• '* • 4. *\ *-'V ,N*^ f^M***-** tjnBik .** **■ rr Surgeon General's Office <-s><®><»<^'^'®'<*^ INTRODUCTION. I CANNOT permit the reader to perufe this DifTerta- tion, without previoufly foliciting him, generoufly to withhold any critical remarks on the little inaccuracies he may obferve, as it is a firft production, whofe compofi- tion and publication were limited within a fliort time. I muft beg him likewife to excufe frequent repetition, as it originated from a defire of perfpicuity, and although I may thereby have deftroyed all beauty of compofition, I fhall not regret the facrifice, if it has enabled me more fully to communicate my ideas ; as clearnefs of fentiment, particularly in medicine, is always more to be wifhed for, than elegance of expreffton. And laftly, as there are feme opinions advanced in it, which are not univerfally received, I muft alfo requeft him to fufpend his judgment, until he has firft difengag- ed himfelf from all prejudice ; and calmly weighed the ar- guments, which are adduced in fupport of them. AN INAUGURAL DISSERTATION ON OPIUM. THIS blackifh brown, gummi-refinous fubftance, of a bitter naufeous tafte, and faintifh difagreeable fmell, is the in fpifTated juice of the white poppy, Papaver Sem- niferum of' Linnaus: we generally obtain it from the In* dies in fmall lumps, wrapped up in leaves. For the particular manner of cultivating the poppies and of extracting the opium from them, I muft refer the reader to a letter on that fubject from J.Kerr, furgeon, at Bengal, as communicated in the fifth volume of the medical ob- fervations and enquiries, and to Raynal's hiftory of the Indies, where he will find it fo fully treated of, as to re- quire no further comment here, I mail therefore proceed to enquire into Its moft general effects upon the animal Jyflem at large, and more particularly upon that of the human fpecies. Previoufly to noticing the operation of opium on parti- cular functions, a more general queftion arifes; whether, when exhibited internally, it acts lolely by its application 8 O n O P I U M. to the nerves of the Prima via P or whether fome part is alfo abforbed, and operates by being united with the blood? From the experiments of Dr. A. Monro, * where- by he found, that frogs, under the influence of opium, expired fooner when the heart was left in the body and the circulation free, than they did, when it had been ob- ftructed by removing its ventricle, and tying its vefTels, I am induced to believe, that it may operate in fome degree by being abforbed and united with the blood, not as was formerly fuppofed, by rarifying or any way changing this fluid, (for the fmallnefs of its dofe, and its fudden operation, are fufficient proofs againft fuch an opinion) but rather by its being fufpended therein, it will have an opportu- nity of exerting its influence upon the nerves of the in- ner furface of the heart and blood vefTels; and the fmall- nefs of the dofe can be no objection to this opinion, for it is as eafy to conceive that the one hundredth part of a grain may produce a confiderable operation upon the in- ner furface of the vafcular fyftem, as that a grain fhall produce fuch a general effect by acting only on the ali- mentary canal. Another queftion is, whether opium nets directly un- on the part to which it is applied? or whether it? efledts are entirely owing to its operation upon the brain ? From innumerable experiments it appears, that opium deftrcys motion mod particularly in the part to which it is imme- diately applied, and that it has this effect alfo upon parts cut off from all communication with the brain ; hence we are led to conclude, that it may operate upon the nervous * Phyfical and literary ejfays. On OPIUM. 9 fyftem without the intervention of the brain ; but as opium, applied to the abdominal mufcles of frogs, did not deftroy the motion of the heart nearly fo foon in thofe that had previoufly had their brain and fpinal marrow deftroyed, as it did in others in whom thefe parts were left entire, * we muft alfo conclude, that the more general effects arifing from opium muft be produced moftly from its influence being communicated from the nerves of the part, to which it is applied, to the fenforium commune, and thence re- flected back upon the fyftem at large : I fay moftly in this manner, becaufe in the fame feries of experiments it is proved, that fome general effects may be in- duced without this interpolation of the brain, for not- withftanding the heart was not affected in thofe in which this organ was deftroyed, to fuch a degree as when it re- mained entire, yet its force and frequency were evident- ly diminifhed, as appeared by comparifon with others in a fimilar fituation, that were not under the operation of this medicine* Having eftablifhed thefe fundamental principles, viz. ift, That opium acts primarily and efpecially upon the ner- vous fyftem. 2d, That it exerts its effects moft particu- larly upon the part to which it is immediately applied. 