K-i

> \V^

GEORGE ' BURGESS ^ MAGRATH

LIBRARY

OF' LEGALr MEDICINE

FOUNDED -IN HIS -HONOR

1933

i^m ^mmt^'^JSL^!^^!^^t.^EiS-mitmjM:,

<^ Harvard Medical Library in the Francis A. Countway Library of Medicine -Boston

VERITATEM PER MEDICI/JAM CILJ>ERAA1US

tH.3

3?^

s

Digitized by the Internet Archive

in 2011 with funding from

Open Knovyledge Commons and Harvard IVIedical Schooj

http://www.archive.org/details/treatiseonvenomo02font

TRE ATISE

ON THE

VENOM OF THE VIPER;

O N T H E

AMERICAN POISONS;

AND ON THE

CHERRY LAUREL,

ANDSOMEOTHER

VEGETABLE POISONS.

TO WHICH ARE ANNEXED,

OBSERVATIONS ON THE PRIMITIVE STRUCTURE OF THE ANIMAL BODY J DIFFiRENT EXPERIMENTS ON THE REPRODUCTION OF THE NERVES ; AND A DE- SCRIPTION OF A NEW CANAL OF THE EYE.

WITH TEN DESCRIPTIVE PLATES.

TRANSLATED FROM THE ORIGINAL FRENCH OF

FELIX FONTANA,

NATURALIST TO HIS ROYAL HIGHNESS THE GRAND DUKE OF TUSCANY, AND DIRECTOR OF HIS CABINET 6f NATURAL HISTORY,

BY JOSEPH SKINNER,

NAVY SURGEON, AND MEMBER OF THE CORPORATION OF SUROE0I»8 OF LONDON.

THE SECOND EDITION,

VOL. IL

LONDON:

PRINTED FOR JOHN CUTHELL, NO. 4, MIDDLE ROW, HOLBORN. M.DCC.XCV.

HARVARD MEDICAL SCHOOL LIBRARY OF LEGAL MEDICINE

CONTENTS

OF THE

SECOND VOLUME.

PART THE FOURTH,

C^HAP. I. — Examination of the remedies employed

againft the bite of the viper - - i

CHAP. II. — If the bite of the viper is naturally mortal to man - - - 34

— — — ' ^ — -'Treatife on the American poifon^

called lUcunas - - - ^^

' ■ —Firf "Tra^ on the Cherry -laurel 143

_ <»._ — Second Tra£i on the Cherry -laurel 156

" Experiments on fever al vegetable

fubftances - - - 1 8 f —Conftderations on the nerves in dif-

eafes - - - 186

— ' — Experiments made at London in

177^3 ^-'^d 1779, on the reprodu5fion of the iisrves ~ - , ^ 203

CHAP.

( ii )

CHAP. II. — Ohjervations on the primitive Jlruc- ture of the animal body - - 2 K

— — ' on the ftru5fure of the

nerves - - - ihid

— on the firii5iure of the

brain - - - 241

on the firucliire of the

tendons - - - ' 256

'Reflections on the motions of the

mufcles - - - 277

'Microfcopcal erroursy and confe-

quences deduced from microfcopcal obfervations on feverai. excrementitious, and other parts of the body I on animal, miner al, and vegetable f ub- Jlancesiandonfofjils^metalsy^c, - 284

'Letter to Mr, Adolphus Murray^

Profeffor of Anatomy at Upfaly in the year 177S, on thefubje5f of the difcovery of a new canal of the eye - - , - - . jio

SUPPLEMENT • - 3,5.

INDEX.

EXPLANATION of the PLATES,

ERRATA.

Page 17, line 20, for he, read //.

* 98, — II, for banks of the Amazom^ read la7iks of the

rhuer of the Amazons. ' 201, 3> for Sir Robert Pr ingle, read Sir John

Pringle.

r-. 294, 24 and 25, for lamina, read lamina.

'-' 312, — '— " 26, for ^vhich is ivrapped in its fukjiance, read

in the fuhjia7ice of <v:hiih it is infolded.

PHILOSOPHICAL RESEARCHES

INTO THE

VENOM OF THE VIEER.

PART IV.

CHAP. L

Examination of the Remedies employed agdinjl the bite of the Fiper,

After having examined the quality of the viper's venom, and being much better acquainted than hitherto with the nature of this poifon, it ap- peared to be no longer difficult to find a remedy for iti This is the ufual way of reafoning, and is the fouree of numberlefs remedies, which fuc- ceed each other, and are at length found by expe- rience to be hurtful, or ufelefs at leafl. The fluid volatile alkali owes its greatefl repute to the re-

B ceived

2 !• O I^T T A N A

ceived opinion that the nature of the viper^s ve-- nom was difcovered. Juilieu, from the authority of Mead;, deemed it an acid, and this was fufficient %a give the volatile alkali the reputation of being a true antidote againft it*

The authors Vv^ho fucceeded Juffieu copied from each other.- They adopted the remedy, and m mode of adion, and they found it a good one, be- caufe the bite of the viper is not always fatal in its confequences. For my part, I am of opinion, that even when the nature of a polfcn is well known, and the effedis it produces on animals,^ we may very ealily be at a lofs for its remedy, J^othing is lefs difficult to conceive than this, if tve reiled: how very ignorant we ftill are as to the animal machine, and how much we are in the dark and in uncertainty, as to the qualities, or the virtues of bodies.

Be that as it may, it is clear that the authority of certain writers has- brought into fafhion a greater number of remedies, than has been intro^ duced by the fallacious experiments of others, of the fcarcity and price of the remedies themfelves,- The bezoar, for inflance,, the unicorn, and rhino- ceros, are of the latter difcription. Were we to examine by the rigid touchflone of experiment, the long lift of remedies, to how few would they not be reduced? It is on this account that the beft colleftiqn of receipes is invariably the fhortefl. V/e have already feen above, in what eflimatio» the fluid volatile alkali, regarded as a fpecifick,. 5 fliould

ON I^OISONS. 3

fliould be held. All my experiments iliow it to be totally ufelefs, even when taken inwardly. It does hot appear that it can have the fmallefl effed: when applied to the part bitten. It is almoll needlefs to obferve^ that the volatile alkali^ whether given internally, or applied to the part, can in no way ferve to corredl the acidity of the venom, lince the venom is certainly nor, acid ; whence it is that thefe boafted qualities of an alkalefcent principle, this neutralization of falts, are mere fancies and errours produced by ill experiments. I believe beiides, that even though the venom of the viper fhould be acid, and deilrudlive to animals as an acid principle, we ought to expeft little or no- thing from the volatile alkali applied externally. To the end that the volatile alkali fhould faturate the acid of the venom, it would be necelTary that it Ihould find its way into the part bitten, and Ihould there mix and unite itfelf vv^ith it. It appears to me, that in general, the volatile alkali does not reach the mufcles through the ikin, at the place where the poifon has penetrated. 'Tis at leafl what I obferved in thofe animals that have a compad: ikin, like that of the human bod v.

Experiments on the effects of the Volatile Alkali upon the bite of the Viper.

I cut a piece of the fkin under the belly of a guineapig, the incifion being in the Ihape of

B z a pareK

^ FONTANA

a parelklogram, three fides of which were fepa^ rated from the anunal, the fourth Hill hanging to it. I pierced the cut fkin with the dried teeth of a viper, which penetrated it through and through. Under the hairy fide of this ikin^ thus prepared, I held a bottle filled with volatile alkali, and having a mouth of four lines diameter, but could never per- ceive that any fmell was communicated to the in- fide of the fkin, how long foever I kept it over the bottle, and however great the llrength of the vo- latile alkali, which was adive to a degree.

I repeated this experiment on rabbits, that have a fkin flill thinner. The event was the fame : no fmell could be perceived through the Ikin.

1 moifiened the inner part of the fkin of a guinea- pig, which I had previoully pierced with the dried teeth of a viper, as before,, with a little diluted nitrous acid. Whatever quantity of the volatile alkali I threw upon the outer part of the fkin, the nitrous acid never appeared to be faturated, or in the fmalleft degree weakened. At another time I moifiened the fkin of another guineapig, prepared as above, with a difTolution of copper in well di- luted nitrous acid, and kept the outer part of the Ikin wet with the fluid volatile alkali : the difTo- lution of copper did not change its colour ta blue.

It is then certain, that in general the volatile alkali does not penetrate through the compadt fkin of a quadruped ; the reafon of , which is, that the tooth of a viper being very fmall, does no more

than;

ON POISONS, 5

than difplace the parts a little, and in proportion as it is withdrawn, the ikin, by its elailicity, reco- vers its former lituation, and clofes the hole. It on this account frequently happens, that the bite of a viper does not caufe the animal to bleed. If a confiderable veiTel has been pundlured by the toothy the blood iifues out, coagulates, and prevents the entry of other fubflances.

The human Ikin is thicker than that of rabbits and guineapigs ; it is of a very clofe contexture, and very elailick. If the fluid volatile alkali were a true fpecifick, whenever it could unite itfelf with the viper^s venom, it would be inefficacious againfl tlie bite of a viper in man, or could at befl ferve only for bites in the ikin altogether fuperficial^ which are never to be dreaded in any quadruped^ however fmall, and much lefs in luan.

But if the volatile alkali is ufelefs when applied externally to the part, from the difficulty it finds to mix with the poifon ; why may it not be ufe- ful, if we contrive to introduce it into the parts bitten ? greater or fmaller incilions may be made in animals, and the volatile alkali conveyed by this means to the wounded mufcles. Will it in tliis cafe be a fpecifick ? Will it at leaft be ufeful ?

To fully elucidate this I made the following ex- periments.

I had feveral animals, fuch as hens, rabbits, iguineapigs, &c, bit in the leg, and fome minutes after made deep and extenfive incifions into the wounded parts, I walhed thefe incilions with pure

B 3 volatile

6 FONT ANA

volatile alkali, and covered the legs with linen bandages. I got ready an equal number of ani- mals of the fame fize, and of the fame kinds, to ferve as a comparifon. Thefe were likewife bit in the leg, but I neither made incifions, nor applied to them the volatile alkali. The refult of twenty- four experiments was not favourable to this me- dicine applied to the incilions, and the violence of the difeafe was even more conliderable in the for- mer than in the latter.

I cannot herepafs over an experiment which w^as fuggefted to me by the Due de Chaulnes, and which I made a little time after, with his affiftance, on a pigeon, in the prefence of a celebrated phyii- cian and chymift, Moniieur Darcet, I mixed to- gether equal proportions of venom and volatile alkali, and introduced a part of this mixture into the pe(5toral mufcles. The pigeon died at the end of eleven minutes. As I had fome fufpicion that in the operation, I had penetrated into the cavity of the thorax, I thought proper to repeat the ex- periment on other animals. Bciides this, I varied the quantities of the venom, and of the volatile al- kali, and likewife made ufe of fiuid volatile alka- lies, prepared without lime. Of fix pigeons who were poifoned in the breaft, and fix others in the leg, not one recovered, and all died in a very ihort fpace.

I put into a fmall glafs, three drops of viper's venom, and twelve drops of fluid volatile alkali. After having mixed thefe two fluids together, I

put

ON POISON e. 7

;put half a drop of them on the divided fibres of one of the mufcles of a pigeon. It died at the end of thirty hours, with the fymptoms of poifon, but in a moderate degree.

I repeated this experiment on another pigeon, the mufcles .of which I had laid bare, and wounded in ieveiaKplaces.. into thefe mufcles I introducecj a fmail piece of wood well covered with the venom taken from the glafs. The pigeon furvived, al- though the fymptoms of poifon difcovered them^ felves.

I repeated this fecojid experiment on another pigeon, and introduced as'above, the piece of wood covered with the venom. The animal lived, and had fcarce any aliment.

I made a frefli experiment with the piece of wood dipped in the venom, and in lefs than an hour :the pigeon died.

The little uniformity in the refult of thefe ex- periments m.ade me fufpedl, that the poifon had .not well communicated itfelf to the mufcles, and that the ufe of the piece of wood was not the beft way to communicate the .difeafe. Some fucceed- ing experiments confirmed me in this fufpicion.

I formed then the idea of introducing into the mufcles of pigeons, the Vrcnom from the fmall glafs, by means of a thread repeatedly doubled; I palTed the threads well rubbed over with this poifonous mixture, through the mufcles, and left^' them there,. Six pigeons who underwent this ex-

B4 periment,

8 FONTANA

periment, all died in the fpace of thirty-feven mi- nutes.

It is, however, poffible, that the fluid volatile alkali contrads the velTels in fuch a way, that the venom cannot be eafily abforbed ; but be that as it will, we fee clearly that when it is well applied, it is mortal as before, and that the volatile alkali does not diminilh its adivity.

Thefe experiments not only demonllrate the ab- folute inutility of the volatile alkali againfl the bite of the viper, when applied externally ; but they at the fame time prove ilill further, that it cannot have a diredl and fpecifick operation, when it is even taken internally. If the venom of the viper pre- ferves all its malignant qualities when in immediate union with the volatile alkali, how can it ever be deprived of them, by meeting with it, when it is; itfelf united in the animal, with an immenfe quantity of fluids, and difperfed in fo many parts ?

Experiments on the tnefficacy of different SuhJIances againjl the bite of the Viper.

The fame experiments may ferve equally to ex- clude from the number of fpecificks, the many bo.iled remedies againit the venom of the viper. I united a great number of fubftances with this poifon, but did not obferve after all, that it loft its hurtful qualities, I mi^^ed it with acids, with al-

kaliesj.

ON POISONS. 9

kalies, with neutral falts, with oils; but it con- tinued to deftroy the animals, whenever it had found its way into their wounds.

I likewife made direft experiments on thefe fub^ ftances, to be more certain of their inutilit)^ I Ihall not here enter into a detail of thefe experi- ments, becaufe it would be too long, and becaufe I think it of little confequencc ; it will be fuffi- cient for me to fay in a general way, that I ap- plied them to the parts bitten by the viper ; even making incifions, to give the venom a freer com- munication. In thefe experiments I tried oil of vitriol, the nitrous acid, the phofphorick acid, and the mineral acid, (Tacide fpathique^) and I found them all to be at leaft ufelefs. Alkaline falts, cauilick and not cauftick, whether mineral, vegetable, or animal, had the fame effed:. I was ilill more attentive to the neutral falts, and above all to fea fait, which feveral efleem a good remedy, but which I alfo found ufelefs. As to oils in general, and efpecially that of turpentine, they ap- peared to me to be of fome real ufe. The bell: mode of application is, to foment for a long time the part of the animal that has been bitten, in the oil made extremely warm. Some guineapigs that according to the probabilities that refulted from my experiments on thefe animals, would have died, were perfed:ly cured by it. It is very true that they had been hit by a lingle Viper, and only once, and that two of the feet bitten, had loll the

ikin.

lO F O N T A N A

{kin, and were in part crippled, which was pro- bably occalioned by the too great heat of the oiL

I made repeated experiments by dipping the part that had been bit in various fluids. The plung- ing it into very Vv^arm water, and keeping it there, appeared to mc to be truly advantageous. The pain was evidently leiTened, the inflammation abated, and the colour lefs livid arid changed. I found the fame eifed-s from lim.e water, and from water mixed with comm^on fait, and, other faline fubftances* Although the immerfion is neither a fpecifick,nor a certain remedy, it is always attended with a greater or lelTer degree of advantage, \yhich I 'think is in thefe cafes due to the mere fomentation with warm Vv^ater.

i obferved in the courfe of my experiments, that -dogs and cats recovered with a facility propor^ tioned to the violence of their vomitings ; and wiihing to follow this indication of nature, I made a great number of experiments on dogs. Here I was very often led to believe the emetick a good remedy, as I fometim.es met with feven or 4£ight cafes which terminated in the facne way, and were altogether favourable. The emetick I made ufc of was the ftibiated tartar, which I gave ii^ water, in different dofes, and at different periods. The refult of fome of thefe experiments contra- .didcd that of others, but feveral 8f them were very favourable and uniform. Am.ongil a g^eaf number of other trials, I had a dozen dogs bit }j^ the leg, each by three vipers, and by each repeat- edly^

ON POISONS. 11

edly. To fix of them I gave emetick tartar, to the others nothing. All of the firfi recovered ; four of the others died in lefs than three days. I cannot therefore take upon me to determine the tartar emetick entirely ufelefs, but it is certainly no fpe- cifick, no affured remedy.

I wiflied to try cantharides^ not becaufe I was Urongly induced to believe them good againft the bite of the viper, but only becaufe I wiilied to fee how an adiive fubftance, and that too in fome de- gree poifonous, would ad: on an animal attacked with the fymptoms of poifon.

I applied the cantharides to the bitten part, and likewife caufed them to be taken internally. I foon perceived that, applied to the part, they were evi- dently injurious, and that there was a fpeedy dif- pofition to gangrene and fphacelus. To introduce them ilill better, I made inciiions.

Thofe taken internally furnifned me, like the emetick, with equivocal conclufions, in proportion to the uncertainty of which ^ I multiplied my ex- periments, and was at length affured that the can- tharides, are neither a fpecifick, nor an efficacious remedy, although, I can neither declare them hurt- ful nor ufelefs,

I conceived greater hopes from the bark, which is avowedly a powerful antifeptick, and very ufe- ful in cafes of gangrene. For the fhort time the complaint lafts, the viper's poifon produces a true local gangrene, and the bark was therefore promif- ing, I began my experiments with the iimple pow- der.

12 MONTANA

der, which I threw on the part bitten, into which I had made feveral inciiions. Not perceiving that it had a certain good effed, I had recourfe to the bark in infufion, I bathed the wounded part of the animal lengthways, fom.etimes keeping it for along fpace entirely plunged in the warm infufion. At other times, I plunged it repeatedly in, but it was all in vain : I could never affure myfelf that it had a real and conHiant advantage, although I cannot condemn it as entirely ufelefs.

It was neceffary to make an incredible number of experiments, before I could determine the little certainty of emeticks, cantharides, and bark, op- pofed to the bite of the viper : thefe experiments are beiides extremely inconvenient, as one operates principally upon dogs, and they are for the^mofl part of very long duration. A dog when he fur- vives, frequently remains iick ten, fifteen, or even twenty days.

I wifhed to try befides. if fcarifi cat ions more or iefs deep, and the^ai!^ual cautery, were certain re- medies. The conclulions I obtained, which were very numerous, were not favourable to thefe two methods, which are however propofed by authors with great confidence. It appeared to me on the contrary that the fcarifications, very far from being ufeful, rather did harm ; the part bitten, and afterwards fcarified, being the more difpofed to gangrene. In a word, neither the fca- rifications nor the cautery had any.ufeful efFedt.

It

ON p o I s o isi; s. I J

It remained for me to try two other remedies which many celebrated phyficians prefer to man/ others.— The theriaca and the fat of the viper it- felf.

I employed the theriaca by laying it on the party which had been bit^ and afterwards fcarified. I re- newed it feveral times, and kept the part well cover- ed with pieces of linen fpread with the fame. I likewife gave it internally, but all without cffc^ i it did not appear to me to be of any ufe in dimin- ifliing the animal's complaint.

Mead in his treatife on poifonSy fpeaks of ^ rc^ medy which was reckoned in his time, a real fpeei-^ iick againfl the bite of the viper. He fays that the viper catchers in England ufed it with fo much confi- dence, that they were no more afraid of the bite of a viper than of a common prick.

Mead contrived to ferret out this remedy, which was yet a fecret. He difcovered that it was the fat of the viper itfelf, which they rubbed over the bit- ten part. To be ftill furer of the efficacy of this reme- dy, he had the nofe of a dog bit by a viper, and ap- plied the fat to it. The animal recovered, and on repeating the experiment, the refuk was the fame. Being thus alTured of the efficacy of the remedy, he fat about explaining philofophically how it oughs to correct the action of the poifon. He found that the glutinous corpufcles of the viper's fat were calculated to enclofe the volatile faits of the poifon^ and fo to prevent their uniting into chryilailine falts^,.

ta

14 F O N T A 14 A

to which the poifon owes its force of a6:ivityi

Mead^s principal miiiake confiils iii having fuppo* fed that the bite of a viper on a dog's nofe Vv^as abfo- lutely mortal. On another hand what dependance ought we to place on two experiments only ? It has been feen above^ how different the confequences are w^hen the circumflances even appear the fame^ and how little trufi ihould be placed even in uni« form confequences^ provided the number of experi- ments be not very great*

Bites of the viper on the nofe^ are lefs dangerous than in all other parts of the body. If Mead had multiplied his experiments more, if he had varied them as he fnould have done, he w^ould not have been deceived, or would have been fooner convinced of his crrour. From hence principally arifes the ilownefs in progrefs of the fcience of natural philofo- phy, a^dthis is the fource of an infinite number of miflakes which continue to disfigure medicine, and to prevent its advancement*

I have likev/ife tried eled:ricity againfl the bite of the viper, and have not Only found it ufelefs, but it has even appeared to be hurtful. It is at leafl certain that in the animals to which I applied it, the complaint became more violent, and that they died fooner. In many, I threw fparks from the con-- duftor, on the part bitten; and in others drew fparks from the part, keeping the animal faflened to the conductor : in both ways I found eledricity more hurtful than beneficial*

ON POISONS. J5

Application of Leeches to the Bite of the Viper.

1 had a pigeon bit in the leg by a viper, and in- ilantly applied to the part three leeches which faf- tened very well. In twenty minutes it died, the leeches being fwoln with the blood they had fucked from it.

I repeated the fame experiment on two other pi- geons, which v/ere but jufl bit when the leeches were applied. They both died in eighteen min- utes,

The fucking the parts lit hy ihe Viper^

I was defirous to fee if by fucking the part im- mediately after its being bit, the poifon could bs prevented from diffufnig. itfelf. I met with a per- fon who made no difficulty of fucking it.-

I had the bites of two pigeons fucked^ without dilating them, and thofe of two others, after having dilated the holes made by the teeth, and begun to fcarify. . All four died in lefs than tweAty-feven mi» nuteSe

The fame experiments terminated the fame way with quadrupeds ; after which I am not afraid to pronoun'ce that neither fudioh by the mouth, nor the application of leeches, is a certain rem.edy agaiilfL the bite of the viper.

I fnall not dwell on feveral other methods I have tried ag:ainil the venom of this animal, and which

Yhzscr

i6 fontAna

I have found more or lefs ufelefs, and fometime^ hurtful* I have applied feveral earths, ehymical preparations, and vegetable fubflances, td the bitten part, and have fometimes even given them inwardly to the animals. I think it ufelefs to infert a catalogue of fuperfluous remedies.

On the utility of amputating the Limbs bit hy the

Viper^

We have already feen that the adtion of the viper's venom is not inflantaneous ; that it requires a certain time for its effects to be perceived in the bitten parts ; and that the external malady does not communicate itfelf fuddenly to the animal. We have alfo feen, that if the part bit by the viper be fuddenly amputated, the animal furvives. All thefe experiments together fupply a certain remedy againft the bite of the viper, when one can pradlice it with facility. It is natural to fup- pofe, that by lopping off the difeafed parts, the life of the animal may be faved ; but the amputa- tion ought not to be much retarded, becaufe it is at leafl certain, that the fooner it is performed the furer its effed:s. In pigeons it begins to be even fatal at the end of fifteen feconds, at which time the internal malady is communicated, which the amputation encreafes, and haftens death, inftead of diminiihing one and retarding the other, as I have been fatisfied by feveral experiments.

Before

ON POISONS. t^

Before I examined into the advantages of am- putations on animals bit by the viper^ I vvifhed to fee whether the internal m.alady would be com- inuhicated in a feniible way^ and fo as even to oc- calion death in other anim.als^ in the fame fpace of time as in pigeons. It was neceiTary to try it on animals that die with much greater difii- culty than thefe kft, but w^ho would die to a cer- tainty, and in a fpace not too diflant from the in- trodud:ion of the pbifon. I made choice of very fmall guineapigs, becaufe I knew by experience, that they had all thefe qualities.

I had a guineapig bit feveral times at the extre- mity of the foot, w^hich at the end of twenty fe- Conds I cut off betwixt the tarfus and the tibia« The animal lived; and fecmed to have no other complaint than that caufed by the operation. ^ I had another guineapig bit repeatedly at the ex- tremity of the foot, by a viper, and at tihe end of forty feconds cut off the leg as above. He reco- vered in the fame way with the former.

A third guineapig received feveral bites in the foot, from a viper, a minUte after which I cut off its leg. It recovered as v/ell as the others.

I had another guineapig bit repeatedly by a vi- per, in the foot, which in eighty feconds I cue bff ; this one likewife recovered.

I had another guineapig bit repeatedly in the foot by a viper, and two minutes after cu: off Its leg ; it recovered likewife.

>0L, IJ, e I had

iS F O N T A N A

I had another guineapig bit feveral times by It viper, in the foot, which at the end of three mi-' nutes I cut off : this one recovered too. ,

I had another guineapig bit feveral times by a , viper, at the extremity off the foot, and at the end of four minutes cut off its leg : it died three hours after, having a lividnefs of the mufcles of the leg, and the auricles and heart filled with clotted blood,

I had another guineapig bit repeatedly in the foot by a viper, and at the end of four minutes^ cut off its leg : it recovered.

It mull be obferved, that the feet amputated aC the end of three or four minutes, have unequivo- cal figns of local malady ; thefe figns are even ob- ferved before, although with more difficulty, are not fo certain, and do not exifx always.

Neither of the guineapigs bitten in the feet, and mutilated in lefs than three minutes, died ; but of the two mutila ed at the end of four minutes one- died, and the other furvived. There are even here then, as well as in many other cafes we have feen above, circumflar:ces in which the bite of the vi- per produces greater or Ivrifer effedts ; but v/hat is more important, and dcferves all our attention, is, that the internal malady is not communicated to the aniirial till very late, in comparifon to that, in the cafes of the pigeons, or more properly, that it does not become m^ortal till after a long time, and that the cutting off the part bitten may be made 4 witk

ON P o i S b N S. ^Q

V^^ith ail poilible advantage and. fafety, within the limits of a much greater time.

But let us continue our experiments, the num^ ber of which has been too fmall to fupply us with Certain concluiiona;

I had a guineapig bit feveral times in the foot by a viper, and cut oif its leg at the end of four minutes : it recovered.

I had another one bit repeatedly in the foot by a viper, and cut off its leg at the end of five minutes : it recovered.

I had another guineapig bit in this way in the foot, and at the end of fix minutes cut off its leg ; it died ten minutes after.

I had three guineapigs bit in the foot by a vi- per, each one feveral times, and in four minutes cut from each a, leg : they all recoveredi

I had three others bit in the foot in the fame manner, and in iive minutes cut off a leg from each 'of them : they all three recovered.

I had three others bit in the fame way, and in fix minutes performed the operation : one only re- covered.

I had three others bit as above, and iti ten mi^ nutes cut off a leg from each : they all died;

From all thefe experiments it appears that this dledudion may be made> that every thing is to be expedied from the amputation of the leg, if per-^ formed on guineapigs before fix minutes are el^p- fed after .^heiijbeing bit by the viper.

€ 51 ^ it

^0 F 0 N T A N A

It is natural to fuppofe, that in larger animate the amputation may be made much later ftili than fix minutes, and experience has demonflrated it in very large rabbits ; but we may Humble on ano- ther inconvenience which confines this method very much : pigeons are not endangered by the amputation of the leg ; (mall guineapigs bear that of the extremity of the foot, but not always that of the leg ; larger animals are more apt to die when a great part of them., fuch as the kg, is lopped off; fuch an operation in thefe cafes is not only ufelefs but dangerous.

It does not, however, follow that amputation, even in large animals, may not be ufeful againft the bite of the viper ; in general it is fo when the animal bears it eafily, provided it be done at a con- venient time. As amputation may be very ufeful in a great number of cafes, I thought it incum- bent on me to make experiments, and to vary thein^ feveral ways, on different animals.

Rabbits and Dogs that had their ears bit and cut off,

1 had a rabbit's ear Lit a fmgle time by a viper,

and m thirty feconds cut it off fix lines below the

part bitten. The animal bled a great deal, but did

not die, nor even appear more difordered than

another rabbit, the ear of which I cut off, witlw

out having it bit.

I had

O N P O I S O N S. 21

J had a fecond rabbit bit feveral times by a viper, and a minute after cut off the two ears, fix lines below the bite. It recovered without any lymptom of poifon.

I had a third rabbit bit in both ears, by two vi- per-s, each of them repeating its bites, and in two minutes cut off each ear^ eight lines below the parts bitten ; it recovered as well as the other two.

I had two other rabbits bit feveral times in both ears, each by two vipers. At the end of fix mi- nutes I cut off the ears, eight lines below the bites. Both recovered, without any intermediate fymptom of poifon.

I had a fmall dog bit in the ear, which in a mi- nute I cut off fix lines below the part bitten. The <iog recovered without any other fymptoms than thofe common to fuch an operation.

In the fame way I had another fmall dog bit re- peatedly in the ear by two vipers, and in fix m.i- nutes cut off the part. It recovered without ha- ving had any other fymptoms than thofe refulting from the operation.

Again, I ckufed a young and fmall dog to be bit in both ears by two vipers, and by each re- peatedly. In twenty minutes I cur off the parts. It recovered without having any fymptoms of poifon.

I repeated this lafl experiment on two other dogs, ^nd it fucceeded equally, fince both of them lived. *Tis very true they were much difordered^ but not

C 3 more

%2 F G N T A N A

more fo than dogs are ufed to be when their ear? are cut ofT^ without havmg been bit.

As it is not common for either rabbits or dog^ to die when bit in the ears^ above all, if they are fomewhat large, the experiments on thefe animals only ferve to prove that the effe(fls, at leaft local^ do not fubliil after the bitten parts are cut off.

Animals that have received hhes on the Slih, intd^

which i'ficifwns have been afterivards made,

I had a very fmall guineapig bit repeatedly by; a viper pn the ikin of the back, and to prevent the yiper-s w^ounding the mufcles, I kept the ikin raifed with pincers, the teeth piercing it througl^ and through. I held it thus for four minutes, and then diiTedted it away in fuch a manner that none of it rem:^ined for leveral lines round the part bitten. The animal recovered in twenty-foup hours, the incinon in its fkin being covered witt^ an efchar. It eat as ufual, and^ appeared to fufFer nothing except what was -fimply caufed by the in- cifidn, as I afiured myfelf by preparing another guineapig, to ferve as a comparifon, and which re- covered in the fame, time, but had not been bit by Z. viper.

I had another guineapig bit feveral times on the ikin by a viper; I kept the fkin raifed for four minutes after its being bit, and at length cut it* It had already the marks of poifon upon it^ that is ' ' ' ' ' to

ON POISONS, 23

^ ■

to fa5% livid and black fpots, and the fe fpots ex- tended for fome fpace round the part bitten,

I had another guineaplg bit repeatedly by a vi- per on the ikin, which in four minutes I dif- {•e&icd away. The creature recovered without any fymptoms of poifon,

I had three rabbits bit as above, but made no incifions; they all died, one in lixteen hours,, another in twenty-fix, and the third in thirty-two. In this laft the fielh bitten was gangrened inter- nally, and the cellular membrane, the pedoral mufcles, and thofe of the abdomen, were filled with black and extravafated blood. The two other rab- bits had likewife evident marks of difeafe and gan- grene, but in a leffer degree.

I had two fmall guineapigs bit as ufual on the ikin, and in twenty minutes made the inciiion. Both recovered very well.

As the bite of the viper is ufually mortal in thefe Animals, even when it does not penetrate beneath the ikin, the incifion into the part bitten becomes a fure remedy for them againil its venom. I re- peated the fame experiments on dogs and rabbits, and the refult was the fame. The cure is certain, and the local complaint avoided, as likewife the internal one, in a great meafure at leail, although the amputation of the parts bitten be made much la- ter,

C 4 Comh

24 F O N T A N A

Cmnbs and Gills of Fowls Bit, and afterwards cut of-.

It has been feen above that the bite of a viper in a fowl's comb does do injury to the comb, but a great deal to the giils. This fad is not the lefs true fbr being fingular^ and is the. refult of rnany uni- form and conflant experiments.

As the venemous eiTeds donotdifcoverthemfelves in the comb, but in the gills, which are attacked with a complaint generally fatal to the hen, it was natural to fufpect that the giils being cut off, the animal would recover perfedly.

I had a fowl bit, then, and that repeatedly, in the comb, by a viper, and in twenty fecpnds cut off the gills.

It recovered without any fymptom of illnefs, con- tinuino; to eat and drink as ufinal.

r had-the comb of another fowl bit repeatedly by a frefh viper, and in forty fecoiids, cut off th§ gills. It did not appear to have any complaint.

I had a fowl's comb bit feveral times as above, bv two vipers, and in fixty feco.nds cut off the gills. It recovered without any ailment.

I had the comJos of three fowl's bit repeatedly by two vipers, and cut them off, one in four minutes, aiother in eight, and the third in ten. They all re- covered, the gillsof the third were difeafed .at the end of the ninth minute.

It has been feen that when the gills, and not the combs, are bit by the viper, the complaint does

^9\

ON POISQNS. a^

liot find its way to the combs, but remains in the gills, is more dangerous than if the viper had Ijit the comb ; and is ufually fatal.

I had a fowl's gills bit feveral times by a viper, and cut them off in twenty feconds. It recovered without any apparent illnefs.

1 had the gills of another fowl bit repeatedly by a viper, and cut them off in fixty feconds. It reco- vered, without any external fymptoms of com- plaint.

I had three other fowls bit repeatedly in the gills by a viper, and in three minutes cut off the parts. The fowls did well, without betraying any ail- ment.

I had the gills of three other fov/ls bit in the fame way, each by two vipers, and that repeatedly, and cut them off in four, fix, and eight minutes. The fowls all recovered, without any fymptom of poi- fon, as if the gills had not been bit by the viper, but only cut off.

All the experiments hirherto made, tend in them- felves to give the moil flattering hopes that a reme- dy more eafy, more univerfal, and lefs painful than amputation, may be found againfl the bite of the viper.

It has been feen that the nerve does not ferve to communicate the difeafe of the venom to the ani- mal ; that this difeafe communicates itfelf by the blood ; and that wounds of the fkin, venomous, |DUt fuperficial, are attended with no dangerous con- |e(^uences. The two firfl truths point out with cer- tainty

%^ F (^ N T A N A

tainty tliat to prevent the complaint from communis eating itfelf to the animal, it is fufficient to flop the circulation of the blood ; the third demonftrates that it is not neceffary to fiop it totally, and in the Tery fmall veffels. Nothing, as I fee, can be more comformable to the theory of the poifon, and its modes of -a^ing on the human body.

This o-reat and ufeful truth oudit to be founded 0n a number of incontrovertible experiments. I thought that the pigeon, of all animals, .would farniih me with the kail equivocal proofs,- and therefore preferred it to all others. I knew that the bite of the viper is certainly mortal to it ; that it dies in a few minutes ; and that an imperceptible quantity of poifon is capable of killing it in a ihort time. A fmgle bite of the viper is capable of intro- ducing as much poifon into a pigeon, as would kill 200 of them.

i had a pigeon bit once in the leg by a viper, the part having been previoufiy tied Vvith a filk ribbon^ jufl above the joint. Thefymptoms of local mala-r dy appeared very foon in the leg: in four hours it was Ciuite livid and fwelled beneath'the ligature ^ but all above remained in its natural ilate. I took off the ligature, and a fjiort tim.e after obferved that the leg was lefs fwelled and livid. In ten hours its colour was almoil natural, and it was but little fwel- led. In twenty-two hours nothing remained but a "few difcoloured fpots at the place where the teeth had entered. In fixty hours there Vv>as abluifh caft

over it. In three days it was pcrfedly found.

I tied

ON POISONS. 1^

1 tied a ribbon about a pigeon's leg, and had it bit feverai times by a viper. In ten hours the leg was fwelled and quite lived, difcharglng in feverai places ablagkiili humour. I removed the ligature. In twenty-two hours the leg was fwelled as before, and black as a coal. In forty hours, ail the mufcles feemed to border upon fphacelus. In three da3^s the leg was lefs fwelled, and difcharged lefs matter. In five it feemed in a healing itate. In feven it had in a great meafure regained its natural colour. Thd animal recovered in ten days.

I repeated this experiment on four other pigeons, but fearing that the ligature in the former one had been too tight, and had in a degree increafed the local malady, I made the ligature much loofer. Neither of the pigeons died, but their legs were fomewhat fwelled and livid. In ten hours I took off the ligatures. Two of the pigeons recovered the fifth day, the other two on the iixth.

It is an experienced truth, then, that the ligature made in the part bit by a viper, prevents the com- plaint from communicating itfelfto the animal, no internal difeafe fupervening, during the time it re- mains on. It is iikewife an experienced truth, and equally important, that at the end of a certain time, the venom does not communicate itfelf to the fyf- tem.

Although it be true, as it indeed feems very pro- bable, that on taking off the ligature, the venom is partly abforbed by the veflels, and carried with the hiopd into the circulation, it is however obferved

that

Z% F O N T A N A

that k is no longer in a {late of poifon^ and capable of killing the animal. It is known that the fmalleft poffible quantity of venom kills a pigeon in a few rninutes, and experience ihows, that none of them die when the ligature is made, although taken off at the end of a certain time.

Befides^ i^ is not difficult to conceive that when once the venom has produced its ordinary effe6l on the bloody and on the parts bit by the viper, it ceafes to be hurtful, MoH bodies operate in this way, and the viper's venom may very poflibly dcr compofe itfelf in producing the local malady, and unite with the blood : but it requires a certain time to b,e brought ir^to this ft:^te, and to be ren- dered inacftire and innocent, In the cafes cited above, the ligature was left on for t^n hours, 'Tis very true, that all this feems contradicted by the experiments I have myfelf piadp on the venom, which, when mixed witji the blood, does not or^ that account ceafe to be a poifon. We have feen heiides, that the venomous fyrnptctms excited ir^ the mufcles of a pigeon's leg, cqmm-unicate theniT felves very readily to the bared mufcles of the leg pf another pigeon, if they are plac-ed for fome tim^ in contact v/ith each other. But in all thefe cafes,^ the trial has been made a few minutes after the pigeons were bit by the vipers, or after the venorn had united itfelf with the blood. To determine after what time the ligature may be removed with* out danger, I made the following expcrii^ients.

Ihad

ON 1» O I S O N S. ip

I had a pigeon bit in the leg by a viper, and in twenty feconds applied a ligature. In four hours the leg was fwelled and livid^ and difcharged on all fides a blackiih humour. I now removed the ligature, the parts above which were in a natural Hate. In ten hours the leg was lefs fwelled and almoil of its ufual colour ; there was, however, a degree of fwelling above the ligature. In twenty-^ two hours the leg was fcarcely fwelkd, although flill a little Vit'id ; but the part above the ligatSi^e was both livid and fwelled. In lixty hours there w^as fcarce any mark of aikxient, and on the fourtli" day the pigeon feemed perfectly recovered.-

I had a pigeon bit in the leg by a viper, and m Sxty feconds m.ade a ligature. It died in threef quarters of an hour, its leg having had a livid ap-^ pearance before it was bound.

I bound the leg of a pigeon at leafl as tight as in any of the eaf^s related above ; in a ihort time it fwelfedy but not eoniiderably ; in feven hours it was more fwelled, but with fcarce any difeoiora- tion. On taking off the ligature at the end of ten hours, the tumour in the leg fpeedily iubfided, but in return it fwelled a little above the ligature. Ixi twenty-two hours it w^as fcarcely fwelled or dif- coloured. In thirty hours the pigeon was perfe<ftly recovered.

I had a pigeon bii: repeatedly by a viper in thfe leg, it being previoufly tied ; in thirty minutes I took of the liG;amre ; the leg was fwellcrd and livid. In fix hcurs ks livid appearance was leiTened, but

a fwcliing

JO r 6 N T A N A

^ fwelling appeared above the ligature. In twenty- four hours the leg was flill fwelled, and had a bluifli caft : the fwellin^ above the ligature had reached the abdomen and breaft. In forty hours the pigeon died, the parts above the ligature being inueh difcoloured.

I had a pigeon's leg bit repeatedly by a viper^ and tied immediately after. I then had it bit feve- ral times by a fecond viper, and in an hour took off the ligature. In t^venty-four hours the leg was fvvelled, but inconfiderably ; in forty the pigeon was perfe6:iy well.

I had a pigeon's leg bit twice by a tiper^ and in- iiantly tied with a ribbon in the ufual way. In four hours I took off the ligature^ and found the leg exceedingly fwelled and livid. In twenty-four hours thefe fymptoms bordered upon fphacelus^ and in thirt)^-fix the pigeon died, with fymptoms of -difeafe above the ligature^

I had a pigeon's leg bit repeatedly by a viper^^ _and immediately tied it. In twenty minutes I took off the ligature, and found the leg in a livid ilate^ but fcarcely fwelled; In eight hours it Was vio^ lently fwelled, and livid. In twenty-four hours .all was nearly in a gangrened ftate, and in thirty-^ ^nine the pigeon died.

I had a pigeon's leg bit three times by a viper^ -and immediately made a ligature, which in thirty minutes I took off; the leg was fwelled and dif- coloured, but in eight hours the fv/eiling was dimi-

nifhed^

OK i» O I S O N s. 31

niflied. In twenty-four it had almoft regained its natural (late, and in fifty was perfedily found.

I had a pigeon's leg bit repeatedly by a vipeij and immediately paffed a ligature round it^ which in forty two minutes, I removed, and found thje leg livid and fwelled. In eight hours thefe fymp^ toms were much diminished, but a fwellmg and difcoloration appeared above the ligature* In twenty-ft)ur hours every fymptom of complaint was leiTened, and in thirty-lix fcarcely perceptible- In iixty hours the pigeon was fully recovered.

I had a pigeon bit once in the leg by a viper^ and infiantly made a ligature, v/hich in two hours I took off. The leg was much fv/elled and dil^ coloured, but in twenty four hours had almoit refumed its natural colour, except at the places \vhere the teeth entered, and which were covered w4th fmall dark black fpots. In fixty hours ail difappeared, and the pigeon recovered in threje days.

I had a pigeon bit repeatedly in the leg by z viper, and immediately paiTed a ligature round it^ W^hlch in an hour and an half I took off. The leg was at firfl livid and fwelled, but in eight hours thefe fymptoms were abaced, and very confiderabi5r fo in tw€nty-four. In thirty-fix hours the part was fcarcely difeoloured, and in three days the pigeon was perfedly well.

I had a pigeon's leg bit repeatedly by a viper, and palTed a loofe ligature round it, which whep done, I had bit feveral times by a fecond viper^

111

^i F O N T A N A

in thirty minutes I took off the bandage. Th'e leg was fweiled, and difcoloiired in the parti» pierced by the teeth. In twenty-four hours thefe fymptoms were abated, and thb pigeon recovered bn the third day.

I had another pigeon^s leg bit feveral times by a viper; and after palling a weak ligature round it, had it bit by a fecond. In an hour I removed the ligature * the leg was livid and fwelled ; but thefe fymptoms almoft difappeared in the fpace d£ twenty-four hours. In forty-two the natural co- lour \^as well reilored ; the pigeon recovered in three days:

It f^ems that frdm all thefe cafes this dedudlio'ti may be m.ade, that the ligature applied imme- diately, and left for a determined time on the part bitten, is a certain remedy againfl the venom of the' viper. It entirely prevents the internal com.plaint, and we obferve the animal to fecovef-, although tlib external and local one continues to exifl:.

