions of the se- 
 veral functions; it is named asthenic disease^ 
 or disease of weakness, corresponding with 
 
71 
 
 the nervous or putrid diseases of former wri- 
 ters, aud requires exciting agents for its 
 cure. 
 
 "The second is a strong system, wound 
 up to a high pitch of excitement. It is an 
 exhuberance of health and vigour, and is 
 marked by violent movements. It is named, 
 in opposition to the former, sthenic disease, 
 corresponding to the phlegmasia or inflam- 
 matory diseases of other writers, and is cured 
 by abstracting stimuli and diminishing ex- 
 citement. 
 
 "Thus all our diseases depend upon a 
 state of preternatural debility, or upon a state 
 of preternatural strength, and this is the 
 foundation of the scale which has health for 
 its middle point; below this are arranged the 
 diseases of weakness, — above it all the dis- 
 eases of excessive strength, — and in both di- 
 visions of the scale, diseases are so arrang- 
 ed, that the worst forms are set off* at the 
 greatest distance from the middle point, to 
 mark them as the widest deviation from the 
 healthy state. 
 
 "But to illustrate still farther the nature 
 of these two distinct forms, or classes of dis- 
 
ease, we must observe their respective causes. 
 Sthenia, or excessive strength, or contrac- 
 tile power in the muscular fibre, is simply 
 the effect of many or of powerful stimuli acting 
 on the system. Asthenia is the immediate 
 effect of withdrawing these ; but asthenia is 
 not so simple as its opposite state ; for debi- 
 lity (according to this doctrine) varies in its 
 nature according to its various causes. 
 
 "1st. By abstraction of exciting powers, 
 is produced a species of debility named di- 
 rect. 
 
 "%dly. By long or violent application of 
 strong exciting powers, the excitability is 
 exhausted ; both the excitement and strength 
 of the whole system fail. This species of de- 
 bility is named indirect. 
 
 "3dly. When the exciting pow r ers are 
 withdrawn, and the direct debility produced, 
 it is at the same time combined with a new 
 species. — By merely withdrawing the stimu- 
 li, such weakness would be produced as 
 should be temporary only, and might be done 
 away by reapplying the usual exciting pow- 
 ers; but where the stimuli are withdrawn, 
 excitability is accumulated; and when it is 
 
73 
 
 accumulated in an undue quantity, it cannot 
 bear the usual stimuli, and will not give out 
 the usual healthy excitement." 
 
 This system turns on the hinge of direct 
 and indirect debility; for direct debility, 
 caused by the absence of exciting powers, is 
 attended with accumulation of excitability. 
 Indirect debility, caused by superabundant 
 stimuli, is attended with exhausted excitabi- 
 lity ; the former is most easily cured, since 
 we have only to apply a due quantity of sti- 
 muli, and gradually raise the excitement to 
 the standard of health; the latter is more dif- 
 ficultly cured, because the excitability being 
 in a great degree exhausted, the system is 
 less susceptible ; we have, therefore, less ex- 
 citability to operate upon, for the restoration 
 of excitement and consequent health. 
 
 " The abstraction of stimuli is an imme- 
 diate cause of weakness. High excitement 
 is a state of the system which the excitabili- 
 ty cannot long endure without being exhaust- 
 ed, so that stimuli themselves produce ulti- 
 mate weakness; therefore, since high ex- 
 citement is temporary only, and has but one 
 cause, while weakness is a permanent state, 
 
and has many causes, the diseases of debili- 
 ty, must, in a very great proportion, exceed 
 in number the diseases of excessive strength, 
 and diseases of excessive strength must, ulti- 
 mately, end there." 
 
 If 97 of 100 diseases arise from weakness 
 (as taught by this author) an inquiry into 
 the truth of his doctrine must be of the ut- 
 most importance. 
 
 TREATMENT. 
 
 " Though there be many individual dis- 
 eases, there are but two states or different 
 conditions of the system, and two methods 
 of cure. For all those diseases which stand 
 above the point of health, nothing more is re- 
 quired than withdrawing the stimuli of food, 
 drink, heat, &c. or aided by the reducing 
 or debilitating evacuations and abstractions, 
 such as bleeding, purging, &c. 
 
 "For all those diseases which stand be- 
 low the point of health, the natural stimuli 
 of aliment, drink, heat, &c. are to be em- 
 ployed; or the less natural, but more diffusi- 
 ble stimuli of the pharmacopeia, the chief of 
 
7* 
 
 Which are aether, alcohol, volatile alkali, 
 musk, and opium, or its spirituous tincture, 
 wine and alcohol. 
 
 " The agents which cause the one form of 
 disease, are the cure of the other; in the one, 
 we raise the excitement till it arrives at the 
 point of health; in the other, we depress it 
 to the same point : having effected this, by 
 the powers of medicine and regimen, we are 
 to keep it there by the powers of suitable re- 
 gimen, and moderate exercise, &c." The 
 great object, in the practice of our author, is 
 to hit the point of health : neither to stop 
 short of that point nor to pass beyond it ; for 
 by either practice we miss our aim. 
 
 " By profusion of stimuli we may convert 
 a disease of weakness (or of a nervous or ty- 
 phus character, according to this doctrine,) 
 into a disease of inflammation, or too high 
 excitement, or we may carry it beyond that 
 point into indirect debility. 
 
 u By too sudden and copious an abstrac- 
 tion of stimuli, we run into the opposite ex- 
 treme ; converting into a disease of direct de- 
 bility, what was formerly a disease of too 
 high excitement, or violent inflammation. 
 
76 
 
 u The use of stimuli, in asthenic disease*, 
 is to he regulated by the causes. In all cases 
 of indirect debility, in which the excitability 
 has been exhausted, the strength must be 
 raised by the immediate application of more 
 powerful stimuli : after which, these are to 
 be slowly reduced in quantity or strength till 
 the excitability is restored, after which, mo- 
 derate or ordinary stimuli will suffice to sup- 
 port the excitement of health." 
 
 " In all cases of direct debility, where ex- 
 citability is accumulated, the immediate ap- 
 plication of powerful stimuli would destroy 
 the weakened fibres, or occasion convulsive 
 motions in them ; weak stimuli must there- 
 fore be first used, the superabundant excita- 
 bility must be first gradually wasted, and 
 the doses very slowly increased till we raise 
 the excitement to the point of health." It is 
 the peculiar characteristic of this doctrine, 
 that it directs a method of cure, in many re- 
 spects, different from that of all others. In 
 proportion, therefore, as it is erroneous or 
 correct, it should be estimated, and therefore 
 should be refuted or confirmed. 
 
 According to this theory, diseases consist 
 
14 
 
 entirely of a state of excitement, to a certain 
 extent, higher or lower than a state of health; 
 for the author says " Health consists either 
 in moderate excitement, or in such an ex- 
 haustion of the excitability as daily occurs, 
 when the sleeping state of the system is in- 
 duced by the various actions and offices of 
 life ; whereas, a state of too high excitement 
 constitutes that form of disease which is ac- 
 companied with strong action of the arterial 
 sy* tern, and belongs to the class sthenia, (or 
 phlegmasia ;) and too weak excitement, ac- 
 companied with low, weak, or feeble action 
 of the arterial system, constitutes that form 
 of disease which belongs to the class asthe- 
 nia, or preternatural debility." 
 
 The indications of cure, we are told, are 
 to be formed and prosecuted according as 
 the nature of the one or the other form of the 
 disease is indicated by the remote causes to 
 which the patient has been subjected ; and 
 not according to the indications of the symp- 
 toms, which this author considers fallacious, 
 and apt to mislead ; and according to this 
 hopeful opinion, which might be suspected 
 to have been fabricated in an hospital of lu« 
 
 g 3 
 
78 
 
 natics, the excitability, which is only a dif- 
 ferent name for the vital principle, becomes 
 accumulated in quantity in proportion to the 
 privation or abstraction of customary stimuli, 
 by which the due ratio or relation between 
 it and the healthy excitement had been main- 
 tained, and that, as the powers which sup- 
 port life are diminished, life itself, or the 
 principle on which the phenomena of life de- 
 pend, is increased. 
 
 But the fact is, that excitability and ex- 
 citement, instead of being in an inverse ratio 
 to each other, as supposed by Dr. Brown, 
 are observed to decline in an equal propor- 
 tion through all the different stages and de- 
 grees of every disease whose symptoms indi- 
 cate great debility in the principal functions 
 of the human body; this is particularly evi- 
 dent in cases of typhus gravior, cyanche ma- 
 ligna, &c. According to this doctrine also, 
 by the abstraction of customary stimuli aid- 
 ed by the evacuating remedies, in cases of 
 exhausted excitability, from the application 
 of too strong and too many stimuli, direct de- 
 bility is said to be superadded to indirect 
 debility; this opinion, however plausible it 
 
79 
 
 may appear, is contradicted by numerous 
 facts. 
 
 If the usual refreshing drinks and aliment 
 are withheld from a patient in an advanced 
 stage of malignant fever, or gangrenous sore 
 throat, and only cold water is given, no ac- 
 cumulation of excitability or susceptibility to 
 action will take place; but, on the contrary, 
 the exhaustion and torpor will rapidly pro- 
 ceed, unless counteracted by suitable exciting 
 agents. 
 
 If a person, previously exhausted by fa- 
 tiguing exercise and exposure to the heat of 
 the sun, drinks a large quantity of cold wa- 
 ter, or plunges suddenly into a cold bath, 
 the excitability will not be increased, and 
 the sense of exhaustion thereby removed, 
 but, on the contrary, those greater degrees 
 of exhaustion will be induced which dispose 
 to spasm of the stomach, convulsions of the 
 muscles, or to tetanus, &c. 
 
 The doctrine of excitability increasing in 
 the whole or some particular poruon of the 
 system, in consequence of the abstraction of 
 customary stimuli, appears to be not only 
 exceedingly hypothetical, but is contradicted 
 
80 
 
 by facts familiar to every observing physi- 
 cian. — In the last stage of typhus fever, for 
 instance, when debility is hourly increasing, 
 instead of the excitability becoming more 
 abundant, (which can only be ascertained by 
 the greater or less motion of the living fibres, 
 observable upon the application of stimuli,) 
 the patient is very frequently observed to be 
 insensible to the impression of the most pow- 
 erful stimuli; and sometimes so insensible, 
 that flies may crawl over that tender organ 
 the eye, without creating any uneasiness. 
 But the circumstances attending the varie- 
 ties of the sthenic or inflammatory class of 
 diseases, entirely refute this doctrine.— in 
 these, the author supposes that the excite- 
 ment is increased, and the excitability di- 
 minished, in consequence of the operation of 
 too powerful stimulating agents. If, how- 
 ever, the state or quantity of excitability is 
 to be measured by the degree of susceptibi- 
 lity to the action of stimuli, who, after a mo- 
 ments reflection, will have the folly to say, 
 that in such cases, the excitability is dimi- 
 nished, when the system, or that part of it 
 which is the seat of disease, is afl'ecied by 
 
81 
 
 such stimuli as would not be felt in a state 
 of health. 
 
 According to the theory of this eccentric 
 teacher, every variety of the sthenic class 
 depends upon a state of excitement to a cer- 
 tain extent above the standard point of health, 
 which he has attempted to exemplify by an 
 imaginary scale, and every variety of the as- 
 thenic class depends upon a certain defect 
 of excitement below the same ; and he teaches 
 that the indications of cure are to be derived 
 from these opposite states of excitement. 
 
 In refutation of his doctrine of life, it may 
 be observed, that the actions which are pro- 
 duced in the living body by the operation of 
 stimulating agents, are not the cause of life, 
 as asserted, but merely the phenomena and 
 effect of life, or of the action of appropriate 
 stimuli upon the principle of life. — Life may 
 and does exist, without organic action ; but 
 organic action in the living body cannot be 
 produced without the presence of the vital 
 principle, or excitability. — Life is the pri- 
 mary or efficient cause, of which organiza- 
 tion is the secondary or instrumental cause; 
 and organic action itself, is the proximate 
 
82 
 
 effect, which proceeds from the impression 
 made by exciting agents upon the living prin- 
 ciple seated in the animal solids. 
 
 So long as the relation continues to sub- 
 sist between the excitability or susceptibility 
 of the system to be acted upon, and the pow- 
 ers of the agents applied, it receives the sup- 
 ply that it constantly requires, and the agree- 
 able sensation of health, is the effect. 
 
 If life was the forced state that Dr. Brown 
 and his followers suppose it to be, the ap- 
 plication of stimulating substances or excit- 
 ing agents, duly proportioned to the existing 
 state of excitability, would preserve mankind 
 in perpetual health, and render them immor- 
 tal; for, instead of being forced to die, they 
 would be forced to live // 
 
 If the principles of his doctrine, relative 
 to the proximate cause of disease, were cor- 
 rect and true, no disease by which the whole 
 system is affected would be incurable; for, 
 if disease depends only upon weakness or 
 strength of the living system, and weakness 
 and strength depend upon different degrees 
 of excitement above or below the standard 
 point of health, and nothing is to be ascribed 
 
83 
 
 to the fault of the solids or fluids; so long 
 as excitability remains, so long as the sys- 
 tem lives, and so long as we have at com- 
 mand stimuli of all degrees of power, dis- 
 cernment and judgment in their application 
 would be all that would be necessary to re- 
 store the disordered system to a healthy 
 state. 
 
 Like the fanciful and enthusiastic Van- 
 helmont, Dr. Brown unfortunately imagined 
 that genius could supply the place of expe- 
 rience and observation, and rejecting with 
 disdain the facts which had been collected 
 by his predecessors, he rashly formed plans 
 of treatment which, if adopted, would in 
 many cases prove fatal, and particularly in 
 apoplexy, and dysentery, and in thfc first 
 stage of phthisis pulmonalis, &c. 
 