3d, That the general effects whichit exerts upon the fyftem at large depend upon its influence on the brain; but .that 4thly, it may produce fome general effects without its in- tervention, I fhall go on to examine the effects of opium more particularly upon the animal economy. * Phyfical and literary efays.and obfervations, Vol. II. IO On OPIUM. In the ANIMAL FUNCTIONS, the operation of opi- um has always been remarkable for allaying pain, whence its generaltitle of anodyne and paregoricjbut as pain may origi- nate from diiferentc aufes, fo the ufe of opium to relieve it has been attended with different refults : thus in that pain, which arifes from inflammatory diftention as in phrenitis> hepatitis-, pneumonia, &c. though it frequently will give fome temporary eafe, yet, as.it has a tendency, as will be -Ihewn prefently, to encreafe the caufe of the complaint, the pain retunrs with augmented violence j indeed fome- times in thefe cafes, it is faid not even to give temporary eafe, but to enereafe the pain from its firft operation. But in that fpecies of pain which arifes from irrita- tion, as from gravel or a /lone in the bladder, or from the venereal, or from the cancerous virus, &e. it is a fure and never failing palliative. In a third fpecies of pain, that arifing from fpafm, as gajlrodynia, cholic-, &c. Opium is not only an effectual palliative, but frequently an excellent and fovereign remedy. Opium does not relieve pain by its caufing fleep, be- caufe it often has this effect without inducing that ftate, and when it does, the pain generally ceafes firft. In the voluntary mufcles, opium occafions a fluggiflinefs and averfion to motion, and a weaknefs in their action when attempted to be moved. With thefe effects upon the body, opium alfo induces a placid tranquillity of mind, which is often followed by that weakened and depraved ftate of the intellectual powers, in which drunkennefs confifts, deftroying all fenfe of pro- priety, reafon, and prudence, and indeed almoft every On OPIUM. i i djftinguifhing mark of man : hence in the Indies " Thofe -" who are defirous of attempting fome defperate action, " intoxicate themfelves with its fmoke; in this intoxica- "" tion they fall upon the firft object that prefents itfelf, " upon ftrangers as well as upon moil inveterate ene- " mies."* The powers of fenfation, motion, and thought, being thus diminifhed, foon terminate in that ftate which con- ftitutes Jleep: this conftant attendant upon the ufe of o- pium, has been eftablifhed, by the obfervations of phyfici- ans, from the time of Hippocrates to iheprefent day; and it has heen confirmed, by the general confent of piankind, ever true to their obfervations, in giving it the term of foporific, hypnotic, and Jomnijic : Yet there are not wanting thofe who, by fpeculative reafoning and par- tial obfervatiorq, deny its pouelTmg this power, and affert a directly oppofite operation, except with perfons in a ftate of debility : That it induces fleep in a healthy perfon is a fact too firmly fixed to require any proof. I fhall' there- fore only enquire into the foundation of the opinion of thofe, who contend that it fometimes induces wakefulnefs. That infmall quantities it will not always produce fleep, where there are powerful ftimuli applied at the fame time, or where the fyftem is in a very irritable ftate, I allow ; and I believe it is this negative operation (if I may ufe the expreffion,) of opium, which has led many to fuppofe that it produces watchfulnefs, when in fact, this difpofition was caufed, either by the nature of the difeafe or by fome ftimulant applied ; I had an opportunity a few months fince * Raynal's hijlory of the Indies, 12 On OPIUM. of witneffing a cafe directly in point. A convalefcent, from the gr-Tat irritability of her fyftem, having paft one or two reftlefs nights, was induced, on the fucceeding e- vening, to take a dofe of laudanum, and with as little fleep as before ; here immediately the caufe of her watch- fulnefs was affigned to and indeed noted down in proof of the flimulant operation of opium, but unluckily for the idea, the following night was attended with the fame de- gree of watchfulnefs, without its enlivening aid. Had this patient's irritability been fo far overcome by the night fucceeding the one on which fhe took the laudanum, as to have permitted her to enjoy a little fleep, or had the want of it on that night, not been particularly obferved it would be confidered an incontrovcrtable fact, that the pcrfon had hcen kept awake by opium ; but from her previous and fubfequent watchfulnefs, there can be no poffibility of fup- pofmg that fiie would not have kept awake equally well without opium, and the only reafon for its not produe- i•"■.£"*- fleep muft evidently have been owing to the dofe not beipc; lar^e enough to overcome the great irritability of her fyftem. From the experiment of Dr. I. Ramsay upon himfelf,* it aocears that thirty drops of Tinct. Theb. did not make hi;n drowfy immediately upon taking it, but feemed to have a contrary effect, for he felt more enlivened after it; this circumftance he imputes to the operation of the opium, but I rather fuppofe it was owing to a very different caufe ; for he was profecuting his ftudies, became drowfy over them and then determined to take opium • to accomplifh this, required fome exercife, perhaps the neceffity of go- * See L-eigh on opium. On OPIUM. 