I have obferved in general, that the local ma- lady is violent in proportion to the tightnefs of the ligature, and the time it remains on the parf. It is at leail what feveral experiments, which', for brevity's fake I omit here, have indicated to me. It is of the gfeateft importance to know with fofne precilion, the leail poliible time the ligature fliould be left on, and the leail poflible degree df force required to prevent the venom's communica- ting itfelf to the animal, without bringing on a gangrene of the p?.rts.

ON POISON'S. 33

As to the preffure of the ligature^ it was fo vtry flight, that I could not have thought it capable of preventing the progrefs of the venom. I generally made ufe of a very thin foft ribbon, of four lines breadth at mofl, which I paifed feveral times round the thigh, above the articulation of the tibia with the femur, and tied it with a knot. Sometimes I forbore the knot, tying the ribbon with a piece of fine thread. In this way 1 had a great number of pigeons bit in the leg, and removed the ligature an hour after ; they all recovered, arid none of them have iince died.

This experiment conilaritly fucc^eds, when well made, and when the ligature is pafled round the thigh as it ought to be.

Now, if we consider that a very fmall quantity of venom kills a pigeon, and that in a few -minutes^ it will feem clear, that the ligature* ought to be a flill more certain remedy in Animals larger than pigeons, and which die with far greatet difficulty.

I was fo fully perfuaded of the efficacy of this method againil the bite of the viper, that I did not hefitate to addrefs a detail of it, ericlofed, in a letter, to the Marquis de Condoreet^ fecretary to the Royal Academy of fciences, begging that he would be pleafed to depoiit it in the Academy. I informed him in this letter that my method was fo very certain, that of ioo pigeons bit in the leg by vipers, I fearcely rifked the lofing one, al- though it is fo delicate a creature that the

Vol, IL D fmalleft

34 ]^ O N T A IT A

fmalleft quantity of venatn is fufEcient to kill ir^ It will be feen by and by, what led me into an er- rour as to the geiier all ty o{ this remedy, and how much we ought to be guarded againfl the mofl^ promiling analogies, as I have already hinted fevs:- ial times in this w^ork.

tata

CHAP- IL

If the She of the Viper h naturally' mortal to Man ?

Jill now I have treated of the bite of the viper in animals; it is my prefent buiinefs to fpeak ©f it as it relates to man himfelf ; and this forms the moil: ufefui part of the work. And here I am not afraid to advance freely, that the bite of the viper is not absolutely mortal to man, and that thofe have been miflaken who have regarded the, difeafe cau fed by the viper's venom as one of the moil dangerous, and from which it is impoliible- to recover.

We have feen that the lefler animals, fuch as* fmall birds, die in a few minutes, from the venom of the viper, if they have but been bit effediu- ally, or rather^ if the viper has penetrated with its-

teetb

ON P O t S O N s. 35

teeth far enough into the body, to leave there the quantity of venom it ufually forces from them when it bites ; this Gircumflance I have verified in more than 200 fmall birds. The fmaller pigeons themfelves are in the fame predicament ; not one of them efcapes death > if the viper is in good or^ der, and they have been effediually bit ; we mull except here the fmall number of cafes in v/hich the vehoiti introduced into the animal, is thrown t)Ut again with the blood, as the animal in thefe cafes furvives from not having had the complaint. Pigeons wheii bit, live longer than fmall bircls^ and the period of their exiilence after being bit^ has an agreement with their fize and weight, compared with thofe of the fmall birds themfelves.

If from pigeons we pafs to fowls that have been bit, we already find a very great difference, both a^ to the intenfenefs of the complaint, and the tirrie they live* We have feen that many of them do not die^ although feveral times bit^ and that others die much later than the pig ons and fmall birds.

If a great number of experiments made on fowls be fufircient to eilabliih an indudlive proof, I do not heiitate to affert that the time of their death has likewile fome relation to the (ize of their bodies.

'What 1 have faid of fmall birds and pigeons, in their relation to fowls, may be equally faid of fmall guineapigs and rabbits, compared with the greater animals of their fpecies. Thefe fmall animals infal- libly died when bit effedually, but a great number ^the larger ones recovered., however they had been ■

D i bit.

36 t O N T A N A

bit. They had very dangerous iilnefles proportioned to th.^ number of vipers employed, and the number of bites they had received from them, but ufually recovered.

I have obferved that very fmall dogs die eafily, even though bit by a lingle viper, and but once ; but amongft the middle iized dogs, a vaft many not only furvive, but reiifl the poifon perfectly well, without any remedy being adminiflered. In pro- portion as the dogs become larger, they the better refift this poifon ; five bites from three vipers were not fufficient to kill a dog that weighed nearly lixt)'' pounds.

Now let it be noticed than a man is about three times as big as the dog of which I fpeak, and let- any one judge if a viper can kill him with afingle bite!

It has perhaps never happened that a man ha^ been bit by more than one viper, and ihould it ever happen, fuch cafes will be always very rare, lince it To feidom occurs that a viper bites a man more than once. A very few contrary cafes do not create an obftacle. It does not appear then that the ufual bite of a viper can be mortal to man ; but there is an obfervation which I have verified in almofl all the. countries through which I have palTed, and from, which I could draw any informa:tion, that feems clearly to demonflrate that the venom of the viper is not naturally fo. I obferved that it is very rare to find two perfons bit by the viper, above ^11 in the country or on the mountains, who make

life

ON POISONS, 27

Kfe of tke fame remedy. I have known fome cured with the theriaca alone, taken internally or applied to the part ; others with common oil ; others with flimulants, fuch as the ftrongeft fpirituous li- quors ; and others on the contrary with fedativ.es. In Ihort, there is no kiad .of fubHaace or medicine, that fome one has not tried in this difeafe. What is very ceitain is, that w^ith all this none have died ; at leafl I could never fubftantiate any cafe in which a grown perfon died with the limple bite of a viper. Now if we confider that perfons bit by the viper re- cover, however they are treated, and even with re^. medics altogether contrary to each other, we fhall foon fee that the bite of the viper cannot be lb dan- gerous as has hitherto been imagined. A complaint yielding to all thefe remedies, even to thofe of op- polite natures, can never be a dangerous one.

I have informed myfelf very carefully, in all the countries through which I have occafionajly pafied, of perfons bit by the viper ; I have myfelf examined more than ten or a dozen, and have heard mention of more than fifty, either from phyficians, furgeons^ or perfons who were prefent and ailifted the lick. Of fo many bitten, not one is dead ; and I have never heard but of two perfons who are faid to have died from having negleded to take remedies. It was not pof- fible for me to gain any information of one of thefe p^eople, whatever enquiries I made into the fubjed:, fo that I even doubt the truth of the fad:; but J know that the other died at the end of twenty days,

s?/ith a gangrened arm. He was fcarcely bit, when D 3 very

38 F O N T A N A

very deep fcarifications were made, and in three da^^s the parts had already gangrened. The Count de Carburi, confultlng phyfician to the King, at Paris, faw eight perfons in the hofpital at Turin, all of them bit by 'the viper, and faw them all reco- ver, akhough each had a particular treatment. Of thefe eight, he treated one with the volatile alkali. It remains now to reply to a difficulty, if it can ,

however be called fo.

Some one may perhaps object that my experi- ments were made on animals, and that the argument does not hold good, betwixt an animal and a man, betwixt a man and a dog. Difficulties of this kind have been made at all times, either through igno- rance or envy, by thofe who are galled at the feeing others add to the number of new truths, or by thofe who are ignorant of the laws and correfpondence which nature has eilabliilied betwixt animals.

I fnould be aihamed to endeavour to prove that there is a perfed analogy in the cafes I have adduced, and that we m.ay very well draw conclufions betwixt an animal and a man : it is fufficient to perufe what Boerhaave, Mead, Albinus, and Morgagni, have written on the fubjedt^ and the ufe thefe great mer> have made or it..

Common oil was believed in England to be a cer-. tain remedy againft the bite of the viper, and expe- riments were made with it on a man, in the prefence of fevcral members of the Royal Society of Lonr

don.

The Royal Academy of Sciences of Pans havmg

ON POISONS. 39

feeen informed that an "Engliih peafant had found a pecifick in olive oil, and that he had made the ex- p/eriment with it on himfelf, in the prefence of feve- ral members of the Royal Society of London, the Academy deemed the diicovery of fuch importance, that it deputed two of its members, MeiEeursGeoffroi and Hunauld, to verify the experim.ent. Thefe two Academicians hadfeveral pigeons bit, and likewife fe- veral chickens, two cats, a goofe, a turkey cock, and :ight dogs. The refult of their experiment" was that olive oil could not be regarded as a fpeci- fick. No experiment was made upon the human fpe- cies, and this illuftrious body declared however that oil is in no way a fpecitick againfl the bite of a vi- per, and that it has not the fmalieil efScacy in cu^ ring the difeafe caufed by it {a).

The two Academicians made a few general ob- fervations on the animals bit by the viper, which are as follow,

L That there is no coagulation in the blood, but on the contrary, every iign of fluidity.

IL That the ferofity is extravafated into the cel- Jular membrane., and has a bloody appearance.

IIL That the arteries are empty and the veins filled.

IV. That the blood is coagulated in the auricles and ventiicles of the hearty but without any cpnfift^ ^nce.

In the report Melfrs. Geoffroi and Hunauld made ,09 the fubjedl, we i ike v/ife find the recital of two

(aj Mem. de I' Acad. Roy. des Sc. de Paris. Aunee 1737. D 4 perfons

4Q F O N T A N A

perfon^ cured, who had been bit by the viper ; but they were treated in a way more likely, in my opi- nion, to Qccafion their deaths, than to afford them relief.

To one was given a great quantity of Burgundy, ' and repeated fcarifications made. This patient was actually ill for two mpnths, whereas he would otherwife have probably recovered in two days, ha- ying only been bit in the finger.

The pther was likewife bit in the finger : liga- tures and fcarifications were tried, and after all he was very ill. Thefe two cafes evidently demonftrate to me, that the bite of the viper is r^ot much to be dreaded, fince though fo improperly treated, it did not occafion death.

Mead, a few years after, having read the experi- ments made by the Academy at Paris, on the in- efficacy of oil in the bite of the viper, adopted them entirely without difficulty^ and believed with this illuftrious body , that oil could have no efficacy, and that they had decided well in the affair. Afterajudgment pronounced by fo illuftrious a body ; after Mead has fubfcribed to it , I do not believe that any one will be fufficiently hardy to throw doubts on the applica- tion of my experiments, made on fo many different kinds of animals, and repeated on fo great a number of each fpecies.

Th " venom of the viper is poifonous to all animals with warm blood ; at leafc I have not as yet been able to find any exception. Being in Italy, I ex- tended my experiments to all the animals I was

abl^

O N P 0 I S O N S, 41

,able to procure, and the complaint difcovered itfelf ill each of them when the viper had a^ually de^ pofited its venom in the parts bitten. In every fpecies of animal the complaint is violent and deadly in proportion to the fmallnefs of the creature bitten ; and its violence alfo depends on the quantity of the venom introduced. However^ to fuppofe that what deranges the animal economy with fo much adiivity and flrength, in different animals^ and encreafes its effedis in proportion to the encreafe of its bulk, can at the fame time be not at all injurious to man, would be hazarding a fuppofition at once abfurd, incredible, and unlikely. Let a fingle example be brought of a poifonous fubftance^, whether animal^ vegetable, or mineral, which kills, or is productive of violent complaints in fo ihort a fpace, in animals with warm blood, and has with all this no baneful effedts on man, and it may then be faid that the ana- logy betwixt the efFedsof a poifon on man, and of the fame poifon on animals, is not admiflible ; or rather it may be faid that this is a lingular cafe, an exception to the general rule. The examples of cats, which furvive the bites of feveral vipers, inftead of favouring, dellroy this hypothelis. It is true that the cat, a fierce animal, makes a flrong reliil- ance to this poifon ; but it reiifts it precifely becaufe it is in comparifon with other animals, very (Irong and robu{l,and isneverthelefs, in fpiteof its flrength, itfelf attacked with the complaint caufed by the l^ite of the viper ; and this complaint becomes vio- lent^ painful, and lafting in proportion as the quanti- ty

4Z F O N T A N A

ty of the venom introduced into the body of the creature by the viper is increafed. I doubt not, if inftead of five or fix vipers, ten or fifteen for ex- arnple had been employed, but the cat would have fiiedy becaufe the difeafe woiild then have been very ^^iolent, snd more than equal to the llrength of the snimai. In fadt, kittens dieas well- as oiher creatures, although bit by very few vipers, precifely becaufe |:hey ^re lefs robuil than when grown up.

Reply to Monfteur JnJJieu,

It now remains to reply to a diiiiculty which fs- ifoiirs the volatile alkali, and which, previous to my experiments, might have appeared very great -and iinaniwerable. This difficulty folely confiils in the cafes where perfons bit by the viper were happily cured by the volatile alkali ; fuch for example as the fine cure we read of in the hiilory of the Acade- my of Sciences of Paris, by M. Juffieu, of a young man who was bit by a viper, and treated with eau de luCe.

I think I ought to enter upon my reply by remar- . jcing that there are very few cafes fo complete in their circumflances, asthatpfMonfieur Juffieu undoubted- ly is. Sannini indeed fpeaks of three perfons bit by fnakes, and cured by the volatile alkali ajone ; but we are ignorant of the quality and effedis of the venom of thefe fnakes, which certainly were not vi- pers, although l)e believed them more noxious than

the

ON POISONS. 43

the rattlefnake itfelf. Befides, Mead is of opinion that the rattleOiake kills in a very ihort fpace of time, even in a few feconds. The urft of the three per- sons Sannini treated with the volatile alkali, had been bit feveral hours before the remedy was appli- ed, and was notwithftanding fo well recovered on the following day, that he returned to his ufual employment of fifhlng. This Author likewife fpeaks of a little infed: called centipedes, the bite of which he deems mortal, and fays that he was himfelf cu- red of it by the volatile alkali. But neither is the (Irength of the venom of this animal well known, nor have there been fuihcient experiments on the fubjed.

Monfieur de Mafcena fpeaks of a cure made with the volatile alkali, in French Guiana, on a perfon bit hjd. fnake. He was treated with eau de luce, and recovered (a). The fnake is not named, and it is not known whether or no it is really noxious ; but could it even be proved that a perfon bit by the rattlefnake had recovered on ulirig the volatile alka- li, ought we thence to conclude that the volatile alkali is a fpecifick againft the bite of that crea- ture ? I have already proved in a demon ftrative way, that i-t is certainly not fo againil the bite of our vi- per, whiph does not differ elTentially from the rat- tlefnake, except }n its iize. It is true that the latter- being feven or eight times as large as our viper, is confequently capable of conveying feven or eight times the quantity of venom, from whence the dif-

C^v^ Journal dePhys, aout, 1777.

cafe

44- ' F O N T A N A

leafe may become proportioiiably greater and more dangerous. Doctor Mead fpeaks of a man who was bit in London by a ratllefnake^ and who recovered hy having the part fucked, and by bringing on vo- mitings with oil and water^ This cafe may lead one to fufped; that the bite of the rattlefnake itfelfis not always mortal, fince the bite of our viper is not cured to a certainty either by fusion or by vomi- tings brought 'on by fwallowing oil. But why fliould the bite of the rattl^fnake be invariably mor- tal to fo large a creature as man^ when w^e have {qqvl that five bifes received from feveral vipers were not fufficient to kill a dog, weighing only a third of a man's weight ? I cannot indeed fee why the bite of a rattlefnake, which rnay be reckoned equal to that of feven or eight vipers, fhould always be fatal to the buman fpecies.

The greater quantity of the rattlefnake's venom IS not then a conclufive argument that it muft invariably kill fo large a creature as man ; an^ why . ihould it be equally dangerous, v^hatever part of the body may be bit, at what time foever it may Jiappen, and in whatever ftate it may be found ?

It has been feen above that wounds or bites in the nofes apd ears of animals are attended with lit- tle danger ; the fame may be fald of thofe of the ikin, which heal better than the mufcular ones.

But v/ere it even granted that the rattle-fnake may by its bite introduce a fufficient quantity of venom to kill a man, how many caufes may there not be to prevent the introduction of this quantity of venom into the wound fo as to produce fiich an effed: ?

o ir P O t ^ O N s^ 45

In the courfe of our experiments on European vi- pers, we have feen maily cafes in which there has been little or no complaint in confequenceof the ve- nom introduced : and what is the poifon that may jiot become innocent when diminiihed in quantity ? The rattle h.ike maybe defhitute of venom, a cir^ cumflance which I have fometimes obferved in our vipers. It may bite fo fuperficially, or fo ill, that the poifon introduced may not be fufficient to occs- lion death. A vein, an artery, torn by its toothy is fometimes capable of forcing out either all the. the poifon, or a part of it at leaft. We have obfef- Ved all thefe cafes as they relate to our vipers, and they may be equally applicable to rattlefnakes.

To form a proper judgment of the ftrength ofa rattlefnake's venom, and that of the other fnakes of French Guiana, and likewife of the advantages, of the volatile alkali in ihe difeafe caufed hy it, it would be neceflary to make a great number of ex- periments, as I have hitherto done on the European vipers. Befides, if the volatile alkali is totally ufe- lefs in the bite of our viper, how can it have any efficacy, how can it be a certain remedy in the bite of fnakes which they pretend to be mAichmore ve- nomous ? I am inclined to believe that the common bites of thefe fnakes are npt deadly in their nature^ but that they become fo in fome particular cafes and by accident, as by the number of bites received^ and the injudicious manner of treating the part bit- ten.

If attention be paid to the complaint produced

by

4§, # o N 1: A K A

by the viper's venom, it will foon appear that tM animal bitten may eafily die if badly treated, or if difordersare excited in its economy by perfons little Skilled in this difeafe, which is not unlikely. A large tumour is generally formed round the pare bitten ; there is an extravafation of black and livid blood in the cellular membrane, even at a great diftancefrom the bite; and lallly, a coniiderable gan- grene is frequently formed, which deflroys the ficin and cellular membrane, and extends to the mufcles. Who does not fee that in thefe cafes the gangrene of' itfelf, and uninfluenced by the venom, may be fa- tal, if the patient be by accident badly treated ?, And this may be the cafe in the inflance of any ohe's dying from the bite of the viper j there remains a large local wound, which maybe confidered as cau- fed by the mere mechanical attion, and this wound may be well or badly treated. We have feen above- that the venom of the viper kills by its general action on the animial, which does not die from the fimple local malady of the part bitten, but is deilroyed by. the venom, although the part injured be wholly extirpated.

Although I have not had the good fortune to difcover a certain fpecifick agalnft the bite of the viper, I have however the pleafure to afTure the pubiick, that this bite is not fo dangerous as has. been hitherto univerfally believed, and that in an. inftange where a perfon may have the mis-fortune to be bit, life fnould not be defpaired of, even though no remedy be applied.

OK T o t ^ o ii s, 47

If I have demonilrated the inutility of a remedy which was belic^ved a certain one^ if i have de^ ftroyed the hopt; of difcovering a fpecifick a^^ainll the viper's VLnom, I have st leail the confoiation of having fubdued the frightful idea that has beea entertained^ that the bite ©f the viper is ufually mortal*

I am of opinion, that of loo men bit, each of them once by a fingle viper, either in the foot or the hand, parts which are ufiiaily expofed to the bite of this animal, not one of them would pro- bably die, even though they ihould make ufe of no remedy.

After having (ttn the efFe& of the viper^s bite on eight different kinds of animals, as well thoie with warm blood, as thofe with cold ; after having had more than a thoufand of them bit in fo inam different parts of the body, by feveral vipers, and that repeatedly, I believe no one will deem the opinion I have delivered a raili one; an opinion which even becomes the neceffary confequence of what we have hitherto obferved.

The ligature made ufe of againfl the bite of the viper in the pigeons, was the immediate confer quence of thefe very experiments. After having difcovered that the viper's poifon did not attack the nerves, that its whole adion was exercifed oa the blood, and that the difeafe was only communi- cated by means of the circulation, it was eafy to percieve that this circulation being flopped, the Cjifeafe caufed by the venom would be fo too. I * trleJ

48 F O K T A N A

tried this method with the greateft fuccefs, dnd found it a certain remedy in the cafes of the ani-^ mals for which I made ufe of it. It did not how- ever appear poflible to me but that the ligature had- been propofed by fome author, lince it is an idea that feems to prefent itfelf fo readily. It is very true that Redi, who treats of the venom of the vi- per in two diftln£t works, makes no mention of the ligature, and Mead himfelf^ who fpeaks of a great number of remedies, fome even that are without efEcacy, takes no notice of it;

I have for feveral years made refearches into the remedies ufcd in different countries againfl the bite of the viper, and could produce more than fifty recipes given me for the mofi part by country people, or by ideots. In one of thefe recipes men- tion is made of the ligature, but this ligature is joined to fo many other things to be done before and afterwards 5 and all of them fo abfurd, that no one would ever take the pains to examine, if any thing were td be expected from the ufe of this method. In general thefe recipes not only contra- did each other, but what is flill more, one remedy is oppofed to another in the fame prefcription. Some are introduced, having a fedative tendency^ and others on the contrary which difpofe to irri- tation. Some amohgfc them are cooling, others heating. The remedies themleives are in a great part abfurd and ridiculous, notwithilanding which the perfon who gave me thefe recipes affured me of their efEcacy, and feveral of them had been bit by

vipets/

ON POISONS. 4p

Pipers, and treated with them. I confefs that I have not had the patience to verify any of them by experiment, except fome few that feemed the leafl abfurd, and thefe I found totally ufelefs, and fome of them even hurtful. But at length I found in an authour, a method of treating the difeafe caufed by venomous fnakes, in which the ligature has a confiderable fhare. This authour is the celebrated Kempfer, w^ho fays he made ufe of it with the greateft fuccefs, in his voyages to India, and cured, fcveral perfons by this method.

Had I known Kempfer's method before I made- rny experiments on the pigeons bit by the viper, and which were cured by the iimple ligature, I ihould never have made ufe of it, and could not have believed it a certain remedy. I was too much perfuaded that the nerves had a great Ihare in the. difeafe of the venoiti : it was necelTary for me to know that all was brought about by the circu- lation ; it was moreover neceifary that the internal difeafe Ihduld not be communicated to the animal •^ as'to bccalion its death, till at the end of a cer^ tain time. I vv^as tlpen ignorant of all this, and was even perfuaded to the contrary. The bite of the viper in pigeons, convinced me that the internal malady w^as already communicated to the animal in twenty feconds, and that its death w^as riot occa- . lioncd by the external and local malady, but by the internal one. In thefe circiimftances it was eafy to believe that Kempfer's method would come too ]gte, and would be ufelefs on that very account ^-VoL. II« E alone.

^6 F O N TANA

alone. But I faould have had other reafons fof not trying it : Kempfer, in all his voyages, make& no mention of vipers, but fpeaks very much of venomous fnakes which are not yet well known^ it is not yet determined whether the venom of thefe is analogous to that ©f the European viper,- and whether it caufes a like difeafe.

1 could not belides have any confidence in a me- thod which I fliould rather have thought a hurt- ful than a good one. That of Kempfer conliils in feveral things whigh he defcribes as equally ne-^ ceiTary againft the bite of a fnake. He begins by a ligature above the part bitten, and then proceed* to fcariiications. He fqueezes the blood from thct wounded part, covers it amply with theriaca, and applies above all pieces of linen fpread with the fame. During the whole courfe of the difeafe h^ gives his patient fadorificks,

KempferViH^thod confifts then,, as we fee, rn fivo <Dr fix particular remedies, and it cannot be deter* fnined what good or what harm each of them may fee produdive of. Befides, every thing concurs to' give me a fufpicion of this method : there remains a doubt whether the ligature is proper or impro« j)er ; and S know by experience^ that fcarifications in the part are more hurtful than falutary, and that- fudorificks, like the volatile alkali, are of no ef- ficacy.

How many experiments ought not Kempfer t<^ liave made, to be certain that his method was good ^td effeaw^l ^gainft the bites of the many fnakes

O fi POISON So 5?

lie fpeaks of;> Imce to exclude to a certainty the fluid volatile alkali from the remedies employed in the bite of the European viper^ I was obliged to make more than 600 experiments ! he ought to have affured himfelf whether the venom of thefe Jnakes was in its nature mortal ; he ought to have known the average number of animals deflroyed by- it; and he ought to have multiplied and varied his experiments a tKoufand ways on all the different kinds of thefe fnakes.

But what is Hill more, Kempfer himfelf would have made me doubt his remedy, and his authority for it : in the fame work in which he fpeaks of this remedy, he alTerts that thejione of Fedro de Cobra cures equally well the bite of thefe fnakes.

It is in the firil place difficult to conceive why Kempfer has preferred the ufe of a long, com- plicated, painful, and difficult method, whilfl he h,d4 p,ne fp ^afy, commodious, and certain as this ijp^, which is found every where in thofe coun- tries : it fnullbe confeffed that this is far from giv- ing any confidence* It is befides known from the experiments of thofe two great Italian natura- iiils, Redi and Valifnieri, that this ftone has no efficacy in curing the bites of bur vipers ; whence it follows, either that the venom of thefe fnakes Kempfer fpeaks of is totally different from that of our vipers, or that Kempfer afferts the truth of par* ticulars abfolutely falfe and badly attended tp, and that his authority can on that ^^C9unt hstve no

weight*

E, a I now

52 :^ O ^^ 1* A N A

1 now think myfelf at the clofe of my prefent work, and fiatter myfelf that my labours may be- ef fome utility.

The bite ^f the viper conyeys to the perfons bitten the dread of its being fatal, and terrifies whole families. The perfualion of the difeafe being mortal/and that not a moment is to be loll, caufeS the application of remedies either violent or hurt- ful. The dread itfelf may increafe the complaint ; and there have been perfons who have received al--- moft imperceptible bites in the hands or feet, and vyho perceiving an in ftant after a vrper near them, haVfe ftiddenly fainted avvay.

I knev/ a man who feeing himfelf bit by a viper, fell into a fwoon from the iimple fright ; he re-» mained in this ftate miore than an hour, till he was obferved-by accident, and brought to himfelf by means of cold water thrown upon his face. Ani- mals in general who feem the mofl to dread the Lite of the viper, arid who tremble at tha very fight of this creature, die the foonell. Dogs,- who' are enra'ged when bit, and attack the vipers furi-' oiiily, make a great reiiilance to this poifon : I have at leaft thought I perceived fo in the courfe of my experiments on thefe animals. It cannot be doubted but that violent affediions of the mind, and the dread of approaching death, muft flrongly in- fluence the ftate of a ficknefs in man, • A perfon may very well die under thefe circum- ftances, who would not have died from the com^ p?aint ^loue caufed by the venom. A fimple bite.

of

OK P O I S ON S, 50

of a viper is not in its nature mortal ; and were there even two or three vipers, although the <:omplaint would become more violent^ it Vv^ould 4iot be" fatal in its effeas. Should a man even be bit fix or feven times by a viper, and ilieuld ail the ve- nom contained in its veficles be conveyed into the wound, yet ought we not to defpair of him. The complaint would become violent, but there is as yet no certainty that it would be mortal. A real confolation then, and a truly ufeful difcovery re- ftr^ts from having better examined than hereto- fore, the effedts of the viper's venom on animals of different lizes, and on man himfelf.

Experiments on the utility of the Ligature agahtft the bite of the Viper in fmall Birds,

Mere curiofity, and perhaps again the vanity of being able to cure with the fimple ligature the fmaller animals bit "by the viper, induced me to undertake various experiments on fparrows that had been bit ; and the refult of thefe experiments created doubts as to the ligature itfelf in larger animals, which I fhould otherwife never have en- tertained. I had not even a momentary doubt, fince a pigeon could be cured by the ligature, but that a rabbit, a dog, and ev^n a man, might be cured with flill greater eafe. The analogy was not only applicable in this cafe, but the n-^iture of the pigeon, the a^^ion of the venom on its blood, and

E ^3 th,e

f^. FONTANA

the effedts it produces on the animal, were fo many dired: proofs that the ligature ought to be a remedy certain in proportion to the largenefs of the ^imal, and the difficulty with which it dies. I was neverthelefs deceived : fo true it is that na- ture does not permit us to guefs at her operations ; that we know very little beyond experiment ; and that we feem even to be forbid to reafon on expe- riments themfelves. But let us proceed to thofe on the fparrows.

I had a fparrow bit by a viper once in the leg, which had fcarcely been bit when I bound it with a filk ribbon above the part. In thirty-five mi- nutes I removed the ligature, and the fparrow died twenty minutes after.

I repeated this experiment in all its circumftan- ces : the fparrow died ten minutes after the liga- ture was removed,

I had another fparrow bit once in the leg by a viper, and immediately applied a bandage above the bite : I took it off at the end of an hour, and half an hour after the fparrow died.

I repeated this experiment on another fparrow without varying the eircumftances, except that I removed the ligature at the end of fifteen minutes : in fifteen more the fparrow died,

I bound a fparrow's leg, and kept it in that ftate for four hours, when it was fcarcely altered in its appearance. 'I then contrived that a viper ihould 'bite it repeatedly above the ligature, which after •Vhree hours I took off. At the end of twent}^ hours

the

O N r O I S O N s. 55

tlie fparrow feemed Very lively, and fed. In eight days I found it .dead, although the leg was entirely healed.

After all th-e cafes hitherto related of the fpar- rows, it appears that the ligature may be fome- times an efFe6:ual remedy againfl the bite of the ■viper. The laft fparrow, which died at the end of >e,ight d.ays, proves nothing againil the ligature, fmce without it, it would have j^een dead in a few mi- nutes. I obferved befides, that the fparrows I kept caged, died of themfelves, and that the fmallefl: movements, or the leaft violence they fuffered, ia having them bit, or in applying a ligature, was fuf- ficient to kill them. Amidft thefe doubts I thought it neceffary to multiply tKe .experiments, and to vary them fcill more.

I bound a fparrow 's leg with a ribbon in the xifual way, and had it bit by a viper. The bite was juft above tjae Jigature : in fev;en minutes the fparrow died,

I bound the leg of ano.ther fparrov/ as above, and had it twice bit by a viper. It died in five hours, although the ligature was not removed.

I tied the leg of another fparrow, and had it bit by a viper below the ligature. In eight hours it <iied, the ligature continuing on the leg.

Having tied the leg of another fparrow, I had it bit twice by a viper, and removed the ligature in four hours after. It died at the endjof eight.

Thefe new experiments ihew that th-e ligature preferves the lives of fparrows bit by the viper^

E4 bw

§6 F O N T A N A

but not always. The fparrows that die feveral hours after its being removed, certainly cannot appear to die of the internal diieafe, lince the fmal- left quantity of the venom introduced into their blood is fufficient to kill them in a few minutes. It is likewife probable that fome of them die becaufe in having them bit by th^ viper, in binding their legs, and above all, in the removing the ligature, thofe who are thus employed, as well as thofe who hold them, mud inevitably do them fome injury. When the ligature is taken off, the leg is already livid and fwelled all over. This can never he fo ■well done but that the creature muft clearly fuffer from it. There are fome of them who no longer fupport themfelves, but beat their breafcs and legs againfl the cage, and in this ilate can neither eat tior drink,

I cannot doubt, after having had a great number of them bit, and having wounded feveral others with venomous teeth, but that all tliefe different caufes concur, more or lefs, to render the li- gature ufelefs in fparrows. Some were tied be- fore they were bit or wounded, others immedi- ately after. In fome the ligatures were removed at the end of four hours, in others fooner. Three I left conftantly bound, and ^leither of them died^i but I took care to nourilh them, without doing them any injur3^ Their legs became black, and intirely dried up. At the end of twenty days they fiew about the 'chamber, fupporting themfelves as well asthey could with the extremities of their feet,

Fiv^

O N P O I S O N s. 5^

Five others died in my hands almoft at the moment I had taken off the ligature^ and immediately after I had given them drink. Twelve others recovered perfectly, and the four 1 aft died in -between fix and ten hours. There were in all twpnty-four.

However favourable the refult of this 1 aft experi- ment was to the ligature, and however probable it appeared that feveral of thefe animals died from quite another caufe than that of the venom, I was not yet altogether eafy, and I thought it proper to repeat my experiments on animals of a larger Jcind, and of a different nature.

Ligatures 'made in the cafes of Fowls hit hy Vipers,

I had a fowl's leg bit feveral times by three vi* pers, and in three minutes bound it with a ftrong filk ribbon. In an hour I removed the ligature, and found the leg fwelled and livid in all the parts beneath it. In three hours the fowl died. The whole fubfiance of the mufcles bit was difeafed, and there were fome marks of complaint even above the ligature, at the fide of the belly, and in the breaft.

I had a fowFs leg bit repeatedly by two vipers, and after four minutes tied it over the part bitten. In two hours the leg was very livid and much fwel- led. I took offthe ligature, and at the end of twen- ty-two hours the leg Hill remained a little livid. The fowl recovered in two 'days.

I had another fowl bit in the leg repeatedly by

two vipers^ and after four minutes bouud the limb

which

38 F O N T A N A

which in an hour became fwelled and livid. Tw6 hours after I took off the ligature ; in twenty-two the leg was lefs livid and fwelled ;. and ii) four days the fovvd recovered.

I bound a fowl's leg very tight, and had it bit repeatedly by two vipers. It could not fupport it- ielf on this leg, which in two hours became fwel- led and livid. In eight hours I took off the liga- ture ; after twenty -two the lividity ftill remained, and even appeared above the part that had been bound, in forty-feven the fowl died.

I had a fowl's leg repeatedly bit by two vipers, and at the end of a minute tied it. In three hours I took oif the ligature, and found the leg fwelled and very livid. Three hours after this the fwelling and lividity had extended to above the ligature, and in fix mc : £ the fowl died.

1 had another fowl bit repeatedly by three vipers in the leg, which I tied two minutes after. In fix liours I took off the ligature, and in fix more the fowl died. The fwelling had reached above the liga^ ture.

I had the leg of another fowl bit repeatedly by three vipers, and tied it three minutes after. At tb^ end of nine hours I took off the ligature; the leg was fwelled and livid, and bled from every> part of it. The fowl recovered by degrees, the leg having a yellow and green hue which continued feveral days.

I had the leg of a fowl bit by two vipers, and bound it immediately af tier wards, but flightly ; in

twelve

ON POISONS. 5^

iweive hours I removed tile ligature, three hours after which the fowl died. The fwelling and livid colour of the leg had reached above the ligature.

I had another fowl bit repeatedly in the leg by two vipers, and immediately bound it, but tighter than in the preceeding experiments. I took off the ligature after twelve hours ; in fix miore the fowl died, with the fwelling and lividity extended to above the ligature.

I had the leg of another fowl bit repeatedly by two vipers, and tied it immediately, but Hill tighter than in the laft experiment. In twelve hours I re^-» moved the ligature, and in two more the fwelling and difcoloration had extended above it. The fowl recovered in five days.

I had three fowls bit in the leg, each by two vi- pers, and bound the parts immediately. Within the fpace of fix hours I removed the ligature from one of them, fufFering it to remain on the other two for twenty-four. In two hours after removing it from the two laft, one of them died; — the other recovered. The fowl whofe ligature was removed in fix hours, died in fix more.

■I had a fowl bit repeatedly by two vipers, in the leg, which I had previoufiy well bound. It died at the end of twenty hours, although the ligature had not- been removed,

Thefe experimients made on fowls, raife great fufpicions as to the cfScacy of the ligature againil the bite of the viper ; it has even appeared to me, and I do npt think myfelf deceived, -that the local

malady

45o P O N T A N A

malady is greater, with the ligature than without iU I obierve thisrdifFerence throughout the whole jour^ nal of my experiments, and it is difncult for me to have been miilaken, fince I have regularly compa- red the local malady of the limbs tied, with that of thofe which were not fo. Several fowls, as we have obferved, die before the ligature is removed, and that at pretty regular intervals. After the ex- periments made on the pigeons which recovered with 'the ligature, all this appeared paradoxical to me, and I could not conceive it poffiblc but that it ought to recover larger animals. I dreaded the not having ■'rriade my experiments on the fowls as I ought to have done ; that the ligatures were either too tight or too loofe; or that I had removed them -either to© foon or too late. In a word every thing feemed to me more probable than that the ligature was either ufe- lefs or hurtful.

In the midft of thefe doubts I determined to make my experiments on fome other kinds of ani- mals more extenfive, and for this purpofe made choice of rabbits and guineapigs.

Experiments on Guineapigs,

I bound the foot of a guineapig very tight, and had it bit repeatedly by two vipers. After twenty- four hours I removed the ligature, and found the foot fwelled and livid. In thirty hours it was lefs,

livid

ON :? d I s o N s. 6i

ih'id, but more fwelied : the creature recovered tti four days.

• I had the foot of a gulneapig bit by a vipex, and applied the ligature a few feconds after. In the fpace of an hour there were marks of difeafe in the part bitten. I removed the ligature, and after ten hours there were fcarce any appearances of its having been bit.

I had the leg of a guineapig bit repeatedly by a Viper^ and a minute after I bound it. In fifteen minutes the foot was fwelied and livid. I removed the ligature, and in ten hours the animal had fcarce any marks of difeafe. It recovered in twenty- four.

I had the foot of a guineapig bit repeatedly by three vipers ; and bound it a minute after. In two_ minutes the fymptoms of difeafe had already difco- vered themfelves. At the end of twenty hours the foot was very much fwelied and very livid. In twenty-four the leg difcharged blood and ferum^ In two days there was fome fwelling above the liga- ture, and ten hours after, the part bitten was cover- ed with an efchar. In fix days a total recovery took place.

I had a guineapig bit repeatedly by a viper, m the foot, which in two minutes I tied. After twen- ty minutes I removed the ligature, and found al- ready marks of difeafe in the leg. In an hour the tumour had reached the ligature. Xhe creature died in twenty hours^ with the leg fwened and livid;

and

j62 F O N T A N A

and the lividity had extended to the mufcles of the belly andbreaft.

I had the leg of a guineaplg bit feveral times by a viper, and bound it at the end of two minutes* In twenty minutes I took off the ligature, and found the leo; difeafed in the ufual way. In fix hours it was ftill a little fwelled, but not livid, and was hea- led in twenty-four.

I had a guineaplg limilar to the former one bit'

/feveral times by two vipers in the leg, which I

bound a minute after. In thirty minutes I removed

the ligature. The animal had fymptoms of difeafe

in its foot, but recovered in lefs than three days.

I had a guineapig*s foot bit repeatedly by a vi- per, and at the end of twenty feconds bound it. I removed the ligature fifteen minutes after, and al- tQsudy found marks of difcafe in the part* In two minutes more I perceived a motion of its head, as if it was convulfed, and in four hours it died. All the mufcles of the leg^ abdomen, and bread, were livid and inflamed.

i had another guineapig bit feveral tiines in the foot by a viper, and immediately after bound the part. In fifteen minutes I removed the ligature,- the local malady- difcovering itfelf in the leg. lit thirty-two hours there were fcarcely any ligns of" complaint, and in the fpace of forty-two, a perfed: recovery took places

It appears by the experiments hitherto related, that the ligature is capable of curing guineapigS that have been bit in the foot by the viper.

A com-

ON POISONS. 6^

A comparative experiment was necelTary to con-

Tince me that the bite of the viper was fatal to this

fpecies of animals. I had fix guineapigs limilar to

thofe 1 have jull fpoken of, bit each of them in the

leg by a lingle viper. They all died in lefs than

twelve hours.

Although fatisfied of the utility of the ligature, I

thought however it would not be amifs to multi- ply my experiments Itill more/ and to vary them m fome of the particulars.

I had the foot of aguineapig bit feveral times by a viper, and bound it, but very loofely. In thirty- minutes I removed the ligature, and found every" appearance of difeafe in the part bitten : hov/ever int. ten hours there was fcarcely any f^vvelling or lividity ; in thirty it was quite well,

I had another guineapig bit feveral times by a vi- /per, in the foot, and bound it {lill more loofely than in the preceding experim.ent. In an hour I, removed the ligature ; in ten there were fcarcely any- marks of difeafe, and in forty it recovered.

I had a guineapig bit repeatedly by a viper in the foot, and bound it, perhaps fiill lefs forcibly than in the laft. In two hours I removed tHe liea-: ture, and found the foot very livid and m.uch fwel- ied. In ten hours all was diminilhed, and in twen- ty-four there were fcarcely any marks of difeafe.

I had the foot of a guineapig bit feveral tim.es, and at the end of two minutes bound Ir. Soon as ir was bound, I had it bit again repeatedly by a fe- Cpnd viper. In thirty minutes I took off the liga-

turCy

64 F © N t A N A

ture, which was very loofe. In twenty-four hotir^ the foot was fwelled and very livid ; in five days the ?aiimal recoveredi

I had the foot of another guineapig repeatedly "bit by a viper, and in ten minutes tied it. I then had it bit by a fecond one. In tvventy minutes I removed the ligature, which was very loofe. In twenty-four hours there were fcarcely any fi gns of difeafe.

I had another guineapig bit in the foot repeated- ly by a viper, and in three minutes bound it, caufing it to be bit afrefh by a fecond. In twenty-four hours there fcarcely remained any appearance cf difeafe in the foot*

The utility of the ligature feems to. be m6re and more demonfiirated, and it appears alfo that a- very weak one is fufhcient. It- is true that it mufl be left on for fome time, otherwife the internal m.ala- dy is excited in the animal, and it dies in a flidrt fpace after.

Various experiments made oil guineapigs, bit aS above by vipers, have pointed out to .me that when the ligatui;e is removed in ten minutes, or perhaps more, after they have been bit, the animal dies ve- ry fuddenly, and that of the internal malady.

It is not difficult to difcover wdien the guineapigs die of the internal malady. When the complaint begins to commiunicate itfelf internally, the gui- neapig moves its head in all diredions, and feems td be convulfed. In this cafe death is certain, and follows in a faort time. I made thefe experiment^

^ on

OK POISON^. 65

ten very fmaUguineapig?, and I chofe thernfo/ that the eonlequences might be the lefs^qnivocaL

Experiments m Rahytts\,

Not content with having tried the ligattire oil guineapigs, I wifhed to try it once more on rabbits. I generally employed fmall ones> beneath the mid- djing fize. ....

I had a rabbit^s leg bit repeatedly by tw-o vipers and tied it immediately after. In nine hours it was greatly fwelled, with a difeharge of blood. In this ftate I removed the ligature; twelve hours ■ after which the leg was livid an-d gangrened^ in thirty . hours the rabbit died. -

I had the kg of another rabbit bit repeatedly by two vipers^ and tied it three minutes after. In an .Jl^ur {^df,a^ h^lf I took off the ligature* Infix ■Jiours t^e leg was very much fv/elled and livid .aibout the part bitten. In thirty hours the leg was fcarcely fwelled^ but remained livid. In three ad^y^S the animal appeared to be recoveredi >

I had a third rabbit:bit fev^raj times Tin^He,.}e.g by two viipers, and in two minmte,s b,ound the. part. Af- ter an ho\;irI removed the ligati^re, and found th^ leg fwelle<ii , In the fpace of twenty-four a difchargp ■^nfued, and in three days the ikin was corroded, and a fore formed. In fix days the rabbit was well recovered. Vol, II, F I had

66 Montana

I had the leg of a rabbit bit repeatedly by two vi* pers, and four minutes after I bound it. In aa hour and an half I removed the ligature. In four hours the leg was very much fwelled^ and difchar- ged a good deal. ^The fabMt died in thirty-fix hours ; the tumour of the leg having extended to above th^ ligatUre, where there Was aifo a livid ap- pearance.

