ARMED FORCES MEDICAL LIBRARY Washington, D. C. A N Inaugural Diflertation, ON THE RATIONALE of the OPERATION of OPIUM on the Animal Economy ; WITH Obfervations on its USE in DISEASE. SUBMITTED To the EXAMINATION of The Reverend JOHN EWING, S. T. P. Provost; THE TRUSTEES and MEDICAL FACULTY OF the UNIVERSITY OF PENNSYLVANIA, ON THE MAY, 1797, / « _ "t^l^ls. • / ~^ For the Degree of DOCTOR OF MEDXCptE. i Nullius addiElus, jurare in verba Majijlri. ^«v«| ^5^- Hor. ' ^:(f \ BY JOIIX I WVS. }l. B. OF DOVER, STATE O J DLLAAVARE. PRINTED BY W. C. SMYTH, DELAWARE GAZETTE OFFICE, AVILMINGTON, »797- PREFACE. 9r I MS true, there are fome of narrow minds and A. grovelling conceptions, who confider every propofed innovation, as wild and chimerical; and look upon every attempt to depart from the beaten track, as the rafh inconfiderate effort of a warm imagination, or the glittering fpeculation of a bewildered mind ; that may pleafe and dazzle for a time, but can produce no real, or permanent advantage. These fceptics value themfelves, upon believing nothing in contravention of the opinion of the times— upon inventing arguments againft every new doctrine, and when arguments cannot be found, upon treating the adventurer with contempt and ridicule; fuch have been the mod formidable opponents, to every great and ufeful difcovery, for their principles and preju- dices, tending to equalize all capacities and characters, cannot fail to infatuate the indolent, the envious and the timorous. The danger indeed of admitting great and important innovations, without the exafteft fcrutiny, cannot be too ftrongly inculcated, nor the views of thofe who «re forward to promote them, without due examination, reprobated Avith too much feventv. But is it not pof- fible to run into the oppofite extreme, and bring upon fociety the very evils, Ave with to avert ; bv an obfti- nate oppofition to thofe gradual and neceffary reform- ations, which the genius of philofophy demands ? 'Tis a negligent reverence for erroneous opinions, which hare been fan£Honed by time, accompanied with an inattention to the encreafing lights in fcience, that has fo aftonifhingly retarded the progrefs of medicine. No fyftem of Phyfical education it muft be confefTed is fo perfeft, but that various prejudices may fallen upon the intellect, fo as to acquire over it an influence, not inferior to the mod incontrovertible truths; hence it is that much of the tims of a Phyfician muft of ne- ceflity be taken up, by correfting the errors he had been accuftomed to give an implicit confidence; and unlefs he agree to fubmit the whole of his inquiries to free invcftigation, his hard-earned learning, inftead of enlightening the world, will only give additional cur- rency, and beftow additiona-1 authority, to eftabiiTncd errors. A N INAUGURAL DISSERTATION. NOTHING furely, deferves our ferious confidera- tion, more pre-eminently, in all the ftudy of Medicine, than the operation of medical fubftances on the human body. True it is, we have been much mif- led by the fpeculative reafonings of learned men, anx- ious to elevate their characters, and amplify their emo- luments; great, very great, are the injuries which humanity has fuftaincd, by their erroneous opinions and abfurd theories. The animal body may be divided into three general constituent parts, viz. the fimple fibre, folida viva, and the circulating Mafs. The fit ft mentioned was by Dr. Booerhaave, and his difciples, confidered as fre- quently difordered by excefs of rigidity, and too great laxity, and that thefe preternatural ftates being cafual, were alterable by medicine. The more modern phyfi- ologifts however, at the fame time that they acknow- ledge the poffibility of a morbid condition therein, contend for its being a conftitutional infirmity very little under the influence of remedies. The circulating fluids have alfo by Galen, and his numerous followers, been efteemed the refidence of complaints :—Thefe theorifts talk much of acrimonious crudities, and other vitiated ftates of the fl jids, with a feeming inconfeiouf- nefs of the fallacy of their reafonings, or uncertainty of their inferences: not recollefting the mueiic i alter- ations which fubftances taken into the itomach, are fubjecled to, by the myfterious powers of digeftion, nor are they more mindful of the vigilance with which the abforbents perform their duty, which {landing as a faithful centinel, fternly refufe entrance to all ar- ticles inimical to the health of the fyftem; That the folida viva are the principal icst of difeafe, and the medium through which, medicine operates [ 6 ] their prevention and cure, 'tis humbly prefumed, is fufficiently eftablifhed by the celerity with which an opiate relieves the immediate effect of an aftringent in the fuppreffion of hemorrhages, the inftant operation of aether in quieting the fpafms of the fyftem, and other analogous cafes. Opium indeed is proven to have an immediate and direct operation on the nervous fyftem by the experiments of Dr. Whyt, which (hew the heart to be irritable after being feparated from the human body, and to be thrown into contractions on the application of ftimufants; and alfo to have its power of motion fufpended, nay even deftroyed by the application of opium. The fame principle is daily evinced by the ufe of it topically, with a view of re- lieving local pain. 