13 ing into another room, either for laudanum, or liquid, or veffel in which to take it: if fo it requires no ftretch of imagination to conceive his being lefs difpofed to fleep af- ter it, than whilft he continued quietly dofing over his books, for it is by no means uncommon for perfons who cannot refift a continued inclination to fleep, whilft fitting up unmolefted, and at eafe to lofe all difpofition thereto, by the time they have undrefled themfelves to go to bed : but even putting the cafe in the mod unfavourable light poflible, even fuppofing the laudanum and requifites for taking it all ftood at his elbow, ftill it muft be allowed, that the train of ideas which had admitted drowfinefs, was broken in upon by introducing a new fubject to the mind, which, befides its novelty, actually required particu- lar attention, for fays he " I determined to try (and con- " fequently to obferve) the effects of opium." And it is eafily conceivable, how fuch a change of thought and ac- tive employment of the mind, fliould overcome, for a time, a confiderable difpofition to fleep : however in two hours notwithftanding his determination, he found it very difficult to refrain from fleep. He then took from ninety to an hundred drops of the fame tincture, which foon rouf- ed him from his drowfinefs, and not without caufe, for the fhock from the very thought of having taken fuch a quantity of opium, after obferving fuch confiderable ef- fects from a much fmaller dofe, and which had yetbutjuft began to operate, would I conceive have been fully fuffici- cient to refift the influence of a much greater dofe than thirty drops of laudanum; but obferve, in a fliort time, as foon, I fuppofe, as the fecond dofe began to operate, he found himfelf delirious, which was foon fucceeded by inability to walk, vertigo and finally fleep. From thefe 14 On OPIUM. confiderations I am led to believe, that this experiment, can no way fupport the opinion of opium's having any power of keeping a perfon awake; for even fhould we al- low that the doctor had no fear or dread from taking fuch a large dofe; yet his fanguine expectation of fuch an o- peration, (which he feems to have gained from an erro- neous idea of the firft's having drove away fleep) would alone be adequate to the production of fuch an effect. Dr. Kuhn mentioned in his lectures, a man, who after having been bit by a dog, that was wrongfully fuppofed to be mad, actually had all the fymptoms of Hydrophobia fur pervene ; if then expectation will bring on all the dread- ful fymptoms of fuch a difeafe, need we be furprifed that expectation fhould fufpend, for a time, the foporific ope- ration of thirty drops of laudanum ? Opium exerts a particular operation upon the NATU- RAL FUNCTIONS. Inducing, ift, In the ftximach, a weaker action as is evinced by its deftroying appetite ; this has been eftablifhed by many ex- periments, and confirmed by daily obfervation, particu- larly by the circumftance of its being purehafed at exor- bitant prices, by the unhappy fufferers in the famine of 1770, in China, to allay the cravings of hunger.* Here I cannot proceed without obferving, how cautioufly we fhould avoid being captivated w*ith any particular opinion, for we are then not only blinded to its imperfections, but we alfo look upon its veryblemifhes as ornaments; as appears by a perfon's having lately brought this fame fact, to fupport a favourite opinion, in illuftration of opium's encreafmg the appetite.f * Kerr's letter in medical obfervations. \ Dr Handy's inaugural difertation. On OPIUM. 15 2d, In the mtef}inesi a diminution of their periftaltic motion, as appears by its conftantly producing coftivenefs, as well as by experiments on the brute creation, in whom, (by opening their abdomens) after giving them opium, the inteftinal action was not only found to be both flower and weaker than natural, but in a little time entirely to ceafe.* 3d, In the fecretories and excretories of the body, a weaker action appearing in a diminution of all the fe* cretions and excretions, except that of fweat. The VITAL FUNCTIONS likewife fuffer in their action by the operation of opium. The pulfe and refpi- ration become flower and fuller, and the heat of the body is diminifhed. I know that thefe effects are denied by fome, but from an experiment made upon myfelf, where- by I found, that in about twenty-five minutes after tak- ing thirty drops of laudanum, the heat of my body dimi- nifhed 20 by the thermometer, and the frequency of my pulfe, which until that time had fuffered no perceptible change, was leffened four ftrokes in a minute, and con- tinued fo near forty minutes, when fleep terminated my obfervation ; from the fame effect of a diminifhed fre- quency of the pulfe, only in a greater degree, being ob- ferved by Dr. Bard in an experiment upon himfelf,f as well as from the experiments of Dr. Leigh, where, in all the cafes in which opium was adminiftered alone or in an aqueous menftruum, it uniformly produced this effect, e- ven io as to leffen the pulfe fourteen and fifteen firokes :$ from thefe then, and many other obfervations, which * Edinburgh phyfical efays tool. II. i Dr. Bard's inaugural difertation. % Leigh on opium. 