I had three rabbits bit in the leg as above, but as they were deftined for a comparifon, made no ufe of the iigatuf e. Two died in thirteen hours. The third had a fore in its leg, which was otherwife "iiiticli difeafed ; but it furvived. •

The experiments as yet made on rabbits feem to prove that the ligature is not a certain remedy againft the bite of the viper in thefe animals, fince we have feeh_them die when it has been applied, and reco- ver fonietimes without it. I repeated thefe experi- ments on eight other rabbits, which I had bit in the ■'kg, each by two vipers. The ligature was not re- '^moved till after fix ' hours. Five of the "eight ^died/^'- - ■'■■ ^'

Seeing that the limple ligature was not ufeful to ill animals, I willied to try if, joined to fcatifications, it would be more (o ; and as the local difeafe is formed of blood, partly diflblved, partly coagulated, which corrodes and gangrenes the folids, I thought of uni- ting to the fcarificatiohs an antifeptick, fuch as the bark.

ON POISONS. ^7

Ligatures and fcarifications tried on Fowls and RabiJits*

i had a rabbit's leg bit by two vipers, and imme- diately tied it : in two hours the leg was fwelled, livid, and bloody;. In this jftate I made four longi- tudinal inclfions into it, at the part where the vipers had bit, and abforbed with linen the blood that flow- ed from the Inclfions. In this experiment I found that the mufcles were gangrened. The rabbit died in ten hours*

I had a fowl bit in the fame way by two vipers, an^ immediately applied the ligature. In two hours the leg was fwelled and livid ; I made fcarifications as. above. In four days the leg was covered with an efchar, and In ten the fowl recovered.

I had another fowl bit by two vipers. In the leg, :which I immediately tied. After two minutes I made the fcarifigations, walliing the blood from the tvounds for a long time with warm water, and cover- ing the leg with linen. In two days a black efchar •formed on the part ; in three days and an half the fowl died.

I had the leg of another fowl bit by two vipers and immediately tied it, making the fcarifications, and wafliing it with warm water. This being done, I lire wed a great deal of powdered bark on the inci- lions, and covered the whole with linen. In twen- ty hours I removed the ligature, and the fowl reco- vered in a few days.

F 2r Ire-

68 # O' l^T* ^ A K Jt

I repeated tfie above experiment iiT all its circtitiiV ilances, on another fowl. After twenty hours I re- m0Y€?d the ligature, and in twenty mare the fowlf died.

I had two <:hictens bit, emh. -of thtm % two vipers, feveral times in th© leg, whinh I bound a iho^rttiiiie 'after. I made tkc fcarifi cations, and ba- thed them lengrhways witk the Toiatik alrkali, very much diluted wlt^ water. After eight hours I re- moved the ligatiire from one of them, which died Ml thrfeeko^a^SiiTLore. At tbe fame time I k>ofene(i' the ligature of the other, and two days after it d-ied.

• I htid a fowl bit in the leg by two vipers; i bound the pvart, fcari&d it, waihed it, and covered It abundantly with the cortex. It died in the ipace of feven hours, even before the ligature was t©^ moved,

i had another fowl bit in -the leg by two vlper^^ atid immediately afterwaix^s tied: itv I made fcari* •f cations into it, and moiflen€4 It with warm water in which common fait had been 4ifr6lved. The fowl died in feteen hoiirs^- tfeiigature Hill remaiji- ing on*

This^ expcrimei^ I repe-at^d on two other fowls^ and made ufe as above, of the diflblution of foa falt> In twenty -four hours I removed the ligatures, and in twenty-four hours more the fowls both died.

After making the fcariiications, I tried the infu- fion of the bark on^ two other fo^ls bit as above.

In-

3:

^ n p p I s o N s. -6^^

fa twenty hours I removed t}xe ligatures^ and in. 4:w€nt-y more the fowls both died.

I had another fowl bit by two Yipers. in the leg^ which I immediately tied. I fcarified it, waihedi .it, and kept it immerfed in lime wat^r which I had made warm., for twenty-fiy e minutes. After twenty :hours I removed the ligature. la thi^ee days, thg fowl died.

I made the feiie experiment on another fowl^ keeping its leg for two hours in warm lime waten .Jn twenty hours 1 took off the ligature, ,and in thirty-five the fowl died.

1 repeated the ligature and fcarifications on ^ twelve other fowls, the leg of each having been bit t»y two vipers, and immediately tied. Four were fcarified, and the parts kept during an hour in a ilrong infuiion^of bark in warm water. In four .others they were ^kept for an hour in fimple wsLxm water, and thofe ,of the .laft four in a mixture of warm water and the volatile alkali. I covered the legs with linen, and in fix hours removed the liga- tures. Three of thofe treated with the bark, two treated with warm water, and three with the vola.- tile alkali, died.

The refult of the numerous Jatter experiments on the ufe of the ligature agaiaft the bite of the vi- per, neither affords us that certainty, nor that gene-^ .rality, we might have expedied on beginning them. Not that the ligature ought to be rejected as totally vfelefs, fince we have found it a certain remedy to pigeojpts and guineajpig?. It might feecon^e fo to

*JO F O N T A N A ^

Other animals, and perhaps would be ufeful to all, were the circumftanqes with which it ought to be tried, better known. It appears in general, that nothing ought to be expedted from fcarifications, whether larger or fmaller, or more or kfs flmple, lince we have feen the very animals fink under this operation, who would the eafiefl have recovered with ligatures only.

The ligature, by confining the blood to the part, produces a greater local complaint, and a ftronger difpofition to gangrene : for this reafon it fliould be pretty loofe^ and ought to be removed as early as poffible.

I cannot determine what utility it may be of in man, becaufe I have made no diredl experiments; but as I am of opinion that the viper's bite is nor mortal to the human fpecies, the ligature in this cafe can do no more than' diminiih the difeafe : a very flight one may perhaps b>e fufficient, and it may probably be removed in a little time. But expe- riments are wanting to enable me to fpeak to a cer- tainty, and thefe experiments are very rarely to be made on men.

I wiihed to fee if the difeafe which the viper's venom caufes in animals, diminiihes when the in- cifions are made above, below, or around the part bitten,

it feemed natural to fuppofe, that as the venom of the viper finds its way into the blood by the cir- culation, it would alfo introduce itfelf into the parts purpofely woujided, at leaft into thofe that ap-r

prqached

O N P O I S 0 N S. J I

|)roached the neareft to the part bitten. _ lathis cafe it likewife feemed very probable, that th,e quantity of venom being thus diminiflied by its more extenfive diflribution, not only the internal 4ifeafe, but alfo the external malady would _^^e ;di- miniihe-d too ; and that by this means the ga2)grene of the part.would be flopped, or at leaft rendered 2efs dangerous.

But the following experiments ihow the little de- pendence to be placed on analogical proofs, and probable reafonings in matters of fadt.

I had the leg of a fowl bit repeatedly by a iingle, but very large viper^j^- I made two fmall incifions into the inner part of the leg, above and below the part bitten. The fowl -died at the end of an hour, with the part bitten conliderably "difeafed, but withp out any change in the two artificial wounds.

I had another fowl bit repeatedly in the leg by a viper, and made a little incifion into the mufcles 43ppoiite to -the part bitten, and a fecond one iato the mufcles of the other leg. In fix hour^ tiie fowl was much difeafed. In thirty hours the leg was Hvid, even at a great diftance from the part. In €xty hours the fowl died, with the leg in a gan- 'grened llate. In all this time I obferved no change in the two incifions.

I repeated this experiment on different animals with the fame fuccefs, and never perceived that the artificial wounds, were affedled by the venom ; 1^.> that it feems to be a truth eflablifhed by experimeji,^, ;<that the venom once introduced into the blood, and

F 4 circU"

ft F O N T A N A

circulatbg with that fluid, may occafioii death | but that it cannot conin:iunicate itfelf to fimple in- cifions, even when made in the vicinity of the parts bitten.

I feel that I have been two prolix, I might have been lefs fo, and perhaps even mare clear, had I followed the fynthetick, inftead of the analytical method. I preferred the latter, prefenting my expe- riments in the order in which I made them, I have not even dreaded the difclpling my errours, and the Ihewing how often I have been obliged to begin over again. The analytical method is certainly nei- ther the Ihorteil nor the mq^ favourable to a wri- ter ; but it is the iTioil certain, the moll iuminousj, and the only one w^hich leads immediately to a dif- covery.. It infpires the I'eader with confidence, Ihows in what way the naturalift has fearched into nature, and in what way fhe has anfw^ered to his refearches. His faults are at the fame time obfer- ved, the efforts he makes to come at the truth, and the difficulty of attaining it.

Works that prefent fomething new, ought all to be written in the way I have m^ade choice of inpro- i:eeding thus far. When the methods are feen which have led to difcovery, the merit of the work, and the authour*s opinions will be the befl judged of; all will b^ free from that myftery and referve which abound in writings formed on the fynthetick plan, in which the traces are wanting |:hat have guided to 2f difcovery. But rrian loves rather to be admired

than

ON POISONS. Jrj

ehan ufe&U marvellous than true, difEcult than im- partant,

I have made more than 6000 experiments; I hav^ bad more than 4000 animals bit ; I have employed upwards of 3000 vipers^ and may have been de- ceived ; fome effential circumllance may have efcaped me : I may have negledied fome other, not thinking it neceliary ; my confequences may Jiave been too general, my experiments too few in number. In a word, I may very eafily have been miftaken, and it would be almoft impoffible that I Ihould never have been fo in a matter fo difficult, fo obfcure, and likewife fo new. It is fulEcient for me. to declare the having written nothing but what i have feen, or at lead have believed to fee.

In reviewing my journal of experiments, I per- ceived fome miftakes in it, and found that I had written in fome places, what I could not poflibly have obferved. It likewife happened to me fe- yeral times, in copying the experiments from the journal, to read in one way, and write in another. This is a new fource of errours into which I may eafily have fallen. How little certain are we, even Jn things we believe ourfelves befl fkilled in, and in which we have the leaft apprehenfion of being mif- taken 1 I know but one clafs of people who never err i thofe who do nothing, obferve nothing, and make no experim.ents. All others are led into lerrours ; and the m.ore experiments they make, the itiore they are deceived : but we muil not defill on Ithat account from confulting nature, and ought not

to

'^4 F O N T A N A

tG bluih when a Newton himfelf, who w^as fcarcclf ever miflaken in the fublimefl calculation, has been deceived in matters of mere fad: and experiment.

it is incumbent on me likewife to obferve, that a part of my experiments on the venom of the viper, was made in the rudeft fcafon, -in winter. It is natural to conceive, that the vipers I employed could not be in full vigour ; that they would exert !efs ftrength in biting the animals ; and that not having been nourifhed for feveral months, their ve^ nom would be in a lefs quantity. I can eafily con^ ceive, that in a more favourable feafon, as in the fummer, and in a warmer climate, the effedls would he in fome way different, and in general greater.

I might Hkew^ife have been deceived by thofc who furniihed me with the vipers, I had a cuf- "^om in the beginning, of returning thofe I had em- ployed in biting the animals, when I had no occa- sion to kill them. I have every reafon to believe, that the vipers already made ufe of, have been fold to me a fecond time : this i no fooner fufpedred, than I determined to kill them without referve, after having employed them in my experiments.

On all thefe accounts, and perhaps on many others which I am ignorant of, my experiments might be liable to fome variation, w^ere they to be repeated ; but this does not render the principal truths I have deduced from them lefs certain. I hope t;hat my work will be diftinguifhed by the -experiments, inductions, obfervations, and confe- quences it contains. If my confequences are falfe,

and

ON POISONS. 75

and my indudions unjuft, my readers will foon peixeive it, and no errour will be occaiioned by them. But if I have been miftaken in the fads themfelves, if I have not made my obfervations well, my miflakes will be communicated to others, and will ferve as a bafis to a falfe theory. It is for this reafon that I have endeavoured to be as exadt as poffible in the fads, and have entered into a long detail on feveral of them. In feveral places I have defcribed my experiments at length, and in a great number. I might have been lefs tedious ; I might have given the fmiple refults ; but I muft then have been believed on my word, and my readers have been deprived of the pleafure of judg- ing for themfelves, which can alone lead to evidence and convidion.

Befides the greater part of my experiments re- late to queflions entirely new, and in regard to which either nothing has been done before, or the obfervations badly made. It was therefore necef- fary to extend them in fome meafure, and I hope my readers will thank me for fo doing.

Now, that a bails of experiments, and of deter- mined fads, is formed, on the bite of the viper, the naturalift will continue his refearches with more eafe^and will prefent them with more brevity.

APPEN-

^6 MONTANA

A P T END I X

TO THE

RESEARCHES

INTO THE

¥ E N O M OF THE VIPER.

Two years after having made at Paris, where I then was, the experiments on the viper's yenora which have been related in this work, I was inform- ed in London, on my making fome flay there, that a certain fpecifick againft the bite of this creature, was juft difcovered in Italy. The little fuccefs I had met .with in France and in Italy fome years before, in my fearch into an efficacious remedy againft the venom of this creature, gave me a very earneft de- fire to enrich my work with fo important a difco-

very.

His

O N J* O I S O N s. 7^

His Excellency, Count Belgioyoib, AmbafTador from the Court of Vienna to L^ndon^ wlio efteemisf the fciences becaufe he knows the importanee of them, had the civility not only to procure me th^ treltife publiihed in Italy on this remedy, but like- wife to give me one of the Jiones which are the fubje€t of this treatife, and to which are afGribed' th€ faculty of curing the bit^ of the viper. This- bad been fent from Milan, and had been prepared by the author himfelf. On this occafion I was Ihown fererkl letters from Milan and Vienna, whicii related wonders of this new, but already fa- mous remedy. Miracits had "been doi^e witli it, they faid, at the firft of thefe two places/' and t-hey affirmed that the beil phyiicians of that famous city had a knowledge of them. They likew^fe added, that the rare and very important difcovery had been made, that the fo much boafted cobras Jiones w&xq mt^^ ^thing more thran calcined hartihorn.

The'tfetife Tread was entitled, Tr£alifi m The Efficacy of an Alexipharmick againfi the Venoifi of Vhs Viper ^ by the AbM de Tecmeyer{a), It contains di» vers experiments which defei'V€ attention, and which tend to prove that calcined hartftiorn is a certain remedy -agarnit this creature's bite. ;

The perufual of this treatife gave ine ^'ftiil greater defirc'of verifying, myfelf, the utility of this ^boafted remedy ; iince the on-ly .way to be af«

. ;M to ■ _ ■

' {a) This treatise Avas printed in the EAjeeoLTA tyi O^tns* «0'irrScELTi, of Milan,

fured

7§ .FONT A N A

fured of an experimental truth, is- to have recour^ to experiment itfelf. The . different cures related by the Abbe Tecmeyer, however brilliant and ex- traordinary they may be, are neverthelefs neither fo numerous nor fo varied, as I at leaft ihould have defired them in fo important a matter. Neither could I conceive that - hartfhorn, calcined only to blacknefs, as the Abbe Tecmeyer will have it, could be a certain remedy, whilfl calcined w^hite, in w^hich way I had tried it in France-, I had not found it of any value. I hov/ever thought it necefiary before I ventured my opinion, to make a great number of experiments on different animals with this /q?z^, which I ihall agree with the authour in call- ing fo.

It is likewife true-that on reviiing this treatife, it appeared to me that the authour of this new fpe- cifick gave too much extenfion to his remejdy, and that many things are there advanced too readily^ •which have either not been fufficiently proved, or are not altogether certain. -

For example, he is of opinion that the . fmall piece of burnt hartlliorn applied externally to. the wound made by the viper, heals it by virtue of the volatile alkaline falts contained m the hartlhorn from which it is prepared ,

He maintains that the viper's venom is princi- pally compofed of acid falts, and quotes the au- thority of Mead, and his own obfervations made with a microfcope. He even fays, that with this

venom

o N ^ o t S O N S. 75f

Venom he has changed the blue dye of the turnefol red. -

He believes that burnt hartlhorn abforbs the ve- nom of the viper, becaufe it turns milk yellow, after it is removed from the part bitten.

He finds his remedy efficacious againft this ve- nom, ten hours, and even more after the animal has been bit by the viper, and when the fwelling is vtvf great, the fymptoms very violent, and the indica- tions of approaching death very certain.

He finds it equally ufeful againil the bite of a mad-dog; ai^d fuch is his good opinion of thefe marvellous Jiones, that he believes by virtue of them, the having cured wounds made in the pof- teriors of a man with the teeth and claws of a ti- ger.

Laflly, he does not think it impoffible but that the tooth of the caiman, a fpecies of crocodile, fimply carried in the pocket, will cure the bite of a viper.

He afferts afterwards, that Redi is miftaken in fuppofing that the cobras Jlones are no fpecifick againil the bite of the viper ; and he believes that this celebrated phyfician made his experiments on falfe ones. The thing is certainly poffible; but if -the true and efficacious ftones are nothing more than pieces of badly calcined hartlliorn, I do not fee what could have induced them to impofe on Redi, in giving him falfe for real ones, fince the latter might fo very eafily have been made. Befides, it appears that Kempfer thought but little of thefe true ftoiies, called by the Indians de cobras di cabcllo^

and

S6 [t d N T A N A "

Bnd tliat he did not place the fmailefl confidenticf • in them. In his Amienhates Exdtic^ he fpeaks erf til em in the following manner : de efficacia hujits iapidis, et qtm in dies cum ipfo dijlinguuntur it India experimentis multa ^dictnda, i?iqulrenda, dubitanda 'uemreM^^a), Saltern fateor ingenue penes me valorem lapidis femper manjijfe in fufpenfo, dum quid err oris ^ et fallacia fublatere pojfet propriis experimentis non ex^ ploraverim {b). And he knew them lb well that ht defcribes them, and neither believes them natural Hones, nor engendered in the brain of the fnake; he even fecms difpofed to think them made ^ liartfhorn : fubjlantiam^ fays he, in fpeaking of the(b Hones, obtinet jirr/iam et duram^ levem tamen^ Mc ihi porofamy et quodammodo cvrneam, iM ut appareat for- matus ex cornu cer-vi in vapor e vel liquor e aliquo mace^ rato tlnUoque ; niji forte fragmmtum jit lapidis Con- noor variegati it a hie lapis JlBus a patria Conmor muU tutrix provincial lufitanis ibidem ^ Pedra frigue dMa ^ ^ualitate refrigiraTtte^ ejlqiie tripUcis differentia Jive coloriSy nimirum albus, citrinus et obfcur^ cceruleus, qui pojiremo nephritico lapidi in omnibus prater levitatem Jimiilimus eji^ ^.otquot videre mihi contingit per In- diamfirmam et infularem pr^diUa cenditionis et figura fuerunt. §ualifcumque figura fuerint prima fronte op- parehunt baud quaquam naiurales^ et in terebro vipera^ * quod vulgo creditur, genitos ejfe, et Ut frufira fmrit^ qui illos in anguium capitibus quarerint (r)*

{a) Kempheri Amsnitates Exoticse, Lemgoviae^ 1712*

Fafc. III. p. 579. {h) P. 580. -n.. [c) P. 581,

Such-

ON POISONS* 8l

Such are the opinions of the Abbe Tecmeyer In this treatife, and I confefs they have appeared to me very lingular.

But fhould it even be true that burnt hartihorn cures the bite of the viper, I can never be induced to believe that fuch an efFed: is due to the alkaline falts of this fubflauce. I have demonflrated^ fo as to place it beyond a doubt, that the fluid alkali it- felf is of no utility in this difeafe, and that the ve- nom of the viper in fubilance, mixed with alka- line falts, preferves all its activity, and kills as heretofore*

It is beiides an errour, that the venom ' of the viper is compofed of falts, and that thefe falts are acid ; and it is alfo falfe that it changes the tindlure of violets red. In the courfe of my work I have already pointed -out the errour of Mead, and of other naturaliils, who have fucceeded him, as to the falts in the venorn of the viper. It is lingular to fee millakes repeated by others, which were re- futed more than ten years ago.

The flight change of colour obferved in the milk, which is in itfelf in a degree yellow, cer- tainly cannot be caufed by the hartlhdrn's abfarb- ing the venom, on being applied to the part bitten ; ,for'a quantity of milk fcarcely fufficient to cover the bit of hartshorn, will not become yellow if the venom of feveral vipers be united with it. This colour of the milk is caufed by the blood's being abforbed by the hartihorn when applied to the

Vol. IL G ^ bitten

z'

8i F O N T' A' N A

bitten part ; and in fadt it tinges it equally wken applied to a part wounded but not envenomed.

But it is time to proceed to experimeiits, which can alone determine whether a piece of burnt hartf- horn is, or is not, a certain remedy againft the venom of the viper. It has been feen in feveral parts of this work, how little truft Ihould be re- pofed in experiments, even when they appear the moft conftant. I have fometimes feen five, fix, and even more animals recover, one after another of the bite of the viper, and fhortly after as many of them die, without my having done any thing to them in either inflance : and 1 have fometimes met with the fame confequences in applying the fame re- inedies to the fame animals in the fame circum- llances. In one inflance I Ihould have judged that fuch a fubftance was a fpecifick againft the bite of the viper, and in another that it was either hurt- ful or totally ufelefs.^ This is the rifk we incur iri not fufficiently multiplying experiments. I do not pretend to have myfelf guarded againft this incon- venience in all the parts of the prefent work on the venom of the viper, although it is true that I have varied and multiplied the experiments exeedingly, as much at leaft as my circumftances at the mo- ment permitted me.

But in the prefent cafe I imagined that a limited number of experiments would fuffice to determine the utility of this remedy. The many obfervations 1 had already made on the bite of the viper, and the knowledge they had given me of the animals

1 wiihed

ON POISONS. 8§

I wlihcd to employ, enabled me to forbear the hiultiplying them Itill more.

The firfl thing to which I applied myfelf to fucceed in my e^iperimehts, was to procure a fuf- ficient number of pieces of hartlhorh, prepared in the way defcribed in the above cited treatife, and quite black. I had taken them from that part of the horn which is fixed in the animal'ss head. Applied to the tongue, they adhered llrongly to it. I prepared many of them, and df this number I chofe the bell, to the end that my experiments might be made at the fame time, on the fame animals, and with the farrie circumilances. After having made ufe of them, I put them in milk or in wine, as the authour direds, and having left them there for feveral hours, I afterwards ex- pofed them a great while to the fun^ or to a gentle lire, till they adhered to the tongue as before. I had likewife the advantage^ as I have mentioned before, of having had one of them brought from Italy. I made ufe of thtf^Jiones feveral times^ with the fuccefs that will be feen.

Before I give the principal confequences of mv fexperiments,4 I think it proper to obferve, that I began them in London ill the month of March, and did not finiih them till the latter end of the month of May. Although it was the mildeft feaforf that had been felt for fome years in England, it did not prevent feveral days being very cold, in confe* quence of which my vipers feemed to me to be much benumbed and very inadive. In general 1

G 2 thought

§4 ' ? O N T A N ^

thought that I found them lefs adive there than iiS France, and leis fo in France than in Italy ; fo that the confequences of my experiments on thefe ani- mals mull differ fenfibly^ but only from greater ta lefs. It is however true that vipers are venomous in all countries, and that their venom can kill. To accomplilh this aim in cold climates, with as much certainty as in warm ones, it will be fufHcient ta make them bite the fmallell animals, or to employ feveral to bite a fingle one. In this way the effeds may be rendered nearly equal in all countries, and at all feafons. Thus then, the adlion o-f the viper'^s venom is in proportion to its quantity, when all other circumflances are abfolutely equal; they however vary to fuch a degree, that one can fcarcely pronounce any thing certain on th^m, even when every poffible ilep has been taken to fucceed, and to caufe all the trials to be quite alike in their cir- cumflances. Lee us proceed to experiments.

I had a pigeon bit once in the right leg by a vi- per, and at the fame inftant applied to it the Italian flone^ which immediately faftened, and remained on. Seven minutes after the pigeon gave tokens of difeafe, and was dead in twelve. I detached the ftone by force, and put it in milk for other experi- ments.

To make a comparative one, I had another pi- geon bit in the leg by a viper, and it died in fix- teen minutes.

I exprefled the venom from the teeth of a viper forced into the mufcks of a pigeon's leg, and ap- plied

<3 N F O I S O N S. 85

plied the Italian Jlone, which faflened immediately to the wounds. The pigeon died in eighteen mi- nutes, without tHeJione having detached itfelf.

I made the fame experiment on another pigeon, with teeth taken from a fecond viper, and it died in twenty-two minutes.

I had a pigeon's leg bit once by a viper, and im^ mediately applied the Italian Jlone, which did not loofen of itfelf. The pigeon died in four hours.

To make a comparative experiment, I had ana- ther pigeon bit once in the leg by a viper, and ap- plied thejlone wrapped in a piece of bladder, bind- ing it to the part. The pigeon died in eight hours, the bandage having probably retarded the adtion of the venom.

Another pigeon bit in the leg by a viper, died in two hours, although the Italian Jione iliil adhered to it.

I had another pigeon bit twice by a viper, and made a v-ery fmall opening with a lancet at the place where the teeth had penetrated, imm-ediately ap- plying to it the Italian Jlone. The pigeon died in iix minutes, thejione flill adhering.

I had fix other pigeons bit by as many vipers. To four I applied the Jlone, to the other two I did not. One of the laft died twenty minutes after, the other in an hour. The firil four all died in lefs than twenty minutes, and one of them at the end of eleven. Tht Jio?ies were iliil attached to the parts bitten. - •

G 3 This

86 FONT A N A

This experiment was repeated on fix other pi- geons, to each of which 1 applied a Jione. They all died ; three in fixteen minut'es, and th?ee in twenty-feven. Five of the flones continued to adhere : the one which fell, belonged to a pigeon that was one of the iatefl: to die.

) Experiments on ^adrupeds,

Perfuaded of the little efficacy of thefe Jlones in the cafes of pigeons, I wifhed to fee if they would be of more ufe to quadrupeds. I^ made choice of fmall guineapigs and very fmall rabbits.

I had a guineapig bit in the leg by a viper, and having dilated the wound a little, applied the Italian Jione to it, which fallened very well. It died an hour after, the Hone flill remaining on.

I had the leg of a guineapig bit by a viper, as above. This one died before the {lone was applied to it, and almoil at the moment of its being bit : a very rare cafe, and fuch as I have obferved only once in the courfe of rny experim^fits on the ve? nom of the viper.

I immediately had another bit in the fame way, and applied nothing to it : it died four hours after.

At the clofe of thefe lall experiments I had fix guineapigs bit fuccefilively ; to four I applied the Jlone, to the other two I did not. Three of the firft died in two hours, and one of the ^wo laft in

twenty-

8t

twenty-fix minutes. The two others had no per- ceptible complaint.

Thefe experiments on t^e guineapigs likewifc bear witnefs to the inutility of the propofrd re-, medy.

I however made flill fome others on rabbits, and can certify that the refult of them was entirely con- formable to that of the preceding ones. The de- tail of them here would be tirefome. The fad: is^ that they not only did not prove the Jione ufefui againll the bite of the viper, but gave the cleareil evidence on the contrary, of its being totally ineffir cacious.

Let not particular cafes be urged againft me^ .cither of animals recovered, or of men who have been bit and have not died, after the application of the cobras Jlone, Experiments on m.en prove no- thing, lince the viper's venom is not ufualiy mor- tal to thern, any more thaa it generally is to large animals. To determine if this fione is ufefui or not, experiments mud be oppofed to others made on animals on whom no remedy has been tried, and it is necelTary to make a great number of them. For example, let one hundred animals, fuch as pigeons, fmall rabbits, and guineapigs, be coir ledted, and let them be bit by as many vipers, an equal number of times in the fame parts. Let half of thefe animals be treated witii cobras Jloncs, or other boailed remedies, and let thofe which re- main be left tothemfelves. Let the number of thofe that die on each fide be remarked, and if there is . G ij. a very

88 F O N^ T A. N A

a very fenfible difference in favour of the remedy applied, I Ihall fay that that remedy is, probably ufeful. If the fame experiment is repeated two or three times on the fame number of animals, and the confequences are always the fame as in the firft cafe, I ihall then fay that the utility of the remedy is a truth demonflrated by experience, but it will not, on that account, be a fpecifick, a certain re- medy. To be fo, it will be neceifary that none of the animals, or at leafl a very few of them, die. But after the many experiments I have made, I look upon this fpecifick as impoflible, or at leafl I do not think it will ever be difcovered. This is pot a confoling idea, buC it feems juil. I do not wifli to difcourage any one, or to keep others from making new refearches; but too fanguine a hope frequently caufes that time to be loft, which might have been ufefully employed.

I hope that certain perfons will not be fo eafily ^ difpofed to believe in prodigies, and to trumpet forth dreams as very important difcoveries; and that certain other perfons will miftruft their own ftrength a little, and even fometimes their own ex- periments: for it is eafier to believe tlxan to judge, and it is likewife eafier to fee imperfedily than clearly.

Experiments according fo the method propofed hy Kempfer,

I fhall finifh my experiments on the venom of the viper, by a detail of what I have obferved iir

making

O N P O I S O K S. 89

making trial of Kempfer's method againfl the bite of that animal, that is to fay, in employing fcari- iications and the theriaca. I relate it the more willingly, fmce in trying Kempfer's method, I thought it proper to make fome experiments which ought to be rendered publick.,

Kempfer propofes theriaca, fcarifications, and !!• gatures, as a certain remedy againil the venom of the viper and other fnakes. In the courfe of my experiments I have already proved the inutility of theriaca applied to the part bitten, or taken inter- nally; and have obferved that fcarifications and liga- tures, inflead of beings ufeful, are conliderably in- jurious. It is true that I never have united thefe remedies; it would^ however, appear tome very lingular, could they be only ufeful Vv^hen joined together. It is the more neceiTary to have recourfe to experiment, lince Kempfer, a very grave au- thour, aiTures us that he has found his remedy con- ftantly efficacious, „and has cured ail the perfons to whom he could apply it in time.

I had a guineapig bit once by a viper, either in the leg or foot. Having applied a ligature, I made flight fcarifications in the part, fqueezed out the blood, and covered the whole with theriaca, oblig- ing the animal to fwallow the fame, mixed with water. The guineapig lived, but a part of the foot gangrened, and it was never afterwards of any ufe. I had another guineapig bit twice in the foot by a viper. Having made the ligature, I fcarified the part nightly, prelTed the blood froiia it, and co- vered

yO FONTANA

Tered all with theriaca, with which I rubbed the foot well. The animal fwallowed a great deal of theriaca mixed with water; it loll the ufe of its foot, but recovered.

By way of making comparative^ experiments, I prepared two guineapigs as above, but only made the ligature and fcarifications^ neither applying the theriaca, nor giving it internally. One died in five hours; the other lived, but like the former ones, loft its foot.

The confequences of thefe experiments are nei- ther uniform nor in fufficient number, to decide as to the inutility of Kempfer's method. I thought it neceflary to make frelh experiments, and to vgry them a little, operating likewife on different ani- mals.

I had the leg of a guineapig bit twice by a viper. It was tied and fcarified, the blood fqueezed from It, then well covered with theriaca, which, when diffolved, I made the animal drink repeatedly. It died in two hours.

Another guineapig, fomewhat fmaller, was treated in the fame way, and died in four hours.

I had another guineapig bit as ufual, and did no more than fcarify and apply the ligature : it died in four hours and an half*

I had another, a much larger one, bit, and did not treat it all. It died in three hours. . I had four others bit. by as many vipers, each twice in the foot, and treated all of them accord- ing to Kempfer's method. Two died in lefs than

four

ON POISONS, ^1

four hours ; the other two came off each with the lofs of a foot.

Havmg had fix other guhieapigs bit as above, I treated three as ufual^ but not the other three* Two of thofe treated died, and the third recovered without lofing its foot. As to the others, one of them died, another was very ill, and the third reco- verecj, but loft its foot.

With fome ones I afterwards had bit, I tried fca- rifications and ligatures, and covered the wounds with theriaca, Vv^ithout making them fwallow any; others, on the contrary, fv/allowed the theriaca, ^dthout having fcarifications made, or ligatures or theriaca applied to the part bitten. The confe- quences appeared to me to indicate the inefiicacy of the theriaca applied to the part, and to admit conclufions that the fcarifications and ligatures do a great deal more harm than good, becaufe in general they difpofe the parts to gangrene the readier. I could not determine that the theriaca taken inter- nally was ufelefs, fince the events, though neither fufEciently conftant nor numerous, were more fa- vourable to it than not : but to be better aflured of this, a greater number of experiments are neceifary, ^han that I was enabled to. make; and although the utility of it fhould be fhown, I believe that many other fubftances capable of accelerating the motion of the blood, would be equally ufeful.

I made many other experiments on pigeons and fmall rabbits, conforming myfelf to Kempfer's method, but did not find them more favourable to

his

^Z FONTANA

Ills fyilem, than thofe cited above; fo that I do not liefitate to declare that this method is neither cer- tain nor ufeful^ ar^d that on the contrary it muft appear in the highell degree dangerous, efpecially to large animals.

But Vv^hatever may be the inefficacy of the re- medy propofed by Kempfer, 1 however found it Angular that feverai of the pigeons recovered, al- though the difeafe of the venom declared itfelf with the moft violent fymptoms. This appeared to me fo ilrange, that I determined to repeat fe- verai experiments^ and to examine afrefh whether different fubilances I had tried before, and found totally ufelefs againft this poifon^ were really fo.

Suhftances employed againjl the Bite of the Viper ; to wit, quicklime, magnejia, caujlick alkali, ahforhent earths, and calcined hartjhorn,

I had a pigeon bit in the leg by a viper, and Having made two flight fcarifications, I covered the part with quicklime, which I kept on with a loofe bandage. The pigeon had the difeafe of the ve- ndm; the leg fwelled and blackened, and a fore formed itfelf: but in fix days all came about.

Having had another pigeon bit as above in the foot, and having fcarified, I applied quicklime; it died in twenty minutes*

I re^

O N P O I S O N S. ^3

I repeated the fame experiment on two other pi- o-eons ; they were both very ill, but neither died : in feyen days they were perfectly recovered.

I was defirous of repeating the fame experiment on fix other pigeons ; two only died, although all the lix had the difeafe : however one of them loft its foot by a gangrene.

I took two of thefe recovered pigeons, and had them bit each feveral times in the leg, by two vi- pers. Having made the accuflomed fcarifications, I applied the quicklime ; one died in twenty-feveia minutes, the other in lix hours. • Of fix other pigeons bit and treated as abovcj with fcarifications and quicklime, tv\^o died, thf^ other four all recovered in nine days. Two. of them had the mufcles of their legs fo gangrened, that they never could ufe them afterv/ards.

I repeated the fame experiments on fmall guin^ear pigs and rabbits, and the confequences of the^ were far lefs favourable to the ufe of. the "quick- lime, than in the cafes of the pigeons. I however in my firil attempts fancied it not to be totally ufe-. lefs; but hov/ever it be with quadrupeds, it is cer- tain that I deemed it of ufe to pigeons, all of which ufually die when the difeafe of the venom communicates itfelf to the part bitten : fuph is ^t leaft the refult of experiments made at Paris. The pigeons' legs when bit, became fwelled and li- %^id, with fymptoms of gangrene; and feveral of the abdominal mufcles, as well as all thofe fur- rounding the wound, were b]ack.

3 It

94 t o n r A n A

It is belides true that I have had confequerices Very analogous to thofe of the lime, on applying abforbent earths, fuch as the different boles, but above all, Engliib pipe-clay, to the parts bitten. Many of the pigeons recovered, although the great- eft number died, with all the fymptoms of the dif- eafe of the venom.

However I very much fufpedt the utility of thefe remedies^ and the cures they have effeded, becaufe I have met with feveral recoveries without apply- ing any remedy at all. I have had pigeons repeat- edly bit, and the venom was well communicated to the parts, fince feveral of them loft their feet by the gangrene vv^hich fupervened ; the inflammation and ftoppage of circulation were extended to a great part of the body, and the animals recovered, al- though not perfectly till at the end of eighteen of twenty days. I generally obferved at Paris, that the fmalleft quantity of Venom was fufhcient to kill a pigfeon, lince it had fymptoms of the difeafe, fo that I am now perfuaded that there may very caiily be a difference betwixt the venom of one vi- per, and that of another; betwixt the venom of vipers of one country, and of thofe of another ; and betwixt the venom of the fame vipers at dif- ferent feafons. In this way may be conceived why great fcorpions are mortal in fummer, and not iri winter ; and why the pigeons bit by a lingle viper^, and treated with oil before feveral of the Members of the Royal Society at London, recovered. It muft> however, be obferved^ that it is not impoJEble but

that

OK POISONS. 95

that the poifon Introduced into the animal was not fufficient in quantity to produce a dangerous com-r plaint. We have {Qen feveral fi milar cafes in the. cpurfe of the preceding experiments.

TREA-

96 F O N T A N A

f

TREATISE

ON THE

AMERICAN POISON

CALLED

T I C UNA S*

ANI5 ON SOME OTHER

VEGETABLE POISONS.

l HE experiments 1 made at Paris four years ago on the venom of the viper, and which are a continuation of many others I had publilhed ten years ago in Italy on the fame fubjedt, have enabled fne to fpeak with certainty on the nature and pro- perties of this poifon* The unexpedled and im- portant effedts which I have obferved in applying

* This poifon Is thus called from the name of the Indians amongflwhom it is prepared. Mem. del' Acad, des Sciences. Ann. 1745> p. 490.

the^

ONPOXSONS. 97

ihe venom of this animal to living bodies, have prefented me new truths as to the animal economy ; and thefe new truths have by degrees conducted me to a doubt of certain medical theories which are not fuflicienrly proved, or which have become too general amongfl praditioners.

I have iince wiihed to extend my refearches to other venomous fubilances, and was deiirous to ex- amine^ if poilible^ one of the mod adive vegetable poifons. I figured to myfelf that animal poifons^ as for example, that of the viper, v applied to a wound, do in truth difFafe themfelves in the body of the animal^ but do not on that account become augmented, as does dn the contrary the variolous venom (a), or that of a mad animal* I figured to myfelf, I fay, that thefe poifons had a great ana- logy betwixt them, and that they adied in the fame way, and on the fame parts of the animal : but oa the other hand, I could conjediure nothing as to the adtion of vegetable poifons, which I had not yet examined, and it did not feeni to me poifible to eflablifli'any certain principles on them, even after reading the principal fymptoms they excite. The mode of making experiments, which had been fol- lowed^ was very different from that I had employed in examining the venom of the viper, and the de- dudlions drawn from them feemed to be too vague and uncertain;

(a) The matter of the fmall-pox.

Vol. IL H On

^8 F O N T A N A

On mv arrival in London, I was enabled to fa-* tisfy myfelf with eafe on the fubjedt. Mr. He- berden, a celebrated phyfician there, and member of the Royal Society, procured me a great number of American arrows well preferved, andwell cover- ed with the poifon ; he had befides the complaifance to get me a good quantity of the poifom itfelf. I found it enclafed and fealed in an earthen jar, the tin cafe of which iiill remained on it. Within the cafe was found a paper^ on which was written as follows : Indian poifon brought from the hanks of the Amazons by Bon Pedro Maldonado : it is one of the forts mentioned in the Philofophical 'Tranfa^ions^ vol* 47, No. 12*

In this volume of the Philofophical Tranfadion^ mention is made of two poifons of pretty much -the fame adivity ; one called Lama^ the other Ti* £unas.

The poifon contained in the earthen jar^ which I made ufe of, is the Ttcimas. It is not well known with which the poifoned arrows were prepared ; but I found by experiment, that it had the fame ilrength as the Ticunas, fo that I thought it need* lefs to dillinguilh one from the other.

Many things have been written on the adlivity of the American poifons, fo that I thought it advife- able to begin my experiments gradually, taking all poffible precautions. It is thought that the fmell alone on opening the veflel containing it is hurtful, and grievous difeafes, and even death, are appre- hended from the efcape of fome of the particles of

it

oi^i»oisoNi§, 99

it into the air; this at leaft is what we read of in the gravell authours.

I began then, as foon as the jar of poifon v/as opened, to make a young pigeon inhale the impreg- nated air^ and kept it with its head in the jar for feveral minutes; when I drew it away, 'twas as well as before. I loofened with a chifel feveral bits of poifon, to raife a little dufl: in the jar, and again plunged into it the pigeon's head ; it did not fufFer in this fecond experiment, any more than in the firil.

From this moment I did not hefitate to expofe myfelf to this vapour, and to examine the fmell of it, which fecmed to me naufeous and difagreeable. Several very fine particles of it entered with the mv into my mouth, and I found them to tafte pretty much like liquorice. Thus then is the fmell of the dried poifon innocent, and fo likewife are the par- ticles which find their way with the air into the inouth or nofe, and reach the lungs.

But it appears that the circumilance in which they dread this poifon the mofl, although it is ilill exter- nal, is when it is reduced to vapours by live coals^ or when it is boiled a long time, and rifes in a thick fmoke. I caft feveral fmall pieces of the dried poi- fon on burning coals, and made the pigeon inhale the fmoke of them, in the midil of which I kept its head ; it did not betray the fmallefl fymptom of un- eafinefs. I did more; I conveyed this fmoke into a glafs tube fix inches in height and four in diame- ter. When filled, I introduced the pigeon, and it H z did

ICO F O N T A N A

did not feem to fnfFer more than if I had expcfed 5t to the vapour of burnt fugar. I then fat about boiK ing a good quantity of it in an earthen veffel, and .expofed the pigeon to the vapour that rofe from it-. I did this when the poifon began to form a coniift- ence ; I expofed it when it v/as become more folid, beglning to burn at the iides of the' velTel, and to re- duce itfeif entirely into a very tl^ick vapour, and in- to coal. The animal did not luffer in- any ©f thefe t>'iab;y and I made no longer a difficulty of fmelling to it, and of expofing myfelf to its vapour. The fmell of the dried poifon on the live coals is very difguiling, and refembles that of burnt excre- ments.

From all thefs experiments, I infer that the va- pours which rife from the fmoke of the American poi- fon are innocent, whether fmelled to, or inhaled; and Monlieur de la Condamine had certainly been im- pofed upon when he wrote that this poifon is prepare ed by women condemned to death, and that they determine its having attained its point of perfedtion, when the vapours it emits, during the boilings kill the perfon who attends it.