'Tis one of thofe fubftances which diminifh the fenfibility and irritability of the fyftem, and thereby the motions and powers of motion in it ; and is efpecially remarkable, for inducing that fenfation of fenfe and motion, in which deep confifts. Altho' its operation is primarily on the nerves to which 'tis applied, 'tis very conftantly at the fame time imparted to other communicating nerves, more or lefs, accord- ing to the number and fenfibility of the nerves to which 'tis in contact. The effecl: of opium on different parts, is varied by the habits of the fyftem, with regard to it, by the de- gree of ftimulus to which the parts are expofed, and laftly, caeteris paribus, by the ftrcngth or energy of the nervous influence prevailing therein. Thus the heart and lungs are lefs affecled than other prrts, and retain their motions entire, when others are deftroyed, on account of the inceffant flimuli by which they are inftigated; hence alfo the reafon why its effefts are firft difcovered in the extremities, the nervous energy being there molt weak, and e contra. What the pre- cife alteration in the nervous fyftem, which opium occafions during the continuance of its eife&s on them can be, is for fome happier genius to explain. With a view of difcovering the nature of the qua- lity by which opium effects its wonderful influence on our bodies, whether it be intrinfically ftimulant or fe- dative, it becomes requifite to examine the phenomena which occur after the exhibition of an ordinary opi- ate. [ 7 ] Let it not be forgotten however, that our obferva tions to the end that they may admit of conclufive in ferences, fhould be accurately drawn from an obferv ance of its effecls on healthy bodies—the apparent effecl of medical fubftances being diverfified almoft to infi- nity by the peculiarity of the morbid condition, as occurring indifferent difeafes ; thus we find in a re- troceffion of the gout the pulfe often beating an hun- dred and forty times a minute, with extreme pain, anxiety and fever ; adminifter a glafs of Jamaica fpi- rits, and the heat, fever, anxiety, reftlefsnefs and frequency of the pulfe inftead of being aggravated thereby, are uniformly moderated—The pulfe is redu- ced to its natural and healthy ftandard—the feverifh burning and anxiety difappear, and the patient not unfrequently regaled by a calm refrefhing fleep. In this particular inftance then, an undoubted ftimulus appears to exert on the fyftem a fedative influence ; but paradoxical as it mayfeem, to thofe little accuftom- cd to reafon on the laws of the animal economy, it in truth, produces thofe tranquilizing effefts, entirely by its ftimulant virtue. May not opium then, be prefumed in fome inftances, to deceive us by the ap- pearance of exerting on the fyftem a ftimulant quality, by exciting all the powers of it, when in truth 'tis accomplifhed folely by a fedative influene. Let fuch an inftance, ferve to deter us from the hateful practice of eftablifhing primary and fundamen- tal principles from extraoidinary cafes, or deducing general conclufions from particular, folitary fa£ls, a loofe, fallacious method of reafoning too often deftruc- tively indulged. For as in matters of religion, 'tis eafy to fupport the moft unorthodox, heretical opinions, by detached, partial, mutilated quotations of fcripture, fo in medicine, the moft erroneous principles, or fan- ciful hypothefis, may bs contended for, as refting on the fure, permanent bafis of experience from the au- thority of pretended obfervations, or obfervations but lamely and partially made andiiKte^. ertt-e &&, The phenomena which.occur after the exhibition of an ordinary opiate, in the animal economy, are a fulnefs and foftnefs of the pulfe, ferenity and com- pofednefs of mind, with an occafional turgeffence of the blood-veffels, then fucceed languor, laffitude, irrita- bility and uneafinefs, accompanied with a fuppreffion of all the fecretions, and excretions, the perfpiratory B [ « ] difcharge excepted, I might add to the account of the effecls of opium on the body, the cordial, exhilirating influence, it fometimes difcovers on the mind. From obferving that its power is exerted primarily on the ftomach, and from thence extended through the medium of communicating nerves, to the reft of the fyftem invariably attended with a diminution of the refpeclive evacuations, and that the alimentary tube is rendered infenfible to a certain degree, the vifcera uri- naria difobedient to its irritating falts, and the gall bladder regardlefsof the ftimulant acrimony of its con- tents, it may with fome reafon be prefumed that 'tis of a fedative nature. That rule of philofophizing which reftrains the multiplication of caufes to thofe which are true, and fufEcient to explain the phenomena, certainly war- rants the explication of the contrariety of effefts which attend the ufe of medicine, upon a theory of as much fimplicity as may be—the great architect of nature having with marked attention, avoided all unneceffary complication, in the whole of his works. Regarding therefore the fuppreflion of evacuations, and diminu- tion of fenfibilty which attend the uf* of -opium, as teftimony of the prefenceof a fedative