16 On OPIUM. might be adduced, if neceffary, I muft conclude, that this power of its diminifhing the frequency of the pulfe and confequently the heat of the body, is a general and con- ftant effect of opium. Should any one fay, as indeed it has already been faid, in oppofition to this opinion, that from feveral of Dr. Leigh's experiments, it appears that the pulfe was accele- rated after the exhibition of opium ; I admit it, and the caufe is very evident, when we confider the menftruum in which it was given, for in every cafe where this acce- leration of the pulfe was produced, the opium had been adminiftered in alkohol, and there is not the leaft doubt, but that this ftimulant effect muft have arifen from that menftruum, fince in all the other cafes, as above obferved, it had a directly oppofite effect. And that it muft have arifen from that caufe I think is alfo incontrovertibly proved byFontana who having likewife obferved the vio- lent effecls following the exhibition of opium in fpirits of wine, refolved to make fome experiments to afcertain the caufe, from which he concludes, that it proceeded from the fpirit, fince, fays he, this fluid, when exhibited alone produced all thefe effects more violently and quickly, than when opium was diffolved in it.* From the operation of opium upon the heart being much lefs evident than upon the voluntary mufcles, Dr.Haller concluded this organ to be entirely free from its influence ; but from the above obfervations and experiments and from the experimentsof Dr. Monro, by which he found * Traite fur le venin de la vipere et fur puelques p0i- fans vegetaux. On OPIUM. *7 after laying bare the hearts of frogs and injecting a few drops of a folution of opium into their veins, that, "as foon " as the folution had entered the ventricle of the heart, that " organ was rendered incapable of expelling its contents, " and in lefs than a minute thereafter became entirely " paralytic," we are forced to differ from that great phy- fiologift, and to conclude, that the heart as well as every other living part is fubjeft to the operation of this medicine. In fhort the general effects of opium are nearly as fol- lows. Soon after being taken, it diminifhes pain, except thatfrom inflammatory diftenfion, it brings on ferenity and pleafantnefs of mind, followed by a ftate of ebriety, and attended with an indolence and averfion to all volun- tary motion, fucceeded by fleep; it leffens the frequency ■■fcut encrenfes the fulnefs of the pulfe, it diminifhes the heat of the body ; it alfo produces coftivenefs and a gene- ral diminution of all the fecretions and excretions, except fweat; it deftroys the appetite, and it alfo induces a ful- nefs in the large blood vefTels. It is obferved of this me- dicine, that it lofes its force by repetition ; hence a perfon habituated to its ufe will frequently find no effect froth a dofe, which would kill a pcrfon unaccuftomed to it. The above obfervations apply moft particularly to the ef- fects of moderate dofes of opium. When taken in large quantities, it is often immediately rejected by vomiting; if not, it foon produces fymptoms of intoxication, confu- fionof the head, falfevifion, and delirium, which are fhortly after fucceeded by profound fleep, with a full and flow pulfe, and great diftention of the large fuperficial veins; at length convulfions* come on, which, if no relief is obtained, foon * Some cafes terminate in death ■without con.vulfions. 18 On OPIUM. terminates in death. By diffection, the heart and large vefTels are found greatly diftended with blood, and there is generally a flight inflammatory appearance difcernible in the ftomach.* Having pointed out the moft general effects of opium, I proceed to deduce therefrom Its Mode of Operation. In entering upon which, I am confcious, that a man of fafhion would not more furprifehis modifli brethren, in ap- pearing without his hat crown reared four or five inches above his head, or without half a dozen buttons ftrung upon each fleeve, than I fhall many of the faculty in not adopting the new and fafhionable opinion, that opium is a direct ftimulant. I cannot agree to its being a ftimulant—ift, Becaufe fuch an opinion will not account for its effects. 2d, Be- caufe all the phenomena confequent upon its exhibition, may be accounted for fatisfactorily upon a different prin- ciple. It will not account for its effects ; for it appears, that by opium we are enabled to afi'uage the racking torture of theflone, to allay the pain of bubo, and even to deaden the force, and render life, fupportable under the darting flings of an inveterate cancer .* How then does it produce * This appearance in the ftomach, is very different from that highly inflamed and gangrenous ftate in -which 'it is found after death from a ft rang ftimulant; as arfenic or Mere. Corros. Sublim. On OPIUM. i9 this effect? How does it alleviate pain ? It is anfwcred, by being a more powerful ftimulus to the fyftem, than either ftone, venereal or cancerous virus, it deprives us of their fenfation, as the fun by its fuperior fplendor drives from our fight the glimmering ftars, or as the fuperior im- prefiion of a blow on the head, deprives us of the trivi- al fenfation from the extraction of a hair at the fame time; but here we meet with an infurmountable difficulty; where are we to find marks of the fuperior ftimulus of opium ? The fun does not hide the ftars without (hewing us his greater luftre, nor does a blow fail of fhewing a fuperior when it frees us from a lefler pain ; nor can any ftimulus whatever, prevent fenfation from a leffer one without fhewing fome evident marks of its fuperior ope- ration ; opium does not fhew fo great ftimulant effects upon the fyftem as ftone, or venereal, or cancerous vi- rus ; therefore it cannot remove their effects by any ftimur lating operation. This with many others of the effects of opium above-mentioned, particularly the experiment of Dr. Monro, where it diminifhed the motion and force of the heart immediately