Not one of the well informed travellers who have vifited the American continent, fpeaks of this tale they propagate of the accidents which happen to the old women deflined to prepare the Ticunas. Mon- lieur de la Condamine himfelf only fpeaks of it af- ter the doubtful relation of fome native of that coun- try ; and on the like authorities he believes that fait and fugar are fpecificks againft this poifon. My ex- peri-

ON POISONS. lOI

•perinients have however tanght me that they are of no ufe, and that it would be in vain to be flattered with the hope of obtaining a cure by thefe remedies, ihoojld any one have the misfortunje to be really poi- foned by the Ticunas,

There is no fufpicion of the poifon I employed in my experiments having fuiFered or loft its activity through agCg fo-thaji' we cannot afcribe to thefe cau- fes, that the vapours which exhaled from it were not deftrudive, even to the moft delicate animals* It had very well preferved its eifential property of killing very flrong ones, in a very fhort time, and in a very fmall dofe ; and I was always unfuccefsful in my endeavours to oppofe/^^'^^r or fait to it, w^hich are however Monfieur de la Condamine's two fpeci- ;ficks, who has likewife in this adopted the opinion of the American natives.

. This poifon diffolves readily and perfediy in wa- ter, even cold ; as alfo in the mineral and vegetable :acids^ It diffolves .much flower in oil of vitriol -than in the other acids, and becomes black as ink, which does nat happen in the o:her cafes. .

It neither -eiTervefces Vv'ith acids or alkalies, nor .caufes any kind of change in milk.

It neither turns the juice of radifnes red nor green ; and when examined with a microfcope, difcovers nothing regular or faline, but feems chiefly compo- fed of very fmall irregular fpheroidal corpufcles, like thofe of the juices of vegetables. It dries with^ .0\lt cracking, differing in that from the venom af

H 3 the

102 F O N T A N A

the viper, and when put on the tong-ae has a very bit^ ter talle.

From all this I conclude that it is neither acid nor alkaline^ and that it is not compofed of falts vifible to the microfcope.

The order I meant to purfue in my experiments, rather than curioiity, engaged me to examine whe- ther this poifon would be mortal, if put in immedi- ate contact with the eyes, or if it would bring on difeafe or irritation. I had already found that the venom of the viper is altogether innocent when in any way applied to the eyes, as it alfo is to the mouth and ilomach ; and was curious to fee what agree- ] 4Tients there might be betwixt two poifons fo adive, but fo different in their origin. I began then by putting a fmall quantity of the Ticunas dilTolved in water, on the eye of a guineapig : the animal neir ther feemed to fufFer at the moment, nor afterwards, neither was the eye at all enflamed. I repeated this experiment two hours after on both eyes of the fame animal, applying a greater quantity of the poi- fon : its eyes retained their natural ftate, and it did not fufFer the fmallefl: inconvenience. I repeated this experiment on the eyes of two other guineapigs, with the fame fuccefs ; and fuch was like wife the re- fult of all the experiments I afterwards made on the eyes of feveral other animals, and particularly on thofe of rabbits : I never could obferve the fmallefl change in the part, to which I found that the poifon was no more ofFenfive, than if I had bathed it with

water :

* ON POISONS. lOJ

^^'■ater : whence I think I may conclude that the American poifon is not a poifon when applied to the eyes^ and that it has no adtion on thefe parts.

But will it be as innocent when received into the llomach ?

Monfieur de la Condamine, and all the other au- thors who have fpoken of this poifon, believe it al- together innocent, taken internally, and fuch is the opinion of the AmericanSp The reafon it is thought fo, is that the animals killed with this poifon, or ra ther with the poifoned arrows, can be eaten without danger. Such an^argument is more fpecious than convincing, becaufe this fubfhance may be a poifon when introduced into the blood, even in the fmallell quantity, and may not be fo when received into the mouth in a much greater quantity.

There is a relation in the Britifn Journal, dijeikd by Mr. Cleaby, (Vol 13. p. 85) that a fmall bird which had been made to fwallow this poifon, died inftantly. But this obfervation, ifolated^ and de- prived of its necelTary particulars, did not influence the minds of the authors who have treated of this poi- fon, which continued to be notv/ithftanding regarded as entirely innocent v/hen taken internally.

Here follow the experiments I have made on this fubjedt : they ftill ferve to make us cautious how we pronounce, even after having had recourfe to expe- riment.

I made a fmall rabbit fwallow two grains of poi- fon diffolved in water, and forced it to drink a teafpoonful of water to waih its mouth, and carry

H 4 down

104 F O N T A N A

down all the poifon into the flomach. This animal did not appear to fufFer, neither at the time or after- wards.

I made another fmall rabbit drink, as above, three grains of the poifon ; it did not fuffer any more than the former.

Four grains fo the poifon fwallowed by another fmall rabbit, were attended with no ill confequen- ces. I made the fame trial on three fmall rabbits, to the third of which I gave lix grains of the poifon, and it continued well like all the others.

I thought thefe experiments might be fufficient to aifure me that the American poifon is innocent taken internally, as is the venom of the viper ; but I was miftaken. I had the curioiity to try it on a young pigeon, vf hich I made fwallow fix grains of it, and it died in lefs than twenty-five minutes. I repeated this experiment on two other pigeons, both of which died in thirty.

Thefe lail experiments, which feem to contradid: the preceding ones, obliged me to make a great ma- ny new ones on rabbits and guineapigs. I made a fmall guineapig fwallow five grains of the poifon, and found it dead in twenty five muiutes. — — I made a fmall rabbit fwallow even to eight grains of the poifon •, in thirty minutes it had no apparent com- plaint ; in thirty more it began to totter on its feet; in four minutes more it fell infenfible ; and in four

Others was quite dead. 1 made two rabbits and

two guineapigs fwallow each about ten grains of the poifon : one of the rabbits died in lefs than forty-

fiv2

ON POISONS. 105

five minutes, and the two guineapigs in twenty mi- nutes.

Thefe confequences led me to imagine that a grea- ter dofe of the poifon would saufe a more certain death, and that the fame quantity of it would pro- duce different effeSis on the fame animals, according to the ftate of the ftomach. I had generally obfer- ved in making the above experiments, that animals, when they fwallowed this poifon on a full Homach, either w^ere much longer in dying, or had no com- plaint. I made trial of this on three rabbits and two pigeons, which I kept a long time without nouriihiiient : they all died in lefs_ than thirty-five minutes with only three grains of the poifon. I re- peated this experiment on five more of thefe ani- mals, with their fcomachs filled, and only one of them died.

1 deduce from this as an eilabliihed fadl, that the American poifon taken internally, is a poifon ; but that a coniiderable quantity of it is required to kill even a fmall animal.

The particulars related above of its being innocent in a fmall dofe, and mortal in a greater one, induc- ed me to believe that the viper's venom, which is innocent when taken internally in a fmall quantity, would be mortal if the dofe of it v/ere increafed. The numbed fenfation itcaufes on the tonp-ue, and which continues fo long, feems a fufficient proof that this venom is not altogether innocent in this way, and that taken in a greater quantity it may readily occafion death.

I re-

to6 F O N T A N A

I referve to fome other occafion the making thU experiment, and ihaii then employ the venom of eighteen or twenty vipers, to be fwailowed by a fmall animal on an empty llomach, and I venture to pronounce beforehand that it will probably die ; fince, if fo very fmall a quantity of venom deprives the tongue of motion and feeling, that is to fay, de- Uroys the principles of animal life in this organ, a much greater quantity ought to deflroy them^ in the orsans more elTential to life.

If w^e confider that the venom taken into the mouth muft extend itfelf over a very great and al- mofl moiil furface, and mix itfelf wdth the aliment? in the ftomach, and that the inhalent velTels are ve- vy fmall, it will appear no longer furprifmg that it is not hurtful when taken in a fmall quantity, which is what we obferve in the American poifon,

I began my experiments on the latter, and em^ ployed a lancet, covered with a dilTolution of it in water. With this inftrument I wounded a fmall gulneapig three times in the leg, at certain inter-. vals ; the lancet was well fuppiied with poifon, but the animal did not fuifer at all. I m.ade the fame trial on three other fmall guineapigs, and on a rab- bit, and neither of them died or w^as difordered by it. In all thefe cafes the blood iffued freely from the wounds, whence I fufpeded that ihp poifon, in- Head of communicating itfelf might have been forc- ed out, as I had obferved of the viper's venom, ■which was often prevented in that way from doing

harm.

My

ON POISONS. 107

My fufpicion was foon confirmed by the experi- ments 'that followed, I impregnated a fingle thread with the poifon,. and pafTed it through the fkin of 3 guineapig, near one of its teats ; it had no com- plaint. I impregnated another thread three times doubled, and letting it firil dry a little, as I feared that the poifon was prevented from lying on the ft:in by the threads paffing acrofs, I paiTed it through the :fkin of a fmall rabbit's thigh, near its belly. Jn fix minutes it appeared feeble, and began to tremble, and fell motionlefs a minute after ; from timic to time it was feized with flight convulfions, and in fix minutes more was dead.

I repeated the fame experiment with the doubled thread, on two other rabbits and three guineapigs ; in iix or feven minutes they became feeble, fell down, were feized with convuliions, and died in the fpace of thirty.

I wiihed to fee if the American poifon could be communicated to animals and be mortal to them, being limply applied to the ilcin fcraped, or juft en- tered with the point of a lancet. I had obfcrved at Paris, that the venom of the viper did adtually produce a local malady in thefe cafes, and that it changed and corroded the Ikin, bur did not go fo far as to kill. The American poifon, on the contra- ry, never produces the local miaiady, as I obferved in making the experiments related above, and it leaves the wounded parts in their natural ftate, which elTentially diflinguiilies it from the viper's venom. J cut off the hair with fciiTars from the ikin of

a fmall

i08 F O N T A N A

a fmall guineapig's thigh, and fcraped it flightly with a file. It did not bleed, but was moift, and covered with fmall red fpots. I wet it with a drop of a folution of poifon in water, and in ten minutes the creature was convulfed, and a Ihort time after fell down motionlefs, being from time to time more or lefs convulfed : it died in twenty minutes, the fkin to which the poifon was applied not being changed. This experiment made on two other gui- neapigs, and a fmall rabbit, ended the fame way ; they all died in lefs than twenty-feven minutes with very violent convulfions.

I wifhed to fee if the larger animals could refift this poifon, when fimply applied to the pundtured or fcraped fkin. I Ihaved the fkin of a large rab- bit, and pundlured it flightly in feveral places with the point of a lancet, moiflening it with feveral drops of the poifon. In fifteen minutes the crea- ture drooped, bowing its head at intervals, andT be- ing fcarce able to fupport itfelf ; however in lefs than twenty minutes more it became as lively as ever. I repeated this experiment on another, but fmaller rabbit ; in ten minutes it began to move to and fro' its head, and could fcarceiy walk or fup- port itfelf on its feet ; but twenty minutes after it recovered its ufual fpirits.

I ftiaved about an inch of the fkin of a very large rabbit, a little blood oozing from it. Upon this fKin I put about three drops of a folution of the poifon. In fix minutes the rabbit was very feeble and much diibrdered, and a minute after fell as if

dead.

on POISONS. 105^

dead, being fcarcely obflrved to breathe. From time to time it was convulfed, but in lefs than for- ty-lix minutes was able to walk very well; foon af- terwards it began to eat, and appeared perfed:ly re- covered.

I fcraped the fkin of a fowl's thigh, and applied thepoifon to it : no illnefs enfued, although 1 twice repeated the experiment on other parts of the fkin,

I flightly fcarified the ilcin of a pigeon's thigh, and applied to it the poifon diffolved 'in water. Im twenty-five minutes the pigeon became fo w^eak as not to fupport itfelf, and at intervals was convulfed. Soon after it fell infeniible, and remained in this {late more than three hours. However it afterwards recovered gradually, fo that in half an hour more it did not feem to have at all fufFered.

This experiment w^as repeated on five other pi- geons : three died in lefs than twenty minutes ; the other two fell into convullions, but afterwards rcr covered.

From experiments iince made as well on birds as quadrupeds, I conclude that the American poifon may be mortal, when applied to the fkin flightly fcratched ; though not always, nor in all circum- ilances. The largeH animals eafieil refifl the adiion of this poifon, and even the weakefl, when they do not die, foon become as well as before.

I wifhed to know what quantity of poifon would kill an animal. 1 had made a like fearch in France in regard to the viper's venom, and had determined the quantity. I had great reafon to prefume that a

verv

no to N T A N A

very fmall portion of the American poifon would be fatal to a fmall animal, fince a drop or two of its folution, applied to the fcraped fKin, was capable of killing more than one ; but I wanted the precife quantity.

I moiftened a very fmall bit of cotton with the fif- tieth part of a drop of the folution of the poifon, containing fuch a proportion of water, that the poi- fon fcarcely compofed a fiftieth part. I introduced this into one of the mufcles of a pigeon's leg ; the pigeon felt nothing from it.

Two hours after I introduced into another mufcl6 an atom of the dried poifon fcarcely vilible to the naked eye ; here again the pigeon did not fuffer. I repeated this, lafl experiment on three other pigeons, one of the bits of the dry poifon being pretty large ; neither of them died, or appeared to fuffer : how- ever 1 found the bits of poifon whole and undifiblv- €d by the humours of the wounded part.

I applied to the m.ufcle of another pigeon' a bit of cotton much larger than that above, and moiflen- ed it wdth about eight times the quantity of poifon : in fix minutes the pigeon fell, and died foon after* 1 applied bits of cotton moiftened v/ith the poifon^ pretty much in the manner of the foregoing, to two guineapigs ; one died in twelve minutes ; the other fell infenfible in fix, but foon after came to itfeif^

I conclude from thefe experiments, that it re- quires about the hundredth part of a grain of poi- fon to kill a fmall animal, and that the poifon muil 3 neceffarily

ON l^OISONS* III

neceiTarily diffolve, to occafion either death, or fomefenfible derangement of the animal economy.

I made feveral experiments to determine whether the American poifon would be mortal or dangerous, when applied to v/ounds in the combs of fowls, or to the fcratched ears of quadrupeds. The venom of the viper is not ufualiy mortal in thefe parts, but the difeafe, which does not attack the envenomed- comb, feizes the gills, w^hich fwell fo violently as frequently to kill the animal.

I began by repeatedly wounding the combs of fowls, and applying to them the folution, of the -Am.erican poifon ; I did this tvvdce by the mediu.m of cotton wetted with it, without producing ariy complaint. But my experiments on the ears u.t.c~ Ceeded otherwife : after feveral fruitlefs attem.pts to Commmnicate the poifon by fcraping or wounding the ears of rabbits, which did not appear to fuffer^ I at length fucceeded in 'killing two in lefs than thirty minutes after my having applied a great cieal of poifon to the moil fleihy part of the ear, which I had wounded in feveral places with the point of a lancet*

The experiments on the ears convinced me_., that when there are but few blood-veffels, the comipiaint either does not communicate itfelf, or is not niortaL The American poifon is very analogous in this to the venom of the viper : they are both entii:ely in- nocent, in whatever way they are applied to the ten- dons, above all if the latter are free from blood- vefTels ; and likewife to the other parts of the body

that

112 F O N T A fr A

that are fo, fuch as the cellular membrane, or the ligaments : it would be needlefs to enter into a de- tail of thefe experiments, which would not only be tedious, bur, as will be feen by what follows, un- neceffary.

I wifhed to know whether the American poifon was more deftrudiive when iniinuated into the muf- cles, than when applied to the ikin with incifions made quite through it. A large guineapig which two days before had twice undergone tne operatioi'i of poifon applied to the incifed ikin, without any fubfequent complaint, and a third time with very trifling fymptoms, died in lefs than twelve minufes after the application of the poifon to the divided fibres of one of the mufcles of its leg. In three minutes it fell moiionlefs, and with fcarce any iign

of life.

I repeated this experiment ten times, and all the

animals, as well guineapigs as pigeons, and mode^

rate lized rabbits, died ; fo that I have no doubt

but that the poifoned wounds of the mufcles are

more mortal than thofe of the fkin and ears, and of

the combs of fowls. The way to fucceed the beft

is to take a pointed piece of wood of a fpungy fub-

fiance, well fleeped in the poifon, and to force it,

when almofl dry, into the fubftance of the bared

mufcle ; but this method did not fucceed. on my

making trial of it on the combs,of fowls ; I could

obferve no complaint, although the wood w^as well

fleeped, and left for feveral hours in the combs,

pierced through and through.

i now

I

p N POISONS. 113

I now had recourfe to the arrows, employing feveral in piercing the ikins of animals, and many others in wounding the mufcles. In the former cafes feveral of the animals furvived, the large rabbits making the ftrongeil reiiilence ; but in the latter not one efcaped death.

I found in general, that the arrows are more deadly in their effedls than the poifon diffolved in water, and iimply applied to the part wounded.

I obferved that the poifon of the arrows is more a(5tive and certain, if they are previoufly dipped in hot water. Their adtivity is Jftill increafed, if they are fteeped in a folution of the poifon boiled to a liropy eonfifience. Several pretty large ani- mals, fuch as rabbits, tumbled motionlefs in lefs than two minutes, and before eight, were dead. Some of the fmalier ones became ill in lefs than a minute.

I pafled one of thefe arrows well dipped in the boiled poifon, into the comb of a fowl, and left it there a whole day, without the an irnars betraying any fymptoms of pain. The day following I pierced the comb and gills of the fame fowl through and through with two freih arrows pre- pared as above, and left them there ten hours. The fowl flill continued well in the fecond operation^ and I afterwards pafled an arrow into one of the mufcles of its leg, when in forty-two minutes it died.

Vol, IL 1 4r^

it4 ^ o j>t r A N A

^re Acids and Alkalies capable of dejlroying the deadlj quality of the Tigunas ?

Amongft the refearchcs I propofed to myfelf iif 'Examining this poifon^ that of the changes it might' undergo wheit united wi-th acids or alkalies was oncy as it had. alfo been in examining the venom of the viper, I had found th^t neither the ftrongeft mineral acids, nor the moft adtive alkalies, depri- ved this venom of its hurtful qualities, and wilhed to fee if they would a& as little on the American poifon. For this purpofe I dillblved it in the three mineral acids, as alfo in diftilled vinegar, and rum^ 'and in a few hours made the following experi- ments.

I made flight inciiions into the ikin of a fmall guineapig, and wet it feveral times with the fplu- tion of the poifon in nitrous acid. What the ani- mal fufFered feemed to refult from the wounds and acid alone, and in an hour it became as lively asr ufual. Two hours after, I repeated this experi- fnent on another part of the ikin prepared in the fame way^ employing a folution of the poifon m rum; in lefs than four minutes the animal died.

I wounded the ikin of a fmall rabbit flightly, and applied to it feveral clrops of a folution of thepoifoa in oil of vitriol : the rabbit felt no ill efFedls from it. In four minutes I wounded another part of the ikin .«is before, ^nd applied to.at feveral drops of a folu^

tioQ?

ON I*dISONS. ll§

tion of the poifon in diftilled vinegar : in four minutes more the animal fell^ and died in iix.

I prepared as ufual the fkin of a fmall rabbity and wet it with a folution of the poifon in marine acid : the animal did not fufFer from it. Six hours after^ I applied to another part of its ikin a folu- tion of poifon in rum, and in forty-five minuteS' it fell into convullions, but recovered in lefs than an hour*

From thefe firfl experiments it feems probable, that mineral acids render this poifon quite innocent, ^nd that vinegar and rum on the contrary, do not alter iti I continued my experiments on the fo- lutions of it in vinegar and in rum, and the con- fequences were a little varied. Of fix animals treated with the folution in vinegar, only two died ; two others had all the fjmptoms of the difeafe caufed by the poifon ; and the other two w^ere not affected by it* Of fix others treated with the folution in rum, live died, and the iixth had an attack of the difeafe ; this feems to demonflrate that the tkunas dilTolved in thefe two fluids, pre* fervesits deadly qualities.

On the contrary, I repeated the experiments on the folution of the poifon in mineral acids, on fix animals, neither of which died, nor difcovered fymptoms of complaint*

I fufpe^^ed that the poifon might probably be innocent in this cafe, not b^caufe it had loft its de- leterious qualities, but rather becaufe the too great a^ion of the mineral acids on the fkin, and on the

I z vefTels

Il6 f O N T A N A

vefTels which are cauterized and hardened by them^ might prevent its infinuating itfelf into the parts^ wounded. To clear up this doubt, I evaporated over the fire the folution in the mineral acids, and when the poifofi became dry, 1 applied it to dif- ferent parts of the fkin in feveral animals, but with- out any one being difeafedby kw

It appears then, that the mineral acids deprive the American poifon of its hurtful qualities.- I fay limply that it appears ib, beeaufe it Hill may be fufpedied, that a little of the acid may remain in the poifon after the evaporation^ and that this acid may produce its ufual efFedl on the veffels of the ikin. I ought to have repeated thefe experiments after having waflied the poifon in feveral waters, but at that time I wanted animals to examine into the truth of this freih fufpicion, and have never iince been able to return to the fubjedt.

As to alkaline falts, I can venture to fay, that I have not found them in any way to change this- poifon, or to render it lefs deadly than before. It is true that I neither repeated nor varied thefe ex- riments fo much as necelTary. I fhould have done this, if I had not found great difficulty in procuring animals, and had not had an eye to much more in>- portant experiments.

It was natural to fuppofe, iince acids prevented the adtion of the poifon on animals, that they might alfo be a remedy againft it.

I got ready the ikin of a fmall guineapig in the iifual way, and covered it well with poifon; in

about

ON POISONS, II y

•about forty feconds I walhed it with the nitrous acid, and afterwards with pure water : the animal had no complaint. Tv/o hours after I laid fome of the poifon on one of its mufcles, and immedi- ately applied the nitrous acid ; it inilantly fell convulfed and without llrength, and in two minutes died.

I .repeated this experiment on the mufcles of another .guin^apig, and had fcarcely applied the poifon, when I wafhed the parts with nitrous acid a little diluted with water. Tv/o minutes after it became convulfed, and- died in four.

I poifoned the mufcles of four pigeons as above, and wafhed them immediately after with nitrous acid. In a minute all the pigeons expired. Fear- ing this might be the effedt of the nitrous acid^ rather than of the poifon, I tried iiitrous acid very much weakened op. four other pigeons, all of which died, thgugh mych latero

I wiihed to fee if the fimple application of ni- trous acid to the mufcles, would kill pigeons and ftiiall guineapigs. I made the experiment on two of each fpecies. Both' of the pigeons died foon after, but the guineapigs furvived, although one of them fuffered a good deal.

It feems then that acids are ufelefs and danger- ous, when applied to the poifoned mufcles of an animal.

I J How

llS MONTANA

Hqw long is the Ticunas in difcovering its deadfy ^e^s in Animals that have been poifoned with it f

I fhall not fpeak of other remedies I have tried, becaufe experience has convinced rne that all are ufelefs, whether applied foon or late, exteriorly or interiourly. When the poifon is deeply fixed, when it is already introduced into the humours, every remedy comes too late.

A very nice enquiry, and one that might be ufe- ful in certain cafes, remained to be made. My ex- periments on the viper's venom Vv^ere the occafion of this enquiry into the American poifon. I had determined the. time the former requires to diffufe itfelf in the body of an animal, and in what time the cutting off the envenomed part may be ufeful, to prevent the venom 'from communicating itfelf by the circulation, to the animal.

I introduced an American arrow, previouily dip- ped in hot water, into the mufcles of a pigeon's leg, and left it there. In four minutes I made a pretty tight ligature about the part wounded, and juft below the femur. In twenty-fix hours the animal had no other complaint than that caufed by the fimple ligature, which on my taking out the, arrow, I untied. The part was a little fwelled and livid, and continued lame for feveral days, but did not occafion the animal's deaths

: 1 I pierced

ON 5* O I S O N S. %1^

' I pierced the mufcles of another pigeon with ? frefh arrow, as above, and in fix minutes made the ligature, leaving the arrow in the part. Jn four minutes the pigeon could not fupport itfelf, .and Ihortly after fell infenfible, dying at the end of ^x more.

: 1 repeated this experinsent on another pigeon, leaving the arrow in the mufcles. In eight mi- iiutes I bound the kgo Three minutes after, the .creature became ill, but in a Ihort fpac6 recovered. In twenty-fix hours it was fiiill alive, although the mufcles were become livid. J took off the ligature^, and it died two hour^ after,

I fubmitted a fourth pigeon to the fame trial, and made the ligature five minutes after, leaving ;the arrow in the mufcles. It died in two hours.

I repeated this experiment on four other pigeons, ;and in two minutes made the ligature : not one of them died. Ten hours after I took off the liga- ture, when three .died^ and the fourth recovered -perfedly,

I made the fame experiment in all its circum- llances on four other pigeons, except that I did not take off the ligature till thirty hours were elap- fed. One only of them died, in two days. Its .death was certainly owing to the tightnefs of the ligature, which produced a gangrene of the m^if- cles.

I repeated this experiment on m\^di fmayer pigeons, that can bear the lofs of the leg beneath the femur; not one of thofe died that had theit

I 4 Ic^s

I20 FONTANA

legs cut off in th« fpace of two minutes, and only two out of ten, when they were taken off at the end of three.

Fewer pigeons die with this method than with the ligature, when the fame time is obferved : the reafon is, that the am_putation neither caufes death, nor any remarkable derangement in the animals ; inftead of which the ligature frequently brings on a gangrene, which is fometimes mortal, in the parts wounded by the arrow.

I made the fame experiments on fmall guinea- pigs and rabbits, fometimes cutting off the wounded leg, fometimes making the ligature : the confe- quences were partly analogous to thofe I noticed in the pigeons, though fomewhat lefs conftant an4 certain. I have in general obferved that the Ame- rican poifon requires a certain time to communi- cate itfelf to the animal ; that this time is much more cpnliderable than that required by the venom of the viper; that the efFeds of the former on animals are more vague and uncertain; and, laftly, that the effedts of both may be remedied by am- putating the parts, when it can be attempted with- out danger, and is done in time.

In the experiments I made on the venom of the viper, I found that its efFedts are not alike to all animals, and that there are animals with cold blood to which it is quite innocent. I was curious to fee \{ it would be the fame with the American poifon.

The authours who have fpoken of this laft, tell US that it is poifonous to all animals ; but the b^^

ON POISONS. 121

Kef of a thing is very far from the proof of it. Experiments, and thofe very numerous, muft be made, and I do not perceive that they have made a fufficient number from which a general confe- quence may be drawn.

Experiments on Animals with Cold Blood*

m

I began by infinuating the poifon into the muf-? cles of frogs, which died in a fhort fpace of time, J proceeded to eels, introducing the arrow near the tail ; they all died though very late.

I had found that the venom of the viper is quite innocent to the viper itfelf, and to adders. I could procure only two of thefe lad, and made but few experiments, which I however think de- ciiive. I wounded one of thefe fnakes towards its tail, with an arrow well covered with the poifon, which had the coniiflence of a firop, and left the weapon in the mufcles. At the place where I in- linuated it, I had previoully made an inciiion, to the end that the diffolved poifon on the arrow might the eafier enter the mufcles,. into v/hich I afterwards made fmall incifions about the wound, and introduced frefii poifon. The adder continued well for feveral hours, when I fhut it in a cham- ber, and on entering fix hours after, found it fled, and have never fince met with it.

Ire-

m ' t O N T A N A

, I repeated this experiment feveral times, at cer- tain intervals, on a fomewhat fmaller adder. Tii« lafl time, I forced two poifoncd arrows into the jnufcles of its tail, and left them there for twenty- four hours. I applied the poifon brought to a liropy confifleBce, repeatedly about the wounds, introducing a great deal of it into them with a bit of wood; the adde^. neither die4 nor ftifFered per- jceptibly*

I was enabled to repeat this experiment feveral times on vipers, not one of which died of the poi- fon, although I wounded feveral in the mufcles. Bear the tail with arrows well covered with it in che above confiftence, leaving them iij the mufcles for twenty, and even thirty hours. It is true that fome ones, a fliort time after the application of the poifon feemed lefs lively than ufual, and that the liinder part of the body which was wounded, be^ came benumbed, and lofl its natural motion in a fenfibk degree, and that for feveral hours. On the others the poifon had no perceptible effedt.

After this I can venture to fay, that the Ame- rican poifon, as well as the venom of the viper, i2cc. is totally innocent to animals with -cold bloodo Thefe two poifons have here a very great analogy^ although one is an animal gum, the other a vege- table juice.

It remained for me to examine the action of this poifon on living animals, and to fee what parts of the animal are fo' changed by it, as to bring on ■death*

Every

O N P O I S O N S. lij

Everything concurred to the befief thatitex-? cites one of thofe difeafes which modern phylicians call nervous, and that it afts immediately on the nervous fyfiem. The fymptoms of the difeafe are the mofl precife and decifive in favour of this fper cies of complaints. Convulfions, faintings, total lofs of ftrength and motion, the feeling weakened fo as to be aimoft totally deftroyed, are the^ mofl: common ones produced by this poifon, on animals^ We often obferve that the creature, juil now very lively, in a moment finds itfelf deprived af motion and feeling, and at the point of death. I ufually obferved a fymptom which effectually feems to de- monflrate, that the dileafe produced by the tkunaz is purely nervous. The animal, if it furvived, was as well in a fev/ minutes as before, not appearing to have fuffered at all. It notwithftanding remained in a lethargick ftare, fom.etimes for feveral hours, without any apparent fign of life. This is exactly what happens in difeafes called nervous, the attack of which is frequently very fudden. Now they excite commotions, and now entirely exhauft the ftrength ; but fcarcely do the fymptoms of difeafe begin to dillipate, than the perfon finds himfelf recovered, and fcarcely recollefts the having been ill.

But all thefe fy m p torn. s could not Jmpofe upon me, after having made my experiments on the ve- nom of the viper. The difeafe occafioned b^- it has likewife the fymptoms common to nervous complaints, and the principal aScdlion feems to lie

ia

f24 F O N T A N A

In the nerves, although experience has decided to the contrary. It was likewife neceflary then in the prefent cafe to have recourfe to experiment, and not to be carried away by falfe theories and proba- ble reafonings.

EffeBs of the Ticunas gh Blood drawn from Animals,

To proceed methodically in fo important an en- quiry, I thought it proper to begin by examining whether the Am.erican poifon produced any fenfible alteration in the blood of animals, if mixed witji it on its iffuing warm from the veffels.

I cut off a pigeon's head, and received the warm ■'Jblood in two fmall conical glaffes a Jittl.e heated, about eighty drops in each glafs. In one of thern I put four drops of water, and in the other four drops of an aqueous folution of the ticunas, con- taining fcarcely a grain of the dried poifon. I Ihook each of the glaffes for a few feconds, fo as feverally to unite their contents ; in two minutes the blood mixed with the limple water was coagulated ; that with the poifon did not coagulate, but became darker coloured, and in three hours was Hill in a fluid ftate, whilft in the other glafs the ferum and coagulum were dillindt.

I examined with a microfcope, as well at th}s time as afterwards, the blood in the two glaffes, and found that the red globules were alike in each, having preferved their primitive Ihape.

Thi

^ N POISONS. 12^5

This experiment was repeated feveral times witB the lame fuccefs, fo that the American poifon, in the feircumftances related above, feems ckarly not to change in a perceptible way the red globules of blood. It however deferves to be noticed, that far from coagulating this fluids it on the contrary ab- folutely prevents the natural coagulation of it,- when it is drawn from the veffels. Neither agaia can it be faid to attenuate or diilblve it, fince no- thing of this is remarked on examining it with a microfcope: the red part is Ihaped as ufual, and does not feem to be more fubtil ot more fluidv

The confequences were the fame on? trying the viper's venom; fo that the eifeif^s of thefe two poi- fons, or the changes they caufe, in the blood drawa from the veiTels, feem altogether iimilar. Both, prevent it from coagulating, and neither of them dilTolves or changes the globules- of it: the only difference betwixt the two poifons is that the ve^ nom of the viper turns the blood darker than does the ticunas.

The former does not ad on the globules of blood, even when it is communicated to the living animal, and kills it. I made the fame obfervation as to the blood of animals which died of the American pos- fon, fo that in all thefe cafes there is an admirable agreement betwixt the tv/o. But it has been feen that the venom of the viper produces a fenfible al- teration on the general mafs of blood in animals bitten, I thought it proper to examine with the

fam^

17.6 ■ ■* O N i* A N A

fame attention^ the blood of animals killed by the

On doing this it appeared that the mufcles of animals fo killed^ were in general rendered pale by it. The venous vefTels near the heart feemed mord fwelled than ufual, the blood a little darker^ bu^ not coagulated. The abdominal vifcera were not feniibly changed; the heart and auricles in a na- tural ftate : the external veflels of the heart were fometimes more viiible, and as if injediedi . But I obferved a great change in the lungs, d vifcus very eflential to life* I generally found it- more or lefs fpotted ; the fpors were frequently very large and livid, and fometimes the part feemed quite putrid. This change in fo noble an organ jdeferves the utmoft attention ; it feems to become confiderable in proportion to the length of time the animal lives after being poifoned. I found that the lungs of fome anirtials were here and there tranfparent, above all towards the fides. The air within was very vifible through the external mem- brane, which I examined with d microfcope, and very clearly obferved through it the fmall pulmo^- nary veficles moiftened by a difcharge from veflels that had quite emptied themfelves.

However great the change in fo important a part^, -I could not be perfuaded that it could alone produce fo violent and momentary a difeafe, and that the poifon entirely exercifed itfelf on the blood, and the lungs. ^Tis true that I had the example of thei -viper's venom ading fomewhat in this way; but it

brings

o 3^ p o I s o N s. tzy

t)rings on an alm'^ft general coagulation of th^ blood, whieh is certainly not the cafe with tk<l American poifon.

EfeBs of /fo Tic^uNAs introduced into the Mood Fefi fels of Animals,

In an enquiry fo important, and at tlie famd time fo obfcure, I thought it proper to recur to experiment:, and to examine the effeds of this poi^ ion introduced immediately into the blood.

I had recourfe to the means I had employed 10 introducing into the jugular vein the venom of the viper, making ufe of a Unall glafs fyphon bent at the point, by way of fyringe. Into this fyphon I drew up by fudtion a folution of the ticunaSy and having- opened the vein, injeded it. As I have al- ready d^fcribed the way of making thefe experi- ments, in the treatife on the venom of the viper^ I do n^t think it neceflary to repeat the defcription of them here. They are fo contrived that the poifon mixes with the blood through the medium of -the jugular vein, without touching the part of the vefiels where the incifionS' are made, or even the jugular itfelf,

I put into the fyringe for th6 firft experiment^ four drops of an aqueous folutioti, which fcarcely contained half a grain of the dried poifon. Having introduced the point of the fyringe into, the jugular vein of a very large rabbit, I perceived the liquor

o to

128 F O N T A N A

to flow ^back on the moment of my pufhlng the Cucker^ owing to its not being exadily fitted to the fides of the fyringe : I obferved to the perfons pre- fent, that the experiment had failed, but was fur- prifed to hear in reply, that the animal was dead. i do not think ten feconds paffed betwixt the time of the liquor's flowing back, and the death of the animal, which had adiually taken place. I cannot eflimate the quantity of poifon introduced into the fclood, but as the animal died, fome mufl necelTarily liave found its way thither ; had not this happened, I fhould have fuppofed from the quantity which flowed back into the tube, that not a fingle drop of it had entered the jugular vein.

The death of this animal was much more fudderi than in the cafes of introducing in a fimilar way the venom of the viper into the blood; ^nd the iivhole body was more funk and relaxed, than it is obferved to be in animals that have been dead a long time.

Having put my fyringe in better order, I intro- duced two drops of v/ater, with which I had pre- vioufly mixed about a quarter of a drop of the aqueous folution of the poifon I have fpoken of. I fcarcely began to injed: this liquor by the jugular, when the rabbit fell, without motion and without life, as if Itruck by lightning. I do not think half a drop of the liquor was introduced.

I can fay in general, after other experiments I have made fince, that this poifon introduced im- mediately into the blood by the jugular vein, kills

more

ON POISONS. C29

inore fliddenly than the viper's venom, and in a much fmaller quantity.. Death fucceeds the intro- fdud:ion of it fo quickly as ufually to prevent con- vulfionsV If a fmaller proportion of it is employed, the convulfions and ufual ftruggles are obferved, and the death retarded. It is true that the blood is neither coagulated, nor fo changed in its colour as when the viper's venom is mixed with it, but this does ^ot delay the death of the animal, and the ticunas m immediate contact, kills to as great a certainty as the viper's venom. This is an experienced and an inconteflible truth, however obfcure and diihcuk the caufe of the deaths may appear, in the cafes I have related.

The American poifon introduced into the blood kills milantly; from v/hence it feems beyond a doubt that when applied externally to the wound of .a living animal, it mufl caufe a derangement of the ^^nimal economy, and even death.

EffeBs of the Ticunas on the Ner-v

es.

' The fudden death which follows the introdudlion -of this poifon by the jugular vein into the b^ood ..of an animal, feems an unanfwerable demonftra- tion, that in thefe cafes the adion of the poifon is on the blood alone, and that the nervous fyftem is ^either affedted nor deranged by it. This does not however prove but that the nerves may be more or lefs afFedled by this poifon, when the death hap- VoL. II. K pens

130 F O N T A N A

pens at fomediftance, and when it is applied exter- nally to parts that have been wounded. In thefe cafes convulfions, and ail the fymptoms of a ner- vous difeafe, are principally obferved. Thererves then may very probably be affected by the poifon^ and be the principal caufe of the anirnars death.

Here it was again necelTary to recur to dired: exr periment, as I had done in regard to the venom of the viper, and to fee what derangements and what complaints the American poifon would pro- duce, on being applied immediately to the nerves, without touching the blood v^lTels.

Effevls of the Ticunas applied to the Surface of the Nerves.

I made my experiments on the fciatick nerves of very large rabbits, preparing the nerves in the w^ay I had done at Paris in operating with the viper's venom, and iliall therefore enter into no detail here as to that particular, but fhall relate a few of the principal experiments, to lliow the variety I met with on m.y firft trials : a variety that might have led me into an errour, had I not perliiled in multi- plying my experiments, and varying them till I found the confequences fomewhat uniform. ''Tis to this conftancy, or if you will, to this obflinacy that I owe in a great part the new truths I think I have difcovered, as well in relation, to the viper's venom, as to the ticunas.

Having

ON POISONS. l^l

Having cleared the fciatick nerve of a rabbit", I pafTed under it feveral doubles of fine linen, cover- Hig it with lint well wetted vvith the ticunas of a fi- ropy confidence. I covered the nerve with the fame linen, to fecure the bared iiuifcles of the animal from the poifbn, and lewed the fkin -in the ufual way. In tvv^enty minutes the rabbit began to be convulied, and could notfupport itlelf ; it was dien feized with all the fymptoms of poifon, and died foon after.

I repeated this experimienton another rabbit, and contrived to enclofe the nerve in linen flill better than before. This fecond rabbit continued well for ten hours, but vifiting it on the twelfth I found it JAifl expired. ' I fiifpedted that the poifon applied to the nerve in a certain quantity, might in time penetrate through tht linen, with the humours of the wounded part, and convey its adtion to the mufcles and other adjacent parts. It was proper then either to dimi- nilh the poifon, to prevent its foaking through, or to cover it with-mor^ linen. I chofe the latter as the furer method.

I cleared the fciatick nerve of a rabbit in the ufual way, pafiing under it repeated doubles of very fine linen. I covered it with lint well iteepedin the poifon, putting bits of linen over the whole. The rabbit lived twenty-four hours, when it died fuddenly, but I could not fufped: its death to be caufed by the poifon.

K 2 I got

133 F O K T A N A

1 got ready the fciatlck nerve of another rabbit as above, covering it with poifon and bits of linen as ufuai. It died m forty hours without any fymptoms of the diierfe of the poifon.

I made the fame experiment on the fciatick nerves of three other rabbits, taking the utmofl care, af- ter applying the poifon, to have them well covered with linen, to prevent all fufpicion of the poifon's having foaked through. -One of thefe rabbits die4 in three days ; the other two were alive at the end of eight.

I got ready the fciatick nerves of two other rab- bits exadly in the fame way, but without applying the poifon, for a comparative experiment, One of them died in thirty-fix hours, the other was Hill living at the end of the eighth day.

I thought thefe experiments fuiScient to deter- mine whether the ticunas, applied externally to the nerves, is capable of producing any difeafe or de- rangement in the animal ; but I wanted to know whether it would be equally inadive when applied to wounded nerves, or rather to the very fubilanc^ of them.

Experiments with the Ticunas on Nerves cut or wounded,

I prepared the fciatick nerve of a rabbit as above, ?ind having pierced it federal times through with a lancet, laid the poifon exadtly on the wounded part,

The

ON POISONS. 133

The rabbit lived five days, when it died without any fymptoms of difeafe. I repeated this experi- ment in all its circumilances on another rabbit, which was ilill alive eight days after.

I varied this experiment a little on the nerves of three other rabbits. Inllead of making feveral wounds with a lancet^ I made a longitudinal open- ing into the nerve of more than five lines in length, into which I introduced threads well Heeped in the poifon, and covered all fecurejy. One died in lixty hours without any fymptoms of the difeafe of the poifon ; the two others were living eight days af- ter.

I thought it proper^ again, to vary this fecond experiment, by cutting the nerves of a few rabbits, in the way I had done in examining the venom of the viper. I cut the fciatick nerve as far as I could from its origin, that fo I might enclofe it in linen. The part of it cleared in very large rabbits was about an inch and an half : having put linen be- neath the nerve, I covered the cut part well with the poifon, and placed linen o ■ er all as uluaL

I made this experiment on iix rabbits, two of which died in forty hours, two in three days^ and two were ftill living on the fourth.

To make "?. 'comparative experiment, I prepared the nerves of two rabbits as above, but did not ap- ply the poifon. One died in thirty-iix hours, the other furvived the third day, ,

The uniform confequences of thefe experiments

on the nerves, made me think any further ones un-

K 3 necef-

134 F O N T A N A

necelTary ; and I believe thofe will agree with mcy who are accuilomed to make experiments, and are not prejudiced by ill-founded hypothefes. The A- merican poifon, as is here feen, in whatever way k is applied to the nerves, is not a poifon to them, and does not produce in thefe cafes any fenlible de- rangements in the economy of a living animal : this is proved by immediate experiment. To fuppofe what we do not fee, to believe what is co-ntradidted by experiment, is fubilituting dreams to real ob- jedls, embracing errour for truth, and adopting chi- mxrdd for fadis.

The American poifon then, agrees with the vi- per's venom, in being quite innocent to the nerves, in v/hatever way it is applied to them ; like the vi- per's venom it kills in the fmallelt quantityy and that inllantly, if introduced into the blood by the jugu- lar vein ; and its adlion is altogether on the blood, let the principle or mechanifm by w^hich it caufcs death be what it will.

The effects the viper's venom produces on the blood are more clear and decided ; there is an un- queflionable coagulation of it, not to be perceived in the cafes of the ilcunas : w^e however obferve in this lail a great change in the lungs, which become violently difeafcd.

The fudden death of an animal, when the poifon is injeded into its velTels is really furprifing ; it fcarcely feems to have had time to reach the heart, Tseither can we conceive how animals with cold blood; frogS; for iuftance, that exift with aa

impeded

ON Poisons. 135

impeded circulation^, can be killed by it; although it is' true that they die much later than animals that have the blood warm. The blood or any hu- mour, changed by a poifon, may indeed gradually produce in thefe animals, more coniiderable de- rangements than are caufed by an impeded circula- tion.