 If disease depends only on excitement to 
 a certain extent above or below the healthy 
 point, and if excitement last no longer than 
 its cause, how comes there to be any perma- 
 nent disease? 
 
 If a man in health, drinks wine to excess 
 one day, and none the next, the excitement 
 immediately subsides and he feels debili- 
 
84 
 
 tated. This is not the case in disease. If 
 perineumony be produced by the excessive 
 stimulus of heat, after previous exposure to 
 cold, as his doctrine supposes, why is it not 
 removed by abstracting that stimulus and 
 exposing the patient to freezing air, or im- 
 mersing him in a bath of cold water, which 
 is said to operate only by abstracting excess 
 of animal heat? 
 
 Another circumstance which shews the in- 
 correctness of the Brunonian doctrine, is, the 
 effect produced by different articles of the 
 materia medica, all of which are pronounced 
 by our author to operate only by a stimulat- 
 ing power. 
 
 If all the powers which produce action in 
 the animal machine operated only as stimu- 
 lants, they must all have one common na- 
 ture or quality, and differ only in the degree 
 of power. But there can be no doubt that 
 individual stimuli differ widely from each 
 other in their nature and mode of action; 
 some produce hilarity, as wine and opium ; 
 one produces phrenzy, as the seeds of the 
 belladona, or deadly night shade ; a second, 
 colic, as the acetate of lead ; a third, tempo- 
 
85 
 
 rary mania, as the seinina stramouii ; a fourth, 
 cholera and convulsions, as arsenic and sub- 
 muriate of mercury; and a fifth, strangury, 
 as cantharides, &c. From this it appears that 
 stimuli differ in quality as well as in degree of 
 power; for if they differ in degree only, then 
 might the first stimulus in a more concen- 
 trated form have produced the same effect; 
 of course, nosology must be something more 
 than a mechanical scale, and our pharmaco- 
 peia, something more than a rising series of 
 stimulant powers; otherwise, opium, aether, 
 and alcohol, as strongest stimulants, could 
 by dilution give out all the lower degrees of 
 stimulant power, and -every variety of dis- 
 ease of the asthenic class, should recede be- 
 fore its appropriate degree. 
 
 But if ipecacuanha operates upon the sto- 
 mach, jalap and rhubarb on the intestines — 
 If nitre affects the kidneys, cantharides the 
 bladder, and mercury the salivary glands, 
 they must have some peculiar quality super- 
 added to their stimulant power, and their 
 stimulant power must be only a subordinate 
 effect. Tf they are stimuli, they are such as 
 
 H 
 
86 
 
 operate only on certain parts of the system, 
 while they have no effect upon others. 
 
 If bark cure an intermittent, or mercury the 
 syphilis, which neither opium, aether, nor 
 brandy can do, then it ought to be the chief 
 study of the physical! to discover these spe- 
 cific and peculiar powers. 
 
 If all stimulants were the same in kind, 
 and only differed in degree, or were uniform 
 in their action, water, heated to a certain de- 
 gree, would intoxicate, as well as wine or 
 alcohol. 
 
 Many other facts and arguments might be 
 offered to prove the imperfection, inconsis- 
 tencies, and errors of the Brunonian system 
 of physic, and the pernicious tendency of the 
 practice which it inculcates, especially in 
 diseases of a mixed character, such as ver- 
 nal intermittents, dysenteries, apoplexies, 
 &c. ; but as these must be obvious to every 
 person of common discernment, that is ac- 
 quainted with the animal economy and the 
 rules of inductive philosophy, it would be su- 
 perfluous to add any thing farther on the sub- 
 ject, in proof of the doctrine of this ingenious 
 teacher being glaringly erroneous in its prin- 
 
87 
 
 eiples, inconsistent with the laws of the ani- 
 mal economy, and dangerous in its applica- 
 tion to practice. I shall, therefore, proceed 
 to the consideration of the Theory or Doc- 
 trine of Diseases, published by the late Dr, 
 Erasmus Darwin, author of the elegant 
 poem called "The Botanic Garden." 
 
 According to the theory of this ingenious 
 writer, the sensorium possesses four distinct 
 powers or faculties, which are occasionally 
 exerted, and produce all the motions of the 
 fibrous parts of the living body. — These are 
 
 ist. The faculty of producing fibrous mo- 
 tions, in consequence of irritation, excited by 
 external substances. 
 
 2d. The faculty of producing fibrous mo- 
 tions, in consequence of sensation, which is 
 excited by pleasure or pain. 
 
 3d. The faculty of producing fibrous mo- 
 tions, in consequence of volition, which is 
 excited by desire or aversion. 
 
 4th. The faculty of producing fibrous mo- 
 tions, in consequence of association, • which 
 is excited by other fibrous motions. 
 
 The author considers the exuberance, 
 deficiency, or retrograde action of these fa- 
 
88 
 
 eulties of the sensorium, as the proximate 
 cause of every individual disease; and, ac- 
 cording to this view of the subject, he has 
 divided all diseases into four classes, accord- 
 ing as they depend upon the disordered state 
 of one or other of the above mentioned facul- 
 ties. 
 
 These four classes are divided into distinct 
 orders, genera, and species. 
 
 The orders of the different classes are 
 named from the excess, deficiency, or retro- 
 grade action of the proximate causes. The 
 genus from the proximate effect; and the spe- 
 cies, in general, from the locality or situa- 
 tion of the disease in the system. 
 
 The superior advantage of classing dis- 
 eases according to their proximate causes, 
 in the opinion of Dr. Darwin, is, 1st. more 
 distinctly to understand their nature by com- 
 paring their essential properties. 2dly. To 
 facilitate the knowledge of the methods of 
 cure; since, in the natural classification of 
 diseases, the species of each genus, and in- 
 deed the genera of each order, with perhaps 
 a few exceptions, require the same geLtjral 
 method of treatment; and lastly, to discover 
 
89 
 
 the affinity of a disease not previously known, 
 by comparing it with those with which the 
 physician is already acquainted. 
 
 Dr. Darwin supposes that the faculties of 
 the sensorium depend upon the presence of a 
 subtile elastic fluid secreted by the brain, 
 which he denominates "sensorial power," 
 or the spirit of animation. 
 
 In the first volume, page 6th. of his Zoo- 
 nomia, he says "the similarity of the tex- 
 ture of the brain to that of the pancreas and 
 some other glands of the body, has induced 
 the inquirers into this subject to believe, that 
 a fluid, perhaps much more subtile than the 
 electric aura, is separated from the blood by 
 that organ for the purposes of motion and 
 sensation. 
 
 "When we recollect (adds this ingenious 
 author) that the electric fluid itself is ac- 
 tually accumulated and given out volun- 
 tarily by the torpedo, am! the gymnutus elec- 
 trials, that an electric shock vvih frequent- 
 ly stimulate into motion a paralytic limb, and 
 lastly, that it needs no perceptible tubes to 
 convey it, this opinion seems to be not with- 
 out probability; and the figure of the brain 
 
 h 3 
 
90 
 
 and nerves seem well adapted to distribute 
 it over every part of the body. 
 
 "All bodies possessing life and motion 
 have a peculiar organization,' and the muscu- 
 lar parts possess a principle of excitability, 
 or a capacity of contracting and shortening 
 their fibres, in consequence of impressions 
 made on them by external agents." 
 
 The section on stimulus and exertion, in 
 Dr. Darwin's Zoonomia, contains the prin- 
 ciples which constitute the ground work of 
 his theory; of which the following is a brief 
 abstract, 
 
 "1st. There is diffused throughout the 
 animal system, a certain property which 
 may be denominated sensorial jjower, or the 
 principle of animation.* 
 
 "2d. When stimulating substances are 
 applied to the body they produce motion in 
 the muscular fibres by their action upon this 
 sensorial power or principle of animation." 
 These produce a certain effect which he calls 
 exertion, and which by others is called con- 
 traction. 
 
 * This is what Dr. Brown calls " excitability.*' 
 
9i 
 
 "3d. If the stimulus be greater than cus- 
 tomary, it exhausts the sensorial power; but 
 if the stimulus applied be less than the sys- 
 tem has been accustomed to, the sensorial 
 power becomes accumulated and superfluous. 
 
 "4th. The exertion (or contraction of the 
 fibres) is varied ; first, by the quantity of 
 sensorial power, secondly, by the quantity 
 or forcible impression made by the stimulus, 
 and thirdly, by the proportion which these 
 bear to each other. 
 
 "5th. If the sensorial power and the sti- 
 muli are in due proportion to each other, and 
 neither have gone to excess, or fallen too 
 low, the exertion and excitement produced, 
 is moderate and regular, and constitutes 
 health. 
 
 "6th. When the exertion is too strong, 
 and the excitement too high, either from an 
 excess of stimulus, from an excess of the 
 presence of sensorial power, or from an in- 
 crease of both, it constitutes disease : and 
 
 "7th. When the exertion (or excitement) 
 is much diminished, either from a deficiency 
 of stimulus, or from deficiency of sensorial 
 power, or from a deficiency of both, it also 
 
92 
 
 constitutes disease, but of a different charac 
 ter from the former : 
 
 "The diseases of the former kind, re- 
 quiring depleting and debilitating remedies, 
 and those of the latter, stimulating and invi- 
 gorating ones." 
 
 From this brief abstract it appears that 
 the theory of Dr. Darwin and that of Dr. 
 Brown, bear a striking resemblance to each 
 other in several particulars ; they, however, 
 differ materially from each other in several 
 other respects. 
 
 They agree in the doctrine that the ap- 
 plication of stimuli will increase exertion or 
 excitement, and that the abstraction of sti- 
 muli will diminish it : they agree in suppos- 
 ing that the exertion or excitement, simply 
 varied in degree above or below the usual 
 scale of health in each individual, consti- 
 tutes disease; and that it constitutes health, 
 when at a medium. They also agree in the 
 supposition that a diminution of action, from 
 the abstraction of stimuli, is accompanied or 
 followed by an increase of sensorial power 
 or excitability. 
 
 But though they both agree with respect 
 
93 
 
 to the existence of excitability or sensorial 
 power, Dr. Brown does not pretend to know 
 from what source it is .derived, or how it 
 originates; whereas, Dr. Darwin considers 
 it to be a subtile fluid secreted by the brain, 
 and from thence distributed to every part of 
 the living system. 
 
 They disagree with respect to the nature 
 of stimuli; Brown supposing them all to be 
 of the same nature, varying only in their de- 
 gree of power; while Darwin contends that 
 they are different in their nature, some being 
 particularly adapted to act on one part of the 
 body, and some on another ; thus " antimo- 
 nium tartarasatum, taken into the mouth, 
 produces little or no irritation, but when 
 swallowed produces so great an irritation in 
 the stomach, as to invert its motion and oc- 
 casion vomiting :" again, ipecacuanha acts 
 upon the stomach, mercury on the salivary 
 glands, squills on the kidneys, and cantha- 
 rides on the bladder, and jalap, senna, sul- 
 phate of soda, &c. upon the intestines, &c. 
 
 Dr. Brown supposed that an increase of 
 either excitability or of stimuli so as to pro- 
 duce an increase of excitement, would pro- 
 
duce an increase of strength ; whereas, Dr. 
 Darwin asserts that, to produce strength, it 
 is necessary that the quantity of sensorial 
 power and force of the stimulus should both 
 be increased. 
 
 As the theory of Dr. Darwin agrees with 
 that of his cotemporary Dr. Brown, in mak- 
 ing disease to consist only in different de- 
 grees of excitement above or below the stan- 
 dard of health, the objections which have 
 been urged against the most material part of 
 Brown's, will apply with equal force to the 
 most material part of Dr. Darwin's theory. 
 
 Though Dr. Darwin considers stimuli to 
 differ in their nature and properties from one 
 another, he supposes, with Brown, that there 
 is no direct sedative or article of the materia 
 medica that produces sedative effects in the 
 first instance, but that all such phenomena 
 are the effects of evacuation, depletion, or 
 abstraction of stimulant agents. The follow- 
 ing facts, however, shew this opinion to be 
 erroneous. 
 
 u The depressing passions immediately oc- 
 casion a sense of debility in the vital and na- 
 tural, as well, as in the animal functions. 
 
95 
 
 The effects of fear or grief upon the human 
 body, arising to any considerable degree, are 
 loss of appetite, indigestion, and other symp- 
 toms of dyspepsia ; and that degree of debi- 
 lity which produces the morbid watchful 
 state. The system also under the operation 
 of the depressing passions, becomes more 
 susceptible of deleterious power, as the mi- 
 asmata of marshes, the contagion of typhus, 
 &c. 
 
 u The same total derangement of the orga- 
 nization, follows the excessive operation of 
 these passions, as well as of those of the ex- 
 citing kind. 
 
 " It has been alledged that the depressing 
 passions are only a diminution or abstraction 
 of the exciting passions, not the emotions of 
 an opposite nature, and that they are there- 
 fore to be considered as weak stimuli, and 
 that their operation upon the body is the 
 same as the abstraction of the necessary sti- 
 muli. 
 
 "This opinion is glaringly incorrect; first, 
 because no power can be considered as sti- 
 mulant, unless when operating in a certain 
 degree, it has the effect of increasing action 
 
96 
 
 in the moving powers of the system. But 
 fear or grief, operating in any degree, pro- 
 duces debility. 
 