upon coming into contactwith it; as well as from its conftant effect in diminifhing the frequen- cy of the pulfe and heat of the body, and finally from its direct tendency to induce fleep ; all oblige us to deny the poffibility of explaining its operation from any ftimu- lant power. I have faid all the phenomena refulting from the ufe of opium may be accounted for upon a different prin- ciple : I mean a direct fedative power, whereby it leflens the fenfibility and irritability of the fyftem, and con- fequently the motion, and the powers of motion ,o On OPIUM. in it • or in other words, that it has a direft operation upon and immediately diminifhes the mobility of the ner- vous power. And in the firft place, of its power of di- minifliing pain ; this effect, as before proved, it could not prod nee by any ftimulant operation ; but upon this prin- ciple, it is eafily accounted for ; it does it in the fame man- ner as an intervening cloud deprives us of the fight of the ftars, viz. by diminifning the power of the medium of communication ; by diminifliing the mobility of the ner- vous'power, rendering it unfit for transmitting the fen- fation of ftimuli. It was obferved above, that pains ari- fing from inflammatory diftention, oftentimes are not re- lieved by opium, and when they are, it is but tem- porarily', and they afterwards are augmented ; this is no more than what we would expect, for from its en- creafing the fulnefs of the vefTels, by diminifliing the ex- cretions, and alfo, as will be fhewn hereafter, from its en- creafing the quantity of fluids in the deeper-feated vefTels, by diminifliing more particularly the action of thofe on the furface, notwithftanding it may, by diminifliing the fenfi- bility of the fyftem, in fome degree allay the pain, yet as it tends to increafe the caufe, we need not be furprif- ed if inftead of relieving, it fliould even encreafe the pain. Opium has been extolled for inducing a ferenity and cheerfulnefs of mind, in thofe who have taken it even to fuch a degree fometimes, as to make them exprefs that ' On OPIUM. the warm bath by the ancient Romans, and alfo by many of the eaftern nations at this day, as a great fource of plea- fure, produces this effect, in a fome what fimilar manner to opium, viz. by its relaxing and enervating power, and the fame delicate pleafure, that follows the ufe of opium, Dr. Rush in his lectures mentions, often alfo arifes from blood-letting, and it is by nearly the fame means, viz. by debilitating the fyftem. ■£•„.;. This pleafant fituation is not permitted to be long en- joyed, for opium ftill continuing its deadly influence, goes on encreafing weaknefs in the mental powers, bringing on an irregular train of unconnected thoughts, as is evinced by a Hammering and almoft inarticulate fpeech. This is the ftate which the Eaft-Indians bring on when they " are defirous of committing fome defperate action," for the moral faculty ceafes to reftrain them, and all their fenfe of confcience is extinct, the powers of memory alfo fail them, they cannot recollect the object of their ven- geance, for they fall upon the firft that prefents itfelf whe- ther ftrangers or enemies. It is this ftate of mind in which the Turksare faid to fhew their greateft courage, and I do not doubt but that in this foolifh fituation, they may be led up to the muzzle of a cannon, like an ox to the {laugh- ter ; ignorant of the confequences, they run on and are punifhed, whilft in their fober moments, like wifer men they would have forefeen the danger and avoided it. During this effect upon the mind it alfo gradually dimi- nifhes the powers of the body ; the weakened mufcles firft become indolent and fluggifh in their motion, until at length, if a perfon attempts to walk, he finds them una- ble to fupport his tottering body j thefe, accompanied with On OPIUM. 23 imperfect fenfibility, are followed by ftupor and terminat- ed by fleep. Here then we find that opium in the ANI- MAL FUNCTIONS, gradually and regularly leffens their ■ftrength, until finally it forces them down into the quiet bonds of fleep. This fedative operation is particularly obferved in the ftomach and inteftines, diminifliing their actions and produc- ing want of appetite and coftivenefs: it alfo diminifhes the operation of the fecretory and excretory veffds, by ren- dering them infenfible to the ufual ftimulus of their con- tained fluids. The effects of opium upon the VITAL FUNCTIONS are very clearly elucidated upon our idea of its action. In the former part of this differtation it appeared, that not- withftanding opium produced fome particular operation on the part to which it was immediately applied, yet that its general effects moftly proceeded from its influence upon the brain : we conclude then, that when taken into the ftomach, it particularly leffens its tone, and alfo diminifh- es the energy of the fenforium commune, which muft be felt without doubt moft efpecially in the parts moft dif- tantfrom its feat; whence, as well as from their fympathy with the ftomach, the vefTels of the fuperficies muft be moft particularly weakened in their action, which muft of courfe •rive rife to an accumulation in the larger vefTels; hence the large veins appear diftended; from this accumulation of blood in the larger veffels, an increafe of its natural ftimulus is applied to the heart, from whence in conjunc- tion with the vis infita which this organ poffeffes in a great degree, we caneafily account for its not being fo evidently affected by opium, as the voluntary mufcles are ; yet by 24 On OPIUM. the diminifhed frequency of the pulfe, we find that the mo- tion of the heart is leffened : its irritability being diminifh- ed, it fuffers a greater dilatation from the accumulated blood, before it contracts; this, with the relaxation of the arteries, gives rife to the great fulnefs of the pulfe. The flower circulation fufficiently accounts for the diminifhed heat of the body.