The death which immediately fucceeds the in- troducftion of the ticunas into the blood, may in- duce a fufpicion that this humour contains ^ very adiive, fubtil, and volatile principle, which efcapes the niceil eye, and even the microfcope. Agree- able to fuch an hypothefis, this principle feems highly effential to life, and to be particularly adied upon by the poifon.

What may lead one to fufped: that a very a6live and volatile principle does really exifl in the blood is, that the viper's venom prevents its coagulation when 'tis drawn from the veiTels, and on the con- trary, produces it in the velTels themfelves. One would fuppofe in the firft cafe, that fomething had flown oft' from the blood, which exifls in it when 'tis enclofed by the veflels.

This adtive and vital principle, agreeable to this hypothefis, may be confidered as refulting from the whole animal economy, wichout excluding the nerves, which may even contribute greatly to- wards it.

But thefe are mere conjedlures, more or lefs pro- bable, and not demonftrated by experiment. We mult flick to certain fadts, in whatever way we ex- K 4 plain

t^6 F O N T A K ii

plain them : it is certain then, that the tlcunas does' not ad: on the nerves, and that it adts altogether on the blood.

Previous to my experiments, no one would have doubted its immediate adtion on the nerves, which was announced by every outward fymptom. Thefe fymptoms then, which the phylicians improperly regard as a certain proof that the difeafe is purely nervous, are equivocal, and may prelent themfelves without the fmalleil nervous afFejftion : the mere change in the Mood is fufficient to produce them in an inilant. The greateft phyficians have re- garded the difeafes caufed by the viper's venom and the American poifon, as derangements in the- nerves : it is now their buiinefs to exarriine whether other difeafes, afcribed to the nerves, are not rather difeafes of the fluids, and of the blood. There- are grounds for this fufpicion; the fymptoms are equivocal, and the principles not generally demon- ftrated.

I tio not pretend to deny but that difeafes of the* nerves may occur ; thi^ would be running from one extreme to the other. There are withoiit doubt, difeafes nervous in their origin, and many others- which become fo by the changes that take place in other parts, even in the fluids. The pafEons of the mind fhew us the influence the nerves have on the body ; but this does not prove that all the dif- eafes afcribed to the nerves, are really nervous, and that the ufuai fymptoms of thefe difeafes may laQt be equivocal Befides, it is certain that the

ppifons

OK POISONS* 2^7

poifons we have examined, have no immediate ac- tion on the nerves, whatever may have been hitherto iDelieved.

Some one may objed:, that probably the viper's venom and the American poifon, ad: only on the extremities of the nerves, and on that account are innocent when applied to the trunks of them. But every thing ferves as an objediion to thofe who bufy themfelves in imagining difficulties^ and it i» Very rare to find two things in every refped: alike. For my part, it appears to me, that the internal fubflance of the great nerves, is the fame as that of their extremities; and that the former are fub^ jed: to pain as v/ell as the latter* I do not create hypothefes which are not confirmed by fad:s,

I may "have been deceived in fome of the confe- quences I have deduced from my experiments, and may like wife have been deceived in fome of the experiments themfelves, although I have flrove to fucceed, and have fearched for truth in an unpreju- diced w^ay, I do not doubt but that any one who will apply himfelf after me, to thefe refearches, will find fomething to add, and even perhaps to corred:. It is fuffieient for me to have opened a road to new truths, and to be able to atteil the Veracity of the principal fad:s I have advanced.

The greater part of thefe experiments was made in the prefence of my particular friend Dn Ingen- haufen, Phyfician to their Imperial Majefties, who has difplayed in feveral publications the talents of a real naturalifl. M. Tiberus Cavailo has like- 'Z wife

1^8 F D N T A N A

wife affifled at feveral of the molt important cf them. I conceived that the authority of two per- fons known to the learned, would give an addi- tional credit to my experiments^

On the pot fined Arrows hr ought from the Eajl Indies,

After I had finillied my experiments on the //- cunas, one of my friends at London procured me a number of arrows from the Eaft Indies, on which I made fome experiments, but neither greatly multiplied nor varied them, as well becaufe the arrows were but few in number, as becaufe they feemed to differ from the American poifon, only in having lefs adlivity. This lafl circumitance was probably owing to their not having been fo well preferved as thofe from the Weft Indies, which indeed feemed to be the cafe, or becaufe the poifon had. been prepared many years ago.

I could not fucceed in killing even fmall rabbits by applying this poifon to the ikin, fcraped or llightly fcarified ; although I laid it on. in a greater quan- tity, and upon larger portions of the fkin, than in my experiments with the ticunas : when given in- wardly, in twice or thrice the quantity in which I gave the latter, it produced no fenfible change, even in rabbits that fcarcely weighed a pound.

I pierced the fkin of feveral animals with thefe arrows^ leaving them flicking in it for whole days,

\^ ithout

^ O N POISONS. 159

xvithoUt my perceiving any poifonous affection. But on piercing the mufcles, and leaving the ar- rows plunged in them, I foon found the effedls . feveral of the animals poifoned in this way, died with the fame fymptoms that are produced by the ikunas. They were feveral hours in fickening, fo that this poifon does not feem to differ effentially from the other. It exadlly refembles it when exa- mined with a microfcope, when thrown into the eyes of animals, when tailed, and when chewed. It dilTolves with greater difficulty in w^ater, in which the greater part of it remains in an info- luble Hate.

The only inferences to be drawn from the parti- culars I have related are, that this poifon com- municated to the mufcles, ads with far greater force than when applied to the Ikin ; that it agrees very well with the other poifons, and ferves Itill to perfuade us that the immediate adlion of poifons is not on the nerves ; fince it is certain that the ikin is more fenfible than the mufcles, and is quite interwoven with nerves.

Experiments made with the Ticunas, after my return to Italy in 1780.

I forced an American arrow into the body of one of the fnakes, called anguis miliariSy near its tail* The fnake lived, and fcarcely feemed be- numbed

t^O !!• O N r A K A

tiumbed by it. I repeated this experiment with d frefh arrow on the fame fnake^ which neither died^ nor fuifered a great deal. Thefe two arrows had been previoully dipped in, the /zV^^Zi^j fof ten ed be- fore the fire to the confiitence of honey.

I palled another arrow in the fame ilate, through the tail of a fnake : in four hours it was motion- lefs, and as if dead. . On pricking the body with needles, there were notwithllanding fome marks of irritability, which at length difappeared, fo that I judged the creature dead. In thirty-iix hours it however began to move, and continued in a very feeble ftate for five days more. In its firlt condi- tion 'twas apparently dead ; in the fecond certainly alive: fiothing has furprifed m.e fo much as this kind of return to life, in fo large an animal, in which the fufpenfion of all its vital motions conti- nued fo long a time.

I repeated this experiment afrelh on another friake of the fame kind, fleeping the arrow in warm water before I forced it into its tail : I left it there twenty-four hours, without its producing any effed:* Soon after I forced another of thefe arrows into its body, where I left it for twelve hours, but without ejgea:.

I pierced one of the fore feet of a land turtle that weighed four pounds, with an American arrow^ which I left there for half an hour. In another hour it fcarcely feemed to live, and in two ap- peared quite dead. After an interval of ten hours, 1 removed wdth a ftiarp inftrument the inner fhell,

taking

O K POISONS. 141

taking care that the fieiliy parts fhould be as little torn as polHble. The heart was (lill^ and I fcarcely found any motion in the auricles. But in a little time the heart, together with the auricles, reco- vered all its force, and continued in a^flion for fix hours inceflantly ; the auricles kept in motion for two days, that is to fay, as long as they were inoiltened by the blood which flowed from the neighbouring velfels,

I pierced the fore foot of aland turtle that weighed ^ pound and an half, with an American arrow. la eight minutes it could fcarce move, and in a quarter of an hour was dead. When, the feet and neck were flimulated, they difcovered a flight de- gree of fenfation. Having opened the thorax, I found the heart and auricles quite motionlefs. I touched the heart thrice, and it contradled itfelf once each time, On freeing it from the mem- branes, it began to move very briikly, and conti- nued to do lo for feveral hours. I covered it with the inner fhcll, and in twenty-four hours found it again motionlefs. I pricked it once with a needle, it contracted itfelf a fingle time ; I pricked it again, it contracted itfelf afrelh, and continued ta do fo once every time I pricked it. I left it ex- pofed to the air for three minutes, and it then be- gan to move of itfelf, continuing a very brifk mo- tion for feveral hours. I covered it afrelh with »

the fliell, and on uncovering it four hours after, found it motionlefs. I left it in the air for a few niinutes, and in a fhort time, and of itfelf, it reco- vered

14^ F O N T A N A

vered its ofcillations, which conthiued for fix hours. I again covered it with the Ihell, and on uncovering it two hours after, found it without motion, I then covered it with water, which I kept on it for ten minutes, without its pro- ducing any change. I drained off the water, and the heart was fcarcely left in the air a niinute, when it began afreih to move brilkly, and conti- nued to do fo for feveral hours. Lailly, I put it in the fun, where it foon dried. The auricles like- wife dried in a degree, and all was then ilill, I now wet both heart and auricles ; the form_er con- tinued always motionlefs, but the latter began to move, and continued their motion for eighteen hours, when becoming dry, they loft it for ever. ,

This fucceffion of motions confirms ftill more the dodirine I have eftabliflied on the irritability of animal fibres (^), and fhows that the air is a very ad:ive principle in awakening the fenfibility of mufcular fibres, and of the heart.

It cannot be doubted, but that the ticunas attacks > the principle of irritability in the mufcles, al- though it has no acftion on that of the heart. It agrees in this with the other poifons, which do not ufually ad: on this mufcle or on the inteftines : the motion of thefe laft continues, even after the death of the animal, and when' the irritability of the other mufcles is totally deftroyed.

(a) De Legibus Irritabiiitatis nunc primum fancitis, Xucca, 1775.

FIRST

FIRST TRACT

O N

CHERRY-LAUREL WATER,

X O clofe my refearches on poifons^ I Ihall re-, late various experiments I have mafie on cherry- laurel water, a poifon vv^hich for fome years has been celebrated in Europe. It does not yield to the mofl aftive amongil them, when the great derangements it caufes in the animal economy, and the fuddennefs of its adiion on being given inter- nally to animals, are coniidered. It not only pro- duces the moil: violent convullions and death, in animals even of a middling fize ; but if given in a fmaller dofe, the animal writhes itfelf, draws its head and tail together^ and forces its vertebra out in a way frightful to the view.

In

144 r O N T A N A

In this flate the convuliions and agitations, of the body are very violent, and in the midft of them the animal at length meets with a fpeedy death.

If given to an animal as an injedlion, it equally produces convuliions and death.

With Lefs than two teafpoonfuls of this water taken internally, I have feen middle iized rabbits fall into convuliions in lefs than thirty feconds, and die in a minute. If fwallowed by animals in a large quantity, they die almofl inilantly without convuliions, and vvlth their bodies entirely in a funk and relaxed flate.

When given in a frnall quantity, convuliions more or kfs violent fuceeed, and the body and ex- tremities of the animal become lifelefs ; the hin- der feet firft lofe their ufe, then the fore ones, and fo on. When the animal can neither flir its legs or body, it continues to move its neck and head wery well, railing the latter without difficulty, and turning it freely about. In this ftate the animal retains its fmelling and light, and though it does not ftir its feet of itfelf, it draws them back when they are pricked or violently fqueezed : a proof that they have not w^holly loft their fenlibility.

Cherry-laurel water then is a very ftrong poifon, cither taken by the ftomach, or introduced into the body as an injection. Its adtion is fo fudden and violent, that the animal gives fymptoms of pain almoft on the moment of its being fwallowed. It is true that a fmall dofe of it is innocent ; that is to fay, that a few drops of it given to a fmall

animaj

ON POISONS. 145

animal which would be killed by the fame quantity of the tlcunaSy produces no fenfible complaint : but this does not make an effential difference betwixt the water of the cherry-laurel and the other poifons that are better known.

On diftilling a great deal of water from a few of the leaves, I found it to be quite innocent ; it becomes more adtive if repeatedly diflilled over again from the fame leaves, but is not mortal. If inflead of adding water to the leaves of the cherry- laurel, the diftillation is made in halneo mar'ia^ the liquor that runs off is a very flrong poifon, and very fudden in its effecfts* This is what I have principally employed^ and I doubt not but that ic may be brought to fuch a degree of adivity, as to kill in a fmall dofe, in the fame way with the tu cimas. For this purpofe the liquor that rifes the firll time Ihould be diflilled over again feveral times on frelh leaves, well wiped and almoft dry. I believe that if it were evaporated over the fire, an oily concrete fubftance would be obtained, which would not only equal in a(ftivity any of the. known poifons, but would probably far exceed them alL I referve this experiment for another occafion, when I lliall alfo fpeak of bitter almonds, and the degree of poifon to which their water may be carried, when diflilled dry.

We have feen that cherry-laurel water kills ani- mals when introduced into the flomach or intef- tines; let us now fee the effecfls it produces when • Vol. II. L applied

14-6 F O N T A N A

applied to wounds. One of the many experiments I made on this fubjedt will here be fufficient,

I made a cut of about an inch in the fkin of a large guineapig's belly, and flightly fcarified the bared mufcles in feveral places, applying to them two or three teafpoonfuls of the water mentioned above. In lefs than three minutes the animal fell into convuliions, and died foon after. This ex- periment Ihows that the cherry-laurel water agrees with the other poifons in its a(ftion on the body, when introduced through the medium of wounds.

The fuccefs of this experiment was the fame on other animals with warm blood ; I however ob- fcrved, that the water of the cherry-laurel adts invariably with greater quicknefs and force, when taken internally, even in a fmaller quan- tity.

This lad circumflance deferves, in my opinion, the greateft attention, lince it is a determined fact, that a large wound has infinitely more veffels than the mouth or ftomach, to abforb the poifon almoft at the very inflant : befides which, the nerves con- tained in the wound, both from their number and the flate they are then found in, ought to be very fenfible to the adtion of this poifon.

Not only animals with warm blood die very fud- denly when made to fwallow this water, but thofe with cold blood die too. What appeared to' me very fmgular, fince it is quite different with the other poifons, is that they die in a very Ihort time, perhaps even quicker than the firft. It will be

fuificient

ON POISONS. 147

fufficient juft now to fpeak of eels, creatures very' hard to kill, and the parts of which, when they are dead, continue to move a long time : they die in a few feconds after fwallowing this water, con- trading themfelves at firil, but becoming motion- lefs the inftant after their death, w^hen their bodies are not even fenfible to Simulation. The heart however continues to move, but not fo forcibly as before ; and this motion ceafes m.uch fooner than when they are killed by cutting off the head. It cannot here be denied but that the mufcular irri- tability muil be ilrongly adted on, and that in a particular way. All the animals with cold blood I have been able to procure, were killed by this poifon, and I doubt whether any of them are cap- able of refilling it : if they are not, it ought on that account to be diilinguiflied as the molt ter- rible of all known poifons, from its univerfal fa- culty of dellroying every fpecies of animals.

But how does it kill in fo Ihort a fpace, when introduced into the llomach, where we perceive no veiTels capable of receiving it ? This difficulty requires fome further experiments : we muH fee the effedts it produces when applied immediately to the nerves, and when introduced into the blood without touching the parts that are cut.

I employed large rabbits, making my experi- ments on the fciatick nerve, as 1 had done with the venom of the viper and the ticunas. For brevity's. fake, I lliall relate here a fingle experiment, omit- i ting all the others, which I do not think very ne-

L 2 ceffary.

148 F O N T A N A

eeflary, after the many experiments on the nerves already related.

Having laid bare the fciatick nerve of a large rabbit, for the length of more than an inch and an half, I placed under it a piece of very fine linen, lixteen times doubled, to prevent the water from penetrating to the parts beneath it. I then wounded it lengthways feveral times with a lancet, and co- vered the wounded part, more than eight lines in length, with a bit of cotton about three lines thick, well fleeped in cherry-laurel water, of which it ab^ forbed more than fifteen drops : all of this was communicated in an immediate way by the wounds^ to the medullary fubllance of the nerve, which I covered for feveral minutes with frefh linen, fo that it was impoflible for the poifon to be com- municated either to the parts beneath or thofe ad- jacent. Having made the future in the ikin, and left the animal at liberty, it ran about, eat, and v^as as lively as before, and neither then nor after- wards, feemed at all affected by this poifon, which kills fo fuddenly when taken by the ftomach. This and feveral other fad:s, analogous to thofe of the viper's venom and ticunas, fhow us that cherry- laurel water, in whatever way it Is applied, whe- ther immediately to the nerves or even introduced into their medullary fubftance, has no action on them, either as a poifon or otherwife^

After all the experiments related in tliis work on the venom of the viper, and on the American poifon, which is Itill more powerful ; after having

feen

ON POISONS.

149

leen that neither of thefe two poifons has any ac- tion, when applied in an immediate way to the nerves, whilil they kill the itrongefl animals the moment they are introduced into the blood ; there cannot be a more natural inference than that the water of the cherry-laurel, innocent like the others when applied to the nerves, ought to be likewife dellrudtivc when introduced into the blood ; and yet the cafe is altogether different : fo true it is that we ought to miflrufl analogies, even v/hen they are mofl uniform.

i fat about introducing this water into the jugu- lar vein of a large rabbit, begirrning with five or fix drops, as I had done with the viper's venom and ticu^ nas. The animal giving no fymptom of pain, I thought I had not fucceeded in the attempt, and that the fyringe had found its way into the cellular membrane. I repeated this experiment, introducing afreih> perhaps three or four times the quantity of the water, and afiTuring myfelf previoufly that the point of the fyringe had entered the vein, and that the liquor could in no way force itfelf back : the animal flill continued to be unaffedied by it. I was more furprifed than fatisfied at what I faw. I could not perfuade myfelf but that the cherry-laurel water would be a poifon, and even a very powerful one, when introduced into the blood, fince applied to the nerves, it was quite innocent. I returned then to my experiments, and now introduced a teafpocnful of the water into the jugular vein, from which the animal felt no ill effects. I repeated this experi- L 3 ment

150 FONTANA

ment on another rabbit, and introduced the fame

quantity of the poifon, the creature neither fuifered

at the moment nor afterwards.

The unexpe(lted refult of thefe experiments^

threw me into the greatell uncertainty as to this poi^ Ton ; I was not only puzzled at its mode of opera- tion, but even as to the parts on which it adts, when taken internally or applied to wounds. It docs not ad: perceptibly on the nerves ; it has no adiion on the blood ; and yet it kills when fwallowed, and that in an inftant. The deaths of animals may then be brought on in another way than by the blood and nerves 1 The lofs of motion in a few feconds in crea- tures fuch as eels, which continue to move for whole hours after their heads are cut off and their- bodies in pieces, would induce a belief that this poifon ads on the irritability of the mufcular fibres, it is true that in thefe animals the heart ilill continues to move, but its motion is much diminiflied, and of very ihort duration. In animals with warm blood, poifoned by the water of the cherry-laurel, a very feeble motion ftill exifls in the other mufcles, and if the heart continues to beat for fome time, its motion is feebler than when they are killed in any other way. There is certainly a very great diminu- tion of irritability in many animals, and in many others a total lofs of it, in whatever way this lofs or this dirninution may contribute to bring on fo fpeedy a death, and however obfcure the mechanifm may be by which this aftion is wrought on the mufr cular fibres.

We

ON POISONS. 151

We mufl avow our ignorance in fearcliing into, nature; when we think we. have done every thing, we frequently find ourfelves returned to the Ipot we .fat out from. Experiment, which is the only guide we have in our refearches, undoubtedly fecures us effedtually from falling into errour ; but it does not always draw us into an acquaintance with remote truths; neither does it always lead us to a knowledge of the fecrets of naiiure, nor carry us invariLibly as Jar as we propofed to go.

But if we do not know how the cherry-laurel wa* ter adis, and on what parts it exercifes itfelf in def- troying animals, we however know that when it is applied immediately to the nerves, and even to the medullary fubflance of them, it is quite innocent : and it is not lefs true, as the many experiments hitherto related have clearly demonilrated, that the viper's venom and the ticunaszxQ not mortal in what- ever way they are applied to the nerves, but are al- ways fo when introduced into the blood. Thefe truths, which we were formerly ignorant of, are now cleared up in fuch a way that they cannot be cal- led in doubt, and deftroy all the fyftems which wri- ters have invented on the action of thefe poi ions : it is from thefe fades that we mufl proceed to an in- telligence of them, and of their ad:ion.

The applying the water of the cherry-laurel to the different parts of the brain of a living animal may probably throw fome light onitsadtion; 1 poftpone the doing it till I have more conveniences for that purpofe than at prefent, and Ihall then, I hope, fur- L 4 nifh

152 F O N T A N A

nifli fome new and more interefling particulars as to this poifon, and the parts of an animal on which it ad:s when it deflroys it.

I referve to this opportunity the examining whe-^ ther it adts on the lymphaticks, or rather on the lymph itfelf. I fufpeAed this after trying the ex- periments I have recited, but could not then enter into an inveftigation of it. My experiments on cherry-laurel water are confequently lefs complete than I wifhed : They mull be multiplied and pur- fued more than I have been able to do, and this is ilill another reafon that I continue my refearches on this truly interefting fubje(ft.

On the a3ion of Poifons on the Nerves.

It has been feen in the courfe of this work, that the venom of the viper, and the ticunaSy in what- ever way they are applied to the nerves, are inno- cent; and on the contrary, that when they are in- troduced into the blood, without touching the wounded parts adjacent, they bring on a fudden death. It has likewife been feen, that thefe two poifons throw an animal into very violent convul- iions, and excite the moil decided fymptoms of thofe difeafes, which the phyficians call nervous, becaufe they believe them to arife fimply from a nervous affedlion. It aj^pears, that there can be no doubt in future of thefe poifons being abfolutely innocent when in immediate contadl with the

nerves ;

ON POISONS. I5J

nerves ; and that they have no immediate adion orv the fo}id parts, fuch as the mufcular fibres, the bones, cellujar membrane, and tendons. But this is not fiifRcient to lead to a perfed: knov/ledge of them. The nerves are certainly excluded in the difeafes they occafion, and the blood alone feems to be adted on. But how many different humours do we not find mixed with the blood ? It has even been believed, that it is animated, and it feems more than probable that the nerves are perpetually fecreting a humour which is mixed and circulates with it. May not this humour be eflential to life, and be attacked by thefe poifons, when they are introduced into the vefTels ? In reply to this query, frogs are known to live, as the learned Spalanzani ha? obferved, even after their veflels are emptied of the blood, and in this flate die very readily, if made to fwallow the^fpirit of the cherty- laurel, as I have obferved feveral times. Thus is the firft of thefe two hypothefes proved to be falfe, and the fecond is by no means fufficient to explain the adtion of this poifon on the parts of animals.

The fpirit of the cherry-laurel, which ads but feebly when applied to wounds, which is innocent when applied to the nerves, and which kills when fimply applied to the mouth and eyes, throws us into frefh uncertainties, and fcarcely IjCaves room for conjedures. A fubflance which is a poifon in the flomach, in the mouth, and in the oefophagus, and which is almoft innocent when applied to wounds, *^ a true paradox, and reiterated experiments are

fgarcely

154 F O N T A N A

fearcely fufficient to convince us that the fadl is real.

The only fure confequence to be drawn from fo many experiments is, that an animal may have all the fymptoms of a nervous difeafe, without our being able to aiTure ourfelves that the nerves are 2ffed:€d» The convullions like wife that are obfer- ved in animals from the diminution of the blood alone^^ or the unequal diftribution of this fluid in the different parts, in the way I have demonflrated in feveral parts of my different works, leave no room to doubt it (^).

I have only to wifh at prefent, , that; fome fkil- fill phyfician, gifted with the rare talent of nice obfervation, and divefled of all prejudice for hy- pothefes that want the necefTary fupport of fads and experiments, would find leifure to examine with a critical nicety this important fubjedr, which eonflitutes at this time one of the principal branches ©f modern medicine. Such an inveftigation may at length decide with certainty, whether all the difeafes that are filled nervous^ and which are faid to originate from a change in the fyflem of nerves, iave really fuch an origin ; whether there are cha^ radteriflick fymptoms, invariable and conflant, of this fpecies of difeafes ; whether there is a certain criterion, a fufHciently faithful touch Hone, to afTure

(«) This firft traft on the cherry. laurel, and likewifc, the treatife on the Ticunas, were printed in the 68th volume of the Philofophical Tranfadions.

US

ON POISONS. 155

US of It ; and whether the greater part of thefe difeajfes may not be caiifed by the blood, or other vitiated humours, rather than by the nerves. Is the perceiving the nerves to be in fome meafure afFed:ed, really fufficient to characterize a nervous difeafe ? Can we determine a difeafe to be nervous, becaufe feveral of its efFefe manifell themfelves on the nerves ? An affediion of the nerves may very eafily be attached to a particular clafs of difeafes, aiid yet the nerves not be thecaufe of them; ought we thence to fay that fuch difeafes are nervous ? We do not here demand fublime and abllradted theo- ries, which a lingular effort of genius frequently gives birth to : we are in need of nice obferva- tions; new and well imagined experiments ; dire<3: and ufeful indud:ions, drawn by a calm mind, and one capable of aifembling and combining in the beil manner, the moil luminous particulars. Thres; of the moil learned phyficians of our days have by their writings fully fatisfied the firfl of our demands ; we have now to defire that a fourth will at IcLgth finiih this important work, by applying himfelf afiiduoufly to the lall.

SECOK©

156 F O N T A N A

SECOND TRACT

ON THE

CHERRY- LAUREL

OHORTLY after my return to Florence in 17S0, I had an opportunity of re-examining the efFedls of the fpirit of cherry-laurel on different animals. I therefore thought it proper to give a greater ex- tenfion to my experiments on this poifon, than I had done in England ; and my labours have not al- together been without fuccefs. I have at leaft eilablilhed truths I was before ignorant of^ and have excluded many ufelefs or falfe hypothefes, which might have retarded the refearches of thofe who may wilh to bufy themfelves hereafter on this fubje^t. 1 very juflly obferved fome time ago, that in diftilling the leaves of the cherry-laurel without water, a fpirit was obtained capable of

killing

ON POISONS. 157

killing animals in a very Ihort fpace, although il! was given to them only in a fmall dofe. I like- wife obferved that if water was put on the leaves, the fpirit would become altogether innocent, and pre- ferve nothing but an agreeable flavour. But I did not know whether the eiTentlal oil drawn from the cherry. laurel by diilillation was innocent, or aded as a. poifon ; and whether, fuppofing it hurtful, it wa$ ftill more fo than the fpirit. I likewife did not know whether the deadly effedls of this fpirit were caufed by its having in it more or lefs of this oil in a diiTolved ftate. It was owing to the want of experiments that I was ignorant of all thefQ particulars, and of many others which the authours who have written on poifons have not examined into. None of them, that I know of, have made experiments on the eynpyreumatkal oily and on the extraH of the cherry-laurel ; neither have I met with any one who has made diredt experiments on the greater part of the above particulars, to ferve me as a guide, and yet they appear to me necelTary to the right underftanding the nature and qualities of fo very lingular and a<ftive a poifon.

To proceed methodically, I ftiall give a concife detail of the different produd:ions I have drawn from the cherry-laurel, and of the method I pur- fued for that purpof^. In diftilling the leaves in the ufual way in glafs retorts, and without adding water, I obtained the fpiritous part, (what the chymifts call reclified fpirit). This fpirit was tranf- parent, fragrant, poignant to the tafle, and at the

bottom

Ig^ F O N T A N A

bottom of the receiver there was a certain qisantitf of a heavy, coloured, odoriferous oil, which was bitter, pungent, and burning to the tafte. I fe- parated |this very attentively from the fpirit, after letting it fettle for feveral days. I iikewife em- ployed the fpirit not entirely deprived of the oil, I fhall call this oil, oil of the firjl difiillationy and the fpirit, y/>fnV of the fir ft diftillation,

I took a quantity of the fpirit of the firfl: diftil- lation, and diililled it afreih till there remained about one third in the retort. The fpirit came off more tranfparent, fragrant, and poignant, more bitter and pungent, than that of the firft diflillation. Being left in a bottle to fettle, it depofited a very tranfparent, odorous, burning oil, very like in its external qualities the oil of the firfl diflillation. I Ihall call this, oil of the fecond diftillation, and the fpirit, Jpirit of the fecond diftillation. What re- mained in the retort I ihall call refiduum, or phlegm of the fecond diftillation. I prepared another phlegm l^y evaporating two thirds of the fpirit of the fe- cond diftillation in the fun.

I mixed a quantity of the fpirit of the fecond diftillation with the fame quantity of decrepitated and well dried fpirit of fea fait. I diftilled this mixture with a flow fire, and drew oiF one half : this was of the colour of common oil, and lefs fpi- rituous, pungent, and fragrant than before. It pre- cipitated an oily coloured fubftance, of an earthy appearance, and divided into fmail grains or glo- bules.' I continued the diftillation, and there came

off

ON POISONS. i^g

off a phlegm without fmell, and not fenfibly pun- gent, although put on the tongue, or rubbed on the noflrils. I Ihall call it phlegm of the third difiil^ latkn. The oil I have juft fpoken of, I Ihall call oil of the third diftlllation, and its fpirituous part which came off the firfl, fpirtt of the third diflilld* tion. Both oil and fpirit have the fmell of bitter almonds,

I drew off in the fame way the €Xtra5l of the leaves of the cherry-laurel, purfuing the fteps iai^i' down by chymiils ; and likewife prepared a good quantity of emfyreumatical oil wdth freih leaves* After having furniflied myfelf with all thefe pre- parations^ I began my experiments on animals^ chufing rabbits, guineapigs, pigeons, frogs, and adders. I thought it neceffary to try them on ani* mals of different natures, fome with warm bloc^, and fome with cold, becaufe I knew by experience how much the adlion of poifons varies in different animals, and above all in the larger fpecies of them, in w^hich the economy of the various movementi^ is fo different.

Spirit of Cherry-laurel of the firjl dlftilktion, giveM internally,

I let this fpirit fettle for fome days to feparate the

oil from it, fo that it became clear and tranfparent,

I gave a tqafpoonful to a pigeon of a n^iiddling iize,

3 which

l€o F O N 1* A N A

which in four minutes fell into convulfions, and was for fome time not able toi fupport itfelf ; it however furvived.

I gave three teafpoonfuls to ^ fmall guineapig, which felt ilo ill effedls from it.

I gave two teafpoonfuls to a pigeon, which in a minute could not fupport itfelf ; in another minute It fell into ilrong convulfions^ and died on the third.

I repeated all thefe experiments on the following day, on the fame animals, and the refult of them was the fame.

As the pigeon died whicli (wallowed two tea- fpoonfuls of the fpirit, I wifhed to try it before the oil had funk to the bottom. In this flate it is lefs clear, more pungent, and more fragrant. The want of adivity in the fpirit employed above, arifes, as will be feen, from my having left the oil to precipitate for feveral days, and in reality that which 1 had employed in London was thick, and adled with far greater violence. ^ I gave then to different animals, fuch as rabbits and guineapigs of a middling fize, three teafpoon- fuls of the fpirit in the ftate I have fpoken of, and the greater part of them died convulfed in a very little time : a proof that this fpirit i^ much {Ironger than the other.

Spirit

ON POISONS* l6l

Spirit of the fecond DiJlillatiOn given interndllyi

I gave to a fmall guineapig a teafpoonful of this twice redified fpirit i it died almoil in* llantly.

I made a large rabbit fvvallow a fpoonful of this fpirit. It immediately fell, and died a ihort time after*

I gave four drops to a guineapig of a moderate fize. In the very aO: of deglutition, a liquor of a yellow and green hue poured from its mouth* This frequently happens when the fpirit is fwal- lowed by thefe animals, but never when they fwal- low the oiL It was otherwife without complaint.

I gave a large rabbit fix drops of this fpirit mixed with forty drops of water. The creature lay down fevera_ times on its belly, feemed very vineafy, but did not die*

I gave four drops to a pigeon, which expired in lefs than a minute^

I gave four drops to a frog, which in two mi- nutes was to appearance dead, and the parts of which in two more, although ilimulated, vv^ere to- tally without motion*

Phlegm of the Spirit of the fecond Diftillationi

This phlegm was fcarceiy fpirituous or pungent^ but was very traafparent*

Vol. I'L M I gave

l6z F O N T A N A

I gave it to feveral animals, fuch as pigeon s^, rabbits, and guineapigs. The pigeons to which I gave a teafpoonful all died : of thofe to which I gave only a few drops, fome had no complaint, fome died after a long time, and others were only convulfed.

A few of the very fmall rabbits and guineapigs died, others were convulfed, and others again had no fenfible complaint. Thofe which died, had fwallowed three or four teafpoonfuls.

The phlegm then is lefs deflruAive than the fpirit.

Phlegm of the Spirit of the fecond DiJlillatioUy obtained by evaporating two thirds of it in the Sun,

I put about three ounces of the fpirit of the fecoild diftillation in the fun to evaporate. The refiduum being an ounce, Vv^as liquid, traufparent^f and almoil without fmell : when put on the tongue it was ilill pungent, although much lefs fo than before. I gave half a teafpoonful to a pigeon, which fell inllantly into violent convulfions and died. Five other pigeons died in the fame way. Thefe experiments would lead one to fuppofe, that the poifon neither confiils in the fragrant nor the pungent quality of the cherry-laurel, fince both of them were fo trifling, and the animals notwith- llanding died fo fuddenly.

1 gave a teafpoonful of the fame phlegm to two pigeons, both of which immediately died.

I gave

ON POISONS. 163

I gave three drops to a pigeon, without its having iany efFedt, whence we may infer that this phlegm is alfolefs deftrudive than the fpirit*

Spirit of the fecond Dijiillatlon applied to the Mouth.

1 wiihed to know whether this very adlive and def« troying fpirit would kill, when iimply applied to the inner part of an animal's mouth.

I wetted a piece of linen with it, and introduced it into a pigeon's beak, without the poffibility of a drop of the fpirit pafling into the ilomach, or even the oefophagus. In thirty feconds the pigeon fell into convullions, and died immediately.

I wetted another piece of linen with it, and kept it a long time in the mouth of a middle lized guineapig, which was not annoyed by it. :^

I repeated the fame experiment on two pigeons, both of which died in lefs than two minutes. i I repeated it on two guinaapigs, which continued jfree from complaint.

I This fpirit then is capable of killing weak animals without touching the oefophagus or ilomach.

Spirit of the fee 071 d Dijiillatlon put on the Eyes.

It remained to know whether this fpirit would be iikewife deflrudive, when applied to other tender parts of the body. Here it occurred to me to make Imy experiments on that very fenfible organ, the eye.

M 2 I lee

164 F O N T A N A '

I let feveral drops of the fpirit fall cm the naked e3^es- of a guineapig. It faffered feverely ; but had nei-r ther convuliions^ mfiammation, nor any other fymp- tomof poifon.

I made the fame experiment on the eyes of two other guineapigs, and the confequence was the fame. I repeated it on the eyes of two rabbits, but al- though the fpirit clearly incommoded them, they neither died, nor were convulfed; and their eyes- were not apparently inflamed.

Thefe experiments do not yet prove that the fpi- rit of the cherry-laurel is entirely innocent when ap- plied to the eyes of thefe animals, becaufe they are hard to kill, and make a flrong refiitance to the adiion of the fpirit, when it is fimply applied to the- mouth.

It is true that I covered the eyes of two very fmall guineapigs which weighed only three ounces each^ wdth the fam^e fpirit, and repeated the application of it more than twenty times, but in vain i. they had no fymptom of poifon, and their eyes were free^ from inflammation, although they were very feniible: of pain when I applied the fpirit to them.

But 1 thought it would be right to make fome experiments like wife on pigeons. I moiitened a pigeons eyes feveral times with a piece of linen wet-^ ted with the fpirit : after alhort time it vomited re- peatedly, and fell on its breafl. I'he iris in the vi- ciniry of the tranfparent cornea was a little infla- med, tne pupil moveable, and of its natural fize.

. I let

ON POISONS. 165

I let fall fome drops of the fpirit on the eyes ^f another pigeon, keeping them on the part for more than two minutes; it was feized with convul- fions, and died in a few inftants, without the eyes being inflamed,

I put feveral drops of the fpirit on one of the eyes of a third pigeon, keeping it on for three minutes. The iris was much inflamed-, as were the eyelids in a degree. A fhort time after, the pigeon was feized w4th convulfions, and appeared as if dead. In a quarter of an hour, it recovered by degrees, and at length feemed quite well; however it fell afrefn into convullions, appeared for a fecond time as if dead, and very fo6n after revivedagain. The iris of the eye to which I applied the fpirit, was as red as if it had been injed:ed, the pupil was immoveable and much -enlarged: the iris of the other eye was like wife a little red, the pupil in its natural ftate. After the aniniaFs relapfe and fecond recovery, the pupil and iris were in the flate they were the iirft time; but af- ter the third attack, from which it recovered itfelf perfectly, the pupil became moveable like the other, the inflammation of the iris was much lelTened, and both pupils recovered their natual fize.

I let fall feveral drops of the fpirit into the eye of another pigeon, and kept them there for feveral mi- nutes : the creature fell into convulfions, and could not fupport itfelf. The iris was inflamed; that of the other eye was a little fo, but infinitely lefs. The pigeon recovered by degrees, and I then found the iris immoveable, enlarged and inflamed ; the other

M 3.. was

1^6 F O N T A N A

was moveable in the light, a little inflamed, and of its na^;ural fize. The pigeon fell infenlible three 'times^^ and as often recovered. The pupils and irifles, which were affedied as I have defcribqd, came to their natural ilate in a few hours.

Spirit of the fecond. Difilllation applied to Wounds^^

It was natural to conceive that this fpirit would kill ilill more readily, when applied to wounds. I inade large inciiions in the legs of a pigeon, and in- troduced a great quantity of it, but the creature had no fymptpm of complaint.

I repeated this experiment on two other pigeons^ and the refult was the fame.

I applied a piece of linen wet with the fpirit, to the wounds of V7^o others, and left it there feveral Hiinutes ; the pigeons were not difordered,

I wifned to fee whether it would be as ina<ftive,, when applied to the ped:oral mufcles. Having laid them bare, and v/ounded them in feveral places, I immediately applied the fpirit, and fomented them with linen wet with it. 1 he pigeon had not the fmaileft complaint.

On repeating this experiment on three other pi- geons, the event was the fame.

I was oil the point of concluding that the fpirit of the cherry-laurel, in whatever way it is applied to wounds, is neither poifonous nor mortal, although j|; i^ highly fo when put on the eyes, or applied to

the.

ON POISONS. 167

the mouth. The fingularity of this particular in- duced me to continue my experiments, and they convinced me that I had been deceived..

I railed a large portion of the fkin of a pigeon's breaft, and applied about an hundred drops of, the fpirit. A fnort time after the pigeon fell into con- vullions, and died.

I laid bat'C the mufcles of the leg of another pi- geon, and v/ounded them in feveral places. I ba- thed the wounds repeatedly with the fpirit, and kept them wet with it for eight minutes. The pigeon did not fuffer during this interval, but two minutes after, fell on its bread and died.

I made a large opening in the ikin of a guineapig's back, and made feveral fuperficial wounds in the mufcles : I introduced at the opening in the ikin, a great quantity of the fpirit, and that repeatedly for feveral minutes. It was at firil ilightly convulfed, foon after it fell on its bread incapable of fupporting itfelf, and died in a very little time.

I laid bare the mufcles of a pigeon's breaft, for a great length, and^madc feveral deep wounds in them, I applied the fpirit in fuch a way that it could not reach the ikin, and renewed the application to the wounds more than thirty times, keping it applied for at leaft twelve minutes. It at length vomited, then fell into convulfions, and died very foon after.

It is an eilablilhed truth t]ien, that the fpirit of the cherry -laurel kills when it is applied to wounds, although it is likewife true that it afts much later thsin when applied to the eyes, and mouth, and re-

M 4 ceived

1 68 F O N T A N A

celved into the ftomach^ in which cafes a fmaller dofe ia deftructive. It is very lingular, and flill as certain, that the quantity which kills an animal, a pigeon for exaniple^ in the latter cafes, brings on no feniible complaint when it is applied to wour^ds.

Spirit of the third Dijiillatlon,

I gave hjilf a te^fpoonful of this'fpirit to a large guineapig, which did not fuffer fenfibly from it ; but three pigeons, to each of which I gave fcarcely three drops, died ; as did alfo three rabbits and four guineapigs, to each of which I gave a tea- fpoonfuL A large guineapig and a large rabbit furvived however, after fwallov/ing this quantity^ although each of them v/as viiibly difordered.

Spirit of the Cherry-laurel of the third Diftillatlon, T/iade by mixing a quantity of decrepitated Sea Salt with the Spirit of the fecond Dijiillation,

This fpirit has fcarcely any fmell, and is almoft iniipid. I gave not quite a teafpoonful of it to. a pigeon, which inftantiy fell into convulfions, and died foon after. Two other pigeons died on fwal- jQwing ^ much fmaller quantity; fo that the fea ' ■ ^ fell:

ON POISONS, 169

fait does not feem to have changed the natural qualities of the fpirit.

fhlegm of the third Di/Iillation, zvith fcarcely either fmell or tajie,

I gave three drops of this phlegm to a pigeon, which did not fiiffer from it,

I gave a teafpoonful to a Isirge guineapig ; it fell in a moment into convuliions, but afterwards raifed itfelf and continued well.

I gave the fame quantity to a guineapig of a middling iize, which felt no ill effedis from it.

I gave a teafpoonful to a very fmall guineapig, which continued well,

I made a large guineapig fwallow a fpoonful and an half. It vomited a little foul matter^ but re-* covered.

I gave the fame quantity to a fm^all guineapig : it fell inftantly into convullions, but fhortly after recovered itfelf perfectly.

I gave a fpoonful to a pigeon, which fell im-^ mediately into convulfions^ and died in lefs thau a quarter of an hour.

Oil of the Cherry 'laurel given internally.

It remained for me to examine the oils of the cherry-laurel^ and after having ajTured myfelf by

reiterated

t'J^ -F O N T A N A

reiterated experiments, that there is no efTential difference between them, whether. they are of the firil, fecond, or third diftlllation, I did not think k neceiTary to diiVinguifh jthem, ^nd have therefore employed them indifferently. What was of the moft confequence to me was, to know whether this oil is iikewife a poifon, and if fo, whether it is flronger or weaker than the fpirit. I ihall pa that account relate fome of the experiments I made with it on different animals, and which will fufhce to decide as to its poifonous qualities, and to ihow the frequent anomalifms which refult from the fame fubjedt.

I made a large rabbit fwallow two drops of the ^il, united with two drops of fpirit. It died in a few feconds, fiightly convulfed.

I m.ade a land turtle of a pound weight fwallow about two drops of pure oil. Two hours after, it was become very feeble : in fomewhat more than fix hours it died with all the fymptoms of a lofs of irritability.