 "%Aly. It is manifestly absurd, to suppose 
 that grief is merely the abstraction of joy, or 
 fear of courage. We cannot avoid perceiv- 
 ing, that the depressing passions are not 
 mere abstractions of stimulating agents, but 
 are rather powers, which operate with consi- 
 derable force, inducing direct debility in the 
 system. This class of passions must, there- 
 fore, be considered as sedative powers ; and 
 the conviction that they are such, naturally 
 leads us to conclude, that there are other 
 substances in nature, which also produce a 
 directly sedative effect upon the body. Such 
 appear to be marsh miasmata, and the con- 
 tagion of typhus fever." See Herdman on 
 Animal life. 
 
 If the gas called carbonated hydrogen, or 
 hydro-carbon, which consists of a mixture of 
 carbonic acid gas and hydrogen gas, or of 
 fixed and inflammable air, be inspired in an 
 undiluted state, it is followed by instant 
 death; and when inspired in a small quanti- 
 
97 
 
 vy only, mixed with atmospheric air, or with 
 oxygen gas, and be continued for any length 
 of time, it induces vertigo, dimness of sight, 
 convulsions, aud every symptom of approach- 
 ing death. Its noxious effects are therefore 
 referable to its action on the nervous system, 
 upon ivhich it produces directly sedative ef- 
 fects. From this circumstance, Dr. Bostie 
 observes that "the doctrine of there being no 
 direct sedative power in existence, is one of 
 the most singular contests of theory against 
 experience in modern times." Essay on lie- 
 spiration. 
 
 If the principles of the doctrine taught by 
 Dr. Darwin were true, it would be next to 
 impossible for any person to be deprived of 
 life, by exposure to freezing air in the most 
 dreary climates of the globe, unless there was 
 a total abstraction oi heat from the atmos- 
 phere; for, though. the cold be continued in 
 the same degree, its effects must gradually 
 decrease, from the accumulation of the sen- 
 sorial power, till at length its influence on 
 the body would be the same as when the sti- 
 mulus of heat was greater, and the sensorial 
 power less. 
 
98 
 
 The theory or explanation of the pheno- 
 mena of fevers, proposed by Dr. Darwin, is 
 chiefly founded on a sympathy or association 
 of parts; in consequence of which, it has ob- 
 tained the title of "the sympathetic theory of 
 fever." 
 
 Direct sympathy is used by Dr. Darwin, 
 to express an increase or decrease of motion 
 in the secondary or associate fibres, corres- 
 ponding with the increased or decreased mo- 
 tion of the fibres of the part originally affect- 
 ed. Bat it is impossible that the same mov- 
 ing fibres should be excited at one time by 
 direct, and at another by reverse sympathy, 
 or that the same cause should at one time 
 increase their action, and at another dimi- 
 nish if. 
 
 If Dr. Darwin's physiology was correct, no 
 inequality could continue for any length of 
 time, between the excitability of different or- 
 gans or functions of the body; for, if the 
 sensorial power be a fluid, as asserted by Dr. 
 Darwin, and becomes accumulated more or 
 less rapidly, during the existence of a state 
 Of torpor, quiescence, or inaction, produced 
 In consequence of too violent stimuli having 
 
09 
 
 previously acted on the same, it would over- 
 flow; agreeably to the laws by which other 
 fluids are governed, into every part, till all 
 were on a level, and then every part would 
 be liable to the same or a proportionable de- 
 gree of action. 
 
 If in the intermittent fever, the stomach is 
 primarily affected as this author teaches, the 
 diminution of action in the heart and arte- 
 ries, during the cold stage, cannot be the ne- 
 cessary result of associate motions, or sympa- 
 thy with the stomach; otherwise, the slight- 
 est degree of indigestion would always bo 
 attended with similar symptoms. 
 
 In accounting for the accession of the hot 
 fit, our author observes, that "the sensorial 
 power, which would have been expended 
 in the primary fibres in the mode of irrita- 
 tion, and in the secondary fibres in the mode 
 of association, being accumulated during the 
 cold fit, the arterial system is excited to vio- 
 lent action, in consequence of this accumu- 
 lation, by the agents, which are always more 
 or less in operation so long as life exists. " 
 
 If the organ or part primarily affected, 
 during the cold fit of fever, be excited by it* 
 
100 
 
 accustomed stimulus, and act with less ener- 
 gy, from previous exhaustion of sensorial 
 power, it will, by gradual accumulation, re- 
 gain its natural quantity, and the organ being 
 then in the same state as before the exhaus- 
 tion, and the stimulus of the same force, the 
 subsequent violent action cannot be explain- 
 ed on the principles of this doctrine. 
 
 If the quiescent or torpid organ, supposed 
 by this doctrine to be primarily affected, was 
 suddenly supplied with a quantity of senso- 
 rial power, it might be supposed, after con- 
 tinuing torpid or quiescent a certain time, to 
 glow with unnatural violence ; but if during 
 torpor or the cold stage, the sensorial power 
 is gradually accumulated, and less stimulus 
 be applied than usual, the torpor must gra- 
 dually cease, till at length the body will be 
 affected in the same manner as during its 
 healthy state, as the sensorial power or spirit 
 of animation, will have accumulated in a 
 proportion equal to the defect of the stimu- 
 lus : but this cannot be the case, as the sup- 
 ply supposed to be secreted by, and derived 
 from the brain, cannot have increased during 
 the cold stage, because of the torpor which 
 
101 
 
 precedes and accompanies that state of the 
 system; there must, therefore, be some other 
 cause for the accession of the iiot fit. 
 
 During the cold or forming stage of fever, 
 there is a suspension of the circulation in the 
 extreme or minute branches of the capillary 
 arteries in every part of the body. To ac- 
 count for this state of the vessels, is the great 
 desideratum in theory; but, neither this, nor 
 the accession of the subsequent hot fit, can 
 be accounted for in a satisfactory manner on 
 the principles of either the Cullenian, the 
 Brunonian, or the Darwinian theory. 
 
 In the production of fever, whether the 
 remote cause be marsh miasmata or human ef . 
 fluvia, Dr. Darwin is of opinion that it makes 
 its first impression upon the stomach; the 
 sensorial power, in the muscular fibres of 
 which it expends by the high excitement pro- 
 duced thereby, and that from thence a simi- 
 lar torpor or quiescence is propagated by 
 direct sympathy or association of action, to 
 the rest of the system : In other words, he 
 considers the remote cause of every species 
 of fever, to be a powerful stimulus; the con- 
 sequence of the action of which, is indirect 
 
 \2 
 
102 
 
 debility, from the expenditure of sensorial 
 power. 
 
 In every variety of fever, Dr. Darwin ap- 
 pears to suppose that the remote cause, gra- 
 dually expends the sensorial power in the 
 muscular fibres of the stomach, till, by the 
 intervention of the cold stage, a fresh supply 
 Is generated and accumulated in all the mov- 
 ing fibres of the system, in consequence of 
 which, the susceptibility to stimuli becomes 
 so great that a febrile commotion is excited 
 by stimulants of so low a degree as, in a 
 state of health, would produce no perceiva- 
 ble effect. But from all the symptoms which 
 precede and accompany different kinds of 
 fever, it may be concluded with probability 
 nearly equal to certainty, that the remote 
 causes of fever do not operate in the first in- 
 stance upon the stomach, and from thence, 
 by associate motions, bring the rest of the 
 system into a similar condition; on the con- 
 trary, all the phenomena indicate that tlie re- 
 mote causes of fever are introduced into the 
 circulation through the medium of respira- 
 tion, and thereby carried, by means of the 
 blood, to every part of the system to which 
 
103 
 
 they extend. From the most accurate aud 
 impartial inquiry, it appears convincingly 
 clear that not the stomach, but those parts 
 which are open to the air in its passage to 
 the lungs, and the lungs themselves are the 
 only parts which can be considered as alto- 
 gether, and at all times assailable by the 
 noxious matters mixed with, or floating in 
 the atmosphere; and that it is by the system 
 of absorbents that they find a ready passage 
 to the blood, and by it, to the system gene- 
 rally ; and from the symptoms which usually 
 are the consequence of the reception of marsh 
 miasmata into the circulating fluids, it may 
 be inferred that they produce a proportiona- 
 tely greater morbid effect in the nervous than 
 in the arterial portion of the system ; where- 
 as, the exhalations from the living human 
 body, labouring under that form of fever call- 
 ed typhus, produce a greater degree of mor- 
 bid affection in both portions of the system. 
 If marsh miasmata, the most usual cause 
 of intermittent fever, produced disorder by a 
 stimulating property, their effects would be 
 instantly perceived, like those of other sti- 
 mulating substances: and instead of a cold 
 
104 
 
 stage, they would necessarily produce the 
 symptoms of the hot stage in the first in- 
 stance, and the cold stage could only occur 
 after the febrile commotion or increased ac- 
 tion, produced by the miasmata, had exhaust- 
 ed the excitability to a certain degree, and 
 thereby induced a sense of debility and tor- 
 por of the nervous and muscular parts of the 
 system. 
 
 The opinion, that the stomach is the pri- 
 mary seat of fever, is rendered highly hypo- 
 thetical and improbable by numerous facts. 
 Dr. Cullen, who from his accurate and lumi- 
 nous description of diseases merits the grati- 
 tude of the medical world, states that upon 
 the approach of the paroxysm of fever, " the 
 patient is affected first with languor or a 
 sense of debility, a sluggishness in motion 
 and some uneasiness in exerting it, with fre- 
 quent yawning and stretching. At the same 
 time the face and extremities become pale 
 and diminished in size, and the skin over the 
 whole body, appears constricted and rough, 
 as if cold water had been suddenly applied 
 to it. At the accession of these symptoms, 
 some coldness of the extremities, though lit- 
 
105 
 
 tie noticed by the patient, may be perceived 
 by others. At length the patient himself is 
 sensible of cold, first in his back, and from 
 thence, passing over the whole body. This 
 sense of cold, or chilliness, is what consti- 
 tutes the beginning of the cold stage; upon 
 the approach of which, the appetite for food 
 ceases, and does not return till the paroxysm 
 be over, or a sweat has Sowed fur some time. 
 As the cold stage advances, there frequently 
 comes on a nausea or sickness, which often 
 increases to a vomiting of matter that is, in 
 cases of intermittent fever, for the most part 
 bilious." 
 
 Here the dependent condition of the sto- 
 mach upon the primary moving powers of the 
 system, is plainly to be discerned. The 
 sense of debility, the paleness and shrinking 
 of the face and of the whole surface of the 
 body, the sensation of cold, to which may be 
 added, the smallness and weakness of the 
 pulse, occurring on the first perception of the 
 debility, all shew, that the sensorium or 
 source of the nervous system, is primarily 
 disordered by the cause of the fever, while, 
 at the same time, the state of the stomach is 
 
106 
 
 but little altered, till all these phenomena 
 have taken place. From all these circum- 
 stances, it appears that the disordered state 
 of the stomach is, unquestionably, of a secon- 
 dary or symptomatic nature. 
 
 Upon this ground, Dr. Darwin's opinion 
 that that form or description of fever, with 
 weak and frequent pulse and great prostra- 
 tion of strength, (denominated typhus mitior 
 or gravior, according as the symptoms are ac- 
 companied with more or less debility or sud- 
 den and continued prostration of strength,) 
 is the effect of torpor, or a state of inactivity 
 produced in the stomach by the contagious 
 principle, which gives origin to this disease, 
 expending by its stimulus, the sensorial pow- 
 er or excitability of the muscular fi§res of 
 the stomach, must appear to be mere conjec- 
 ture, unsupported by facts or correct obser- 
 vation. 
 
 If, on the other hand, the sensorial power 
 becomes accumulated, as supposed by Dr. 
 Darwin, in consequence of the inaction of 
 the fibres of a particular part of the system, 
 and in consequence of the abstraction of cus- 
 tomary stimulus, the most indolent and inac- 
 
107 
 
 tive should be most capable of bard labour 
 and extraordinary exertion; and, instead of 
 being subject to diseases of an asthenic or 
 nervous character, or those in which debili- 
 ty of the nervous system is the most predo- 
 minant symptom, on this hypothesis, as well 
 as on that of the late Dr. Brown, should be 
 liable to continual attacks of inflammatory 
 diseases; because, during the inaction of the 
 fibres of any particular organ, or of the ca- 
 pillary vessels on the internal or external 
 surface of the body, the sensorial power or 
 excitability would accumulate to so great a 
 degree as to render the application of the 
 usual stimuli insupportable. 
 
 On a subject so abstruse, as well as. on 
 those that are involved in less difficulty, we 
 are authorised, by the rules of genuine phi- 
 losophy, to reason only from unequivocal 
 facts and the most correct observations. 
 
 From the most careful and impartial in- 
 quiry, it appears convincingly clear, that not 
 the stomach, but those parts which are open 
 to the air in its passage to the lungs, and the 
 lungs themselves, are the only parts which 
 ^an be considered as altogether and at all 
 
108 
 
 times assailable by the. remote or occasional 
 causes of fever; the most usual of which, are 
 noxious matters floating in the atmosphere; 
 and that it is by the system of the pulmona- 
 ry absorbents, that they find a direct pas- 
 sage to the blood, and through it, to the sys- 
 tem generally, and by that means, produce a 
 change in the power of the nervous system, 
 and in the excitability or vital principle ex- 
 isting in the heart and arteries, as well as in 
 the involuntary muscles. 
 