quality, I would afcribe the fulnefs and foftnefs of the pulfe, to the like influence extended to the heart, which by weak- ening the force of its aclion, occafions an accumula- tion of blood in the larger veffels ; which cii cumftance of accumulation arifing from the weakened action of the heart, very fatisfa&orily explains tire palenefs, lan- guor, and corrugation of the furface, which takes place on its ufe. That law of the animal economy, which occafions the excitement of fuch motions as are beft calculated to repel any offending matter, prcfents itfelf as a clew to the folution of the encreafed force and frequency of the pulfe ; as alfo of the occafional turgeffence of the blood-veffels before fpoken of. A parallel inftance in- deed, is to be found in the immenfe commotions, great heat, and febrile aftion, which are produced in our fyftem by the fedative operation of marfh miafmita, cold, fear, &c. This preferving power, is well known in the fchools of medicine, under the title of the vis mediatrix naturx ; wliich though of different explana- tion, muft as a general law, be admitted: Nor have I [ 9 ] any doubt, but that it may be fairly employed here, to account for the ftimulant effects which fo often ap- pear on the exhibition of an opiate. Thefe to be fure, are often evident and confiderable, but do not imply any directly ftimulant power in the medicine itfelf, as they can be fo well explained in the manner mentioned —they being the combined refult of the fedative ope- ration of the opiate, and the refiftance and confequent activity of the fyftem, and not of any incrcafe of ex- citement in the fyftem itfelf, as occafioned by the ope- ration of a direct and diffufive ftimulus. Let us not in this cafe prefume a quality, to ex- plain effects, which are perfectly confonant to the known laws of the animal economy upon the contrary fuppofition. Are we in our fober reafonings upon an important fubject to wander into the regions of imagi- nation ? The licenfe of conjecture, where error would be ruinous, is to be juftified by the principles of mora- lity and juft rules of philolophizing, on no occafion. The confideration, that the ftrcngth of our bodies, depends principally upon the energy of the brain and nerves, precludes the idea of their being weakened by opium, if its. ffect was other than fedative ; except indeed it be indirectly dowe. Is not the idea of its operating fedatively, more rcconcileable to the phe- nomena which take place after its ufe, and more con- fonant to that fimplicity, which nature fo wifely pre- fcrves in all her operations, than the idea of its being a pure, moft penetrating ftimulus, which however plaufible in itfelf, or fpecious in all appearance, in the conjured explanation of a fact, which the enthufi- aftic mind of its progenitor would willingly have de- nied ? The cordial exhilirating influence, which it exerts on the mind, is produced by its compofing the nervous commotions, and introducing fenfations of an agreeable kind, which tend in the fame manner with pleafant intelligence, or joy any how raifed, to infufe new vigour and animation into the mind and fpirits. This idea is greatly corroborated by the reflection tint the paffions which are the oppofites to thofe produced by opium, as fear, grief, &c. have at all times been recko- ned debilitating ; and among the principal caufes, of thofe afteiaic diiieafes* in which opium is alledged to provr beneficial. Is it not apparent that in many of [ xo ] thofe cafes, the favourable change of the complaint, being cccafioned by an elevation of the fpiiits, fhort in its duration, and tranfitory in its effe&s, without any extra alteration in that morbid condition of the habit which efpecially conftitutes the difeafe, that it cannot be confidered as an abatement thereof, or the fmalleft advance towards a perfect cure ? The turgid ftate of the veffels, which is alledged to have been noticed on the ufe of this article, is profe&N ^Wy imputed to the debility of the heart and arterial fyftem, and confequent accumulation of blood, in the large internal veffels ; and contend that any alteration which may have been obferved in the ftate of the flu- ids, is produced by its efficacy in varying the aftion of the veffels. The fmallnefs of the quantity in which 'tis ufually given, and the quicknefsof the operation, pre- clude the poffibility of its having penetrated the circu- lating mafs, and militates in the ftrongeft manner againft its direct and immediate operation on the flu- ids. This brings me to the confideration of its ufe in difeafe. 