* That the motions of the extreme vefTels are more par- ticularly affected, and that a preternatural accumulation takes place in the larger ones, are not mere conclufions from fpeculative reafoning, but facts eftablifhed by actual obfervation ; for Dr. Monro, by the afliftance of his mi- crofcope, found the action of the extreme vefTels in frogs, under the operation of opium, entirely to ceafe, while that of the heart ftill continued; and Dr. Whytt| fays, by opening a frog, that had taken opium, he found the heart ., and large vefTels leading to it unuTually filled with blood. From an encreafed quantity of fluids in the fyftem, by an obftruction of the other evacuations, and from the a- bove mentioned caufes fupporting the force of action in theheartand large vefTels, with a lofs of the refifting pow- er in thofe of the furface, the fweating, induced by this medicine is eafily and fatisfactorily explained, Convulfions often follow from a large dofe of opium • they alfo follow profufe haemorrhages ; here then we fee fame effects induced by the abftraction of a ftimulus as * This diminution of the heat of the body may alfo be wing in fome degree to the evaporation of perfpiration in- duced by opium, f Effay on the vital and involuntary mo- tions. On OPIUM. 25 by diminifliing its force, by rendering the fyftem infenfille to its application. By diffedtion after death, the ftomach appears flightly inflamed; the convullive preffure of the mufcles, as alfo the before mentioned caufes, force the blood internally, whereby the vefTels of this organ, which are particular- ly relaxed by the immediate contact of the medicine, are efpecially diftended, and give rife to this appearance. The effects of opium being diminifhed by continued ufe, perfectly correfpond with an eftabliflied law of the animal ceconomy, whereby " all impreflions which do not excite " to action lofe their force by repetition." Should it be allied, fince there are fo many facts, direct- ly in proof of the fedative operation of opium, and fince all its effects are fo clearly and rationally accounted for up- on fuch a principle; what has given rife to, 'and what has fupportcd the doctrine of its being a direct ftimulus? I anfwer that it originated chiefly with a perfon, who has endeavoured to make himfelf eminent in medicine, by boldly hazarding fome new opinions, in oppofition to an- cient and well eftabliflied truths.* Novelty, which is fo powerful in influencing the hu- man mind, even, as Dr. HuxhaM obferves, to have held A'fclepiades out in his abfurd and cruel practice of denying drink to perfons in a fever, gained alfo fuppcrters to this doctrine. Let us examine the arguments advanced in favour of the * Dr. Brown. Note— Though opium may have been looked upon as pofeffng fome ftimulant operation, by perfons previously to Dr. Brown, yet he was the firft who aferted, that it was a fivi- ple direcj and moft powerful ftimulus, and anti foporific. 2,6 On O P I U M. ftimulant operation of opium. Such an operation has been inferred from its analogy with fpirituous liquors; thus fay they, do fpirits produce a pleafant difpofi- tion of mind ? do they make the diftreffed " forget his po- " verty and remember his niifery no more?" do they " overthrow the minds and underftandings of all that will " be trying mafteries with it?" do they make men forget their friends and familiar acquaintances, and finally to draw their fwords upon their neareft relations ? they furely do, and fo in fome degree does opium. This may be, and yet it is no proof of any ftimulant operation in opium. Should any one alk whether I deny fpirits being poffeffed of a ftimulant power? I anfwer, no, but that they alfo exert a powerful fedative operation particularly on the mental faculties, every one of the above effects clearly proves ; and hence the wifeftof men Solomon, fays, " It is not for kings to drink wine nor princes ftrong drink, " left they drink and forget the law and pervert the judg- " ment of any of the afflicted."* It was from their weaken- ing the mind, and expofing every flaw and imperfection in it, that the poet obferved, Wife were the kings, who never chofe a friend, Till with full cups they had unmafk'd his foul, And feen the bottom of his deepeft thoughts. Horace. I have faid I do not deny that fpirituous liquors are ftirnulants, and fhould it be alked, whether opium like them, increafes the appetite, produces ftrength of body, watchfulnefs, an increafed force and frequency of the pulfe with quick breathing, and raifes the temperature of the body ? I anfwer, no ; and I truft the foregoing obferva- tions have fully proved it to have a directly oppofite effect. * Prov. chap . xxxi. 5. 6. On OPIUM. 