 It would be unreasonable to suppose that 
 marsh miasmata, or the volatile substances 
 derived from putrefying vegetable and ani- 
 mal substances, when received into the hu- 
 man system, act as strong and direct stimu- 
 lants, producing indirect debility by expend- 
 ing sensorial power or excitability, when we 
 gee them so manifestly aided, in the produc- 
 tion of fever, by the abstraction of such sti- 
 muli as the patient has been accustomed to; 
 and, particularly, by cold, hunger, fear, and 
 depleting remedies. The previously stimu- 
 lating power of this cause has never been 
 perceived by the patient on whom it ope- 
 rates, and the very slow progress of the ear- 
 
 
109 
 
 ly symptoms, which is so frequently observ- 
 able, is a strong argument against the fact, 
 and against the validity of this doctrine. 
 Nor can the contagion of the jail or hospital 
 fever be a stimulating substance, wasting ex- 
 citability, and inducing indirect debility, be- 
 cause its effects are favoured, and it is ren- 
 dered more certain in producing fever by se- 
 datives, such as hunger, cold, fear, grief, 
 and depleting remedies ; and because its ef- 
 fects are frequently counteracted by stimu- 
 lating and invigorating means, applied soon 
 after exposure to contagion. Febrile conta- 
 gion has less influence over the robust con- 
 stitution, than over one that is weak and in- 
 firm. It generally operates slowly, and the 
 patient feels indisposition for some days be- 
 fore the fever makes its attack. 
 
 The most constant phenomena of the in- 
 termittent fever, indicate that its source and 
 principal seat is in the nervous system, and 
 particularly in that portion of the sensorium 
 concerned in voluntary motion, or in the 
 fibres of those muscles which in a state of 
 health, are obedient to the will. This,. like 
 the effects of digitalis, is more distinctly in- 
 
 K 
 
110 
 
 dicated at the accession, or during the cold 
 stage of intermittent fever; in which case, in- 
 stead of its cause acting immediately upon the 
 heart and arteries, and increasing their force 
 and fulness, it acts primarily upon the brain; 
 in consequence of which, all the other func- 
 tions and organs of the body, at first, exhibit 
 a corresponding diminution of power and 
 force of action ; but such is the structure and 
 nature of the animal economy, that the heart 
 and arteries soon react upon the confined 
 and distending fluids, in consequence of the 
 stimulus of distension, from the accumulat- 
 ing blood, which being pressed from the 
 extremities through the veins towards the 
 heart, gradually displaces that which was 
 before stagnant in its right cavities, which 
 entering the pulmonary system in. its turn, 
 pushes forward successively into the left ca- 
 vities ; first, that which occupied the pulmo- 
 nary veins, and afterwards, that which had 
 undergone the proper changes in the air 
 cells; when this reaches the left cavities, it 
 stimulates them to action, which at first is 
 feeble, but which, when the excitability is 
 not materially impaired, gradually becomes 
 
Ill 
 
 stronger. If the reaction or contraction, in 
 consequence of this distension, aided by the 
 additional stimulus of caloric received from 
 the air by means of respiration, becomes suf- 
 ficiently strong to restore energy to the brain 
 and due harmony between the different func- 
 tions, health is the consequence; but when 
 the reaction is either too weak or too violent, 
 the feverish paroxysm will continue until 
 such time as an equilibrium, or unison of ac- 
 tion, is restored between the different por- 
 tions of the system. 
 
 If the torpid and diminished power of the 
 sensorium, or the proximate cause of the cold 
 stage, should be so far removed by the sub- 
 sequent reaction of the heart and arteries, 
 that the several functions are restored to 
 due harmony of action, the fever passes -oft, 
 to return no more. 
 
 But on the other hand, when the reaction 
 has been deficient, the fever will only remit, 
 and when it has been so violent as to bring 
 on indirect debility, the blood ceases to sti- 
 mulate the heart sufficiently to produce suffi- 
 cient unison of action in the several func- 
 tions: hence debility gradually increases, aud 
 
113 
 
 after a certain period, langour and a sense 
 of cold returns,-' followed by the same train 
 of symptoms as at first 
 
 In this manlier the paroxysms will con- 
 tinue to return, either at regular or irregular 
 periods, according to a number of adventi- 
 tious circumstances, until, by the constitu- 
 tional powers of the animal economy or the 
 assistance of art, a reciprocal harmony and 
 unison of action are established between the 
 different functions. 
 
 To conclude: If there was no other ob- 
 jection to the doctrine of this ingenious and 
 respectable author, the complexity and intri- 
 cacy in which Ills principles are involved, 
 would be sufficient to render its correctness 
 and validity questionable; because intricacy 
 is contrary to the usual simplicity of nature, 
 and because of the difficulty of applying it 
 to any practical use : I shall, therefore, de- 
 cline anv farther consideration of it for the 
 present, and refer the reader for a more am- 
 ple analysis and refutation of it to a work, 
 entitled '¥ Observations on the Zoonomia, by 
 Thomas Brown, Esq. of Edinburgh," pub- 
 lished in the year 1798, and to the 24th. vol. 
 
113 
 
 of the Critical Review, published the same 
 year. 
 
 In a 'reatise on Febrile Diseases, lately 
 published by Dk. Alexander Philips Wil- 
 son, of Edinburgh, he considers the proxi- 
 mate cause of fever to be '* a change in the 
 laws of excitability." 
 
 "We know (says this author) that the 
 laws of excitability, in fevers, are different 
 from those which prevail in health ; because 
 the same external agents, the same degree of 
 exercise, the same degree of temperature, the 
 same quantity of food, of light, of sound, &e, 
 which in health, occasion regular and agree- 
 able excitement followed by gradual exhaus- 
 tion, in fever, produce excessive excitement, 
 followed by increased action. 
 
 "The state of the living solids being thus 
 changed, there must be a corresponding 
 change in the effects of the internal agents, 
 the circulating and other fluids; hence pro- 
 ceed the phenomena of fever. 
 
 * The proximate cause of fever may, there- 
 fore, be concluded to be a change in the 
 laws of excitability ; in consequence of which, 
 
 K 2 
 
• 114 
 
 the same agents no longer produce the same 
 effects. 
 
 " When a state either of excessive excite- 
 ment, or of atony, exists independently of 
 the application of some artificial agent, one 
 of two changes must, have taken place ; either 
 the quantity, or the quality of the natural 
 agents, or the state of the living solid, is dif- 
 ferent from that which prevails in health. 
 
 "If it can be shewn that the state of the liv- 
 ing solid remains the same, it follows that 
 the deviation from health is owing to some 
 change in the natural agents. 
 
 "If it can be proved that the state of these 
 agents remains the same, it then follows, that 
 the deviation from health, is owing to some 
 change in the state of the living solids. We 
 may go a step farther : If it can be proved 
 that the state of the natural agents remains 
 unchanged and yet produce effects different 
 from those they produce in health, it not 
 only follows that the state of the living solid 
 is changed, but also, that if the change in the 
 state of the living solid will account for the 
 changes observed in the effects of other na- 
 tural agents, we are not in any degree to at- 
 
lis 
 
 tribute such effects to a supposed change m 
 those agents, there being no occasion for any 
 such hypothesis to explain the phenomena. 
 In fevers, many of the natural agents, calo- 
 ric, food, light, and noise, for example, evi- 
 dently remain unchanged ; the difference in 
 their effects, therefore, is owing to the change 
 in the state of the living solid. But this 
 change in the state of the living solid, is ca- 
 pable of accounting for the change we ob- 
 serve in the effects of those agents whose 
 conditions we cannot with precision ascer- 
 tain — as the circulating and other fluids : It 
 follows, therefore, that whatever change may- 
 take place in these, during the progress of 
 fever, and however this change may modify 
 the symptoms of fever, it would be illogical 
 to consider too great lentor, acrimony, or 
 other morbid condition of the fluids, as the 
 proximate cause of fever. 
 
 " With respect to the hypothesis of fever 
 depending on a change in the state of the 
 simple solids, as the natural agents act not 
 on the simple but on the living solids, it is 
 necessary to suppose a change in the state 
 of the latter ; and as this change accounts for 
 
116 
 
 the phenomena of fever, there is no occasion 
 for any other supposition; and farther, as all 
 natural agents excite a morbid action, and 
 as this effect is not confined to any one, but 
 observed equally in every part of the sys- 
 tem, what room is there fo? supposing any 
 one pari: is affected more than every other? 
 Lastly, with regard to fever being a state of 
 accumulated or exhausted excitability, in the 
 sense that Dr. Brown uses those terms, it is 
 only necessary to refer to the facts which 
 prove that no such morbid state exists. It 
 is true, that the phenomena of synocha, are 
 such as we should expect from an accumu- 
 lation of excitability ; but will a surfeit, or 
 an excessive quantity of distilled spirits, fre- 
 quent causes of synocha, occasion an accu- 
 mulation of excitability? 
 
 "It appears then that the living solid is so 
 changed, that a change is effected in its laws 
 of excitability, and that this admitted, there 
 is no occasion for the foregoing hypothesis to 
 explain the phenomena essential to fever. 
 Upon the whole then, the following, as far 
 as it goes, would appear to be a just view 
 of the nature of fever. 
 
117 
 
 •'Every agent, acting on the system in 
 general, is capable of producing three ef- 
 fects — moderate excitement, excessive ex- 
 citement, and atony, according to the degree 
 in which it is applied." The first operation 
 of agents, produces health; the two last, ge- 
 neral disease, which has been called fever. 
 If by the application of artificial, or the ex- 
 cessive application of natural agents, either 
 of the two last states be maintained for a suf- 
 ficient length of time, the living solid is so 
 much changed, that is, such a habit is form- 
 ed, that the natural agents, applied in their 
 usual degree, produce certain morbid effects, 
 till the diseased habit has been counteracted, 
 which, as in other habits, is the more easily 
 effected the shorter its duration has been. 
 Hence it is, that almost any thing making a 
 strong impression, will remove fever at an 
 early period ; and hence, the difficulty of re- 
 moving a fever, is generally proportioned to 
 the time it has lasted. The means which 
 cure a fever at an early period, that is, pro- 
 duce a crisis, seem either to expel the mor- 
 bific cause before the morbid habit is effect- 
 ed : as vomiting during a tit of drunkenness, 
 
118 
 
 or break the morbid habit before it has gain- 
 ed force, as cold bathing during the first days 
 of fever. In the more advanced stage, as 
 the morbid habit is corrected with more diffi- 
 culty, it is corrected more slowly. 
 
 " Whmin synocha, we succeed in changing 
 excessive excitement to moderate excitement, 
 i. e. that excitement which is followed by 
 exhaustion, we have removed the morbid 
 habit and of course cured the disease. 
 
 " The cure of synocha, therefore, depends 
 on the abstraction of stimuli ; but as atony 
 is the consequence of excessive excitement, 
 if excessive excitement has lasted for any 
 considerable time, atony will always be evi- 
 dent, previously to the restoration of health : 
 hence it is, that the symptoms of typhus (so 
 frequently) succeed those of synocha. 
 
 "When we succeed in changing atony 
 into moderate excitement, we have corrected 
 the morbid state, and consequently cured the 
 fever. The cure of typhus, therefore, de- 
 pends upon the due and judicious applica- 
 tion of appropriate stimuli, repeated at short 
 intervals. " 
 
 From the preceding statement, it appears 
 
119 
 
 that every form or variety of fever may be 
 considered as depending on irregular excite- 
 ment, and requires to be treated according 
 to the particular indications of excessive or 
 defective action of the heart and arteries; 
 and not, as taught by Brown, conformably to 
 any graduated scale of stimulation. 
 
 rn 
 
 rhe following is the substance of the doc- 
 trine of diseases, of the late celebrated 
 and ingenious Dr. Benjamin Rush, Pro- 
 fessor of the Institutes and Practice of 
 Physic, in the University of Pennsylva- 
 nia, which he delivered in his lectures 
 with so much eloquence, and in so ele- 
 gant a style, that almost every one who 
 heard him, embraced his doctrine with a 
 degree of conviction, that is usually pro- 
 duced only by mathematical demonstra- 
 tion. 
 
 "As in health," says Dr. Rush, "there 
 exists a constant and just proportion between 
 the degrees of excitement and excitability, 
 
120 
 
 and the force of stimuli, so, in a predisposi- 
 tion to disease, (which predisposition con- 
 sists in debility, and an undue proportion of 
 excitability, or preternatural susceptibility 
 to the impression of stimuli or exciting pow- 
 ers,) the ratio between the force of stimuli, 
 excitement, and excitability is destroyed; in 
 consequence of which, stimuli act with a 
 force, which produces irregular action. And 
 when the excitability is comparatively more 
 abundant in the blood vessels than in the 
 other portions of the system, which, from 
 their being distributed in numerous and mi- 
 nute branches to every part of the surface of 
 the body, both internal and external, is fre- 
 quently the case, from the operation of the 
 remote or predisposing causes of fever, mor- 
 bid, irregular, or convulsive action is pro- 
 duced in them, by the stimulus of distension 
 from the circulating blood ; for the equili- 
 brium or due adjustment between the dif- 
 ferent portions of the system having been 
 previously destroyed or changed, by the sud- 
 den diminution of excitement, in consequence 
 of the abstraction or suspension of the natu- 
 ral and customary stimuli, or from any cause 
 
J21 
 
 which has operated with such violence as 
 to diminish their excitability suddenly, the 
 blood becomes unequally distributed,, and by 
 acting with an increase of quantity and force 
 iti parts not accustomed to either, becomes 
 an irritant to the muscular fibres of the heart 
 and arteries, and thus an exciting cause of 
 fever/' 
 
 Dr. Rush asserts, that both direct and in- 
 direct debility, (the former of which, he de- 
 nominates debility from abstraction, and the 
 latter, debility from too powerful or long 
 continued action,) are always succeeded by 
 increased excitability, or greater aptitude to 
 be excited into action by stimuli, and that 
 the different forms or descriptions of fever 
 are entirely owing to the disproportion sub- 
 sisting between the stimulus received from 
 or communicated by the circulating blood, 
 and the quantity of excitability or aptitude 
 of the muscular fibres of the arteries to be 
 excited into action by the application of that 
 stimulus. His opinion, relative to -debility 
 being the predisposing cause of every form 
 or description of disease, is thus stated in 
 the last edition of his "Medical Observa- 
 
 L 
 
122 
 
 tions and Enquiries i% u Indirect debility, as 
 well as direct debility, is followed by an in- 
 crease of excitability, when it is suddenly 
 induced, or brought on by the violent and 
 rapid operation of stimulating agents; and 
 direct and indirect debility are on a footing, 
 when they are of a chronic nature. In both, 
 the excitability is equally expended, and the 
 system is left in a state in which stimuli act 
 with too little force upon it to excite in it 
 the commotions of fever. 
 