'Tis worthy of observation, that as in phyfiognomy, the human countenance, is varied almoft to infinity, merely by a difference in the affemblage of features, fo in medicine difeafes admit of the greateft pof- fible divei lity, by an endlefs variation in their affocia- ted fymptoms. Hence the impoffibility of a praftical distribution of them, into general claffifications, as ftenic and aftenic, cr phlogiftic and anti-phlogiftic. Hence alfo, the abfurdity and indeed the impracticabi- lity of that Amplification of the practice, which fuch a diftribution is calculated to effect, viz. to prefcribe ftimulants, no matter of what lpecies, provided they be agreeable, in all difeafes of wcaknefs, and refrige- rents together with the anti-phlogiftic regimen, in all difeafe of exceffive excitement, without regarding either the peculiar modification of the difeafe, as arif- ing from the complication of the fymptoms, the charac- teriftic morbid conditition of the habit, in which the diforder confifts, and by which 'tis diftinguifhed from all others ; or the peculiar andfpecific properties of the individual medicine employed, by which 'tis enabled to perform effecls, and operate cures, which no other articles could accomplifh. [ » ] No one will deny that many difeafes require a treat- ment peculiar to themfelves—fuiied to the innate dif- pofition of each particular difeafe ; and that their radi- cal cure, is often to be effected, in no other way. As various medicine are known to poffefs virtues and qua- lities fui generis, as they may be ftyled, virtues peculi- ar to, and characteristic of themfelves, fo in many dif- eafes, there is a peculiarity of motbid condition in the fyftem, independent of the degree of excitement there- in, which belongs to that fpecial difeafe, and differs it from every other. 'Tis the happy adjuftment of medicine, thus pof- feffing peculiar and afceruined qualities and powers, to that precife and diftinguifhed morbid condition of the habit, which from its fpecific virtues, 'tis the beft calculated to remedy, that forms the practical duty of a phyfician : And 'tis a degree of excellence and adroitnefs, inthe management of this nice and impor- tant bufinefs, which constitutes the man of practical eminence ; without which, was he poffeffed of the ge- nius of a Newton, with the erudition of an Ariftotle, he never could become happily Skilled in the profef- fion. Those principles being eftablifhed, I would, tho* with great deference, hazard an opinion, that the now fafhionable medicine called opium, ought not to be re- lied on, as the ultimum the art of phyfic can do, in any cafe, except there be that inexpreffible kind of aptitude, that happy fitnefs, correfponding ^ith elec- tive attraction in chemiftry, fubfifting between it, and the diforder, wherebv it becomes the moft eligible re- medy. How fmall the number of difeafes which opi- um is thus peculiarly Suited to eradicate, in compari- fon with the vaft number in which 'tis daily pr-ftferib- ed! May not this consideration, ferve to eftimate the abufes of it in medicine ? To reftrict the ufe of it abfo- lutely, to thofe cafes, which it is calculated radically to remedy, is not the object of thefe obfervations. The paffion for it, as founded on the pleafant effects that refult from its ufe, is a guarantee againft any fuch event. To be minute and circumftantial in the direc- tion of the difeafes in which it may be properly admi- nistered, is incompatible with the nature of this work. As a general rule it may be Stated as admiffa- [ 12 ] ble, in all thofe cafes where upon the deepeft reflec- tion, there cannot be developed the fmalleft repul- sive force, the lcaft repugnance, or unfuitablenefs fub- fifting between it, and the diforder. The latitude given with regard to its administration, is not intended to licenfe the ufe of it, without accurately noticing its effect on the mind — thereby guarding with much caution the patient from that kind of dependance upon it, which fo often proves fatal by generating a laxity in the ufe of other more efficacious means. How many inftances have we witneffed, of an entire divcrfion of the patient's attention, from the proper fources of relief, by the enchanting effects of opium ? So unhappy a confequence, refulting from the exhibi- tion of an article, thus potent and common, ought to have its proper operation on the minds of thofe, whofe erudition and character, give weight to opinion and force to their example. Habit when eftablifhed in its dominion, over the unreflecting and illiterate, is not to be eradicated but with the extremeft difficulty. None of the many argu- ments which are to be adduced againft the admifiion of thofe of evil tendency, are of more Serious import, than the consideration of their extent, as to time, be- ing utterly incalculable. In this view, lateft pofterity may have caufe to lament the injuries fuftainedby the folly and indifcretion of the prefent generation. The influence of fafhion is not more juftly deplored, or extenfively felt by any, than the votaries of medicine. So rapid and mighty is its torrent, that nothing, but the greateft aid which philofophy can afford, is ade- quate to its refiftance. To eftimate the poffible harm of an evil habit, is not more the duty of the moralift and divine, than the enlightened phyfician. I conclude with a hope, that if the theory here adop- ted, Should not be cherifhed with general approbation, that it will be received as a pledge of equal freedom in all future enquiries ; prefuming that this circumftance will of itfelf, give a claim to a degree of regard. 'Tis from the diffufion and prevalence of a free fpirit of enquiry, that we are to look for improvements in the healing art. May it not be faid, that in this sera, fo aufpicious to the happinefs of the American people, that medicine languishes, or becomes tardy, in her progrefs of improvement ? FINIS. I r Ma/LHist L'tJlS'u 17*17 '•! ^M~\m m C.W" -J ^••■< t $-*?*-XM3A2W* x&iy $S *>■ sTawh