I gave a large guineapig four drops of the oil, from which it felt no ill effecfts.

I. gave fcarcely three drops to a pigeon, which idled in two minutes.

I made a large guineapig fwallow half a tea- fpoonful. It remained well for more than half an liour^ but afterwards fell into violent convullions, and died half an hour after.

I gave

ON POISONS. 171

I gave a pigeon a third of a teafpoonful of this ml; in a very little time it could not fupport it- felf, and died in lefs than half an hour.

I made a large guineapig fwallow about fix drops of the oil mixed with forty drops of fpring water. It immediately gave fymptoms of uneaii- nefs ; had feveral Teachings to vomit ; but a ihort time after became well and continued fo.

I gave a fmall guineapig fix drops with forty drops of water. It was very uneafy ; but neither fell, was convulfed, nor died.

I made a frog fwallow three dropS;, and in two minutes it was quite dead : the heart flill prefer- ved its motion, and the feet flirred, on Simulating the crural nerves.

This experiment v/as repeated on two other frogs with nearly the fame confequences.

Notwithflanding the little conformity in all thefe experiments, we may conclude that the oil of the cherry-laurel is a violent poifon, and kills both animals with warm blood, and thofe with cold. We may determine it to be far lefs active than the fpirit, and that accidental circumftances, and a diverfity in animals, are fufficient to prevent its noxious efFed:s. It is very ftrange that it kills an animal with cold blood much quicker, as we have feen, than one that has the blood warm.

Oil

173: J O N T A JJ7 A

Oil of the Cherry-laurel applied to the Mouth.

I wiilied ro fee whether the oil of the cherry-' laiirel,, which is a violent poifan when received into the ilomach, would be fo too when only in- troduced into the mouth and palate, without enter- ing the csfophagus. The experiments \ have re- lated on the fpirit of the fecond diftillation^ led to a fufpicion that this may be the cafe.

I made a piece of linen a little moiil w^th: oil, 2nd introduced it into the mouth of a very fmall guineapig. I prevented it from ihuttjng its mouth, to avoid the linen's being coniprefled fo as to force the oil into the ilomach. After keeping it in this liate for two minutes, the animal was as well as» 'before.

I repeated this experiment on another fmall guineapig, and rubbed the inner part of the mouth feveral times with the linen. The animal foon be* came very dull ; but neither died, nor was con- vuifed,

I repeated this experiment on two other pretty large guineapigs, neither of which difcovered any fymptom of complaint : but theie experiments are not deciiive, becaufe thefe animals are very hard to kill, and becaufe a greater quantity of the oil was perhaps neceffary. I had recourfe then to p'^geonsj which are fo eafily killed.

I wet

ON P O f S O N S. 173

1 wetted a piece of linen with the oil, and intro- duced it into a pigeon's beak, in fuch a way that it could not reach the ftomach or even the Gelbpha- gus. The pigeon died foon after.

I repeated this experiment on four other pigeons^ three of which died very foon. The fourth had fcarcely any complaint.

I think that we may conclude that the oil of the cherry-laurel ad:s as a poifon, even when it neither touches the oefophagus nor ilomach ; and that for this end it is fufficient for it to be in con- tad: with the inner psrt of the mouth.

The confequences of thsfe experiments are en- tirely analogous to Vv^hat we have feen above m making ufe of the fpirit of the cherry-laurel.

Oil of the Cherry-laurel applied to IVounds^

We can no longer doubt but that the oil of the cherry-laurel is a poifon, and a very violcn-t one' too, when taken internally. It now remains to know, whether it is a poifon when applied to- the wounded parts of an anim.aL Experiments alone can decide this, and thofe we have already made on the fpirit of the fecond difLillation lead us to pre- fume, that it is likewife a poifon in tLefe circum- ftances*

1 thruft a bit of wood dipped in this oil,, into a pigeon's leg, and obferving that after fifteen mi- autes the creature was not diibrdered by it, I took

174 F O N T A N A

it out, and introduced a great deal of the oil intd the wound, which was very deep ; the pigeon not- withllanding, neither died, nor was convulfed.

I made a wound in the body of a fmall tortoife, towards its tail, and introduced the oil freely ; the tortoife was not difordered by it.

I made a wound in a pigeon's leg, bathing it feveral times with the oil, with which, put on linen, I likewife covered the wound. The pigeon was not difordered by it*

I wounded the legs of a pigeon in feveral places, and rubbed the wounds with this oil. It did not fuffer fenfibly.

The confequences of experiments on two other pigeons, three rabbits, and four guineapigs, were the fame, notwithftanding that I did not fpare the oil, with which I covered the wounds repeatedly^ as I had done after wounding the mufcles of thefe animals.

I wounded the ped:oral mufcles of three other pigeons^ and covered the wounds with the oil ; neither of the pigeons were at all difordered by it.

It appears beyond a doubt, that the oil of the cherry-laurel, which is a poifon when fwallowed, has not this quality when applied to wounds, of the parts at ieaft, on which I made my experi- ments : this is quite contrary to the nature of the viper's venom and other poifons, which are in- nocent v;hen fwallowed, and deilrudlive when ap- plied to wounds. If any thing probable can be advanced to account for this difference betwixt

the

ON POISONS. 1^^

the oil Bf the cherry -laurel, and the venom of the viper, I do not fee what can explain the variety of adtioil in the former, on the different parts of an ani- mal; this is a very iingular circumllance, and what one would leaft exped:. 1 mufl: however con-^ fefs that my experiments are not altogether deci- five, although I made them on pigeons ; becaufe I did not employ the fame quantity of the oil, as I had done of the fpirit. I was in want of this fubftance in the greater part of my experiments^ and have not till nov/ had conveniences to make it afreih. Notwithflanding this, it is iingular that what is poifonous when taken inwardly, fhould be innocent when applied in a much greater quantity to wounds.

Oil dried in the Sun.

1 placed about two drachms of the oil of the therry-laurel in the fun to dry, till about half was wafted ; the refiduum was yellow, bitter, fragrant, and pungent. I gave about three grains of this in weight, mixed with twenty drops of water, to a pigeon, which fell a moment after, was convulfed violently, and died very foon. I repeated this ex- periment on three other pigeons, and the confe- quences were the fame. It is therefore certain, that this concrete refiduum is a ftrong poifon, and

that

176 FONTANA

that the evaporating a part of ic in theTun^ does riot at all deprive it of its hurtful qualities. .

The refiduum of the oil of the cherry-laurel dried in the fun, is a true refin ; when precipitated from fpirit of wine, by the means of water, it is no longer poifonous.

It has been feen that the concrete part of the oil of the cherry-laurel expofed to the fun^ is a Urong poifon. It does not diflblve in water, but is eaiily and perfedly difiblved in fpirits of w^ine. It is a relinous fubftance then, which retains a de- leterious quality. To know wdiether it would ftili retain it, if diilolved in fpirit of wine, and preci-^ pitated by water, I threv/ a great quantity of dif-^ tilled water on this foiution of it, and when irhad funk in the form of a v/hite farinaceous powder, I waihed it in feveral waters. It had fcarcely pre- ferved any fmell, but when put on the tongue, and chewed, it was ftill pungent. I gave twenty grains of this fubfiance, whilfl ftili wet^ to a very fmall guineapig, and as much to a pigeon ; neither of v/hich either died or felt any ill effedts from it.

I repeated this experiment on two other guinea- pigs, and the event was the fame. It follows theny that this refin, after being difTolved in fpirit of wine, and precipitated by the means of water, be-- comes innocent, although it preferves in a degree its fmell and pungency ; and it appears that this- fmell which is left^ together with the pungent and cauftick quality, is not fufficiently deleterious^ 4 to

ON POISONS. 177

t6 kill, or produce any fetllible derangements in animalsi

ExtfaB of the Cherry-laureL -

I made a guineapig fwallow about thirty grains of this extrad: ; it had no efFed: on it.

I made the fame trial on a rabbit, which felt as little.

I gave about fifteen grains to a pigeon, without any fenfible effedt. ^

I repeated this experiment on two other pigeons, with the fame fuccefs. We may infer from all thefe e:^eriments, that the extradt of the cherry- laurel is quite innocent.

Empyreumatical Oih

I made a guineapig fwallow about twenty drops of the empyreumatical oil of the cherry-laurel ; it vomited foon after, but fpeedily recovered itfelf, and continued well.

I gave a fmall pigeon twelve drops of this oil. It vomited feveral times, was very feeble, but fdon recovered.

I gave about thirty grains to a rabbits It vo- mited repeatedly, but was foon re« eftablilhed*

Vol, II. N I gave

1^8 F O N T A N A

I gave to two pigeons twenty drops each ; they vomited feveral times, were very w^eak, but nei- ther died nor were convulfed.

Two guineapigs and three rabbits had the fame vomitings^ but neither of them died nor fuifered a great deal.

We may conclude from hence, that the empy- reumatical oil of the cherry-laurel, is rather an emetick, than a poifon, fince it does not kill evea the moil delicate animals, although exhibited to them in a very ftrong dofe.

From what has hitherto been faid, the followdng^ fadls may be deduced.

ijl^ That the fpirit of the cherry-laured is a poifon.

ddly. That the oil of the cherry-laurel is like- wife a poifon.

idly. That the fpirit of the cherry-laurel, almoft entirely deprived of its fmell and pungent tafle, i& likewife a poifon.

The poifonous qualities do not feem to con- fift in the fragrant and pungent particles, and this is further proved by the oil, dried, and afterwards difTolved in fpirit of wine and precipitated from that menflruum, which is Hill fragrant and pun- gent to the taile, but is no longer a poifon.

Befides, the dried oil is a true refin, and con- tinues to be a poifon even in that Hate. The de- leterious principle then in this refm is deflroyed by the fpirit -of wine- As

ON POISONS, 1^^

As a little oil and fome fragrancy remain in the

Ipirit of the cherry-laurel^ even when dephleg-

mated, the deleterious principle of this fpirit may

be the fame with that of the oil, and that which is

found in the refin. ,

It is not belides proved, that the oil is more powerful and active than the fpirit. It has not however appeared invariably fo, when given to animals*

It is true that we find the fpirit of the cherry- laurel to be lefs ad:ive than before, when it is eva- porated, and reduced to a third, or deprived of its mofl fpirituous parts by diilillation ; in this Itate it has lofl a good deal of its original fmell and taile^ which may be faid to contribute in a great meafure to its poifonous qualities : but on the other hand, after the oil has been precipitated by the fpirit of wine, it flill preferves its tafte and fmell, and is however no poifon.

So that after all thefe experiments, notwithfland- ing that they have been greatly varied and multi- plied, we are ignorant in what the poifon of the leaves of the cherry-laurel really conlifts ; we arc ignorant of the mechanical ad:ion of this poifon ; and we are ignorant on what part of an animal it adts, when it caufes its death ; we have notwith- {landing learned by our experiments, and by the particulars we have related, many truths we had no previous knowledge of, and which we could not have divined : thus is the knowledge of man always accompanied by ignorance. We do not

N -i feem

l86 F O N T A N A

feem permitted to go beyond fimple experiment^ and it is to that alone that we ought to confine ourfelves. But how many cafes are there where either experiments are filent, or where we cannot fucceed in conceiving any thing decifive from them !

What however deferves our principal attention is, the feeing that this poifon, when limply applied in a very fmall quantity to the eyes or to the inner part of the mouth, without touching the oefophagus, or being carried into the Itomach, is capable of killing an animal in a few inftants ; whiift applied in a much greater quantity to wounds, it has fo little adrivity, that the weakeft animals, fuch as pigeons, relifl its adtion.

This circumftance appears to me a very parti- cular one, and deferving of a further and very nice inveftigation. I do not defpair of an opportunity of returning to the fubjed:, and fhall then endea- vour to give a greater certainty and extenfion to my other experiments on this poifon, particularly to that of injediing the water of the cherry-laurel into the veins of a living animal. I found it quite innocent to the few animals on whom I tried it in this way in London, in fmall dofes : this is very different from the action of the other poifons.

EXPERT-

EXPERIM ENTS

ON SOME OTHER

VEGETABLE SUBSTANCES,

On the 'Toxicodendron,

1 WAS defirous of making a feries of experi- ments on the Toxicodendron, which the moft ce- lebrated writers have in general regarded as a very flrong poifon, although fome modern naturalifls have not found it fo to certain animals. But I was forced to abandon my enquiries into this plant in the very beginning, having had the misfortune to poifon myfelf three times fucceflively with the leaves of it. Thus have I dearly paid for my fcepticifm and want of precaution, in becoming, myfelf, the fubjed of my experiments*

N 3 I begaa

l82 F O N T A N A

I began by expreffing the juice of the leaves, which I made feveral animals fwallow; they neither died nor fell iick, although they fwallowed a pretr ty large dofe of it. I likewife gave it in the form of an extrad:, and this preparation had no more efFedt than the other ; the perfon indeed who gathered the leaves, had a complaint which very much refembled an ery fipelas, particularly in the beginning. Whilfl he detached the leaves from the plant, two very fmall drops of their milk fell on the back of his hand. Three days after, two fmall dark fpots made their appearance at the place where the milk had fallen, and in three days more, his whole face, eyes, and neck, began to fwell, becoming red and inflamed; as did alfo his breafl, and hands. He had no fever, but was neverthelefs obliged to keep his bed for upwards of fifteen days, and the epider- mis fell off by degrees in fmall portions^ cauling a continual troublefome fenfation, at once of fmart and itching. It feemed to me very ftrange that fo fmall a quantity of this milk fliould pccafion fo extenfiv^ and troublefome a complaint, and that it adted fo late. Other poifons have no adiion when applied to the epidermis, at lead none that has been obferved. I was inclined to think, I mull confefs, that it was an accidental complaint, ariiing from fome othef caufe.

I was flill more confirmed in this opinion, on ap- plying a great deal of this milk to the bared ikin of feveral rabbits, guineapigs, and pigeons, after ha- ving made thefe animals fwallow it mixed with the

crumb

OK POISONS. 183

crumb of bread, and after I had at length applied it to wounds I had purpofely made in the ikin and mufcles. I could not perceive on any of thefe trials and experiments, that it created the ilighteft incon- venience to the animal. I was at length fully ground- ed in my perfuafion, on letting feveral large drops of this milk fall on the hands of two gardeners, who indeed at the end of three days had the black fpots I have mentioned, but were not fick. I was no lon- ger afraid to make the fame experiment on myielf. Ifcarcely touched the back of my hand with a leaf of the toxicodendron which I had cut near the ftalk, and could with difficulty perceive the ikin to be wet at the place where I had applied it.

Three days after there appeared a dark fpot, and in three days more, my whole face began to fwell, particularly the eyelids and tips of the ears. I ex- perienced a terrible fmart for fifteen days, and an intolerable itching for fifteen m^ore ; even the hands fmarted and itched, above all betwixt the fingers, which were become red, and were covered here and there with fmallveficles filled v^ith a tranfparentand Iharp humour: I had no fever, but my pulfe was very quick. The fkinof my face, particularly about the eyes and eyelids, v/as extended and filled with an aqueous fluid, and eafily retained the print of any thing that touched it. The epidermis fell offln fmall fcales, and I felt a moil troublefome itching through the whole procefs of the difeafe.

At the end of fome days, and when I thought my- felf perfectly recovered, I was making experiments

N 4 , on

l84 F Q N T A N A

on the air of the leaves of the toxicodendron, and whatever precaution I took, could not avoid touching fome of the leaves with my fingers; this was in the parts where they had not been cut, and where there could be no fufpicion of there being any milk. Six days after, all the parts that had fwelled the firft time, fwelled a frefh, although not fo violently, nor did the fwelling lafl fo long. My eyes and eyelids however gave me a great deal of pain, and got well the latefl.

After an interval of twenty days, I wifhed to ex- amine the air of fome leaves of this plant, which I had caufed to be got ready by another perfon, and I touched a few of the leaves when under water. In four days, my face and eyes fwelled a third time, although not fo violently as on the two firfl.

It cannot be believed after this that the milk of the leaves of the toxicodendron is innocent when applied to the human ikin ; but on the other hand, it is ve- ry lingular, that an atom of this poifon produces in a few days fuch remarkable fymptoms, and in fuch remote parts, whilft the juice and milk of the leaves are quite innocent to animals, as well externally as internally, and even when applied to wounds. Its not acting on the two gardeners, was certainly owing totheir hands being extremely callous, and I did not think it proper to apply it to the parts where the epi- dermis was more delicate; this firft trial was however fufficient to aflure me that parts which are become callous, refift this poifon.

ExpE ■

ON POISONS, 185

EXPERIMENTS

With the Oil of Tobacco.

1 made a fmall incifion in a pigeon's leg, and applied to it the oil of tobacco. In two minutes it lofl the ufe of its foot.

I repeated this experiment on another pigeon, and the event was exactly the fame.

I made a fmall wound in the perioral mufcles of a pigeon, and applied to it the oil of tobacco ; in three minutes the animal could no longer fupport itfelf on its left foot.

This experiment repeated on another pigeon, ended in the fame way.

I introduced into the pedtoral mufcles of a pi- geon a fmall bit of wood covered with the oil of tobacco I the pigeon in a few feconds fell infen- fible.

Two other pigeons, to the mufcles of which I applied the oil of tobacco, vomited feveral times, all that they had eaten.

Two others with empty ftomachs, treated as above, made all poflible efforts to vomit.

I obferved the vomiting to be the moil conftant effedt of this oil, and that the lofs of motion in the lower part of the extremity to which it was

applied

1 86 fontana

applied was merely accidental. Not one of the anin:ials to which I applied the tobacco died.

Conjiderations on the Nerves in Difeafes,

Let me be permitted to objecfl for the lafl time, to the too great readinefs in the modern pradiice of phyfick, of having recourfe to the nerves, to explain the greatell part of the difeafes incident to the human body. The ancients had fcarcely an idea of this fource of fo many difeafes, to which fome of our moft modern writers have even be- lieved that the whole of them fhould without any exception be attributed.

My doubts only relate to the too great extenfion that has been given to the fundtions of the nerves, in the difeafes of the human body; and I flatter my- felf that my arguments may make fome impreffion on thofe who do not fufFer themfelves to be carried away by hypothefes which have mod frequently been adopted, merely becaufe they have never been fuf- iiciently examined

Hoffman in the third volume of his Medicinarati- onalis, aflerts that all the difeafes of the human bo- dy are nervous : and amongfl the more modern wri- ters, Mufgrave, a learned Englifli phyfician, has fupported the fame opinion. The mofl moderate of the recent authors who have written on thefe difea- fes, have each according to his particular fancy or

fyflem

ON POISONS. 187

fyllem, either diminifhed or fwelled the catalogue of them, and it is very curious to obferve that fome take the fame pains to exclude feveral difeafes from this number, which others do to prove them to be pervou-s.

But I muft firft eflablifh fome truths, which will ferve to make me better underflood in a matter in which there is fo much confufion and obfcurity. There is no organ in the living body, which may not be difordered by internal and external caufes, ^nd afterwards give rife to fome difeafe. Hippo- crates and the other phylicians of antiquity were well perfuaded that if any part of the human frame were difordered, it might diforder another part in confe- quence; but they did not on that account believe in the confenfus nervorum^ nor in the nervous difeafes of the moderns, of Vvdiich we have made mention in this work. Hippocrates was not ignorant of the power of afFedtions of the muid on man, and how many diforders and changes they are capable of cau- sing in the animal economy ; all this I do not to deny, and thefe are not the nervous difeafes now under ex- amination. Belides, the nerves, as every one knows, are the inflruments of motion and fenfation in ani- mals, and it is on ihem that the moil noble fundti- ons, and thofe the mofh neceflary to life, depend. It cannot then be doubted but that many difeafes are nervous, and that the nerves are in many cafes the fource of very great derangements. But if this can- not be doubted, let me aik phylicians what are the certain fymptoms by which to diitinguilh a difeafe

purely

l88 F O N T A N A

purely nervous; let me aik why it may not be fim^- ply a difeafe caufed by the grolTefl humours, and how they contrive to know that the nerves are imme- diately attacked in the derangements of the animal economy, which they wifh to attribute entirely to. them. I do not take upon" mt the phyfician, but I have heard feveral very ikilful ones fay, thatthefymp- tom.s of nervous difeafes are for the moft part equi- vocal and deceptious.

The moderns have formed a clafs of motions, and of fympathetick difeafes, availing themfelves of the motions of fneezing and of the iris. We know that the famous anatomift Meckel, thought that he explained fneezing, by the ihocks fuilained by the olfadiory nerves, which proceed from the opticl^ nerve, which arifes from the maxillaris fuperior^ from w^hich is derived another nerve^ which in conjunction v/ith a branch of the fixth pair, forms the intercoilal. Meckel, then, aflerts that the fliocks fuilained by the olfad:ory nerves, ought neceffarily to communicate themfelves to the whole of the intercoilal nerve, from thence confequently to the phrenick, and to all the mufcles of the neck, back, and loins. In fad:, true fympathetick motions ihould be the confequence of mechanical fhocks fuilained by all the nerves, and by the communi- cation of their organs, and it is thus that the beil phyfxologiils have coniidered it ; but thefe two mo- i tions of fneezing and of the iris, are purely volun- tary

ON POISONS. I8p

tary (^), not organical, nor fympathetically ner- V0US5 and are not produced by external fhocks, as anatomifts in general have hitherto believed. It will fuffice to read on this fubjed, my work on the motions of the iris (b), to be perfuaded of it. At Jeaft I think 1 have produced both evidence and demonftration on this very obfcure fubje<3:.

Befides, thefe pretended nervous fympathies are fupported on a principle, the fallity of which has been demonftrated by experiment : if you irritate a nerve, you communicate its motion to the branches it throws out above the part Simulated, and it is on this account that the great Haller, when he became a more fkillful anatomift, and a nicer obferver, either doubts, or operi^ly denies the pre- tended nervous fympathies h£ admitted in his youth. Undoubtedly no one will fay that thefe motions are nervous and fympathetick, becaufe the mind in pro- ducing them, employs, the nerves, which are the organs of motion and fenfation. This is not the opinion of Meckel^ nor of thofe who explain thefe motions in a way different from mine.

There are phylicians v/ho account for all thefe nervous difeafes, by fuppoiing that the nerves are become hard, dry, and tough : others on the con- trary, believe them flaccid and relaxed in thefe cafes. " I have always found," fays the great

(fi) The fenfe in which the authoar wlihes the word '-voluntary to be underftood, maybe feen in the work cited below. {h) Printed at Lucca.

Boer-

IpO F O N T A N A

Boerhaave^ " that however eafy it may be to ima- *^ gine a caufe for a difeafe in explaining it, it h *^ afterwards as difficult to prove that this caufe is *^ real, and to be fully perfuaded of it."

Let not thofe who favour the fyllem of nervous difeafes, objed that the nerves accelerate and re- tard the motion of the blood in a thoufand cafes,^ as is feen in fear, pleafure, and in fo many other conditions. It is true that we cannot deny but that, after thefe aifediions of the principle of fenfa- tion take place, we obferve changes and move- ments in the living body, which were not obferved before ; but this is not fufficient to alTure us that thefe changes are brought about by the nerves alone, and that they ad: immediately on the blood velTels. The celebrated Haller, completely ikilled in anatomy, was of opinion, as is feen in his excel- lent treatife, '' De Imperio Nervormn in Arterias^^ that thefe velTels were bound by nervous rings, with which he found the arteries provided in feve- ral places. But as he was alfo a great experimen- ter, as well as an excellent anatomiil, he foon abandoned this hypothecs, which is contradidied by occular demonftration. A nerve, in whatever v/ay it is Simulated, is not feen to contrail, even with a microfcope, and the minutefl: blood velTels are not obferved to fhrlnk or ofcillate when irritated by a mechanical ilimulus ; neither does anatomy con- vince us that there are nervous and mufcular fibres in thefe minute velTels, which therefore feem

to

ON P O 1 S O N S. 191

to be deftitute of all the inftruments of animal motion.

Befides, we frequently fee perfons violently con- vulfed, without fever, or any fenfible change in the pulfe : it is true that the contrary is fometimes obferved, but phyfiologiils know that in convui-. iions, the motion of the blood may be accelerated by the contraction of the mufcles that force it from the veins into the heart. The celebrated Spalan^ %ani has obferved, that the fpinal marrow of frogs may be irritated, without accelerating the motion of the blood in the mefenterick veiTels of thefe ani- mals. I have tried this experiment on feveral other fpecies' of animals, both with cold and warm blood, and have always found the event to be the fame ; fo that the nerves appear to have no imme- diate adiion either on the veins or arteries, not- withftanding it is true that the paffions of the mind excite very violent diforders in the animal economy.

The derangements I have mentioned, happen, it is true, after certain fenfations have taken place in the animal ; but this does not prove them to be derived from the nerves, and that the nerves have an immediate ad:ion on the organs that are in thefe cafes difordered. It is likewife true, that the fol- lowers of Stahl, wiihing to ellablilh a general prin- ciple which might be applied to all the motions of the living machine, as well in health as in lick- nefs, have had recourfe to the mind, as the prime inover of the whole anim.al economy : I do not 3 pretend

192 F O N T A N A

pretend to combat the exigence of the nervous difeafes in Stahl's hypothecs, according to which all the animal motions are to be regarded as purely nervous, and all the derangements excited in any way whatever in the animal economy, as nervous difeafes. Nervous complaints are the immediate confequence of fhocks which the nerves may have fullained, or of extraordinary affediions excited in the principle of fenfation ; and I here principally confider the iiril clafs of thefe difeafes. We fee indeed that Boerhaave admits of nervous difeafes, although he afterwards taxes StahFs fyflem with falfehood. Haller himfelf is of the fame opinion ; and the two moll modern authours who have writ- ten on nervous complaints^ De la Roche and Tif- fot, do not heiitate even to rejed: the more rational fyflem of the learned Engliih phylician, Whytt, on the principle of anim.al motion, and both of them notwithilanding give a greater or leffer fup- port and extenfion to nervous difeafes.

In a word, I do not believe any one will affert, that any motion whatever, any accidental and fe- condary derangement, is a true nervous difeafe, becaufe it fucceeds to a fenfation excited in the mind. In this cafe it mufl likewife be faid, that the agitations which are caufed by fear, pleafure, and grief, are nervous difeafes : thus, for example, a laborious and painful refpiration, which renders the dilatation of the thorax neceifary, will be a nervous difeafe, notwithilanding there is no affec- tion of the nerves in this cafe, and that the phyfi-

ciariv

ON POISONS. ip3

€kn would not ^rertainl)^ feek to apply a remedy to an organ, which was not abfolutely injured.

I have pointed out in feveral parts of this work, that there are poifons, which when applied imme- diately to the nerves,, do not occalion any complaint i^ a living animal, I have likewife pointed out that thefe poifons when introduced into the blood, without touching any folid part, fuddenly bring on violent convulfions, and the moil decided fymp- toms of what are believed to be nervous afFed:ions. Laltly, I have fhown, that when the wounds of animals are envenomed with thefe poifonous fub- ftances, the animals are feized with all the fymp- toms of nervous complaints.

On another hand, I have already made it appear, that convulfions may be excited in animals, with- out the nervous fyflem being in the ieall afFedted, and that th^ w^ant of an equilibrium in the flrength and in the humours, is fufficient to produce the moft violent convulfions in the mufcles (a).

Here are then all the fymptoms of nervous dif- eafes^ without the nerves having any fiiare in them ; and we fee at the fame tim^e, that thefe contradlions are excited even w^hen the caufes of them only feem to ad: on the humours of the animal, and whilft thefe caufes are found innocent and inef- fediual to the nerves, in whatever w^ay they are applied to them. It is not fufficient then to fee

(a) See the iirft part of my work on the piotions of th§. iris, quoted above.

VoL.IL O all

194-

F O N T A N A

all thefe fymptoms^ to enable U3 to pronounce with certainty^ that the difeafe is purely nervous.

But there is an argument v/hich feems to leave no refuge to the moft prejudiced and mod obftinate ikeptick. It is obferved in regard to the motions, as well involuntary as fpontaneous^ which are VvTOUght by the nerves, that if you flimulate the nerves Vv^hich are carried to the organs of thefe mo- tions^ the latter will conilantly and neceiTarily fol- low. This is a general law for all the mufcles and nerves^ in all animals, and admits of no exception. It becomes then a certain law, a fyre principle, and an infallible criterion of the nature of thefe motions.

The heart, of all others^ is the organ iirfl af- fected in the paffions of the mind and in nervous affettions ; and it is on this firfc change, that a number of others which accompany it depends. Let the brsafi of an anuiial with cold blood be opened, (this experiment is fjbje'ft to left uncer- tainty in thele animals than in thole with warm blood, en whom the effedl is however the fame,) and let the nerves that are fent to the heart be Simulated, in any way Vvdiatever ; it will not on this account quicken its contradions if it is in motion, nor Vvill recover its niotions if it is at reft, although it is fcill in a ftate of contradiing on the leafc ftimulus offeredto its fibres. It is in vain that long pins are introduced into the vertebral canal, and that the fpinal marrow^ and brain are mangled, the heart continues ftill infenfible. The nerves

then

ON POISONS. 195

tlien which are carried to the heart, are in no way the organs of motion inthi§ rauicle, although they are certainly fo in all the others. They can therefore never caufe any fenfible change, however the ani- mal may be aifedied. The experiment is certain^ and the confequences of it diredt (a), and it would be a downright contradiction, that the motions of the heart ihould be brought about by the nerves, whilft the latter are not capable of exciting thefe motions, as has been experimentally demonflrated.

It cannot then be advanced with certainty that the changes in the heart which ufually accompany the affedions of the mind, are wrought by the im- mediate channel of the nerves, and not otherwife; and the only inference which an unbiaiTed philofo- pher can draw from all that we have faid is, that we are ignorant, through what medium, and by what mechanifm, the affedtions of the mind influ- ence the heart.

It may perhaps h)e faid that {he fenfttlve principle in the animal may make certain impreilions on the nerves, which mechanical itimuli cannot imitate; but this fuppoiition is contradidted by daily experi- iCnce, fince the leaft fiimulus to a very fmall nerve at the extremity of a m.ufcle, is fufficient to give it motion: this is a demonflrated truth which has ne- ver been contradidied by obfervation,

(a) This important truth has been demonftrated by the author in his treatife on Anin^ial Phyficks, Volume, i ftp, 92. publifh- tA in Italian in Florence at 1775.

O 2 It

196 F O N T A N A

It may be pppofed that the experiment of the im- mobility of the heart to the fhocks that are given to the nerves, is contradidied by feveral of the moft faraous naturalifls : there is no other reply to this than the recurring to experiment. Any one in doubt, may eafily fatisfy hlmfelf by taking a frog and, after opening its breaft and cutting off its head, wait till the heart is ftill, or m_oves but Howly, to render the experiment more decifive, and then thrufl a pin deep into the fpinal marrow : he will foon fee the event. Care mufl be taken not to leave the frog to itfelf, but to fecure the feet well, other wife there, will be a riik, amidft the violent convulfions that will be excited in all the other mufcles, that the heart itfelf may be agitated, and caufed to rnove in quite another way than by the adion of the nerves. This is undoubtedly what has deceived fo many good anatomiils, who have believed that this motion was occafioned immediately by the nerves. I refer my readers to the experiments related on this fubject, in the work cited above.

It is in my opinion then, a matter demonflrated by the fulleft evidence, that no miOtion of the heart can be in any cafe brought about by the medium of the nerves, although the heart is, of all the mufcu- lar organs, the moil fufceptible to the affections of the mind. Some grounds may after this be permitted rne for doubting that whilft the motions of the heart are never influenced by the nerves, thofe of the other mufcles are invariably caufed by their immediate adio.n^^

A t^QUo

ON P O I S O N S. 197

A thoufand like arguments may be brought in fa- vour of the hypothefis of the nerves; but they are ail indire^a, and only prove that a fenfation in a living animal, is followed by a motion in its body : this is^ not yet fufficient to demonflrate that the effedt has been immediately produced by the adiion of the nerves. Fear retards or quickens the motion of the heart; and yet, as has been feen, the nerves have no immediate ad:ion on that organ, notwithilanding it be true that this change is the confequence of a fenfation.

The learned tranflator in French, (a) of the new edition of Whytt's Englifll publication on nervous difeafes, introduced in the 151ft page of the firft vo- lume, a note againft his author, which feems to me fo very appofite to the prefent fubjeQ:, that I give it entire. Whytt had maintained that hyfterical dif- eafes, (or rather their fymptoms) and the hypochon-* driacal difeafes of men, were in effed the fame; and that both of them v/ere limply nervous. The tranf» lator obferves in his note that '^ this is a fure me* ^^ thod to confound and perplex." lie adds that " the fymptoms Whytt has related, are effed:s ^' which in a greater or lefs degree are common to *' all difeafes. There is not any one in v/hich the *' nerves are not affedied; but the bufinefs of a *' phylician conlifts in knowing, as well as he can^ ^^ the caufe of the difeafe. It is certain then, that ^^ three fourths of the difeafes of women have their ^^ origin in the matrix. The ancients were therefore

(a) The tranfladon was printed at Paris in 1777.

O 3 not

IpS F O N T A N A

'' not miilaken when they beftov/ed the epithet of ^' hyilerical, on thofe difeafes m women m which ^^ the nerves difplay the greateil number af fymp-'

'' toms/'

Several fubitances are announced in the Materia Medica, as nervines^ becaufe they are fuppofed xq have a benign influence on the nerves. For my part, I believe it would be very difficult to prove clearly, that a remedy has an immediate adiion on the nerves, and not on- the other parts of the body.. I do not mean however to fpeak here, of certaia fubllances which, being capable of diflblving, cor- roding, and gnawing the nerves, have affuredly a true immediate adiion on them. It is true, that fpirituous fubflances applied to the noftrils^ feem to ad: inftantly on the nerves, and in a vtxj different way ; but it mull be conndered, that they not only caufe a Ample mechanical pejcuilion on- the pituitous membrane, but excite a particular fenfation in the animal organization. The natural light of the fun, in whatever way it is applied ta the body, is quite innocent, and is not felt by it ; but meeting in fudden contact with the eyes^ may make fuch an impreffion on them, as to caufe a violent pain, and even tears. The eye alone is fufceptibie of the impreflions of light, and the other parts, although endov/ed with fenfation and life, are infenfible to it. The difEculty then I have jufl: mentioned, only proves that a flronger percuf- flon on a determined organ, excites a flronger and quicker fenfation in the animal machine, than a

weaker

ON POISONS. 199

weaker one, which is altogether natural, and argues nothing in favour of the hypothefis of the nerves.

But who can affure us that the particles of fcents may not penetrate, even in a few inftants, through a quite porous body, filled with canals and fluids InceiTantly in motion ?

I know it is commonly believed that opium pro- . duces effedis, when introduced into the ftomach^ which are not obferved when it is applied to the other parts of the body^ But who again will here affure us, fuppofmg it an inconteftible fad:, that certain juices which are only found in the fiomiach^ are not requiiite to detach the moft adiive parts of this fubilance, and that this vifcus does not contain very fine veiTels or poroiities, proper to receive thenl, which are not found elfewhere ? I am not ignorant of its having been alTerted, that opium^ when it is "immediately applied to the nerves, pro» duces a palfy of the mufcles : but I recoiled: to have feen fome years _ago, a diforder of this kind clearly occaiioned by the fpirit of wine in which I diffolved the opium, iince it did not enfue v/hen I tried it diffolved in water. This circumftance ap- pears to me fo inte telling, that I ihall not fail to repeat the experiment at my leifure, particularly as the authority of Monro, who has found the contrary, miay be oppofed tO" mine.

There are in the living body paffages we are

yet ignorant of, unknown powers^ and latent prin»

ciples. We fee the necefiity of admitting them^

but we are jgnorant of their nature and mecha-

O 4 nifm.

200 F O N T A N A

nifm. If it is a misfortune to be iti the dark as to a truth, it is a flill greater one to fubfcribc to an errour. We do not attempt to draw erroneous confequences from things we are ignorant of; but a miftake neceffariiy leads us into many others. It is much better then to be ignorant of a truth, than to admit an errour.

I have frequently, in many parts of this work, fpoken of the influence of the nerves in difeafes. I have faid too little on this fubjedt, in proportion to its importance, and certainly a great deal too much in a work that has quite another objed: in view ; but I could not reiiil the evidence my ex^ periments held out to me. They have led me, in fpite of myfelf, to make fome applications to cer-. tain phenomena in the animal economy.

I do not pretend here to undeceive thofe Vv^bo are prejudiced in favour of a principle which fup- plies all the wants of a fyilem of medicine, with a- readinefs proportioned to the u.ncertainty and ob- fcurity of that fyilem ; and I am not to learn that it is a great help to thofe who profefs it. The charadler of obfcure and indeterminate hypothefcs is, that they adapt themfelves to every thing, be- caufe they are capable of being modified accord- ing to particular cafes ; but this is exadtly what ought to make them fufpedied.

I ought however to make an exception here in favour of feveral very fkilful phylicians, who have frankly acknowledged that my experiments render the nature of nervous difeafes in general very fuf-

peded.

ON POISONS, 20t

peeled. I ihall feled: from the names of many others, that of the celebrated Englilh phyfi-cian Sir Robert Pringle, who told me that he had never too great a belief in nervous difeafes, and that for the future he Ihould have lefs faith in them than ever.

I repeat that I will not deny, as the great Albl- nus has done, but that the nerves may in general be the organs of fenfation, or of motion, in ani- mals : this would be going too far ; but it may be doubted that all the motions we obferve in ani- mals depend immediately on the nerves, and that the fubflances which have excited them, as has been pretended of the venom of the viper, the ticunas, and the cherry- laurel (to oppofe the adlion of which all my reflediions ultimately tend) have immediately adied on the nervous fyilem. Neither can it be denied, but that when the principle o^ fenfatlon is afFedied, a thoufand diforders in the aninial economy enfue, any more than it can be affirmed that the nerves can be adied on with im- punity ; but it does not yet follov%^ from this, that all the difeafes commonly afcribed to the nerves^ are owing to the nerves alone.; that they may not rather depend on the humours ; that both mcdi- tines and poifons ad: immediately on the nerves ; and laitly, that the nerves (it is to this that I prin- cipally confine myfelf) have an immediate adion on the other folids.

Irritability feem.s independent of fenfation in an animal; and there is befides nothing v/hich de-

202 F O N T A N A

monftrates that the mufcles are only capable o^ moving by the acflion of the nerves. The prin- ciple of fenfation and the nerves, may have agree- ments v/ith the blood and other humours, Vv^hich we are yet ignorant ^of, and thefe humours, more or lefs changed, may exert their influence againfl the folid parts of an animal. It is permitted to fuppofe every thing, rather than to reliil a dired: and luminous experiment. It is permitted, whcr» we are "about to eilabliih a truth, to imagine a new conitrudiion of parts and of organs, and to furmife new agreements. But to invent a new conftrudion, and to admit unknown agreements, in fupporting an hypothefis, is building the en- chanted palaces of Arioilo, for the reception of Roger and Alcine*

EXPERl-

:>

ON POISONS. 20

EXPERIMENTS

Made at LONDON in 1778 and 1779,

On the ReproduBlon of the Nerves*

■ i. HE knowledge I had acquiredjof the| true ftriic- ture of the nerves, and of the primitive cylinders of which thefe organs are formed^ as will be feen in the following treatife, made me deiirous of ap- plying this knovvdedge to the animal economy. During my flay in London, I did not fail to exa^ mine the mufeum of the celebrated Dr. Hunter^ Mr. Cruikilianks, a young man very prcminng in the fcience of anatomy, and diffedor to the Doc- tor, there Ihowed me a glafs, in which he told me was preferved a reprodudiion of a dog's nerve, one of the eighth pair, which he had cut. The cir- cumilance appeared to rrie altogether new^ and deferving the utmoil attention.

lis 4

504 F O N T A k A

He added, that the nerve had been cut in' the living animal, and that he had removed a por- tion about an inch in length ; and indeed, for the fpace of about an inch, it appeared very dif[:erent from what it was in all the other parts. It was much enlarged, quite irregular and uneven, and feemed formed of a different fubflance from the reil.

Qn feeing this preparation of Mr. Cruikihanks', I had two reafons for doubting the truth of the fact. One was, that I had never obferved in any one of the experiments I made at Paris on the ve- nom of the viper, a true reunion of parts in the fciatick nerves, which I had fo often cut. The other, that in the nerve in queflion^ there might Very well be a reunion of one part to the other^ but not a tYue reproduction of the tvv^o extremi- ties, fo as to form a lingle nerve as it was be- fore.

Thefe fufpicions made me defirous of a particular converfation with Mr. Cruikfhanks, during w^hich I aikcd him, amongfl: other things, what w^as Dr* Hunter's opinion on the fubjecfl. He told me in- genuoufiy, that the Dodior did not perceive a real reproduclion of the nerve in thefe experiments, and fufpedled very itrongly, from the great dif-» ference betwixt the external ilrudture of the part cut, and that of the other parts, that it was not the cafe. I then underftood from Mr. Cruikfhanks, that he had at different times, in the fpace of eighteen or twenty days, divided the two nerves

of

ON POISONS. 205

of the eighth pan*, and the two intercollal ones, m the fame anunal, and that they all feemed to be equally reproduced.

It is beyond a doubt, that the cut extremities of the eighth pair, and of the intercoflal nerves, are capable of reuniting, although apart of them be taken av/ay, and Mr. Cruiklhanks' excellent ex- periments demonftrate it in fuch a way, that it cannot be doubted a moment ; but it is not yet certain that thefe nerves return to their prior flate, by forming a continuance of a true nervous and medullary fubftance, and continue to perform their ufual fundiions. This abfolutely remains to be proved. It is true, that a continuance of life in the animal, after the nerves have been cut, as well as there being no feniible change in the operations of the heart, leads one to fufped: that the eighth pair of nerves has been truly and full reintegrated ; but as it has not been yet proved that the nerves are abfolutely necelTary to the motion of the heart, and as it is known that this vifcus receives nerves from other parts, it is to be doubted, whether this ought to be regarded as a true renewal of the nerves, or fhould be only deemed a iimple union of parts, brought about by the means and inter- polition of an heterogene fubflance, compofed of the cellular membrane. My obfervations on the ftrudture of the nerves enabled me to afcertain vvdth certainty, whether they are really reproduced or not, and this has engaged me to make feveral experiments on the fubjed:. I preferred rabbits,

as

2d6 . F O N T A N A

as the moft convenient for fuch trials, and eafily to be procured. I deflined a great number for the cutting out the fciatick and crural nerves, many others for that of the eighth pair, and fome for that of the intercoilal and eighth pair to- gether.

In fix rabbits, I fimply cut the right fciatick nerve ; and r€moved a portion of about fix or eight lines in length, in fix others. Some of them lived eighteen or twenty days, and others died in the fpace of four or fix. Others lived fo as to en- able me to examine the nerves 1 had cut, at the end of thirty days or more.

I could not perceive the fmalleft appearance in any of thefe animals, of a nervous reproduction. In all of them the extremities were as fmooth and even as when I firft cut them. The nerves were in every part white, and neither thickened nor un- even. In a vv'ord, I had the fullefl; alTurances that in the animals I had employed, there was no re^ produdilon of the nerves.