 "In any variety or form of acute diseases 
 (he says) occasioned by the causes which in- 
 duce either direct or indirect debility, the 
 debility induced, is succeeded by increased 
 excitability; but this increased excitability 
 is not equally diffused through the system, 
 but is most abundant in such parts as have 
 been most debilitated by the operation of the 
 remote causes; hence the concentration of ir- 
 regular action, and morbid excitement, that 
 follows the application of dispropriate sti- 
 muli;" (that is, of stimuli too strong or too 
 weak for the state of the existing excitabi- 
 lity.) 
 
 In this circumstance, as well as in that 
 
123 
 
 respecting predisposition to disease, the theo- 
 ry of Dr. Rush differs materially from the 
 theory of Dr. Brown, though it more near- 
 ly agrees with that of the late Dr. Darwin in 
 this particular; for Dr. Brown supposes that 
 idiopathic fevers, or those fevers in which 
 the whole system is affected without being 
 connected with, or dependent on the affec- 
 tion of any particular organ, the excitability 
 is equally redundant or defective in every 
 part of the system, proportioned to the de- 
 gree of the previous action or abstraction of 
 the remote causes, and is not confined or 
 concentrated in any one particular portion 
 or part, more than another; and that the ac- 
 tion of stimuli on any one part, extends its 
 effects, in a proportionate degree, to every 
 other part at the same time. Dr. Rush, on 
 the contrary, supposes that the susceptibility 
 to the impression of stimuli (which has re- 
 ceived the name of excitability from Dr, 
 Brown, and of the diffused matter of life 
 from the celebrated Sir John Hunter, and 
 the sensorial power or spirit of animation 
 from Dr. Darwin,) exists in a greater quan- 
 tity in the parts that have been most debili- 
 
124 
 
 iated, in consequence of the operation of the 
 remote causes; all of which? he says, occa- 
 sion a predisposition to disease by their de- 
 bilitating effects, either in consequence of the 
 abstraction of natural and customary, or the 
 excessive action of preternatural stimuli, or 
 stimuli to which the patient has not been ac- 
 customed; and adds, that all the predispos- 
 ing causes of disease, whether it appears in 
 the form of phlegmasia or typhus, are debi- 
 litating, differing only in degree, and that 
 all the exciting causes, or those which in- 
 duce irregularity or morbid action in the sys- 
 tem, are stimulating. — and that all the diffe- 
 rence in the symptoms, proceeds from the 
 difference in the quantity or condition of the 
 excitability, and the force or numbers of the 
 stimulating agents applied, or in operation. 
 
 Among the remote or predisposing causes 
 be enumerates, with the generality of syste- 
 matic writers, cold and moist air, fatigue, 
 from too much exercise, fasting or abste- 
 mious living, immoderate evacuations, de- 
 pressing passions of the mind, all of which 
 produce debility, or a defect of healthy ex- 
 citement, by the abstraction of natural and 
 
185 
 
 customary stimuli, in consequence of which, 
 the excitability increases and becomes super- 
 abundant. A similar increase and accumu- 
 lation of excitability, he says, also takes 
 place soon after, suddenly withholding or 
 abstaining from the artificial stimuli of strong 
 liquors, or highly seasoned aliment, that a 
 person has been long accustomed iv. But 
 that in the generality of the different forms 
 of disease, the phenomena or symptoms pro- 
 ceed from the excitability being more abun- 
 dant in one part of the system than another, 
 in consequence of the remote causes having 
 produced greater debility in one part, than 
 in the rest of the system. Hence, the blood 
 vessels being more exposed to the alternate 
 effects of cold and heat than the other por- 
 tions of the system, from their being distri- 
 buted in numerous and minute branches to 
 every part of the surface of the body, both 
 internal and external, they become propor- 
 tionably more debilitated, and of course, their 
 excitability becomes greater than in any 
 other part of the system; in consequence of 
 which, they become the seat of fever,, the 
 
126 
 
 proximate cause of which, is an irregular ae~ 
 lion or convulsion of their muscular fibres. 
 
 *' lie debility, and consequent ex- 
 
 citaMtit^, are equally diifused through the 
 arterial system, the disease will not be ac- 
 companied with any local affection ; but when 
 the arteries of any particular viscus or or- 
 gan are more debilitated and more excitable 
 than in the rest of the system, an inflamma- 
 tory affection will be induced in the organ 
 so debilitated and excitable; therefore, as in 
 all ordinary cases of fever it is seated in the 
 blood vessels — all those local affections called 
 pleurisy, angina, phrenitis, hydrocephalus 
 internus, phthisis pulmonalis, hepatitis, gas- 
 tritis, enteritis, rheumatismus, hydrothorax, 
 ascites, &c. ought to be considered as symp- 
 toms only of an original or primary disease 
 in the sanguiferous system." 
 
 The peculiarities in these states of fever, 
 and the circumstances in which they differ 
 from fever unaccompanied with local inflam- 
 mation, we are told, depend, 1st. upon local 
 debility and increased excitability, the con- 
 sequence of that debility, in the part princi- 
 pally affected. And 2dly. upon the morbid 
 
- 127 
 
 excitement induced in the part where the ex- 
 citability predominates, by the stimulus of 
 distension from the blood, and by the effu- 
 sion of serum, lymph, and red globules in 
 the weakened, excitable, excited, and after- 
 wards inflamed part. 
 
 We are also told, that disease, seated in 
 any other portion of the system, depends on 
 the same cause as fever, viz. debility and ex- 
 cess of excitability; and that its phenomena 
 or symptoms are more or less strong and ma- 
 nifest, in proportion to the quantity or state 
 of the existing excitability, which becomes 
 greater or less in proportion as the debility, 
 induced by the remote or predisposing causes, 
 has been greater or less, and the greater or 
 less force of the acting stimuli or exciting 
 causes; and consequently, that the cure of 
 every form or variety of disease is to be ef- 
 fected, or at least attempted, by the removal 
 from, or guarding against the application of 
 the remote or predisposing causes, and in ad- 
 justing the force of the existing and natural 
 stimuli, as much as possible, to the state of 
 the debility and existing excitability predo- 
 
128 
 
 minani in any particular portion of the sys- 
 tem. 
 
 Among the occasional or exciting causes 
 of disease, and especially of fever, Dr. Rush 
 enumerates sensible heat, marsh miasmata, 
 human effluvia, the contagious matter of erup- 
 tive fevers, poisons of all kinds, excess in 
 eating and drinking, sudden emotions of the 
 mind, bruises, burns, &c. all of which, he 
 says, act by their stimulating power only, in 
 the production of disease. And, although 
 he acknowledges that fever is often the con- 
 sequence of debilitativg causes, without the 
 application of any apparent stimulus, he is of 
 opinion that the circulating blood is suffi- 
 cient, in such a state of excitability, to sti- 
 mulate the heart and arteries to more fre- 
 quent and irregular action. 
 
 In treating of the proximate cause of fe- 
 ver, we are told by Dr. Rush, that "fever 
 is a modification of disease, which has its 
 seat in the blood vessels, and consists in an 
 irregular action or convulsion of the arteries ; 
 and that this convulsion of the arteries is the 
 proximate cause of fever." This, in com- 
 mon language, is making the disease and 
 
129 
 
 proximate cause the same. But this is a vio- 
 lation of the rules of logic, in which it is 
 laid down as a maxim, that cause and effect 
 are never to be indentified. The irregular 
 action or convulsion of the arteries, in which 
 we are told fever consists; cannot be the 
 proximate cause of fever, otherwise it would 
 be the cause of itself. 
 
 If that were possible, every event that oc- 
 curs in the universe might be the cause of 
 its own existence, which is contrary to ex- 
 perience and therefore inadmissible. 
 
 The proximate cause of a disease, accord- 
 ing to the correct signification and true mean- 
 ing of the term, is that cause which is nearest 
 to the effect; and, in medical language, means 
 that condition or circumstance on which dis- 
 ease or a deviation from health directly de- 
 pends; or from whence the symptoms flow, 
 and which necessarily cease to exist on the 
 removal of that condition or circumstance. 
 
 If, therefore, the theory of Dr. Rush were 
 correct, and he reasoned consistently with its 
 principles, in my opinion, he ought not to 
 have considered the convulsion of the arte- 
 ries as the proximate cause, but as the proxi- 
 
136 
 
 mate effect of the stimulus of distension from 
 the blood acting upon the increased excita- 
 bility of the arteries ; for, according to his 
 own expressions, "the irregular action of the 
 arteries is owing to the action of the stimulus 
 being disproportioned to the increased exci- 
 tability." 
 
 A strong objection rises against the opi- 
 nion of the arteries being the primary seat of 
 fever, from the phenomena which are ob- 
 served to precede and accompany the cold 
 stage of the generality of fevers, unaccompa- 
 nied by topical inflammation. 
 
 The cold stae;e of fever cannot be account- 
 ed for, in a satisfactory manner, on the prin- 
 ciples of either this doctrine, or on those of 
 Dr. Brown or Darwin. 
 
 Dr. Cullen's account of the cause of this 
 stage of fever is much more plausible, though 
 it fails most egregiously in accounting for 
 the hot stage. 
 
 It is evident, from the circumstance of the 
 symptoms of fever immediately subsiding, 
 upon the removal of any topical inflamma- 
 tion existing in any of the viscera, that the 
 proximate cause of simple fever and that of 
 
LSI 
 
 inflammation are not the same: though they 
 both betray symptoms of irregular action in 
 the arterial system; otherwise the symptoms 
 of fever would still be continued by " the 
 stimulus of distension from the circulating 
 blood/' after the reduction of the topical in- 
 flammation, until the excitability of the part 
 originally affected, and that of the rest of the 
 arterial system, became adjusted, or in due 
 proportion to each other. That the symp- 
 toms of lever, accompanied by topical in- 
 flammation, do cease upon the removal of the 
 inflammation, is a fact too familiar to every 
 one that has seen practice, to be contested. 
 
 The fever which accompanies local in- 
 flammation, and which is generally accom- 
 panied with strong and frequent arterial ac- 
 tion, is certainly a very different disease from 
 fever unaccompanied with local inflamma- 
 tion. It differs from simple fevec in depend- 
 ing upon the local inflammation, which is its 
 exciting cause. From this, it has its origin, 
 and with the removal of this, as observed 
 bj the accurate and experienced Fordyee, it 
 terminates. 
 
 The regular increase and decrease of the 
 
paroxysms of an intermittent fever; its spon- 
 taneous and often sudden termination, with- 
 out any change that can be perceived or rea- 
 sonably supposed to have taken place in the 
 debility, and subsequent increase of excita- 
 bility, in the arterial system, and at a time 
 when the general debility of the patient has 
 increased to an extreme degree, is a strong 
 argument that intermittent fever, or that form 
 of fever so called, has not its seat primarily 
 or exclusively in/the arterial system; on the 
 contrary, from the affection of the nervous 
 system, and from the phenomena which pre- 
 cede and accompany the cold or forming 
 stage, it may be inferred that the nervous 
 system is equally, if not more concerned in 
 its existence and continuance, than the ar- 
 terial system. 
 
 As the most certain method of ascertain- 
 ing the correctness of any theory or doctrine 
 of diseases, is to subject it to the test of ex- 
 periment, and by comparing the effects that 
 would necessarily result from the application 
 of its principles to practice, with a mode of 
 practice universally admitted to be benefi- 
 cial, I will now proceed to inquire what 
 
133 
 
 would he the probable effects of the applica- 
 tion of the theory under consideration, for 
 the removal of diseases. 
 
 If debility, as inculcated by this doctrine, 
 is always, in acute diseases, succeeded by 
 increased excitability or a greater aptitude to 
 be excited into action by stimuli, and the 
 different forms of fever* with all their vary- 
 ing symptoms, were only owing to the dis- 
 proportion subsisting between the stimulus 
 of distension from the circulating blood, and 
 the quantity of excitahility or aptitude to be 
 excited into action by the application of sti- 
 muli, the remedies which have been observed 
 to be the most efficacious in the typhus, and 
 the acute rheumatism, should be reversed; 
 because, as the debility which precedes and 
 accompanies the typhus through its course, 
 is much greater than that which precedes 
 and accompanies the acute rheumatism, the 
 excitability in the typhus must greatly ex- 
 ceed that in the rheumatism. Therefore, to 
 act consistently with this doctrine, instead of 
 applying stimulants in the typhus, stronger 
 than those which the patient has been accus- 
 tomed to, when in health, those which sti- 
 
 M 
 
134 
 
 mulate less should be employed, and the 
 quantity of his blood dimn shed, to propor- 
 tion the stimulus of distension to the state or 
 quantity of the excitability; whereas, in the 
 rheumatism the stimulating medicines should 
 be increased without any reduction of the 
 quantity of his blood, that the stimulus of dis- 
 tension might reduce the excitability to a due 
 ratio with the stimuli. 
 