27 The above firft mentioned analogy of the operation of opium with fpirits, (at the fame time confidering every effect of the latter as arifing from a ftimulant power) af- fifted by partial obfervation where the nature of difeafe ki producing watchfulnefs has been affigned to its operation, as alfo byrefults of experiments, where it has been charg- ed of producing effects, that have been clearly proved, to have arifen from the ftimulating menftruum in which it was exhibited, is the only flender bafis upon which the doctrine of the ftimulaut operation of opium is fupport- ed, and which I truft muft give way to the fuperior evi- dence of a contrary opinion, as foon as time fhall have worn off its dazzling tinfel of novelty, fo as to permit the cool eye of reafon to inveftigate its inherent quality. I do not think, with the eminent Dr. Cullen, (whofe name I mention with refpect, and from whofe opinion I vary with diffidence) that any of the effects of opium even require us to call in the aid of the vis medicatrix naturce, for their explanation ; and fince " wherever it is admitted, " it throws an obfcurity upon our fyftem,"* and alfo as " no more caufes of phenomena are to be admitted than " are fufficient to explain them,"-f and as I think all the phenomena from the ufe of this medicine have been fa- tisfactorily explained upon its fimple fedative operation ; I have therefore entirely rejected that facultas incognita from this differtation. The Ufes of Opium. The limited nature of my differtation, will particular- ly affect this part of my fubject ; for to do juftice to it * See Culleus firft lines, vol. I. page 25. -j- Sir Jfaac Newton's maxim. 28 On OPIUM. alone would require more pages than this treatife would confift of; having however enumerated its general effects, and thence deduced its nndus operandi, I fhall proceed to give, what I conceive, a rational explication of its ufe ;n medicine. In the firft place, From its power of diminifl:ing the fen- fibility of the fyftem to ftimuli, it is ufefully employed in allaying the pains from the venereal difeafe, cancers, ftone in the bladder, when extraction may be improper, and alfo to foothe the pungent pain following chirurgical operations, attending compound fraclures, &c. &c. alfo ner- vals head' aches, &c. From its power of dimin'iftnng the irritability of the muf- cular fores, it has been attended with the happieft effects in allaying any preternatural action in them ; thus in the hearth relieves palpitation, if it is not fymptomatic of a dif- eafe that may forbid its ufe ; in the lungs it cures afthma when it is purely fpafmodic, and is of ufe in the chin-cm^h, after the febrile fymptoms are gone off. In the ftomach it is the beft remedy for pyrofts and gaf- trodynia, and for vomiting, when this does not proceed from any matter proper to be evacuated, or when it is not accompanied by any affection which may be augmented by its ufe. In this organ as well as In the inteftines, it relieves cholera morbus, is a power- ful afliftant in the chlic, in the dyftntery it alfo allays the pain and troubleiome tenefmus, takes off the conftriction of the colon and thus paves the way for the more fure operation of gentle purgatives, as a radical cure. The atio'n of the inteftines in ftmple diarrhoea feems to be con- linued, by the increafed irritability to their contents,from pn abrafion of their natural raucous covering from the On OPIUM. 29 original caufe of the difeafe, and poflibly alfo in fome de- gree by habit; here then we would at once conclude opir urn to be, as in fact it has proved, a very valuable remedy, for by its firft diminifliing the irritability of the bowels, it allays for a time their encreafed action, thereby coun- teracting the powers of habit, during which time, it alfo by its peculiar operation of thickening excreted fluids, as is particularly evinced in catarrh, it furnifiies them with their proper defenfive coat; thereby proving not only a palliative, but often a radical cure. In the uterus, it quiets the efforts threatening abortions, after the plethora has been removed by bleeding, alfo falfe pains and ftpafms during labour; it is a fovereign remedy in pains following delivery called after pains, it relieves the pains that fometimes attend menftruation; it has alfo prov- ed of great ufe in taking off the increafed action of the uterine veffels, which arifes from great irritation, and thus checking the immoderate flow of the catamenia. Opium, by its relaxing power, is very ufeful in favour- ing the expulfion of calculi from the ureters and urethra, and concretions from the biliary ducts, alfoin taking off the conftriction andpermitting the return of incarcerated hernia. In the voluntary mufcles, opium has been ufed in tetanus, and from its antifpafmodic power, it may prove a pallia- tive ; yet, as the celebrated Dr. Rush* has proved, that this difeafe originates in debility, we fhould not expect it to give any permanent relief, therefore it fliould be accom- panied with proper ftimulants and tonics. As epilepfy is fo often owing to a turgefcence of the veffels of the head, and as opium greatly favours this, not only by its general operation of accumulating the blood in the larger and in- ternal veffels, but alfo by its particularly filling thofe of the * Rujh's medical enquiries and obfervations. 