I mull obferve here^ that I might eafily have hecn deceived in two particular cafes, had it not been for the knowledge I had acquired of the ftruciure of the nerves and mufcles. In one of thefe I had finiply cut the fciatick nerve, in the other I had rem.oved a portion of it of about fix lines in length. In both I could not difcover the two extremities of the nerves, and I found them perfedlly covered and bound together with a fub- ftance partly cellular and partly ficfiiy. What was very

fingular,'

O N P O I S O N S. 207

fingiilar, the more I removed this fubftance with a fcalpel, the more the union and reproduction of the nerves feemed to be really brought about. But the microfcope foon freed me from this fuf- picion, and I at length found that this fubftance was not formed of the primitive nervous cylinders of which I fhall fpeak in the enfuing treatife, but of a cellular membrane, and of primitive iielliy cylinders.

The obfervation of thefe latter particulars made me fufped: that the intercofial nerve and that of the eighth pair, had only prefented an apparent re- produdiion, becaufe in all the cafes where 1 had cut the fciatick and crural nerves, there was not the foiaileli appearance of a reunion or reproduction of the parts.

'Tis true that the conftant reiileifnefs of the ani- mal may prevent a reunion of the divided nerves in thefe cafes ; but the two extremities of them Hiould at lead appear a little changed and rounded, as happens in all the parts where there is a repro- duction or reunion, after their being cut.

But it fiill belongs to experiment to decide ; and we miufi: not form conjed:ures where that can be recurred to,

I cut one of the eighth pair of nerves in a dozen rabbits, and in a dozen others removed a portion of it of fix to eight lines and m.ore in length ; in thefe lalt I alfo removed an equal portion of the intercofial nerve. One of the firfl: died in four days, two of the fecond in three, and a third in eight. I'hofe

which

2o8 F O N T A N A

which furvived^ had no perceptible complaints^ and ate as ufual a fhort time after the operation.

In fome of thefe rabbits, I cut' at the end of twenty-five days the other nerve of the eighth pair, and in fome others removed a portion, as well of the nerve of the eighth pair as of the intercof- ta!. Of €x of thefe lail, three died in a few days.

This is not the place to give a detail of all I cbferved in thefe animals ; 1 ihall for the prefent content my kit with, relating a few general obferva- tions.

In tAvo of them I could obferve no change in the divided nerves, although 1 examined one at the end of eighteen days, and the other at the end of twenty-feven. In a third I obferved that the cut cxiremities of the nerve had changed their fhape and colour, but there was no true reunion, nor apparent nervous reprodudiioo.

in a fourth, which died tw^enty-three days after the operation, the extremities of the nerves w^ere a little elongated in a conical fhape, but were not united : there was indeed a flat membrane betwixt the ends of the nerves, which united them imper- fectly. In all the others where the nerves had htcn limply cut, the parts feemed to be united, had changed their colour, and were thickened. They were in general covered with a cellular mem*- brane, enlarged, and a little red.

As to the nerves of which I had removed a part, there was a reunion which likewife feemed to be

caufed

DN POISONS. 209

taufed by a cellular fubltance much fwelled^ un- equal, and full of blood vefTels. The cut extre- mities of the nerves were whiter than in any other part.

I fought for the fpiral form of the nerves in thefe reproduced and unequal parts, and although I thought I diftinguilhed in a greater or lefs degree, iii tnore than one, the white fpires or bands (a), I could not however difcino-uifh them from one extre- mity of the nerve to the other, fo that I was uncer- tain whether the part reproduced was not rather cel- lular than nervous; neither could I affure myfelf by cutting the cellular membrane, a part of which I iikevvife removed, whether the primitive nervous cylinders really palTed from one part of the nerve to the others although I faw them extended through" this reproduced cellular membrane. I eonfefs that I had not all the conveniences necelTary to render me certain in fo important an enquiry, and which I found at the fame time a very difficult one.

All that I can fay with certainty is, that the cut ends of the nerves are prolonged, that they alter their fhape and colour, and that they are united by a fubilance betwixt them, which is a prolongation of the cellular membrane itfelf belonging to the two cut parts of the nerves. The winding cylinders and blood veiTels pafs from one part to the other, and

{a) It will be feeri In the following treatife, what this fpi- ral fhape or thefe white bands are, of which mention is here made.

Vol, IL P ther»

^lO F O N T A N A

there is an union of the whole, as if the cellular coat of the nerves, which is much thicker and more unequal than in the reft of the nerve, was quite entire.

The difficulty of eftabliihing by immediate and ocular demonftration, whether in the above cafes the nerves are really reproduced, or are limply faf- tened together by a cellular membrane, made me redouble my attention, and multiply my experi- ments>

I do not think I am wrong in advancing at this time, as a certainty, that a like reprodudtion of the nerves may take place; although it cannot be al- ways demonftratively proved, and perhaps is not always brought about, although the nerves feem to be reunited, and reproduced.

I can fay to a certainty that I obferved it in two par- ticular cafes, and in one of the two in fo evident and fure a way, that I think it proper to give here the iigure and defcription of it. But I repeat again^ that a fimple continuity of parts betwixt the cut ends of a nerve are not fuflicient to determine whether the nerves are really reproduced, and that it is more- over not fufficient that a cellular fubllance is produ- ced and elongated, althought it be a continuation of th at of the nerves them.felves. We muft be cer- tain that the nervous cylinders pafs without inter- r uption from one part to the other.

Plate VII. Fig 3. reprefents a nerve of the eighth pair belonging to a middle fized rabbit; I viewed it with a lens which magnified about three

time «p

ON ?OIS0NS. 211

times In diameter. The part of this nerve I had re- moved, was about fix lines in length, and I diffec- ted the animal twenty-nine days after the operation. I found a reunion of the two cut extremities of the nerve, but that the nerve was fmaller than elfewhere at the part where the reunion took place^ which I have marked r, r*

At fome diftance from the point r, r, precifely where the nerve was cut, were feen two white fpots nn^ nn, as they are reprefented in Fig 3 and 4. Thefe two fpots formed two opake rings round the nerve^ and clofe to thefe rings the nerve began to decreafe oil each fide in a conical Ihape, and to prolong it- felf in this way as far as r, r, where both cones met. In Fig. 3, and flill better in Fig. 4, are feen the fpiral bands of the nerve, and thefe bands Were continued as far as r, r, where they were not fo diilindtly feen.

At the two fpots n n^ n n-^ the bands feemed to be interrupted, or rather, the white colour of the nerve in this place prevented their being feen.

The nerve was fmooth throughout, arid was like- wife fo all over the two nervous cones. I wifhed to fee the nerve through a flrong lens, and to examine the cellular membrane. Fig 5, reprefents the nerve obferved with a very firong lens. I found it cover- ed with the ufual cellular membrane. I then exami- ned it with the fiirongeil glalTes, and as is feen in Fig. 6, found it formed of primitive nervous cylinders, o^ which as will be feen in theenfuingtreatife,every|nervc isjcompofed. Thefe cylinders diminilhed in diameter as they approached each other to the point r^ r, of P 2 the

212 F O N T A N A

the two cones, and they were plainly diilinguiflied to be continued, and to pafs from one fide to the other. Fig. 7, reprefents the fame nerve, but part- ly torn by needles, to ihow more diftindity the con« tinuity of the primitive nervous cylinders.

Two things concur to perfuade me that a true re- produdiion of the nerve is brought about. One is^ the appearance of the fpiral bands, which are found even in the renewed and fmalleft part of the nerve ; the other is, the continuity of the primitive nervous cylinders, which removes the fmalleft fufpicion of doubt*

I have had another inilance of a reprodudiion^ almoll exadlly fimijar to that I have defcribed. The two white fpots were Hkewife feen here, and at the part cut, the two cones which met at their points. The fpiral bands were continued in the cones,, and in the continuity of the primitive nervous cylinders was diftinguiihed in every part of the nerve.

It is an eflabliihed truth then, that the nerves cf the eighth pair are capable of a reunion, not only when they have been cut, but likewife when a por- tion of them, feveral lines in length, has been re- moved. In the firft cafe, there is a true reunion of parts, a real continuity of fubftanee, and in a word^ a com.^^lete continuance of the primitive nervous cy- linders and of the external coats which enclofe them. In the fecond cafe the nerve is reproduced, that is to fay, its nervous fubilance is encreafed at the two extremities, and in the prolongation of it, thefe ex- tremities n:ieet, fo as to form an hom9geneous, con- tinued, and uniform w^hole.

A It

ON POISONS. 213

It is iingular that the two extremities of the -divided nerve, meet fo exadily as to be capable of uniting together ; particularly when a very large portion of it, an inch for example, has tfeen removed. In thefe cafes, it feems altogether im- probable that the cut parts fhould meet fo well, and this junction is rendered ftiil more difficult by the great derangement in the iituation of the nerves, that attends the operation. But we mull in the firil place coniider, that ail the parts of the neck, the mufcles particularly, continuing their accuf- tomed functions, oblige the nerves to regain that iituation which thefe parts and thefe motions re- quire.

Again, I muft here obferve, that having twice exprefsly changed the dirediion of the cut extre- mities, fo that rhey prefented themfelves contrary ways, I did not find in the fequel that thefe parts were reunited, or had met each other.

Had I had more time, I ihouid have endea- voured to determine whether this faculty of repro- ducing, in the nerves of the eighth pair, and the intercoffal ones, be common to many other nerves; which feems probable. The fciatick nerves, which are probably of the fmall number of thofe that have not the advantage of reproducing, are per- haps prevented from it, from there being too much motion in the parts where they are lituated, and it would in all Ukelyhood enfue if that motion were diminiflied. It may likewife be a property only belonging to thofe nerves that are the moil efTen-

P 3 tial

214 F O N T A N A

tial to life ; but all thefe points may eafily be cleared up by immediate experiments.

Every one muft now fee^ that a great many in- tereiling truths to the practices of phyfick and fur- gery refult from what I have jufl related. We may now conceive how fenfation and motion itfelf have returned to certain patts which were almofl entirely detached from the bodies of animals. The nerves were hi thefe cafes reunited, and con- tinued to be the inilruments of motion and fenfa- tion. In many cafes of u'gent neceflity, there will be lefs dread of cutting fome particular nerve, in doing which it will be only neceflary to take care that the. cut extremities be placed op- pofite to each other.

There is a phyfiological experim.ent to prove the the reunion of the divided nerves, which want of time has prevented my making. After cutting the phrenick nerves, if once a reunion of the divide4 parts takes places perfectly, and there is a true continuity of the nervous fubftance, the dia- phragm fhould contrad: itfelf, on irritating thefe nerves, in the part towards the head, above where they were cuto

OBSEItVA^

OBSERVATIONS:,

ON THE

PRIMITIVE STRUCTURE

OF THE

NIMAL BODY.

TO WHICH ARE ADDED,

REMARKS ON VEGETABLES anp FOSSILS-

Ohfervatlons on the StrtiBure of the Nerves, made at London in 1779.

Of all the organical parts of which a livmg animal is formed, there is no one in my opinion, the flrudure of which is lefs known^ and the knowledge of which at the fame time is more im-

P 4 portant

2l6 FONTANA

portant than that of the brain, and the nerves that ^re derived from it.

The befl authours have advanced nothing but mere hypothefes on thefe parts, and the moft pe- netrating naturalifts have made obfervations which

have been contradidied by ether naturalifts equally ' . " "^' . . .

fkilful ; fo that after an unprejudiced examination

of the whole, we are forced to confefs the having learned nothing/ and that the texture of theie or- gans is obfcure and uncertain.

The celebrated Haller, after comparing the difFe- rent opinions of anatomifts as ro the ftrutture of the nerves, and principally examining Levvenhoeck's ob- fervations on thellrudure of thefe parts, ingcnuoufly confefles that nothing but fimple conjectures can be advanced thereypon. He however, is difpoled to believe that the Itrudture of the nerves may be cellular.

Among the latter naturaliits who have exa- mined the animal body, there are tvv^o particularly, •who deferve our notice, the learned Father della Torre, known by feveral philofophical works, and fiill more by the microfcopical obfervations he has at different times publifhed, and M. Prochaika, a ikilfulprofeiTor of anatomy,|t Prague, who has given us two very interefling microfcopical works, one on the iieihy fibres, the other on tlie ftrudiure of the nerves.

Father della Torre (a) examines the two fub- ftances, cortical and medullary, of the cerebrum

(a) Nuoye O£eryazioni Microfcopiche. Napoli, t776.

ancj

ON POISONS. 217

and cerebelluin ; he likewife examines the niediiila oblongata, medulla fpinalis, and lallly the medul- lary fubilance of the nerves. He finds that all thefe organs are nothing more than a mafs of num- berlefs globules, tranfparent, and fwimming m a diaphanous fluid, Thefe globules, he fays, are very Imall in the medullary fubftance of the nerves, in which they are placed in almoil a right line, fo that they feem to compofe fimple threads and iibres, inftead of which in the cerebrum they are very large, lefs in the cerebellum, and ftill lefs in the medulla oblongata and medulla fpinalis, where they are not placed in a right line, but mixed con- fufedly together.

Prochaika {a) does not admit of any difference betwixt the cortical and medullary fubftances of the brain, finding both of them to be formed of an immenfe quantity of globules united together by an elaftick and very tranfparant cellular membrane* He does not agree wdth Father della Torre as to the difference in iize of thefe globules, but ob- ferves with him, that they are difpofed in the pervcs in a right line, and appear like a longitudi- nal fibrous ftrudiure.

Albinus, who joined ^he tife of the microfcope to that of the moft fubtil injedions, denies that the cortical and medullary fubitances of the brain are purely vafcular. Others have not only confidered the fubftance of the brain, but likewife that of the nerves, as a ncnorganick fubftance, and a mucous (§) Struftura Nervorum. Vindoborn, 1779.

2l8 1F0NTAKA

pulp. Others again have taken it for a fubftancc purely cellular. And all of them have thought the ufe of the microfcope neceflary to affift the naked light.

By the little that has been faid, it is eafy to per- ceive how great an uncertainty we are in, not only in regard to the ftrudture of the nerves, but that of the brain itfelf. The obfervations of Father della Torre and M. Prochalka however deferve our con- lideration. Independent of their ikill in obferva- tion^ they were not ignorant of all that other na- turalifts had feen^ or had believed to fee, before them. They were therefore lefs likely to be de* ceived, in running over a beaten path, and fo much the more deferve our utmoft coniideration, as entirely agreeing ih regard to the primJtive llrud:ure of thefe parts, which both believe to be, formed of limple globules.

Being in London in 1779, I heard that the cele- brated anatomift, Mr. Monro of Edinburgh, had madefome important difcoveries in relation to the ftrud:ure of the nerves ; but as I was ignorant not only of the detail, but likewife the confequences of his obfervations, I addrefled him in the follow-v lowing manner : '^

*^ S I R,

'^ Although I have not the honour to be perfon- ^^ ally known to you, I take the liberty to requeft

** fome

ON POISONS. 219

*^ fome information as to the interefting difcoveries ^^ in anatomy, which I am told you have made on ^^ the llrudlure of the nerves. I am informed you ^^ have publiihed fomething relative thereto in a ^^ journal, and in two papers read to the Medical ^^ Society at Edinburgh. As I am bufied on this *^ fubjed:, I ihall be glad to know how far you ^' have carried your refearches, that I may be en- ^^ abled to render you all the juilice you deferve, ^^ provided I determine hereafter to give my ob-> ^^ fervations to the publick. I regard your dif- *^ coveries as already publlflied, and confequently ^^ anteriour to mine, but Ihould 1 write on this fub- ^^ jed: before I am fully acquainted with them, it '^ would be out of my power to attribute to you *^ all that is your due, and by paffing over your ^* works in iilence, I ihould incur the fufpicion of ^^ wifhing to appropriate to myfelf the difcoveries ^^ of others. You can run no rifK in communi- ^^ eating to me what you have done, lince on one ^^ han'^l, you have already "made your difcoveries *^ known to a publick body, and on the other, my ^' letter will be always a fecurity to you, again ft ^^ any improper ufe I might make of your corn- ^^ plaifance. Men of real merit are rarely fufpi- ^^ cious and iliy : this induces me to hope that you ^' will beftow fome favour on one who renders you '^ the greateft juftice, and who delires to be in- ^^ ftrudied by the difcoveries with which you have ^^ enriched and advaiiced the fcience of anato- ^*my/^ ^ '

Having

2,2^ If O N T A N A

Having received no reply form Mr. Monio, and fearing that my letter had not reached him, I conveyed a copy of it by his pupil Mr. Craw- ford (a), who was then in London, begging him to have it delivered by fome truily perfon into Mr. Monro's own hands : it was quite ineffediual, as I had no reply from this celebrated profeflbr of Edinburgh.

I heard in the mean time, that mention was made of Mr. Monro's difcoveries in the firft part of the lixtn volume of a journal, entitled. Me- dical and Philofophical Commentaries by a Society in Edinburgh, printed in London in 1779. Not being able to obtain any information on the fubjed: from Mr. Monro himifelf, as I had flattered myfelf, and ihould have wiihed, to do him every juftice, I am under the neceffity of tranfcribing from the comm.entaries I have mentioned, the article rela- tive to the profeiTor's difcoveries, which, to be more certain, I do at full length. " Dr. Alexan- ^^ der Monro, profefTor of anatomy at Edinburgh, '* has lately taught in his ledures many particulars f^refped:ing the brain and nerves, which are en- ^^ tirely new, and vvhich mult lead to very different * opinions refpedi:Ing thefe organs, from what any *^ phyfiojogiils have hitherto entertained : he has ^' alio read a paper on the fame fubjcd: in the phi'- lofophical fociety of Edinburgh.

(a) Auihour of an excellent publication on occult heat.

„0f

4i

OK POISONS. 221

"*'^ Of his defcriptions, which are founded en- » ^ tirely on microfcopical obfervations, conjoined ^ with nice diffedion, and which are illuilrated by ^ numerous engravings, we cannot at prefent pre- ^ tend to give a fufficient account. We may only ^ obferve, that he finds the ftrudure of thefe parts ^ to be very different from what was formerly ima- ^ gined. He has difcovered that the brain and ^ nerves, in all clalTes of animals, in place of ' ftraight fibres, are every where compofed of con- ^ voluted fibres, nearly ^-oW parts ofx an inch in ' diameter, which do not feem to be hollow, but

folid.

^^ He finds that their extent in the fyllem is * much greater than has even been believed ; and ^ that they not only enter the compofition of parts ^ intended for fenfe and motion, but alfo of every ^ other part of the body. Thus he has difcovered ' them penetrating to the very extremities of the ^ longefl: hairs ; and in great numbers entering ^ the^ompofition of the cuticule and nails. He I ' farther alledges, that the bulk of all our organs ^ depends chiefiy on their nerves ; and that when ' mufcles or bowels are cut tranfverfely, many ^ more nerves are divided than when the fame ope- ' ration is done upon the cord, called by anatomiits ^ the nerve of that part.^'

'^ He finds alfo, that a fyilem of convoluted ^ fibres, in every refped; analogous to the nerves of ^ the human body, is to be difcovered throughout ' the whole vegetable kingdom. Nay, that the

'^ metals.

223 F O N T A N A

*^ metals, femi-metals, earths^ and falts^ confift al^ *^ mofl entirely of convoluted and ferpentine fibres, '* fimilar to the nerves of animals in iize and " Ihape.

" How far the teilimony of future obfefvers will '^ confirm Dr. Monro's defcriptions; is not for us to " determine. But we may venture without heiita- " tion to alTert^ that if the account which be has *' given (lands the tell of fceptical fcfutiny, it mufi *^ be confidered as the greatell anatomical difcovery *^ which has been made for many years/'

Mr. Monro's difcovery feems to me principally to confifl: in his having found that the brain and nerves are compofed of convoluted, and not of flraight fibres ; that thefe fibres are about the -g^Vo part of an inch in diaijieter, and that they are not hollow, but folid* He adds, that thefe fibres not only enter into the compofition of the organs of fenfation and motion, but likewife into that of all the other parts of the body ; and he likewife finds them in hairs, in the epidermis, and ir^he nails.

He will likewife have it, that the principal mafs of all organized parts is compofed of thefe con- voluted fibres, that is to fay, of nerves.

Laflly, he finds a fyfiiem of the like convoluted fibres, in all the nerves of the human body, and in the vegetable kingdom ; and believes that foffils are almoil wholly compofed of convoluted fibres, fimilar in fize and form to the nerves of an aiai- iiiab

We

ON POISONS. 223

We may certainly conclude from all this, that Mr. Monro regards the convoluted fibres in ani- mals, as of a nervous nature, although he agrees befides, that they are not found to be inflruments of motion and fenfation in all bodies, as they cer- tainly are not in foffils or plants, any more than in the nails and hairs.

Although the greater part of thefe difcoveries of Mr, Monro feems paradoxical, this is no reafon for denying them ; and the authority of the pro- feflbr would alone be fufficient to induce me to examine his obfervations very attentively, even if the importance of the fubjed:, which is in itfelf very interefling, did not require it.

The new difcoveries of Mr. Monro, are alto-^ gether different from the obfervations on the flrudiure of the brain and nerves, made by thole who have preceded him. I thought it proper then to examine this matter as if it had been en- tirely new to me ; and the opinions of writers have only ferved^-o make me more cautious in pronoun- cing, even where my obfervations were the moil conftant.

I wiflied to examine the nerves as they appear to the eye, in a living animal ; without touching the parts that com.pofe them. I feparated alone, the parts altogether of a different nature, that were contiguous to them. It vv^as not difficult for me to perceive that they appeared formed of bands. more or lefs regular, or of alternate white and dark fpots.

Plaie

224 J? O N T A N A

Plate III, Fig. i. Reprefents one of thefe nerves in which the bands were more regular and dlfliniffc than in the othersi On examining them with a lens which magnified fix times^ e\'ery thing was {een better and more diftindly. I detached the nerve from the animal, without pulling it in any way, and examined it on a glafs* The bands ap- peared exceedingly regular, they w^ere all equally large, and the fpaces from one band to another^ w^ere equal to each other, and equal to the bands themfelves. I thought at firft, that thefe bands formed a true fpire in the nerve, or rather^ that they turned fpirally, as a ribbon would do round a cylinder. This idea feemed to agree with w^hat I obferved^ and what feemed lliil more to confirm it, the nerve rolling in this way on itfelf, the bands feemed to continue their circumvolutions through- out, and I could not perceive them to be formed of detached rings, placed at equal diflanceSi

I wilhed to fee whether this lingular ftrudture^ or fpiral appearance, were common to all the nerves^ and fpared neither time nor labour to alTurc my- felf of it. In the o-reat number of nerves of ani- mals I have examined till this time, I have feeit very few in wdiich the bands w^ere as regular as in the above cited Fig^ i*

Thefe bands in general feerii to form different angles, and to crofs each other, and are often feen of different fizes.

But whether great or fmall, regular or irregu- lar, whether they crofs each other^ or proceed in •' a pa-

ON POISONS. 225

i parallel direction, they are obferved in' all the nerves, to the very brain and fpiral marrow, that is to fay, to the part where the nerves form them.- felves into threads, dr cylinders. A degree of at- ttsntion is required to obferve the fpires in many of the nerves, above all at the place of their origin.

When they are too abundantly covered with cellular membrane,, or if it be in flakes, it mult be rem.oved to better diflinguifh the fpires. In many of the nerves they are feen v^dth the naked eye, without any heed of preparation, fo that this appearance of bands, is a conilant and certain cha- raCLcriflick in the nerves ; and thefe organs of miO<^- tiori and fenfation appear to be compofed in a great part of thefe- white bands, fince when iimple and regular, they occupy about half the length of the nerve.

Thefe nervous bands are not deftroyed, although they are not fo diflindily feen, when the nerves themxfelves are flrongly pulled out, provided the difteniion be not extrem^ely great : in the latter cafe they miay be fo changed as not to be diftin- guilhable. The tenacity in the nerves, to preferve this appearance of bands, feems to confirm ftill more the latter being true fpires, and that they roll round the nerve, as a ribbon does round a cylin- der.

I could not however conceive how the anato- mies who have fearched into the nature and com- polition of the nerves, and flill more the micro- fcopical obfervers, could efcape the feeing thefe

Vol. 11. Q bands^

2Z6 F <5 N T A N A

bands, which are fo readily and conftantly abferved^ in all of them. I have at ieaft found no one who fpeaks of them^ although feme one whofe work*^ I have not read, may have noticed them : this is of but little confequence ; hut it is vdry eflential for us to know that the nerves prefent themfelves in this form, a circumHaace which may tend very much to a knowledge of the nature of thefe organs, that are fo important to animal life.

Let us pafs to the examination of the diSerei^ appearances of thefe bands, and fee with how many variations the nerves prefent themfelves, to the at* tentive eye of an obferver.

Plate III. Fig. i. Reprefents a nerve magnified about fix times, with a lens. re, rr, re, rr, are white bands, all equally large, and at equal diC- tances. 00, ooy 00, 00 y are the opake parts of the nerve, equal in every refpecfl to the bands.

Fig. 3. of the fame plate, reprefents a nerve magnified eight times by a lens. The bands in this^ one crafs each other at different angles, and in dif- ferent parts of the nerve. Fig. 2. is another nerve ©bferved in the fame way* The bands are more drUindt, and approach each other in fome places, inftead of crofiing, but withcrut any regularity^ The nerve in Fig. 6. likewife fliows the white bands, fome of which unite, and others crofs. The little regularity in the bands led me to fufped: that there were feveral orders of them in the fame nerve, and that they perhaps took different direc- tions. Fig. 7. almoi fully confirmed me in this

belief

O 14 P 0 t S 6 N S. ^"if

belief. The bands crolling each other are tl^ere feen in the midft of the breadth of the nerve, forming both iiharp and obtufe angles^ perfectly- equal to each other. But this hypothefis, or this fufpicion, was not yet confirmed by obfervatioti, and might very likely be falfe* In multiplying my obfervations, 1 found in feveral of the nerved' a double order of thefe bands, which met each other, ^5 the cogs of two wheels do, that are fixed td each other.

Fig* 5. reprefents this double order df bands very perfed:ly, as I obferved them in a nerve, with the ailillance of a lens which magnified fix times* The bands of the tw^o orders a r^d c, were equally large^ and every where at equal diftances, aiid ran one into the other for more than a third of th^r length ; as the band 0 is feen to enter into the band a^ and like- wife the band c into the band r« This new obfervati- on convinced me flill more that thefe bands ran along the nerve in the form of concentrated fpires, equally diftant, and every where of art equal diameter. It is true that I regarded them as formed of two nerves uni- ted together by a common cellular flieath, and could in this way account for all the irregularities I obfer- ved in them. The nerve in Fig* 8. completed this per* fuafiort. r , a^ r, a, point out one of the two nerves^ and a, 0, a, 0^ the other. The line of fepraatioh betwixt the upper and lower bands is diflindtly feen, and this line a a, can be nothing elfe than the union of the two nerves. 1 found it no longer difficult to affure myfelf of the truth of this fuppofition, all that

Q^at was

22S F O N T A N A

xvas required being to ftrip this nerve of the com-* mon coverings, and afterwards to fe par ate the nerves of which it might be compofed. Fig. 4, reprefents in effed:, not only a feparation of the nerve from the common Iheath, but likewife of the nerves that com- pofe it. There are four of thefe nerves, viz. a by c e^ 0 r, fm, and iii each of them the bands are fim-^ fie, without meeting each other, or formxing angles^ It miufl not however be thought that a nerve v/hich prefents a fmgle order of bands is perfectly iimple, that is to fay that it may not be formed of other fm.aller ones ; all my obfervatlons prove the fallacy of this. I have always found that the large^l nerves are formed of fmaller ones, and thefe again of fmal- ler ftill; and in the laft, which I iliali [call Iimple^ the bands always appear regular and v/ithout form- ing; angles.

The nerves thefi afe fmall as hairs, and perhaps ftill fiiialler; notwithfcanding which the bands are diiiiindily feeii, even with the v^^eakefI lens'. Wheri they are largei^ and form other nerves, the cellular membrane unites them and vvTaps them up in fuch a way, that the eye cannot penetrate far into thefe iubilances, and confequently a lingle order only oT tands is^d'iftlnguifhed.

This wonderful ilrufture of bands is- common 'then to all the nerves, even the fmallei]: of them, and the irregularity of thefe bands is only caufed by the bands of the fmaller nerves, of which a large one is compofed. I have -endeavoured to ftrip them of their iheaths, as 'well particular as common,

.4 with

ON POISONS. 22G

with the point, of a lliarp needle, fo as not fenfibly to change their ftructure, and am fully convinced that this operation does not deilroy the bands, which therefore feem clearly to depend on the pri- mitive ftru^ure of thefe organs.

Perfuaded laftly that thefe bands were not an ap- pearance or opticle illufion, and feeing that the ve- ry irregularities of them confirmed me ftiil more in the opinion that they were fo many fpires, that is to fay, that they turned yniPiterruptediy round the nerve from one extremity to the other, I proceeded to a iearch into the nature and compoiition of them.

The white colour m.ay at firil nght induce one to judge that it is a pure medullary .fubftance; butthis can alone be decided by obfervadon.

My firft attention was to examine a frnall nerve covered witR its own natural cellular membrane. Fig. 10. reprefents it in the way I favv it v^^ith a very fcrong lens, and covered with water. The two ex- tremities of the nerve, <5;, a, were a little tranfpa- rent, and u:emed formed of very fine threads, inter- fperfed with a great number of very large oval glo- bules. Thefe oval globules and fmall threads are common to all the ilieaths of nerves. The opake and middle part of the nerve a^ a, feemed formed of parallel vvdnding threads, as is feen in the fame figure. ntj m, m^_2LiQ oviform globules obferved.in the cellu- lar membrane of the nerve ; and r, r, r,^ are the fila- ments of the cellular membrane itfelf, fwimming ii^ the water.

0^3 " Every

2^Q F G N T A N A

Every tim6 I examiiied the nerve in this mannef, that is to fay, with a very flrong lens, the band? Ivere no longer vifible, and I could not account clearly for this difappearance.

Inftead of fpiral bands obferved before, I faw pa- rallel winding fibres, everywhere of an equal thicks oefs, running all along the nerve; and yet when I ex- amined this fame nerve with the naked eye, or with a weak lens, it prefenced the white bands as ufual.

I at length removed the cellular membrane qr flieath of t}ie nerve, without changing its texture, and examined it in this Itate with the utmofl attenti- on, but could only diftinguilh the winding fibres, as they ar^ defcribed in Fig. 9. However often I repeated this examination, all my ref^arches were ufelefs : I could only find the wavy, winding fibres, when I examined the nerve with flrong lens'; and tands or fpires, when I obferved it with weak ones, or with the naked eye. If my firft obfervations Hjade me believe that a nerve was really compoftd pf large and very white bands, the latter perfuaded me that it was formed of parallel winding fibres, (q that I could not determine which of thefe two ap- pearances was the right. It is very true that the firfl hypothefis feemed to me lefs likely after the lat- ter obfervations, becaufe with the ftrongeft lens' I pould perceive nothing in the nerve conformable to the firft appearances. I could find no remains of a thread which twifted fpirally round it, fo that it was tieceflary to examine whether thefe bands were not a frue opticle ijlufion. In this ftate of uncertainty,

' Ifaw

ON POISONS. 231

I faw no other ftep to be taken than the continuing to obferve this double appearance of bands on one lide, and winding threads on the other, I diverlified the circumftances of this examination as much as poffible, and by ading in this way, if I did not fuc* ceed in dilbovering whence this double appearance of curvilinear ban4s, and winding threads, arofe, every thing howeve&^concurred toperfuade me, above all when I e^^anjin :d a very fmall nerve not compofed of lelTcr ones, that t}>e nerves (imply contain very fine winding threads, and are wholly compofed of them. The microfcope would not have been capa- ble of prefenting them to the eye in fo conflant a way, and in fo many different circurnftances, in which, on obferving the nerve with the Urongefl lens', the winding threads inflantly fliowed them- felves, if thefe threads had not really exifted. This fucceflive appearance anddifappearance of bands and winding threads, and vice verfa^ perfuaded me at length that the appearance of bands, to the eye, ei- ther naked or feebly armed, was caufed by the win- ding fibres themfelves. By this new hypothefis I T^as conipletely enabled to account for the different appearance^ in the form of the Uructureof the nerves, and there w^s no effett w^hich I did not ealily explain, por obfervation that I did not immediately compre- hends I however fought a more certain proof in a decifive experiment. I wifhed to take nature in the fadt. An obftinate application of feveral days, which I employed in obfervations, enable me at length to fee clearly, and to difcover ;he whole myf-

0^4 tery

232 F O N T A N A

tery. Very flrong lens' caufed the bands to dhap-. pear, and very weak ones the winding fibres.

A llrong or weak light, directed on the objed: by the motion of a reflecting mirrour, produced feiifible changes in the appearances of the nerve ; fo that I faw with the fame lens, at fometimes the bands alone, and at others the winding fibres alone.

I now employed a lens of a middling ftrength, and threw a light upon the objed: in fuch a way as to. diilinguifh clearly the winding, w^avy fibres ; but without feeing the fpiral bands. Without touching, objed: or lens, I fimply turned the mirrour a little, and fo diredied the light on the objedt, that at length the fpiral bands appeared very difiinCtly. On fcarce- ly touching the mirrour, the bands inilantly difap- peared,- and the winding fibres fliowed themfelv.es in' their Head. I again touched the mirrour, when the bands fuddenly appeared afrefh, and by a motion of the m.irrour, they once more gave place to the win- ding fi.bres. Thus I could at pleafure produce this' double appearance, of bands and fibres, by only throwing more or lefs light on the objed:.

Figures 9. and 10. reprefent thefe fucceffive ap- pearances and difappearances. Fig. 10. fhows the nerve flripped of its outward ilieath, and viewed with the lens of middling ilrength. It v^^as fo fur- rounded by light, that the bards or white fpots, r, ^, r, c, and the dark fpots, ^, ^, a, a, were diftindly feen. This double clafs, of dark .and white fpots, forms the nervous bands.

Scarcely did I touch the mirrour, when the bands

fuddenly

ON POISONS. :^Jj

fuddenly dlfappeared, and I fa\v in their place the winding fibres of Fig. 9. When I moved the niir- rouE by almofl infenfible degrees^ I obferved the tacnds difappear as leiHireiy, and the fibres ibow themfelves ; or rather I faw the appearance of bands converted into true parallel winding threads : the bands, c, c, c, of Fig. ic. became the winding and convex fibres r, c, c, of .Fig. 9. and the opake intervals a^ a^ a, a, of Fig. 10. became the con- cave fibres a, a, a^ of Fig. 9.

It was no longer poffible to doubt the. reality of thefe obfervations ; that is to fay, that the bands ' were not real but apparent ; and on the contrary, that the winding fibres were not apparent but real.

All the obfervations I have made fince have con- firmed me ftill more in this, fo thatl can no longer doubt but that the fpiral;bands in the nerves are an opticle iliufion, and that this illnfion is produced by the wavy form of a great number of fi.bres, or parallel threads, running along the nerve.

Amidft the numerous microfcopical obfervations I have made at different times on animals, or on other fmall bodies, no one has coft me fo much trouble as this, or has been fo near to the leading me into an er- rour. I have fhown thefe bands to feveral perfons accuftomed to obferve the fmallefl objedis, and the Itrudture of the human body ; and have met wdth no one who did not fuppofe the fLrudiure of them in the. nerve to be real, and who did not ridicule my affertion, that they could be no other than a iimple appearance*

After

224 ^ ^\^ TANA

After having thus furmounted this firft diffi- culty, and aflured myfelf that a nerve prefents to the view a great number of winding fibres, of ts^hich it is formed, I proceeded to farther re- feavches* I wilhed to know what the primitive ftrudure of the nerves is, that is to fay, whether it is compofed of channels, or of fimple threads ; whether it merely confifls of globules, or con- tains a non-organick, irregular, fpongy matter. This refearch is as important as difficult, iince it tends to nothing lefs than the fixing, once for all^ the ideas pf anatomifls on the nature of the nerves ; that is to fay, on the ftrudture of the organ of mo- tion an4 fenfation in animals. They have difpu- ted for more than three thoufand years, from Hip^ pocrates down to Albinus, from the Greeks to the inoderns, and feem during all this time to have done nothing more than multiply doubts and hy- pothefes.

Without being very fanguine in my hopes of difcovering the firft principles of nerves, I have undertaken the inveftigation with ardour, perfua- ded that the knowledge 1 have pf their winding; fibres, muft be extremely ufeful to me in fo difficult a fearch.

I began my obfervations on a very fmall nerve, which I had ftripped of the cellular membrane. I pbferved the winding fibres narrowly with a very ftrong lens, and determined the fize of them. This done, I divided the nerve towards its extremity in ^ longitudinal direction, by means of a very iharp

needle.

ON POISONS. 235

needle, and divided the parts or threads of it, fepa*^ rating one from the other. I immerfed the nerv^ in water, in which the threads floated. Afuer fe- verai ufelefs attempts, and feveral obfervations either fufpicious or inconftant, 1 at length fuci» ceeded in finding many very fmall cylinders, more or lefs trajifparent, feemingly compofed of a peU iicle, and partly filled with a tranfparent, gelatin fious humoyr^ and with fmall unequal globules, or todies. Plate IV. Fig. 3. reprefents three of thefe tubes, which 1 Ihall c?i\\ primitive nervous cylinders i becaufe thefe are the parts that conftitute the perve, or its medullary part. Fig. 5. reprefents another of thefe cylinders.

To diflinguiih their f^udtur^ and fhape the htt^ ter, I examined a great number of thefe primitive nervous cylinders with a lens that magnified 500 times, fig. i, reprefents one that feemed to have here and there on its outlide fome fragments of Virinding threads ; and fome fpheroidal corpufcle^ in the inner part of the cylinder. Fig. 2. defcribeS another which appeared filled here and there with very fniall globular cprpufcles, immerfed in a gela- tinous tranfparent humour. I have feen others which one would have fuppofed to be filled with a gelatinous fubftance broken confufedly, and fe? parated into different fragments, fo that the gelly of the cylinders may be looked upon as feparated, or <Ji- vided into large, tranfparent, irregular mafTes,

However, all the efforts I made to alTure nayfelf

f the nature and reality of thefe i^rregular cprpuf-

3 cles

2^6 P O N T A N A

cles belonging to the primitive cylinders, did not enable me to judge precifeiy of them. They fome- times feemed to me to be Ipots or irregularities in their external coats, but this I could not deter- mine, and my doubts multiplied in proportion to my obiervations. I had recourle to a very flrong lens, which encreafed 700 times the diameter, and after feveral fruitlefs attempts, I at length affured myfelf that the coats of the primitive nervous cylinders were very rugged and full of irregulari- ties. Fig. 4. reprefents four of thefe cylindersj acyom, rs, ne^ in two of which ^r, r^, the irregula- rities are apparent. Being at length affured of this new^ truth, it remained for me to make my- felf better acquainted with the true nature of thefe irregularities, and to know whether they contained globules or.corpufcles differently ffiaped.

To fucceed in fo difficult a fearch, I began by feparating the primitive cylinders of feveraj nerves, / with the point of a needle.

The extremities of the nerves w^ere placed In water, and I ran the point of the needle along them, to break the cylinders, or deprive them in fome way of their irregularities : I fiicceeded at length in meeting with one that had the form defcribed by Fig. 6.. .About half of this cylinder Vzr, was formed af a tranfparent and uniform thread, and the other half ma, was almofl. twice as thick, lefs tranfparent, irregular, and rugged. I then fufpe(fted that the primitive nervous cylinder was formed 0/ a tranfparent cylinder^ fmaller, and more -' ., uniforni.

OK POISONS. ^3^*

^fiifdriii, and covered with another fubfiance^ the nature of which was perhaps cellular*

The obfervations I made afterwards confirmed ine invariably in this hypothefis^ which at length became an eftabiiihed fad:. I have very often (qqw thefe two parts, that compofe the/ primitive ner- vous cylinder. The exteriour.one is unequal and rugged ; the other a cylinder which feerns formed of a particular, tranfparent, and homogeneous membrane, that appears to be filled with a gela- tinous coniiHent humour.

Fig. 4. reprefents, as has been feen, a group of thefe primitive nervous cylinders, in the Vv^ay I have obferved them on examining the nerve of a rabbit. One of thefe cylinders, 0, m, wsls en- tirely flripped of its external and rugged mem- brane, and had an uniform tranfparent appearance. Another was in a like way llripped, except at one extremity, n^ e, which feemed covered and en- •ciofed by an external rugged membrane. A third, ^r, was almoil altogether covered v/ith this -rugged membrane; the fourth, r, s, entirely fo. "^ Fig. 7. reprefents a primitive nervous cylinder in which, 0, r, the thick part, is covered with a cellular mem.brane compofed of fine threads. The part, r, j, is"ilripped of this cellular mem- brane.

On examining this external covering of the primitive nervous cylinders with attention, it -feemed to he compofed of winding threads, running

along

^3* t O K f A N A

along the nerve, and fo forming a cover to the in- terior cylinders. I was well affvired of this foon af- ter^ by employing a lens that magnified 800 times* Fig. 8, reprefents a primitive nervoiis Cylinder, Covered with its exteriour fheath, which is diftindtly compofed of very fmall winding threads, running along the cylinder.

The progreflion of thefe threads may in fonie tneafure be compared to the canal formed h^ the epididymis, which produces inceflant folds. The threads are very fmall, not appearing to be more than TTo'o-6" part of an inch in thicknefs ; and al- though they are thus fine, they form fo thick acoat round the primitive nervous cylinder, that they al- moft triple its diameter ; this is caufed by their winding and heaping upon each other exceedingly-

Thefe winding threads, which cover the primitive nervous cylinders, I ihallcall the winding cylinders oi' the nerves ; and confidering them collectively, as a wrapper to the above primitive nervous cylinders^ I Ihall call them the external Jloeath of thefe cy- linders.

Fig. 9, reprefents a primitive nervous cylinder^ covered with its external Iheath. The Iheath is woven with winding threads, feme of which are a^ little feparated from others by the point of a needle, Thefe winding threads have a perceptible thicknefs when viewed with very flrong lens*, although mucb finer than the primitive nervous cylinders.

The primitive conftrudtion of the nerves is as fol* lows ; a nerve is formed by a great number of tranf-

parent^.

o u P o I s o K s* Sjgi

parent, homogeneous, uniform, very fimple cylin- ders. Thefe cylinders feem compofed of a very fine uniform tuhick, filled, as far as the eye can judge, with a transparent, gelatinous humour, not folubie in w^ter. Each of thefe cylinders receives a cover in form of an external llieath, which is compofed of an immenfe number of winding threads. A very great number of tranfparent cylinders form together an almoft invifible nerve, prefenting the exteriour appearance of white bands ; and feverai of thefe nerves united, form the larger nerves feen in ani* mals*

i am fully convinced by my own obfervations^ repeated a great number of times with the fame fuc- cefs, that the cylinders I have defcribed, are the? fimple and firfl organical elements of nerves, for 1 have never been able to divide them farther, what-* ever trials I made with the Iharpeft-pointed needles^ I could eafily tear and rend them here and there^ but they always remained fimple as before. I could ftrip them of their Iheaths, andfeparate the winding cylinders of which thefe were formed, akhougk they were very fmall. The primitive nervous cy- linder then appeared tranfparent, homogeneous^, and every where of equal diameter. We fee by this how much even the bed aiiatomifls were in ge- neral miftaken, when they maintained that the nerves were divided and fubdivided without end, without there being any hope of ever feeing, or com- ing at a knowledge of^ their firlt tjireads, or firi^ organical elements.