 We learn, however, from the most unex- 
 ceptionable experience, that such practice 
 would be highly inefficacious and improper. 
 Similar would be the effects of the ap- 
 plication of the principles of this theory to 
 tetanus, scurvy, colic, asthma, dropsy, and 
 all the varieties of disease that belong to the 
 asthenic or atonic class. 
 
 It may therefore be concluded, that the 
 principles from which this doctrine is de- 
 rived are incorrect, or that the author of the 
 theory has not explained it with that clear- 
 ness and accuracy that its importance re- 
 quires. 
 
 If the principles of this doctrine were cor- 
 rect, when the excitability on which certain 
 forms of disease depend; existed to excess in 
 
135 
 
 one portion or part of the system, the dis- 
 ease might be cured by creating an artificial 
 debility in a different part, that it might flow 
 into it from that where the disease has its 
 seat; for, by this method, we are informed 
 by Dr. Rush in his notes on Pringle's Dis- 
 eases of the Army, "purgatives, by inducing 
 an artificial debility in the intestines, with- 
 draw the excess of excitability from the joints 
 in cases of chronic rheumatism, and thus 
 equalize the excitement between the differ- 
 ent parts of the system." 
 
 If it was the effect of purgatives, as sup- 
 posed by Dr. Rush, to withdraw the excita- 
 bility from the joints and lodge it in the in- 
 testines, the practice would be highly objec- 
 tionable; because, if the artificial debility 
 produced by them in the intestines, withdrew 
 the excess of excitability from the joints, it 
 would also withdraw a proportionable quan- 
 tity of excitability from every other part of 
 the system at the same time; in consequence 
 of which, an excessive quantity would flow 
 to, and accumulate in the debilitated intes- 
 tines, and consequently, induce in them a 
 more violent disease, or at least a disposi- 
 
136 
 
 Hon to a more violent disease, than the one 
 that would be removed by such means; for, 
 according to this doctrine, debility, in con- 
 junction with an increase of excitability more 
 predominant in one part of the system than 
 in the rest of it, and stimuli, disproportioned 
 in power or force of impression to the state 
 of the existing debility, are the main links 
 in the chain of the causes of every form or 
 variety of disease. 
 
 If it was a fact, that the increased fre- 
 quency of action, which, for the most part, 
 takes place in every variety of fever, is ow- 
 ing to an increase or accumulation of excita- 
 bility in the muscular fibres of the heart and 
 arteries, it might be expected that this ac- 
 tion is to be diminished, either by prevent- 
 ing the system from' furnishing those parts 
 with their usual supply, by those means 
 which have the effect of diminishing the en- 
 ergy of the sensorium, as well as of the heart 
 and arteries at the same time ; and the means 
 best adapted to produce this effect would be 
 abstinence from aliment, and every kind of 
 drink but cold water, and by diminishing the 
 quantity of blood by venisection, &c. 
 
137 
 
 But these means, in cases of typhus gjj^- 
 vior, or the malignant forms of fever, instead 
 of removing the disease, aggravate all the 
 symptoms, and endanger the life of the pa- 
 tient. The theory, therefore, of the arterial 
 system being the primary and principal seat 
 of idiopathic fever, and that the excitability 
 in that portion of the system is in much 
 greater quantity than exists in them in a state 
 of health, aud especially in that form or spe- 
 cies of fever denominated typhus, is highly 
 improbable. 
 
 If, in such cases, the excitability was ac- 
 cumulated to excess in the blood vessels, in- 
 stead of having recourse to affusions or ab- 
 lutions with cold water, to abstract and di- 
 minish the stimulus of sensible heat, the uti- 
 lity of which has been sanctioned by repeat- 
 ed and extensive experience, Ji unin's ma- 
 chine for the application of dry heat would 
 be much more efficacious: because, a stimu- 
 lus stronger than usual, applied to the mov- 
 ing powers of the body, makes them, after 
 such application, much less easily excited 
 into action by the natural and customary sti- 
 muli ; and, on the sudden abstraction of the 
 
 m 2 
 
138 
 
 stronger and extra stimuli, the motions of the 
 part where the disease has its seat would be 
 less forcibly excited. 
 
 Dr. Rush in his defence of blood-letting 
 states, that a dissolved appearance of the 
 blood, in that form of fever which he deno- 
 minates malignant, "is a sign of the highest 
 degree of excitement and strength of action 
 in the blood vessels, and that its dissolved 
 appearance is owing to the immoderate ac- 
 tion of tlie arteries upon it, which rend and 
 tear it to pieces. " 
 
 To shew that this ingenious and expe- 
 rienced physician has mistaken the cause of 
 this condition and appearance of blood, I 
 need only appeal to those who have had op- 
 portunities of examining the blood, drawn in 
 the latter stage of phrenitis, pleurisy, or rheu- 
 matism, and have compared it with that 
 drawn in the latter stage of the typhus gra- 
 vior, yellow, spotted, or any other form of 
 malignant fever. In the former cases, the 
 blood, while cooling, separates into serum 
 and crassamentum, and becomes almost in- 
 variably covered with a thick, tough, white, 
 or buff-coloured substance, resembling size, 
 
139 
 
 jelly, or glue; whereas, in the latter stage of 
 a malignant Sever, even in cases which begin 
 with strong arterial action, the blood in a 
 late stage of the disease, does not separate 
 into serum and erassamentum, but remains 
 one uniform homogeneous fluid, resembling 
 coloured water; though, in the diseases first 
 mentioned, the force and action of the arte- 
 ries are unequivocally many degrees stronger 
 than they are ever observed in cases of the 
 most malignant fever. 
 
 If marsh miasmata and human effluvia^ 
 acted by a stimulating property, in the pro- 
 duction of fever, as taught by Dr. Rush, they 
 would produce similar effects with other di- 
 rect stimuli, and their action would be prin- 
 cipally confined to the arteries, rendered pre- 
 ternaturally excitable by the abstraction of 
 natural stimuli, or the excessive action of ar- 
 tificial stimuli; an increase of power, or at 
 least of actiou, would appear in them the in- 
 stant the miasmata were received into the 
 system, and came in contact with the muscu- 
 lar fibres of the arteries : but we learn, from 
 accurate observation, that this is not the 
 case; for persons that are exposed in situa- 
 
140 
 
 (ions where marsh miasmata, or the exhala- 
 tions from putrefying vegetable and animal 
 substances, are most abundant, and under 
 circumstances which dispose them most rea- 
 dily to be acted upon, perceive no sensible 
 effect for several days after such exposure, 
 or after exposure to the contagious exhala- 
 tions from eruptive fevers. A period always 
 intervenes of different length on different oc- 
 casions, but always of sufficient length, after 
 such exposure, before any effect is perceiv- 
 ed or any alteration observed, especially in 
 the arterial system, to convince any one that 
 is qualified to discern the relation between 
 cause and effect, that these causes of fever 
 do not act primarily on the arteries, or pro- 
 duce their effects by a directly stimulating 
 action upon the excitability of the system. 
 The symptoms of the forming, or early stage 
 of the fever, by no means indicate that they 
 are the effect of stimuli, whose primary ac- 
 tion is upon the muscular fibres of the heart 
 and arteries, (which would in part be a re- 
 vival of the exploded doctrine of morbific 
 matter,) for those symptoms always indicate 
 defect or depression of power in the muscles 
 
141 
 
 that are subservient to the will, in a state of 
 health for some time before an increase of 
 motion or disordered action is perceivable in 
 the arterial system ; though from a law of the 
 animal economy which, 1 believe, has neve* 
 been perfectly explained, this state of depres- 
 sion is soon after followed by an increase of 
 action, and frequently of strength, in the ar- 
 terial system. 
 
 If the miasmata acted primarily on the sto- 
 mach, as taught by Dr. Darwin, and expend- 
 ed excitability by excessive action, all the 
 functions of the body would shew signs of 
 vigour the instant it began to act on the ex- 
 citability of the stomach, before it was fol- 
 lowed by symptoms of exhaustion, in the 
 same manner as they do upon receiving wine, 
 alcohol, or other strong stimuli into it; or, if 
 they acted with the force and celerity of the 
 electric fluid, a prostration of strength and 
 suspension of excitability would be the im- 
 mediate consequence. 
 
 According to the legitimate rules of induc- 
 tive philosophy, it cannot be admitted that 
 marsh miasmata, or the volatile substances 
 derived from putrefying vegetable and animal 
 
143 
 
 substances, when received into the human sys- 
 tem, act as stimulants, and produce indirect 
 debility, by expending or impairing the ex- 
 citability, by a stimulating action or impres- 
 sion; because, we see fever more certainly 
 produced after exposure to those miasmata, 
 by the abstraction, than the moderate addi- 
 tion of certain stimuli — such as the abstrac- 
 tion of the heat of the body, by exposure to 
 the moist and cool air, so common at night, 
 particularly when aided by abstinence, or 
 too scanty supply of aliment and refreshing 
 drinks, and unusual fatigue, previously to 
 such exposure. The previous stimulating 
 power or property of these miasmata have 
 never been perceived by the patient, and the 
 very slow progress and diminution of power 
 indicated by the symptoms, previous to the 
 accession of the exacerbation or hot stage of 
 fever, in cases of intermittent fever, are 
 strong arguments against its being a fact, and 
 against the correctness of the doctrine. 
 
 If the theory of disease, which was taught 
 by this ingenious and eminent professor, was 
 correct, every form or variety of disease 
 would require such remedies as have the of- 
 
143 
 
 feet of inducing artificial debility in otber 
 parts of the system, greater than that whieh 
 exists in the part where the disease is seat- 
 ed, that the surplus of excitability might be 
 drawn from the part primarily affected, and 
 conveyed into other parts, where it was defi- 
 cient, and the excitement thereby, equalised 
 throughout the system. But if every form 
 or variety of disease consists in different de- 
 grees of excitement, above or below the point 
 of health, as taught by Drs. Brown and Dar- 
 win, aud in the different degrees of irregular 
 action, as taught by Dr. Rush, and these dif- 
 ferent degrees of irregular action, depend 
 upon the unequal quantity of excitability in 
 different portions of the system, or in diffe- 
 rent parts of the same portion, and a dispro- 
 portion between the excitability thus unequal- 
 ly accumulated and the force of the stimuli 
 which act upon it, and the excitability becomes 
 more abundant, in proportion to the abstrac- 
 tion of natural and customary stimuli, as well 
 as in consequence of the excessive action of 
 stimuli, after such action has been suspend- 
 ed for some time, either the theory or prac- 
 tice recommended by Dr. Rush must be 
 
144 
 
 wrong — for blood letting and other deplet- 
 ing remedies, which he recommends in dis- 
 eases which indicate too much excitement or 
 too strong action, by promoting artificial de- 
 bility in the heart and arteries, would occa- 
 sion a preternatural flow and increase of ex- 
 citability into them, and consequently, in- 
 crease the cause on which their convulsive 
 action depends. 
 
 The creed that excitability increases, or 
 that the susceptibility to the impression of 
 stimuli becomes greater in proportion to the 
 degree of debility induced by the operation 
 of the remote causes of fever, or, in conse- 
 quence of suddenly withholding or suspend- 
 ing the action of artificial stimuli, as respects 
 the heart and arteries, is not only hypotheti- 
 cal, but is contradicted by facts that are fa- 
 miliar to every practical physician. In the 
 last stage of the typhus fever, for instance, 
 and in many cases, from its very commence- 
 ment, (late examples of which have been nu- 
 merous in the states of Connecticut and Mas- 
 sachusetts, and in the western parts of New 
 York,) -when the symptoms indicate great 
 debility, as well as in the asthma and colic, 
 
145 
 
 instead of a corresponding or proportionable 
 degree of excitability, the deficiency of exci- 
 tability is so great as to require the most 
 powerful and penetrating stimuli to arrest 
 the ebbing tide of life ; whereas, in most 
 cases of fever accompanied with, or depend- 
 ing on local inflammation, the mildest stimu- 
 li increase the force and frequency of the 
 heart and arteries, and exasperate the symp- 
 toms. 
 
 If the power of both the vital and animal 
 functions, become impaired or diminished; 
 in consequence of the abstraction of a due 
 portion of pure and fresh air, long fasting, 
 fatigue, and exposure to a lower temperature 
 of the atmosphere than usual, or from the 
 abstraction of other stimuli which habit has 
 rendered necessary to support the healthy 
 action of the system ; or from suddenly ab- 
 staining from strong artificial stimuli, that a 
 person has been long accustomed to, can it 
 be said, with any degree of probability, that 
 the excitability or principle of animation, un- 
 der such circumstances, has gone on to in- 
 crease and accumulate in the system, and 
 that because it has not been expelled or ex- 
 
146 
 
 liausted by the strong and more frequent ac- 
 tion, which the application of stimuli occa- 
 sions, it must have increased and accumu- 
 lated. 
 
 In my opinion, we might with equal rea- 
 son, expect an effect without a cause; for it 
 would be highly irrational, and incompatible 
 with observation, to expect that the excitabi- 
 lity or principle of life, the production and 
 renewal of which, requires the functions of 
 health, should be generated and accumulated 
 in greater abundance, while the system la- 
 bours under a state of diminished power, as 
 it apparently always does for a longer or 
 shorter time, previous to, and at the time of 
 the accession of fever. The probability is 
 much greater, and more consonant to reason, 
 that the torpor and impaired state of strength 
 in the voluntary muscles, which precede the 
 invasion of fever, would, in a great measure, 
 prevent any additional productive increase 
 or accumulation of the excitability. 
 