3° On OPIUM. head, by obftructing the refluent blood by a flow refpira- tion, it muft of courfe frequently be injurious; but when the Jiieafe arifes from a particular irritation, as from an aura epileptic*, great pain, or from paflions of the mind, it hns proved a valuable remedy, and when given a little before an expected acceflion, it has frequently put off the fit.f In convulfions not attended with coma as particu- larly the chorea fanctiviti, it has generally been found of great fervice. To its procuring fleep, it owes many of its virtues in cer. tain difeafes, but in none more particularly than in typhus fevtr, where a conftant watchfulnefs feems to be hurrying away the fleeting powers of life : opium checks this fatal career by bringing a refrefhir.g fleep, the want of which wears down the ftrength fafter than almoft any other cir- cumftance whatever ; it may therefore frequently be ad- vantageoufly combined with other medicines in this difeafe. From its cncreaf.ng the fulntfs of the Vafcular fyftem, opium muft be injurious in all difeafes accompanied with an inflammatory diathefis, for this is fupported by, (and every indication of cure is to remove) the too great quantity of fluids already in the vefTels. But as with this operation, it alfo often procures a free perforation, by overcoming the refilling power of the cutaneous veffels, it has even been propofed in inflammatory fevers, and where this effect can be rendered certain, by the union of emetics and neu- tral falts, it has frequently been found a valuable remedy particularly for the cure of the acute rheumatifm. From this power of overcoming the refiftance in the extreme vefTels, it proves fo effectual in taking off the burning heat and fhortening the hot fit of intermittents .\ From its effecl in allaying the operation of the fecretory f Tifot traite de /' epilepftt. % Lind on hot dimatss. On OPIUM. 51 and excretory veffels, it is ufefully employed to check a fa- livation from mercury, and it very probably, from this power of diminifliing the irritability of the excretories at large, may expedite the cure of the venereal diferfs by mercury, by allowing the fyftem to retain more in it at a time, than it otherwife would. By this operation it alfo renders excreted fluids of a much thicker confiftence ; hence, as obferved before, it is of ufe in catarrh and diarrhoea; and it is from this caufe, that it changes the ichorous dif. eharge of irritable ulcers to a well concocted pus, and hence its great ufe, as obferved by Sydenham in the fuppura- tive ftage of the fmall pox. Notwithftanding my having arranged the difeafes in vvhfch opium is employed, as being relieved by fome one of its effects, yet I do not thereby mean to affert that its ufefulnefs in them folely depends upon fuch a particular part of its operation, for every one the leaft convcrfant in medicine muft conceive, that a diarrhceu and catarrh, befide the particular effects, under which they are men- tioned, may alfo in part owe their cure to opium's deter- mining to the furface ; a cholera morbus, to its diminifh- ing the fecretion of bile; a typhus to its relaxing the fpafm of the extreme veffels, &c. &c. all I had in \iew, was to fhew on what particular quality of opium the cure of certain difeafes chiefly depends. There are many other difeafes in which opium may be employed , but having fhewn from what particular effects we are to expect advantage in fome, and alfo from what effects we are to fear its ufe in other important complaints, I flatter myfelf the ingenious reader will not be at a lofsto decide upon the propriety of its ufe in difeafes in general. This medicine may be employed either internally or ex- ternally : internally either by the mouth, in dofes from one 52 On OPIUM. grain toa much larger quantity, the dofe is however to be governed chiefly by the force of the irritation, which it is to allay, for in great pain, as from chirurgical operations, as well as from violent fpafms, as in tetanus and from in- carcerated hernia;, Sec. patients will bear and often require fuch dofes of opium, as would have deftroyed per- fons in health. Or in the reclum : in this way it is proper, where a continued vomiting prevents its retention in the ftomach, as alfo in tenefmus, and more particularly in the dy- fentery, where by being more directly applied to the part, it will allay the encreafed action of this inteftine and take off the conftriction of the colon, without fo materially prevent- ing the operation of purgatives, as if exhibited by the mouth. When opium is given in this manner it muft be in double the quantity that would have^ been neceffary if taken into the ftcmach. It has been externally applied to the abdomen to relieve fpafms of the ftomach and inteftines : to the mouth to check falivations :* to the cheek to relieve tooth ache, &c. &c. . When a perfon has taken too large a dofe of opium, \*e famild endeavour to procure its evacuation as foon as poffible by exhibiting a quick emetic as twenty or thirty grai^of vit. alb. and tickling the fauces with an oiled feather ; we fliould ufe all means in our power to keep Him awake. Blifters and finapifms fliould be applied ; and vinegar has been recommended to be exhibited internally but from fome experiments by Leigh its utility is rather doubtful ; I fhould put more dependance on the ftimulus of vol. alk. Since fevere pain has been obferved greatly to refift its operation, may it not be induced with advantage to pre- vent its deleterious effects in this cafe > * Hunter on venereal difeafe. Med. Hist. VIZ. XI0 c I FW* % % ■■/*} -^Srffl k.-*a* 1^ •fBJfl fee >|