 According to this doctrine, as well as to 
 tho^e of Drs. Brown and Darwin, the exci- 
 tability or principle of life, which is a sub- 
 stance or quality, the existence of which is 
 
147 
 
 only known from its effects, becomes increas- 
 ed in proportion to the deprivation of every 
 thing necessary for its production and sup- 
 port; for, as the powers which support life 
 are diminished, life itself is increased, which 
 is extremely improbable, as well as unac- 
 countable; because every effect must neces- 
 sarily be preceded by, or connected with an 
 adequate cause. Nor does this doctrine cor- 
 respond with facts; for it is notorious that 
 the phenomena of remittent and typhus fe- 
 vers, especially when they have a tendency 
 to terminate fatally, indicate that the excita- 
 bility, instead of increasing or accumulating 
 in a greater proportion as the debility in- 
 creases, particularly in the vital functions, 
 keeps regular pace with it, or diminishes in 
 an equal proportion as the debility increases. 
 Dr. Rush's directions, and the remedies he 
 recommends for reducing the excitement 
 when too high, and raising it when too low, 
 in every modification of disease, without be- 
 ing influenced by the name by which they 
 are called in the different systems of nosolo- 
 gy, which is certainly the only true method 
 of practising with success in the generality 
 
148 
 
 of diseases, furnish a most unanswerable ar- 
 gument against the fundamental principles of 
 his theory. I expect the following facts and 
 enumeration of symptoms and circumstances 
 connected with that description of continued 
 fever denominated typhus gravior, which, 
 with some alterations, are extracted from 
 Dr. Mihnan's Enquiry into the Nature and 
 Sources of the Scurvy, and of (what he 
 calls) Putrid Fevers, published in the year 
 1783, will satisfy every impartial reader, that 
 instead of there being an increase of excita- 
 bility in the muscular fibres of the heart and 
 arteries, their excitability is in an impaired 
 or diminished state. 
 
 " Though the manner in which the various 
 motions of the body are performed, as well 
 as the more intimate structure of its fibres, 
 may be forever concealed from us; yet there 
 are certain properties of these, taught us by 
 experiment, the existence and true use of 
 w T hich, are as well ascertained as any part of 
 human knowledge." 
 
 That property of the muscular fibre by 
 which, on the application of a stimulus, it is 
 enabled to move and contract itself, is known 
 
149 
 
 to be derived from a principle inherent in its 
 fib.e, and which, to a certain degree, conti- 
 nues to exist after all connection is cut off 
 between it and the nerves. For though the 
 destruction of this principle in the muscular 
 fibres, is the certain and immediate death of 
 those fibres, yet there are many causes which 
 may take away sense and motion, and may 
 leave this principle surviving in the muscu- 
 lar fibre ; so that when all sense and motion 
 in the animal machine has ceased, and inter- 
 nal stimuli can no longer be applied, we can 
 for several hours, and in some particular ani- 
 mals for several days, by external stimuli, 
 excite the muscular fibres to contraction, in 
 consequence of this principle not being yet 
 extinct in them. 
 
 The voluntary and involuntary motions 
 of the body, are all dependent upon this 
 principle. — It is by means of it, that the 
 muscular fibres of the heart, being stimulated 
 by the blood flowing into its auricles and 
 ventricles, are made to contract or react, and 
 to propel the blood. The same vital power 
 in the voluntary muscles, being acted upon 
 by the nervous power directed to them by the 
 
 n 2 
 
150 
 
 will of the animal, renders them obedient to 
 its purposes. The vital principle is the ef- 
 ficient or proximate cause, whilst the stimu- 
 li applied, are only the exciting cause of their 
 motion; for, when the vital principle is de- 
 stroyed, no motion can be excited in either 
 the voluntary or involuntary muscles by any 
 stimulus whatever. 
 
 Fontana, the ingenious and celebrated 
 Italian philosopher and physiologist, has 
 examined very attentively the effects of many 
 of those causes which have a power of im- 
 pairing the vital principle, and upon the 
 grounds of extensive and judicious experi- 
 ments, affirms it to be an universal law of the 
 animal economy, that the diminution or de- 
 struction of the vital principle in the muscu- 
 lar fibre, gives it a tendency to putrefaction, 
 and that this tendency will be greater or 
 less, in proportion to the force and quick- 
 ness with which the cause destroying this 
 principle operates. Where the cause is less 
 powerful, and more slow in its operation, and 
 we have time to note with accuracy all the 
 phenomena which succeed the injury of the 
 vital principle, it is observed that the first ef- 
 
151 
 
 feet of the diminution or impaired state of it, 
 is a weakness of the muscular fibre; so that 
 stimuli which could have excited it in health 
 to strong contractions, can only produce weak 
 ones. 
 
 An examination of the symptoms of the 
 mildest cases of typhus fever, must satisfy 
 every unprejudiced inquirer, that its occa- 
 sional cause has induced such a weakness in 
 the muscular fibres, as to prevent stimuli, 
 which, in health, were capable of exciting 
 strong contractions in the voluntary and in- 
 voluntary muscles, from being able to pro- 
 duce any other than feeble ones. It is also 
 observable in more malignant or dangerous 
 cases of this form of fever, that the fibres be- 
 come soft and relaxed ; the cohesion between 
 the particles composing the fibres are dimi- 
 nished, so that the fibre breaks upon moderate 
 pressure or extension — the extreme arte- 
 ries appear paralytic, so as to let the blood 
 escape, and the blood itself loses its power 
 of coagulating when drawn from a vein. But 
 if, (pulsus fterumque frequens;) the pulse 
 for the most part, is increased in frequency, 
 as stated by Dr. Cullen, and is admitted to 
 
15& 
 
 be the case in the beginning of most of the 
 varieties of the typhus fever, be a just part 
 of the character of this disease, may we not 
 conclude, that however the vital principle 
 may be impaired or diminished in the volun- 
 tary muscles, so far from being impaired or 
 diminished in the heart and arteries, it is in- 
 creased. This would be to suppose that the 
 cause which diminishes the vitality or exci- 
 tability in the voluntary muscles, may in- 
 crease it in the involuntary ones. This 
 would also be making the quickness or fre- 
 quency of the contractions oi the heart and 
 arteries, the measure of the vital power in 
 their fibres. He who should calculate the 
 power of the heart and arteries, and judge 
 of the quantity of the existing excitability in 
 their fibres, without taking into account either 
 the stimuli applied to excite their contrac- 
 tions, or the force and effect of these con- 
 tractions when produced, I presume, would 
 he as little likely to form a just estimate of 
 the vital power existing in their fibres on 
 which their contractions depend, as that per- 
 son would be of having an accurate idea of 
 the weight of a moving body, who, without 
 
153 
 
 considering the quantity and density of the 
 matter it contains, should measure it merely 
 by its velocity. To draw just conclusions, 
 therefore, from the quickness of the pulse, 
 we must examine the sources from which it 
 may arise. 
 
 As the vital power appears in these cases 
 to be generally diminished in the system, it 
 does not appear any way probable that it 
 should have suffered no local injury in the 
 fibres of the heart. Instead, therefore, of 
 proceeding from increased excitability accu- 
 mulated in the fibres, from having been pre- 
 viously debilitated by the remote causey 
 may not the quickness of the pulse be ocea» 
 *ioned by increased irritation? 
 
 A minute investigation of this matter, will, 
 in my opinion, teach us that instead of being 
 more irritable, the quick and feeble motion 
 of the vital organ only indicate that it is more 
 irritated. 
 
 It is generally admitted that the blood 
 which flows into the auricles and ventricles 
 of the heart, is the stimulus which excites 
 ihem to contract, particularly that portion 
 which is oxyginated in the act of respiration^ 
 
151 
 
 and the effect is always found to be propor- 
 tioned to the quantity and condition of the 
 blood which enters, and the force with which 
 it flows into the auricles and ventricles of 
 the heart. 
 
 When, at the beginning of a paroxysm of 
 an intermittent fever, a constriction and pale- 
 ness appear on the surface of the body, du- 
 ring which the blood is detained and accu- 
 mulated in the heart and large trunks of the 
 arteries, the pulse becomes, during the cold 
 stage, very small, frequent, and irregular; 
 the heart seems for a while to labour under 
 the load of blood accumulated in, and dis- 
 tending its cavities : but the vital principle in 
 its fibres not being much, if any, impaired, by 
 the occasional cause of the disease, the blood 
 which accumulates within its cavities, by the 
 stimulus of distension, soon excites it to 
 strong, as well as frequent contractions, by 
 which the blood is propelled with force to 
 every part of the body, and all the symp- 
 toms of the hot fit, the heat and redness of 
 the skin, &c. ensue. As the heat comes on, 
 the heart having relieved itself in some de- 
 gree, the pulse becomes more regular and 
 
155 
 
 full, and in these respects increases, until a 
 sweat breaks out. As the sweat flows, and 
 as the circulation becomes equable in every 
 part, and the heart is no longer stimulated 
 by the blood accumulated from a confined 
 state of the circulation, the pulse becomes 
 softer and less frequent. 
 
 But in that species of fever formerly call- 
 ed nervous or putrid, and now typhus or ma- 
 lignant, the vital principle being greatly di- 
 minished or impaired, and the actions de- 
 pending upon it greatly weakened, the heart 
 is unable to free itself from the blood detain- 
 ed in the trunks of the arteries and accumu- 
 lated in its cavities, which, in that unusual 
 quantity, stimulates it, as in the cold fit of 
 an intermittent, to small and very frequent 
 contractions. In these cases, instead of that 
 glowing heat and redness of the skin, which 
 is so conspicuous in the hot stage of an inter- 
 mittent, the same appearance of constriction 
 or stagnation of the blood in the capillary 
 arteries on the surface, the same pale or livid 
 colour continues, the same ghastly or inani- 
 mate countenance is seen in every stage of the 
 disease, though frequently in different degrees, 
 
156 
 
 at different times of the day ; and consequent- 
 ly, the same cause, the impaired state or dimi- 
 nished quantity of the excitability or principle 
 of life, which originally prevented the heart 
 and arteries from propelling the blood through 
 the extreme arteries into the veins, still con- 
 tinues to exist. But this extraordinary cause 
 of the detention of the blood in the large ar- 
 teries, and in the cavities of the heart, is not 
 the only cause of irritation in these cases, A 
 resistance to the propulsive power of the 
 heart, is also considered by physiologists, 
 among the causes which quicken the pulse. 
 The weight and powerless state of all the 
 voluntary muscles, from the impaired state 
 of the vital principle in their fibres, in ma- 
 lignant fevers, must furnish a considerable 
 obstacle to the propulsive power of the heart, 
 which, though less irritable, is much more 
 irritated than in a state of health, or in other 
 forms of fever. 
 
 The blood, then, accumulated about the 
 heart in consequence of the weakness of its 
 contractions, and the increased weight of the 
 muscles rendered inelastic by the occasional 
 cause or causes of the disease, and the in- 
 
 
157 
 
 creased resistance thereby given to its pro- 
 pulsive power, are causes of uncommon irri- 
 tation. In some cases of typhus gravior, the 
 vital principle appears to be so much impair- 
 ed in the muscular fibres of the heart and ar- 
 teries, that the concurrence of the enume- 
 rated causes are not sufficient to produce 
 quickness of the pulse; but when this quick- 
 ness does occur, it cannot be accounted for 
 so rationally from any other causes as from 
 those which have just been enumerated. 
 This is also confirmed by the circumstance, 
 that if by stimulating and invigorating reme- 
 dies, we can excite the heart and arteries to 
 contract, for a certain time, with sufficient 
 force to relieve the heart from the load of 
 blood detained and collected in its ventricles, 
 and to force open the extreme vessels, the 
 pulse immediately becomes more full and 
 regular, and less frequent. 
 
 But, independent of these suggestions, if 
 the sources of uncommon irritatiou have not 
 been satisfactorily pointed out, to ascribe 
 the frequency of the pulse unaccompanied 
 with hardness or fulness, in such cases, to 
 an increase or accumulation of excitability in 
 
 o 
 
158 
 
 the blood vessels, would involve us in the 
 most palpable contradictions ; our theory, in 
 that case, and practice would be at the great- 
 est variance. 
 
 Where the vital principle in the heart and 
 arteries, on which their contraction essen- 
 tially depends, is but little if any impaired, 
 as is frequently the case in an intermittent 
 fever, stimuli are useless or injurious ; how 
 much more would they be so then in cases 
 of typhus gravior, if the excitability became 
 greater in proportion as the strength of the 
 moving powers decreased, as has been taught 
 of late by some of the most ingenious and 
 eminent professors and lecturers of the pre- 
 sent age. 
 
 So far are stimulating and invigorating re- 
 medies from being injurious in cases of ty- 
 phus or other forms of fever accompanied 
 with great prostration of strength, and low 
 weak pulse, that patients, in such circum- 
 stances, unaccustomed to wine, aether, and 
 volatile alkali, not only bear but frequently 
 require such a quantity as at other times 
 would occasion an inflammation of the sto- 
 
159 
 
 inach or brain, or the rupture of a blood ves- 
 sel. 
 
 To restore the contractions of the heart to 
 a healthy state, we are under the necessity 
 to increase the power of its propulsive ac 
 tion, first, by strong and frequently repeated 
 stimulating agents, and to prevent a return 
 of the debility by nourishing and refreshing 
 drinks, tonic medicines, and other invigorat- 
 ing means. 
 
 With what propriety, therefore, could we 
 refer the frequency of the pulse, in which 
 the action is so much weaker than in health, 
 in cases of typhus fever, to an increase of 
 that principle, which we find it so necessary 
 to cherish and increase? 
 
 That debility so conspicuous in this form 
 of fever, both in the voluntary and involun- 
 tary muscles, the petechias or livid spots 
 which generally occur in cases that have a 
 fatal tendency, the haemorrhages from dif- 
 ferent parts of the body, the tendency to gan- 
 grene in parts that have been inflamed by 
 blisters or sinapisms, are all links of the 
 same chain, and are all symptoms of the 
 same proximate cause, the impaired state of 
 
160 
 
 the vital principle or excitability in the mus- 
 cular fibres. All these phenomena are ana- 
 lagous to those observed by the ingenious 
 Italian philosopher and physiologist Fonta- 
 na, when the vital principle was intentional- 
 ly destroyed by the venom of the viper, by 
 the poisonous juices of certain vegetables, 
 and by a violent shock of electricity. Weak- 
 ness was the first eifect — a soft, tender, flac- 
 cid, or loose state of the muscular fibres, a 
 diminished cohesion between their particles, 
 a lengthening of the fibres followed in suc- 
 cession, and were the immediate precursors 
 of putrefaction. The tendency and progress 
 to putrefaction, in the higher grades of the 
 typhus fever, is marked by the same pheno- 
 mena; according to the legitimate rules of 
 induction, therefore, they are to be referred 
 to the same cause — the impaired state or de- 
 struction of the vital principle inherent in the 
 muscular fibres. 
 
 If there is but one disease, and the whole 
 catalogue of diseases to which flesh is heir 
 to, are to be considered as an unit, as taught 
 by Dr. Rush, because every form or variety 
 of disease is accompanied with irregular ac- 
 
161 
 
 tion, we might conclude by the same mode of 
 reasoning, that there is but one medicine, or 
 that the whole catalogue of remedies con- 
 tained in the materia medica is an unit, be- 
 cause every kind and variety of remedy acts 
 upon the excitability or living principle. We 
 might also conclude that there is but one 
 animal, because every animal is a living crea- 
 ture; and all animals possess some common 
 properties, though the figure, habits, actions, 
 and character of some, are entirely different 
 from those of every other description : 
 
 "Some being fixed like weeds to perish 
 where they grow ; w 
 
 Some destined to grovel in the earth (like 
 prisoners in despotic governments,) "shut 
 out from the enjoyment of the common air, 
 and from the free use of their own limbs." 
 "While others spread their light wings, and 
 mount into the viewless air." And others 
 "a watry race, cleave oceairs briny waves." 
 
 We might also conclude for the same rea* 
 son, that plants and animals belong to the 
 same class of beings, because, like animals, 
 plants have life, and receive support from air 
 and water, are invigorated by heat and light, 
 
 o 2 
 
162 
 
 and are rendered torpid or languid, by cold : 
 But how would such a doctrine lead to a 
 knowledge of their respective characters, 
 properties^ offices, and uses ? 
 
 A doctrine which is not supported and 
 confirmed by unquestionable facts and in- 
 ductive reasoning, and that does not neces- 
 sarily conduct to successful practice, instead 
 of being a safe and eligible guide, must tend 
 to perplex and mislead the student and in- 
 experienced practitioneiv 
 
 An attempt, therefore, to banish from me- 
 dical studies a systematic arrangement of 
 diseases or nosology, derived from accurate 
 and repeated investigations of the nature and 
 causes of diseases, (a description of the cha- 
 racters or symptoms of which, render those 
 of a particular kind or description, easily 
 distinguished from those of every other kind 
 or description,) and to substitute in its place 
 an hypothesis derived from a mere symptom 
 or effect of an exciting or occasional cause, 
 acting on a state of the system favourable to 
 its action, (for irregular action, confined to 
 its true meaning, is nothing else,) cannot cer 
 
163 
 
 tainly be justified on the plea of practical 
 utility. 
 
 By the rules of nosology, or systematic 
 classification of diseases, the student very 
 soon learns to distinguish diseases of a dif- 
 ferent nature from one another, and which, 
 consequently require remedies not merely of 
 a different grade in their qualities, but of a 
 different kind; whereas, if he adopts the 
 theory of Dr. Brown, or Dr. Darwin, or that 
 of the more enlightened, ingenious, and en- 
 terprising Dr. Rush, he will, until he has 
 by long and diversified experience acquired 
 a portion of the discriminating sagacity of 
 the last mentioned physician, find himself 
 perpetually at a loss to accommodate his re- 
 medies to the existing state of his patient's 
 excitability, and bring the different portions 
 of his system to an unison of action. For no 
 man, except by chance, can direct his reme- 
 dies with unerring aim, who takes uncertain 
 rules for his guide. 
 
 To conclude, though the doctrine of dis- 
 eases taught by Dr. Rush, and particularly 
 his theory of fever, should appear to accord 
 more with the simplicity of the laws of na- 
 
164 
 
 ture, and to appear to be more ingenious and 
 philosophical than any other that has hither- 
 to been ushered into light, yet by simplifying 
 to such an extreme, and attempting to banish 
 nosology or systematic arrangement from 
 medical studies, I am apprehensive, that, if 
 his theory should be generally adopted, to 
 the exclusion of the rules of practice which 
 he has recommended, and which are sup- 
 ported by the experience and writings of the 
 most enlightened physicians of the present 
 age, it would have a tendency to reduce the 
 exalted science of medicine, which has the 
 most important and useful objects for its end, 
 to the degraded condition of a conjectural 
 and uncertain art, and thereby render confu- 
 sion more confused. And as he has declared 
 himself an advocate for that part of the doc- 
 trine of Brown, which considers life to be a 
 forced state, or the mere effect of certain sti- 
 muli acting upon the organs of sense and 
 motion, and expressly asserts that thought 
 and the operations of the mind are as much 
 the effect of stimuli acting upon these organs 
 as any other phenomena of life, I am appre- 
 hensive that it will have a tendency to lead 
 
16 5 
 
 the untutored mind, as well as the sceptic, 
 to conclude that the intellectual principle 
 will not survive the death of the body, and 
 that when the lamp of life is once extinguish- 
 ed, it will never again revive. The incul- 
 cation of this gloomy and cheerless doctrine, 
 however, was far from the intention of the 
 benevolent and philanthropic author; for, in 
 his introductory lecture in the month of No- 
 vember 1809, he expressly says, "there are 
 many strong reasons to believe that the souls 
 of brute animals, as well as those of man- 
 kind, will exist in a future state, as the di- 
 vine bounty discovered in the gift of their 
 pleasures would be rendered abortive, un- 
 less they were placed in a situation to make 
 returns of gratitude for it, in a state of future 
 existence." 
 
 If life was a forced state, as has been al- 
 ledged, the application of exciting agents 
 duly adjusted to the varying state of excita- 
 bility would preserve mankind in peipetual 
 health, and, as has been already remarked, 
 render them immortal; for, instead of being 
 forced to die, they would be forced to live 
 
166 
 
 so long as exciting agents are applied, or 
 could be procured. 
 
 To the doctrine that life is a forced state, 
 it may be objected that this language con- 
 veys very incorrect ideas, for the actions 
 which are produced in a living body by sti- 
 mulating agents are not the cause of life, but 
 merely the phenomena and effects of life, or 
 of the action of appropriate stimuli upon the 
 principle of life. Life may and does exist 
 without the agency of stimuli in a variety of 
 substances, such as the eggs of animals, the 
 seeds of plants, the solids of torpid animals, 
 and, for a time, in those that are deprived 
 of sensation and motion by drowning ; and 
 in some, after decapitation, particularly in 
 rabbits, and guinea-pigs, especially if artifi- 
 cial respiration is produced by inflating their 
 lungs, as has been lately proved by the ex- 
 periments of Dr. Le Gallois of Paris, and 
 Mr. Brodie of London. The principle of 
 life, therefore, or the efficient cause of the 
 phenomena of life, may, and does exist, in- 
 dependent of organic action, but organic ac- 
 tion cannot be produced ia the human sys- 
 tem without the presence of the vital princi- 
 
 
167 
 
 pie. The question relative to thought and 
 the passions of the mind being the effect of 
 stimuli upon the organs of sense and motion, 
 I shall leave to the consideration and dis- 
 cussion of those that are more conversant 
 than myself with metaphysical subjects, and 
 shall here, for the present, close my obser- 
 vations on the theory and opinions of this 
 learned and ingenious professor, who deser- 
 vedly held the first rank in his profession, 
 and whose talents and industry do credit to 
 his country. 
 
 Doctor Gregory, the present learned 
 professor of the theory and practice of phy- 
 sic, in the university of Edinburgh, has de- 
 voted some pages of his memorial to the ma- 
 nagers of the Royal Infirmary of Edinburgh, 
 relative to the pernicious system of rotation 
 in the attendance of the surgeons in that in- 
 stitution, to an account and consideration of 
 the different sects that have prevailed in me- 
 dicine, from the time of Galen, whose sys- 
 tem he has stigmatized as being more unin- 
 telligible, and where it is intelligible, more 
 extravagantly absurd, than any that had pre- 
 
168 
 
 ceded it, and which, adds this author, of 
 course came to prevail universally, till it was 
 superseded by the systems of Cullen, Brown, 
 Darwin, and the pneumatic chemists of the 
 present day; which he trusts will keep us 
 all alive and merry for a dozen years at least, 
 and when they have served their time, and 
 their hour is come, nam omnibus manet nox, 
 will give place to others as good in every 
 respect, and equally fit to amuse the whale, 
 (alluding to an expression of Dr. Cullen, 
 "that theory is as necessary to amuse stu- 
 dents of medicine as a tub to amuse a 
 whale.") 
 
 In the same memorial, Dr. Gregory as- 
 serts that he neither is, nor ever was, either 
 an empiric or a dogmatist. "He would have 
 been a keen dogmatist, but he found at least 
 99 in the 100 of medical dogmas were false, 
 and many of them stark nonsense. He would 
 have been a determined empiric, but that he 
 found at least 99 in the 100 of empirical 
 facts were as false, and more than that pro- 
 portion of their remedies as insignificant or 
 as dangerous as any of the dogmas of their 
 opponents. 
 
169 
 
 "He has taught the theory and practice 
 of physic in the university of Edinburgh for 
 four and twenty years, without once throw- 
 ing out a tub to amuse the whale. " " He 
 never thought he had ingenuity to make 
 such a tub, or dexterity enough to manage 
 any of the numberless ready made tubs which 
 were floating around him." " He observed 
 to his great comfort that he had no occasion 
 to take that trouble, as the whale lias always 
 found some tub to amuse himself withal, and 
 has never yet shewn the least inclination 
 either to swallow or overset him and his lit- 
 tle bark. 
 
 Notwithstanding the preceding declara- 
 tion, if 1 have received correct information, 
 Dr. Gregory, at present, teaches in his lec- 
 tures, "that as all the symptoms which pre- 
 cede the cold or forming stage of fever, un- 
 connected with local inflammation, indicate 
 a defect of power or energy in the functions 
 of the brain, and as all the other functions 
 except the heart and arteries depend imme- 
 diately upon the functions of that organ, and 
 the heart and arteries depend on it also indi- 
 
rectly through the -medium of the nerves 
 which it receives from the medulla spinalis, 
 and in a secondary manner, by means of the 
 organs of respiration; and as all the other 
 functions of the system depend either direct- 
 ly or indirectly upon the state of the func- 
 tions of that organ for their healthy or mor- 
 bid action, it may be reasonably concluded 
 that the disorder with which they are affect- 
 ed at the commencement of every species of 
 fever, proceeds from a defect of energy or 
 power in the functions of the brain, as their 
 regulator and support; and consequently, 
 that the nervous system is the seat of fever, 
 and its proximate cause, a defect of power in 
 the functions of that organ, and the spasm of 
 the extreme vessels in every part of the sys- 
 tem, both external and internal, which is so 
 conspicuous a symptom of the cold or form- 
 ing stage of fever, and which continues to 
 subsist, in a greater or less degree, through 
 the whole course of the fever, is only a 
 symptom or effect of irritation occasioned by 
 the circulating fluids on parts rendered pre- 
 ternaturally irritable by the operation of the 
 remote causes, and is not the cause of either 
 
171 
 
 the cold or hot stage, or of the febrile symp- 
 toms, as taught by the illustrious Cullen." 
 
 If Dr. Gregory had proceeded with an ex- 
 planation of the manner in which the hot fit 
 is produced by the increased stimulus given 
 to the heart and arteries, in consequence of 
 the increased respiration which occurs du- 
 ring the cold stage, and had pointed out the 
 chemical changes produced in the blood by 
 means of a quickened respiration, his theory 
 would have been complete, and would have 
 saved me the trouble of adding any thing far- 
 ther on the subject. 
 
 Having thus given an abstract or summa- 
 ry view of the principal theories or doctrines 
 of diseases, that have been taught at different 
 periods, by the chiefs of the medical schools, 
 and by the most eminent authors, I should 
 now proceed with my proposed attempt to 
 establish a more correct and satisfactory 
 theory of fever, than any that has hitherto 
 been made public ; but after a more delibe- 
 rate consideration of the subjeet, I have con- 
 
eluded to postpone its publication, until T see 
 what reception the preceding observations on 
 the theories of "others, will meet with from 
 the profession. If the reception should be 
 favourable, it will encourage me to hasten 
 the publication of the theory which I have in 
 contemplation ; and although I have no pre- 
 tensions to superior discernment or ingenui- 
 ty, or to the profundity of erudition of many 
 of my predecessors or eotemporaries, yet so 
 many facts have been accumulated in this 
 inquisitive and enlightened age, and so many 
 improvements have been recently made in 
 different departments of science, that 1 hope 
 I shall not be thought inexcusably presump- 
 tuous, for supposing myself qualified to es- 
 tablish a theory of diseases in general, and 
 of fever in particular, less exceptionable than 
 has hitherto appeared. 
 
 FINIS 
 
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LIBRARY OF CONGRESS 
 
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