This

24-0 \F d R T A N A

This feems to me to be a great ftride towards the underftanding an organ fo eiiential to life, and which tlii now has been hid to the eyeS of the greatefl: ob- fer^ers.

I referve the examining, till I am moreat ieifure^ the matter of which the nerves are compofed, ot filled. This fubjecV when w^^U known, may throw a ver^ 'great light on the knowledge of the animal economy, and perhaps iikewife, on that of a great number of difeafes*

On

¥ On the structure of the BRAIN.

After having examined the flru^lure of the nerves, and their firil organical elements, order re- iquires me to turn my attention to the brain, whence , they draw their principal origin. We know that the .#' brain is compofed of two fubftances, named cortical and medullary, which are diilinguiilied by their re- fpe6live colour.

I have already related the various opinions of authors as to the ilrudture of the brain. Some be- lieve its fubilance to be altogether vafcular, and others will not have it to be fo. There are fome who fup- pofe it fimply compofed of blood veiTelsj others ofi the contrary believe it formed of velTels much fmaller again than thefe.

Malpighi believed the brain, as well as all the

• other vifcera in the body, defdned for particular fe*

cretions, to be glandular. Of the more modern ob-

R fervers,

^42 F O N T A N A

fcrvers, fome believe it to be formed of fimple glo- bules, others of a non-organical and fpongy pulp.

The obfervatlons I had made on the medullary fubilance of the nerves, were a great help to me in examining the brain, although in the cortical fub- ftance I encountered very great difficulties, which I fhould never, perhaps, have been able to furmount, if I had not been previoufly acquainted with the me- dullary fubftance of this organ, in which every thing is {Qen much better, and in a clearer way. 'Tis for this reafon that I fhall begin my obfervation by exa- mining the medullary fubfiance of the brain.

I fhall not fpeak cf the blood veffels that are fcen in the medullary fubilance of this vifcus, and which are well known to anatomifls, particularly fmce the ufe of injc6lions.

I ihall only treat of that part of the medullary fubilance which is quite v/hite, and which is cer- tainly not formed of blood velTels. I cut a fmall and very thin lamina of this medullary fubilance^ and extended it on a glafs wet with water. 1 exa- amined it with the greateft attention, purpofely varying the light, and it feemed to me to be formed of a tranfparent cellular fubdance, cover- ed here and there with very fmall, rounded, wind* ing cylinders. Plate V. Fig. 8, r r. reprefents this fubftance, which, when well obferved, feemed com- pofed, as it were, of a heap of inteilines -, but all was obfcure, and uncertain. At its fide, at a a, there were feveral corpufcles, detached from the cellular fubilance, fwimming in the water. Some

ones

ON POISONS. 243

©nes were larger than the others, they were irregu- lar, and more or lefs oviform. This inteflinal form of the medullary fubftance of the brain, made me fufped: that there might be canals or velTels, and that it might be wholly formed of them. And in reality, having obferved this medullary fub- ftance afreih, as in Fig. 8, with a much ilronger lens, it appeared abfolutely formed of an heap of fmall, irregular, winding, tranfparent inteflines, filled with a gelatinous humour. It was not poffi- ble for me to difcover any more ; it only appeared that thefe fmall inteflines were very fhort, and that fome of them terminated in fmall globules, or fphe- roidal bodies.

However certain this obfcrvation appeared to me, it flill left me a great deal to deiire. I wifhed to fee things clearer^ and to affure myfelf that thefe were canals, which ramified. I employed a lens that magnified in diameter upwards of 700 times, and after feveral fruitlefs attempt-s, I at length fuececded to obferve the part I had before touched with the point of a needle, and which I had wetted afreili with water. I then found to a certainty, that it was really formed of a winding and vafcular fubilance, which folded as the intefiines do, making feveral turns and circumvolutions. Fig. 9, exadily r.e- prefents its manner of appearing to the eye, armed with a microfcope. Globules, which feemed fur- rounded by fomething, were fpread about it ; cer- tain round, or l^lunt bodies, appeared in the intefli- pal fubftance itfejf j and fome of tjiefe iateftjines.

R 2 feemed

244 F O N T A N A

feemed to terminate In thefe bodies. It is however

certain^ that round corpufcies are tenaciouily fixed Xo this fubilance, and that they are detached with diflicuky by water.

I'he point of the needle^ however, had detached feveral bodies from this fabilance, which are repre- fentby Fig, i6. Some of thern, particularly the largefl^ appear to be branched ; orhers feeni to end in the corpufcies I have fpoken of. I can neverthe- lefs form no conjediure on them^ and only reprefent the objeci as I have feen it, I have repeated thisob- fervation a great many tim.es^ but have not yet fuc- ceeded in feeing any thing more. ^Tis true, I have aifured m.yfelf to a greater certainty, that the medul- lary fubilance of the brain^ is not a iimple CQlled:ion of venous and artereal veiTels ; that it is not frmply formed of fpheroidal globules or corpui'cles ; but that it is an organifed, particular fubfcance, com- pofed of irregular cylinders, or tranfparent canals, v/hich fold as the inteftines do, and which I fhall call the intejiinalfuhjance^ on account of the ihiape ii^ which it is feen.

This particular, inteftinal, fubflance, of which the marrow of the brain is formed, is not foluble in water, any more than is the tranfparent matter with which thefe inteilines feem to be filled. The round corpufcies likewife, that have been defcribed, are not capable of being diflblved in water.

Such is the ftrudiure of the medullary fubflan€e

p^ the brain, and in this way I have found it in all

the animals 1 have examfmed. My obfervations o^

4 " mis

ON POISONS, 245

this fubject conclude here, and I can venture to fa^, that I flatter myfelf with not having been deceived. All that 1 could further advanxe on this occafion, would be nothing more than conjedural hypothefes*

Cortical Suhjlance.

The Inteilinal {lru6lure I had difcovered in the tnediulary fubftance of the brain, affiiled me in dif- covering fomething like- it in the cortical fubilance of this vifcus. I fay fomething like it, becaufe I could not after all trace the progrefs and inteflinal ftrudure of this fubilance in fo clear a way^ as I had done that of the medullary one.

I began to examine the cortical fubflafice, in the way in which I had examined the medullary one, viewing a thin lamina of it moiflened with water. Fig. 6, r r. reprefents this lamina obferved with a very ftrong lens. It feemed to be formed of an irregular web, granated here and there, which I Ihould have fuppofed a cellular m.embrane, if I had trufted to a flmple inf[}e6lion, Befide this fubdance, were very fmall, irregular, tranfparent, fpheroidal corpufcles, which feemed filled with a gelatinous humour, and which were not foluble in water 5 they were fmaller than thofe I have obferved in the me- dullary fubftance, but in every other refped like them, I now had recourfe to a fcill ftronger lens, with which I at length ilicceeded in obferving a ftrudure altogether like that I had obferved in the

R 3 , medullary

246 F O N T A N A

medullary fubftance; that is to fay, compofed of a tranfparenr, organlcal, vafcular fubftance, formed like the inteflines* On obferving Fig. 7. its revo- lutions and windings in this fubftance, like thofe in the medullary, will be feen at ;;;, a ; it only leems to differ from the latter in the finenefs of its veiTels, which it is very difficult to fee diftin6t- ly. About it were the corpufcles, r, r, which like- v/ife feemed to be furrounded by fomething. The obfervations I have fmce made, have more and more convinced me, that the fcrudture of the cortical fub- ftance of the brain, is as I have defcribed it, and that it does not differ fenfibly from the medullary fub- ftance, although their colour makes them appear fo diftind. I do not pretend to deny, but that the ufes of thefe two organized fubftances may be a little different; and the different dimenfions of their refpedive inteftinal fubflances, give great reafoni to fufped it.

I wifhed to fee the union of thefe two fubflances, and to obfcrve the end of one, and beginning of the odierj but could not fucceed. It however appeared to me, that the fluid with which the in- teftines of the cortical fubftance feem to be tilled, agrees in its nature with that of the medullary fubftance.

Retina.

After having examined the primitive ftru6lure

of the nerves, and thofe of the cortical and me-

I duilary

ON POISON S. 247

dullary fubilances of the brain, I thought it proper tb bellow a particular attention on the parts in which the nerves terminate, or where they become the organs of a particular fenfe in an animal. For this purpofe I made choice of the retina,' which appeared to me the moil proper organ for my pur- pofe, and the ufe of which is the moil noble. I referved to another occalfion, the examining the nervous expanfions directed to the other fenfes.

Authours are divided amongd themfelves as to the primitive flrudture of the retina^ although they agree in general in other refpedts, as to the nature of this organ^ which they believe to be formed of the medullary part of the dptick nervCo Several have believed it to be a pure web of ner- vous fibres, the primitive fize of which, as may be feen in the works of Porteniieid and Gefner, they have even gone fo far as to determine ; but the exiftence of thefe fibres, and their iize, in thefe authours, are rather founded on theory, than on im- mediate obfervation ; fo that a nice obferver, who does not content himfelf with hypothefes, can havd but little dependance on their calculations.

There are others indeed who have llruck into the path of obfervation, but their refearches have been very fuperficial^ fince they have contented themfelves with fimple ocular infped-ion, or with very common lens'. It hence has arifen^ that they have given us nothing more than vague and ge^ jieral opinions, and have confidered the retina ai

R 4 no

24S ^ O N T A K A

no other than an expanfiou of the medullary pa^ of the op tick nerve.

But others again, more venturous, and accuftomed

to bbferve very minute bodies with very flrong lens^, have carried their refearches Hill farther, and have aiTured us that the retina is not formed of diilind: nervous fibres, but rather of the mu- cous fubfiaoce of the brain, which feveral of thefe obfervers imagine they have difcovered, and which ^ »s we have faid above, is nothing more than a mafs of very fmall iimple i|ihcToidal corpufcles, or as- others have thought, of a confufed non-organick pulp, or of iimple threads^ and cellular lamina.

Some obfervations I had previoufly made on the retina of rabbits, were very ufefui to me in- th^ examination I aftervv^ards entered upon, of the re- tina: of other animals. Had ! not known th^ quali- ties of the former, I iliould perhaps like others have been deceived, and fliould have denied a ftrudture to this organ, v/hich is abfolutely proper to it.

The retina of rabbits obferved v^^ith the naked eye, ^appears very dliferent from that of other ani- mals vievved in the fame way. A particular itruc- ture in the former infiantly fixes the attention of thofe who obicrve it. In the inner part of the re- tina, (fee Fig. 12.) and.oppofite the lov.'er entry of the op-tick nerve, a pretty deep hollow, the edges of v/hich are well raifed, forms itfeif; it is v/ider tovyards the head and upper jaw, than towards the tv;Q corners of the eye. From the bottom of

this

this hollow arlfes a vtrj great number of exceed.- ingly fmail and very Vvdilte nervous threads, v/hicll fpread all arGiind it^ as rays that diffuie thernfelves from a common centre, and form the retina.

If the optick nerve be divided lengthways with a fcalpei, into two equal parts^ the threads of it, which are no other than a contmuation of the above mentioned fdanientSj covrefpond perfetSih'' /With thein, Thefe nervous fiiaoients on their leav- ing the holloWj continually diminiili in lize^ and ramify ; in proportion as they are more diilaot from their origin, they become more numerous^ till at lengthy being (o very fine as to be Icarcely Viiible, they terminate in very fubrle threads at the bep^innias: of that part of the reriiia vvhich I feall collmiwous^ to dillinp;uiih it from the other, which f ihall call ra(iiat:edj ox jUafnentous, The nervous ravs diifufe thcinlblves in every direcliion round the hollow^ but ere very long in two parts^ r^ r^ dia* metricaHv op])cfite to each other, and occupy the greater part of the internal portion of the eye. fo that the unradiated part of the retina is yqvj iinaii in this place, in coraparifon v/ith the otiier two parts which correi|)ond with m^ ?7i.

Thele fniall nervous fiiamcDtSj when very nicely examined, are of a croolced firu(fture, and have the ufual appearance of fpires or bands, alcove all St the other parts where thty arc leall: divided ;' but this is very difficuk tO be didinguiihLd clearly.

Thei^

i jd t '5 N T A " N J«r

Thefe fmall nerves, or radiated fibres^ which are fo eafily diftinguilhed in the eyes of rabbits, eved without the help of glaffes, are obferved with great difficulty in the eyes of other animals. I candidly acknowledge, that if I had not firil feen them in rabbits, I probably fiiould not have found them in other animals, fmce not having any fuf- picion of them, I fhould not have examined the retina with all the attention that is neeelTary to diilinguifh them* I mufl likewife obferve, that it is very difficult to view thefe radiated fibres dif- tindly, and- to verify their exiftence ; to fee them with facility, very ftrong lens' mufl not be em- ployed. The beft are thofe that fcarcely magnify iix or eight times. The retina mufl: likewife be ex- amined at the entry of the optick nerve^ where the medullary part of the nerve is the iargeft. It is only diftinguiilied well and to a certainty, in fome lights.-, I have fucceeded in diftinguiihing it Hill better when I have thrown the marine or fome other acid, well diluted with water, upon the retina, which then becomes white and opake, and the .nervous "fibres are more clearly feen in it. Some- times I have viewed them very well, after throw- wcr fome drops of water on the retina at the entry of the optick nerve. Although I am very certain of the exifience of thefe fmall radiated nerves in the eyes of all the animals, fuch as oxen,. iambs, and kids, that I have hitherto examined, I lliall however be not at all afloniibed, Ihould they be hidden to the eyes of many obfervers, even to

fome

ON POISONS. 251

feme who beil underftand the ufe of the micro- fcope, and view the minutell objedts in the bell manner. Thefe fmall nerves do not efcape the eye on account of their extreme finenefs, but rather on account of the great conformity they have to the ipulp of the retina itfelf, which covers and conceals them, if 1 may be allowed the expreffion, from the obferver. They appear to me to be of the fame length, in the eyes of all animals, except, as has been feen before, in thofe of rabbits, and they dif- appear when arrived at two thirds the fpaee that is found betwixt the entry of the optick nerve^ and the plexus ciliariSy fo that the unradiated re- tina in thefe animals only occupies one third, or thereabout, of the orbit of the eye.

Thefe radiated nervous fibres are very numerous, and feem to be formed of, or covered with, a medul- lary, dark, llightly tranfparent, pulp, which when examined with the llrongeil lens*, fecms to be com- pofed of very fmall tranfparent fpheroidal bodies, well united together, and tied as it were by very- fine tranfparent membranes or filaments.

That part of the retina in which the fmall nerves are feen in a radiated form, ought then to be con- fidered as compofed of two parts, one radiated, the other pulpous, or fimply medullary. The radiated part of the retina, it the eye be examined at the pupil, is covered with a particular fubilance, like a non-organick mucus, and the part beneath this mucus is formed of fmall, decreafing, longitudinal nerves, that is to fay, of nervous rays.

I found

2^± V O N T A J-^ A

I found the unradiated nervous part or the rfe=> tina, to be iikewife compofed of ver)^ fmall ner- vous globules, fjpported by a very fine tranfparent cellular web, in which it feeined in fome way to -tnclofe itfeifi Thefe globules are ffiialler than thofe of the blood. I found tjiem in rabbits to be about -tW part of an inch in diameter, whilf. thofe of the blood were the ~-o^ parte . The globules^ which appear to be formed of a tranfparent gelly^ in the retina of rabbits, do not diffolve in water like the red globules of blood, and are ftrongiy attached to a cellular fubftance, that feems to fupport them. Fig* ii. reprefents a fmall portion of the retina^ with the globules and cellular v.^b.

The nzes and refpective forms of the globules df the nervous part of the retina are reprefented by Pigures lo. and ii. The fmall bodies in Fig. lo. reprefent the globules of the retina^ and thofe of Fie. I V repreient the globules of the blood.

The globules of the retina have a great refem- blance to thofe. that are found in the brain. Wa- ter and acids produce the fame changes in them ; •they are equally tranfparent ; and I have only re- marked, that the globules in the retina are more teg-ular and uniform than the others.

When the retina is kept a long time in water, and wiped a little, llireds of it are often found inore or lefs deprived of thofe globules, and it ap- pears in thefe parts like an unequal, rugged, cel- . hilar V'/eb, formed with fmall hollows capable of

receiving

ON POISONS. . 2^^

^' ^

receiving thefe globules. Fig. 15. exadly repre- |ents the retina in this Hate.

Thus appears the retina when nicely obrerved, and we are fcarcely permitted to penetrate farther into its nature. The part which correfponds to Jthe entry of the optick nerve^ and which extends a great way, is compofed of very line threads of nerves, and of a nervous pulp formed of very fmaii tranfparent globules, attached to a very loof.^, tranf- parent, and rugged web.

The other part of the retina is fimply formed of the ufual globules, and cellular web; and as far as I .could obferve, feenis to have no nervous threads la its compofiuion.

Wiiliing to be better acquainted with the nature of thefe cellular webs of the retina, and how the glo- bules of the medullary part are attached to them, I began afrelli to examine the retina with very iirong' lens', and have at length, after many attempts, been able to diilinguifli moie precifely. I think I may venture to advance that thefe cellular webs are no other than a net-work of very fmall tranfparent crooked vefTels, to which, as is feen in Fig. 14, thefe globules attach themfelves. Thefe crooked velTels refemble very much, in tranfparence, figure, and progrefs, thofe of the medullary fubftance of the brain, and they only feemto differ in their iize, which is fomewhat fmaller, fo that there feems to be a particular inteflinal fubflance^ which is found in ^11 thefe parts.

Since

^54 MONTANA

Since the experiments of Mariotte^ and the calcu- lations of Daniel Bernouilli, wt know that the part of the retina whichcorrefponds totheentry of the op- tick nerve, is blind 5 that is to fay, that the images of objeds exprejled there, are in no way perceptible to us; and this nervous part in man is nothing lefs than a fmall dlfk of the diameter of a paris line. The nervous fibres in this place, are larger and mor€ heaped together than in any other parts; the pulp is likewife larger and more heaped. However in- credible it may appear, it is certain that the fmall nerves and pulp of the retina I have juli mentioned, are not organs of light, and that they only become fo in the part where all is finer, more rare and moreopen* Is this inf nfibility of the retina to the light, caufed by the nerves being as yet too large and not well freed from the cellular membranes ? Or is it cau- fed by the pulp of the retina being too much heaped, preventing in this way the rays of light from reaching thefe nerves ?

But it now remains to make another very impor^ tant fearch, by examining whether the Retina is in all its parts fenfible to external objedts.

At a fmall diftance from the entry of the optick nerve it is as has been defcribed certainly fo, and it clearly continues to be fo at a great difiance from the fame nerve ; the rays of light likewife extend them- felves to a great diilance, when we regard fubftan- ces in a natural way ; but let me enquire whether this vifion is produced at the fpot where the r,ays .end,,.

and

ON poisbi^s. 255

and the mucous part of the retina begins. Do .external bodies there caufe a fenfation r In a word, how far does the organ of vifion extend ? The folution of thefe problems, however difficult they maybe, ^s not impoilible. It depends on an exafi: knowledge of the parts of the eye^ ajid a few experiments pur- pofely made ; I however have not time to bufy my- felf in this fearch. It is generally known that in proportion as images are expreiTed at a greater dif- tance from the optick nerve, the objects are icen more confufedly ; fo that there is in all appearance, afpotorlimit, at fome diilance from the optick nerve, where vifion is the moil diil:in(5t, without our being yet able toalTureourfelves whether it be at the precife place where the nervous part of the retina begins.

The blood veffels of the part, and principally the venous ones, are generally covered with the nervous fibres of the retina, and with its mucous fubitance. They are at leail very often obferved to be fo in the eyes of oxen ; but thefe veiTels are in many places totally deprived of every nervous fubflance, and in thefe parts frequently crofs the retina, and its adjacencies, breaking its order and texture, and fo rendering it in many places infen- fible to external objedis, although it does not ap- pear fo to us, on account of the great mobility of the eye.

Fig. 10. and 11. of Plate IV. reprefent two lin- gular canals, with intermiffions here and there. It i^^y be fufpedied that they are lymphatick veffels; above all that of Fig. 11. I cannot decide as to

their

256 F 0,N T ANA

t^.eir nature^ having fo feldom met with them. I found thefe two veiielSj in examining the fubilancc of the brain.

It remains for me to make an obfervation or two, on certain figures of Plate V. which have been improperly introduced^ by an errour of the engra- ver^ into that plate.

Fig. I. reprefents feveral oviform bodies of dif- ferent iizes'j which are found in the external cel- lular coat of the nerves.

Fig. 2. reprefents very fmall corpufcles which I have obferved in examining the medullary fub- ilance of the nerves. In Fig, 3. are other ovifornn bodies^, which are globules of the blood of a rab- bitj and lead to a comparative judgment of the re- fpediive fizes of one and the other.

Fig. 4. reprefents feveral winding cylinders of the adipofe membrane.

Fig. 5. reprefents two threads, m^ a^ one placed at the lide of the other, to ihow their lefpettive iizes, m belongs to the adipofe membrane, and a to the external cellular membrane of a nerve. They are of an equal fize^

©>^

On the structure of the TENDONS^

Jl HE obfervations I made on the llruclure of the nerves, and of the undulating progrefs of their primitive cylinders which caufes the uncom- mon appearance of bands I have before defcribed, fiimulated me to examine with all poflible atten- tion the ftrud:ure of the tendons. I did not find any difficulty in dbferving a certain fplral form in them, although it did indeed appear lefs regular to me than in the nerves. This apparent fpiral fortii is obferved, not only in regarding externally the larger tendons, but even the very fmalleil of them. Thefe bands however, when better examined, have rather the appearance of longer or ihorter winding fpots, which a nice obferver will eafily diilinguilh from the bands that are feen in the nerves, and which we have defcribed. When a tendon is exa-* , Vol. 11. . S mine

258 F O N T A N A

mined with a lens that magnifies but a few times^ w^hite fpots are perceived through the cellular membrane that covers it, as they are reprefented by Fig. I. Plate VI. in which the tendon is mag- nified fix times. Fig. 2. reprefents another tendon likevv'ife obferved with a very weak lens, and in which the fpires, or fmall curvilinear fpdts, were more re- gular, and very much refembled thofe obferved in the nerves. This fpiral flrudiure of the tendons is likewife obferved with the naked eye, though not fo diilindbly as wkh a microfcape.

My principal attention was to examine nicely the elementary threads of the tendons, their fize and their progrefs, I at firfl fufpedied that their progrefs was analogous to that of the primitive nervous cylinders, and that the fmall white curvi- linear fpots owed their origin, or their apparent exiilence, to it.

This lafc refearch feemed to me the m'ore- impor- tant, fince. it tended to decide whether, befides the whole nervous fyiferaV other organical parts were to be! found *;n an animal, of an undulated and winding texture, like that of the elementary parts of the .nerves.

All; the tendinous fubdance in general, or rather all the .tendons, when examined with a microfcope, feemed to be formed of ^a vafl many very fmall, fimple, longitudinal /^{/67>, feparated one. from the other by the cellular membrane. Each of thefe fafci^, which. I fhall call primitive fafci a, bccaufe they are not compofed of fmaller ones, is formed of

4" ai>

ON P O I S O N S. 259

an infinite number of extremely fine threads^ which I Ihall call primitive tendinous cylinders^ becaufe tbe)^ are not fubdivicled into fmaller ones, in what- ever way they are prepared or examined. Thefe primitive cylinders run along the tendon for its whole length, and are folid throughout ; that is to fay, neither vafcular nor hollow. They are much fmaller than the primitive nervous cylinders, and are tied together in the primitive tendinous /^z/67^, by an almoil imperceptible, fubtle, and elailick cellular membr^ane. Thefe primitive cylinders ap- peared to me of the fame fize throughout the whole of the tendon in an animal, and like wife in ail the tendons. They are homogeneous cylinders^ every where uniform, neither hollow, nor formed of fmall veiicles or globules ; in a word, they are canals.

All the refearches I made to difcover whether thefe cylinders werecompofed of other fmaller parts, were totally fruitlefs, fo that I am obliged to con- fider them as non-organick, primitive folid threads^ Thefe primitive cylinders then, which compofe the tendinous fubftance in its lafl decompoiition, being many of them united together, form the primitive tendinous /^/i7> ; and it is from feveral of thefe lafl that the tendon is at length compofed. As the cellular memljrane w^hich binds together the pri- mitive tendinous cylinders yields eafily, and as at the fame time that of the primitive fafcia itfelf is tranfparent, it is eafy to diilingulfh the progrefs of the primitive tendinous threads, and this progrefs

S 2 is

26o F O N T A N A

is fo very like that of the primitive nervous cylin- ders, that it would be difficult to diflinguifh them. The tenduious threads elongate, and form undula- tions in the whole fubflance of the tendon, and the appearance of a fpiral ftrudture and of bands in the tendons, as well as in the nerves, is caufed by thefc undulations.

Fig. 3. reprefents a primitive tendinous fafcia^ which appears formed of a vaft number of primi* tive tendinous threads. Thefe threads, parallel to each other, run along the tendon, forming regular undulations, from whence, as has been faid, arifes the appearance of bands or fpires. At r, r, two of thefe threads are feen, purpofely feparated from each other with the point of a needle.

Fig. 4. reprefents another tendinous /j/v^, com- pofed of primitive threads, r, r, r, obferved in water, and flripped of their cellular membranes. The cylinders here are neither undulated nor wind->^ ing, becaufe they have been pulled out, and de- ranged from their natural fituation by the needle with which I feparated them.

My refearches into the flrudturc of the cellular membrane of the nerves, which, as we have feen, is no other than a web of very fmall, winding, tranf- parent cylinders, led me to think that the cellular membrane of the tendons iliould be of the fame nature, that is to fay, quite filled and woven with the fame cylinders. \ have in reality obferved rhem with very little difficulty, and found them of

the

ON POISONS. 261

t'ke fame fize and form as in the nervous membrane, and their progrefs to be alike in both.

Fig. <. reprefents a fmall portion of the mem- brane, or cellular web, of a primitive tendinous fafcia. It was formed of a great number of wind- ing cylinders, of which a few only are exprefled in the engraving, that they may be the better diilin- guifhed, and are indicated by the letters r, r, r, r, r, r, r. I obferved them with the fame lens with which I obferved thofe of the cellular membrane of the nerves, and the primitive tendinous threads of Fig. 4. and 5. explained above. The lizes of thefe threads of the tendon, and of the cylinders of its coat, are equal to thole of the winding cylinders of the nerves, and almoil equal to thofe of the primi- tive tendinous threads themfelves, fo that they may be all regarded as pretty alike in lize, without falling ioto any fenfible errour.

On the Tendinous part of the Diaphragm*

Fig. I. of Plate VII. reprefents a portion of the diaphragm of a rabbit, a, />, ^, r, is the fleiliy part ; ^, m^ r, r, the tendii\ous part; n, is the trunk of a nerve that enters the diaphragm, and <?, r, is a vein. What deferves attention is, that the nerve n, has all its ramifications towards the flefliy part of the diaphragm, and none towards the tendinous part. 1 have however found nerves in other ani-

S 3 maisj

262 • F O N T A N A

mals, which led towards the tendinous part ; but they had no further ramifications in their progrefs towards it ; and I have not till now obferyed in any cafe, any nervous branch which ended in the tendinous part^ as happens in the iiefhy one, where they decreafe rapidly and difappear. /, f, /, are the branches of the nerve n, 0, Oy 0, 0, are the branches of the vein a, r^ towards the iieihy part, y,y, are very fmall branches of the fame vien, run- Ding inalmofl a ftraight line along the tendinous part of the diaphragm, and forming, as is feen, a very few fmaller branches, u, u, u, u, u, u^ u, are very fmall longitudinal velTels without ramifications, which, rifing from the vien j, r, run along the tendinous part.

The tendinous fubflance is bright like filver, and tranfparent ; and its branches, even the fmalleft of them, are opake. If the fmalleft thread of a nerve were received in it, it would be eanly feen ; and this very difierent miode of ramification which the nerve aifumes in the two different parts of the dia- phragm, is as com.plete a proof that the tendons do not receive nerves, as it is certain that the mufcles do receive them. ; it is a -compiete proof that thefe two animal fubftances are perfectly different from each other ; and it proves the falfity of one ever having been, or having ever degenerated into, the other, as m.any anatomifts have believed.

The phyiical reafon why the 'nerves do not ra- mify towards the tendinous parts of the diaphragm, and why the vefTels fend very few ramifications,

and

ON POISONS. z6,^

and tliofe fcarcely perceptible^ to thefe parts^ may, I think, be principally afcribed to the fubftance of the tendons itfeif, which prefenting a greater ob- ilacie than the fieiliypart, does not allow a great and free vegetation, either to the nerves or veliels.

When the tendinous part of the diaphram is nice- ly examined, as well with the naked eye as with glafles, the ufualfmall fpots and bands are obferved in it, formed in the accuiliomed way, of undulating threads. Fig. 2, reprefents a very fmall portion of this part of the diaphram, in which, obferved with a very ftrong lens, is feen the undulated progrefs of the primitive tendinous threads.

The ramifications of the blood veffels likevv^ifede- ferve fome coniideration. The veui throws out all its principal branches towards the fielhy part of the diaphragm, or rather, its principal ramifications ; and thefe are very fmall. A vafl number however of very fine vefifels, without the ufual ramifications, and almoft parallel, run in a right line by the tendi- nous part, and pafs into the oppofite flefhy part, where they ramify, and at length lofe themfelves.

On the StruBure of the Mufcles.

My obfervations on the tendons led me to ex- amine the mufcles, or rather their elementary fi- bres. The firudure of the mufcles, when obferved, is more regular and lefs uncertain than that of the tendons, although obfervers do not agree as to all

S 4 the

264 F O N T A N A

the particulars. The learned Prochaika deferves here again a particular homage, for having fup- plied us with a fmall work, entitled, ^^ Came Muf- culari : Vindob. 1778, in which he leaves us very l)ttle to defire on this fubjedt.

This ikilful profeffor finds an appearance of whit- ifh wrinkles, on examining the mufcular fibres with a very Itrong lens, and is perfuaded that they are no other than fuperficial impreffions made by the veflels, cellular cylinders, and perhaps likewife the nerves, which furround the fiieath of the mufcular fibres themfelves. He is of opinion, that when a mufcle is boiled in water, thefe veflels and very de- licate threads ihorten, embrace the fibre here and there, and imprint on it the whitifli wrinkles or crevices.

Prochaika reprefents the appearance of thefe wrinkles by Fig. 12, of Plate IV. in his work, and this Figure is perfedlly fimilar to Figures i and 2 of Plate VI. of mine.

I obferved in breaking the mufcle by degrees, with very fharp-pointed needles, that it is at length brought into very fine threads, which no pains can divide again into lefler ones. I fhall call thefe fila- ments primitive jii^JIoy threads.

Some hundreds of thefe threads united together, form a fimple fafcia, which I fhall call primitive fej}:yfufcia. The mufcle is at length formed of a great number of thefe fafcise. , 1 examined thefe fleihy fafcise with all poflible at- tention, and with lens' of -ro- part of an inch in the

focus.

ON POISONS. 265

focus, but have never fucceeded in finding a flruc- ture altogether limilar, either to that of the tendons, or that of the nerves. The greater part of the fmall white fpots that ran tranfverfely acrofs the fafcia, were curvilinear, femicircular, uniform^ and unin- terrupted.

Fig. 65 Plate VI. reprefents four primitive ileihy fafcis, in contact with each other, and covered with their cellular membrane. Two m^ m, s, s, are, as I have faid, fpotted circularly, and in the two others, r, r, ^, J, the fpots feem in fome places to form a certain number of fmall angles, fuch as are defcrib- .ed in the Figure. This is all 1 could obferve to a

certainty.

Fig. 7 reprefents a primitive flefhy fafcia, cover- ed like the four others, v/ith cellular membrane^ but only in part. I fucceeded in railing this cel- lular membrane, as it is defcibed in the plate, atone of its extremities, and in obferving the primitive fleihy threads, and at the fame time, the fmall circu- lar fpots. The primitive flefhy threads arc folid cy- linders, equal to each other, and very perceptibly marked at equal diflances, with refemblances to fmall crevices or wrinkles. I could not perceive a true undulated progrefs in thefe threads, and the fmall curvilinear fpots of the primitive fafcia, ap- peared to me to be occafioned by the fmall indent-^ ed marks of the primitive flefliy threads, m, 0, r,c, is the part flill covered with the cellular membrane; dy e, are primitive fleihy threads, feparated from each other.

2.66 F O N T A N A

Fig. 8, reprefents a primitive llefhy fafeia, co- vered with its Iheath. After feveral attempts, I fucceeded in Gripping it entirely, as it is drawn in Fig. 9. It was compofed of a very great number of foiid homogeneous cylinders, which were inter- rupted at equal dillances, by very fmall marks or lines, which, obferved in different pofiticns, might have palTed for ftnall globules. 1 cannot decide as to their true nature, obfervation not carrying me further. Sometimes one would fuppofe thefe ap- parent globules to be fo many wrinkles, formed by the contradion of the threads themfelves.

1 obferved them, both immediately after the ani- mal's dea<h, and when they were on the point of be- cdming putrid. Fig. 9, does indeed reprefent thefe cylinders a little undulated, and fo they appear to the naked eye ; but they could not be in their real iiate, after the preparation they underwent. The let- ters, r, r, r, r, exprefs primitive ileihy threads, a little feparated from each other, and forming a re- vinion at a.

Thefe fucceffive obfervaticns forced me to allow fome difference betwixt the progrefs of the tendinous cylinders, and that of the iielhy cylinders ; the ap- pearance of fpots in the primitive flefliy fafeia^. like- wife feems a little dilTerent from that of the fpots of the tendons.

I alfo paid a particular attention to the coats and cellular membrane of the mufcles, and found them to be formed, as in the tendons, of the ufual tranf- parent winding cylinders. Fig. 10, reprefents a

fmall

ON POISONS. 267

fiiiail portion of the cellular membrane of the muf- cies, which is feen to be no other than a web of ve- ry fmall cylinders, m^ m, r, r^ fhows their pro- grefs and lize, which are exadiy the fame as iu the tendons and nerves.

Difference hetzvlxt Nervous, Tendinous, and Mufcular Suhjlances^

After all that has been faid on the ilrudure of the nerves, mufcles, and tendons, thefe three fub« llances ought readily to be diilinguifhed one from the other. It has been feen that the nerves are com- pofed of tranfparent primitive cylinders, which ap- pear to be filled with a mucous fubilance. Thefc cylinders are much larger than the primitive ileihy cylinders, and primitive tendinous cylinders, fo that it is abfolutely impoilible to confound them together. The primitive nervous fibres have ano- ther charadieriflick in their progrefs ,* they run fer- pentining and undulating, whilft the iielhy fibres tend very much to a right line.

The primitive fiefhy threads of the primitive nervous cylinders are inftantly diflinguifned, not only by their being fo very fmall, and by their pro- grefs, but likewife by their folidity. They are in no way either vellels or canals, but folid cylinders, homogeneous throughout. The apparent flrudlure, not only of the fimple primitive fiefhy thread, but

likewifq

268 F O N T A N A

likewife of the flelhy fafcia itfelf^ is befides altoge- ther different; and when we are a little accnflomed to examine them, it feems no longer poflible to be miftaken, and to confound one with the other. It is true that the primitive tendinous threads have an undulated and winding progrefs, like the primitive nervous canals, but they are much fmaller, and like the ileihy threads, are quite folid, fo that it is impoffibleto miflake them for the primitive nervous cylinders, which feem to be filled with a diflin<fl fubfiance. Neither can the flefny threads be eaiily miHaken for the tendinous threads, although both of them are folid and of equal bulk, becaufe the latter are. evidently diflinguifhed by their winding progrefs, which is not feen in the flefhy threads; and becaufe they do not alter in fize or ihape on their progrefs, in oppofition to the flelhy threads which are interrupted continually by fmall crifpa- tions and nodoiities.

Thefe charad:eriilicks being once well eflablifli- ed, I repeat that it is no longer poffible to confound thefe three animal fubflances, the nervous, the fielhy, and the tendinous, together. I have many times made the proof of this, without ever having been deceived. I em^ployed a perfon to put the fmallell imaginable particle of a nerve, a mufcle, or a tendon, at his choice, under my microfcope ; thefe particles were detached with the point of a ve- ry fine needle, from the above fubflances fwimming in water j a moment's examination enabled me to

know

V ON ]? O I S O N S. 269

know them to a certainty, and to difllnguiili to which of the three fubflances they belonged.

It would be fuperfluous to dwell on the impor- tance that the diilindiive charadterifticks I hav€ fixed on the primitive {lrud:ure of the nerves, mwf- cles, and tendons, may be of to anatomy, and to animal phyficks. It is flill doubted whether many of the parts endued with motion^ have, or have not, mufcles. No one can be ignorant of the dif- pute on the fleihy fibres of the uterus, particularly on the exiftence of the mufculus orticularis of Ruifch. When we fee an Albinus pafs this mqfcle in filence^ when fpeaking of the uterus ; a Haller who cannot find it ; and Ruifch himfelf who appears to difvaow it in his old age, we remain in fufpence on viewing the excellent refearches a great Engliih anatomiil has made into this mufcle (^a).

All the difficulty lies in knowing whether what is by fome called a mufcular fubftance in the uterus, is really fo. The exiftence of a fubflance in this vifcus is inconteftible, and this fubilance by fome is iliid to be flefhy, whilfl others openly deny it that quality, A very fmall particle examined by a good obferver in a microfcope will decide the queltion. The charaderifticks of the ilefhy fibre are too clear to be confounded with other animal fubflances. The nature of it may then be determined in a few infi:ants, and the quefiion, which to the great fcan- dal of anatomy has exiilied for half a century, may be decided.

(^) Ifunter de XJtero Gravida,

The

276 P O K ± A 1^ A

The fame may be faid of the other parts of the animal machine, and a like trial maj be made, when there is a doubt whether anj'" parti<;ular part does, or does not, receive tendinous fibres^ The ehara^erif- ticks of thefe htR are no more equivocal than the flefh)^ fibres, and a m.icrofcope may determine to a certainty whether fuch parts are tendinous or not. ■ ■

In a word, I believe the well eftabliihing the cha- rad:erilticks of the three fubftanrces, -the- iiervous^ flelhy, and tendinous, to be highly advant^gedus;; and if I had found my felf in favourable fituati(Mis,i Ihould already have made applications which would have been ufeful to the knowledge of the human bo- dy, and Ihould probably have dillipated many doubts, and terminated many qiieflions^, as to the ftrudture of many of its parts. Wherever, ' for example, there are tendinous fibres, it would not be difficult to explore them, and to afcribe to every part the tex- ture it really has. , • : -

I was defirous in tlie mean time of examining, ac- cording to the rules I have eilabliflied above, wh^t the ftru'ilure of the fmall blood-veiTels is; and in fpite of my attention and patience in the courfe of my obfervations, I have not been able till now to fee any thing that might lead me to fufpecl, that there were either nerves or mufcles in the textures oftheircoats. I do not pretend however to aiTert any thing decifive on the fubjed:, and even wifh other obfervers to bufy themfelves upon it, and to fee whether or no I have been miftaken. But they will in the mean time allow me not to admit of thole

theo-

0>f POISON S'. %*ji

theories that have a nervous or mufcular ftruc- ture, of which they fuppofe the blood veiTels to be formed, for their bafis, and which they do not fee.

Many things have been written, and mofl of them uncertain, on the ganglions. It is generally believed that they ferve to colled: the medullary part of the nerves, and to furniih an origin, as if each of them were a fmall brain, to new threads of nerves. By entering upon a fhort invefligation of the ganglions, a good obferver may eaiily know the itrudlure of thefe organs, and form a truer concep- tion of their ufes, which feem to be very important to the animal economy.

Were 1 in circumftances more favourable to t-his fpecies of obfervations, I Ihould not fail to examine all thefe parts, and Hill many others, which I am obliged, for the prefent however, to leave to the induilry of other obferver s* 1 ihall only fay two words on tendons. Anatomifts difpute whether they be or not, an elongation of fielhy fubilance, that is to fay, of the fame nature as mufcular fi-, bres. i can take upon me to fay that I have never feen a primitive fielhy thread, nor a primitive fiefhy fafcia^ become tendinous, however I have multi- plied my obfervations, particularly on the tendi- nous and mufcular parts of the diaphragm, in fmall animals. I have feen primitive fltikj fafci<e terminate as a fielhy fubftance, and have feen pri- mitive tendinous fafci^ introduce themfelves be- twixt the flefliy/^/67>, but it was not .to unite their

fub fiances-

2^2 F O N T A N A

fubftances with that of the others* In a word^ one fafcia does not begin where the other ends, but they introduce themfelves into each other, like the cogs of two wheels that fatten and rife one within the other ; the tendinous threads particu- larly, penetrate a great way amongft the mufcular ones*

On the primitive winding Cylinders of th£ Animal Bodj^ or on the Cellular Membrane^

The primitive winding cylinders I have difeo- tered in the cellular membrane of the nerveS;^ tendons, and mufcles, are of all the parts or or- gans that I know of, in the animal body, the fmalleft. They are, as has been feen, much fmaller than the fineft blood veffels, that do not allow but ' one globule of blood to pafs at a time.^ All the attempts I have made to reduce them into fmaller cylinders, have been inefFedtual, and al- though they are obferved with glaffes of the great- eil flrength, they appear very iimple, and not fur- rounded by other fmaller veiTels.

The philofopher who is not fond of hypothefes,' who admits no other ilrudlures or parts in the ani- mal body as certain, than thofe which obfervation has difcovered in it, will find no difficulty in con- iidering thefe winding cylinders, as primitive Iimple principles, not compofed of other lelTer ones. This is a datum of which obfervation de-

monilrates

ON POISDNS. 275

rlionflrates the reality, and from which we mui! fet out, to reafon fundamentally on the fuhdtions of the organical parts of a living body.

One general purpofe of thefe winding cylinders may be, if they are really veirels, to nourilh the parts in which they are found, or which are fur- rounded by them. According to this hypothefiS, they may perhaps ferve for the nutrition of the primitive Cylinders, as v/ell nertoias, as tendinous and fielhy. But there is another purpofe, ftill more noblCj and perhaps equally important^ to be afcrib- ed to them; the principal funftions of life may even depend on them : the fmalleft changes made in thefe organs^ may caufe the utmoil diforder in the animal economy.;

My experiments on poifons have fliown that they bring about the death of an animal in an un- known way, and we feem to need the difcovery of a principkj an organ in ihort^ on v/hich thefe poifons adt. Who knows but this principle, this organ, may coniiil in the winding cylinders v^e have obferved ? But what can be expeded from an infenlible fubflance^ and one on which poifons do not feem to have any adlion ?

But before we proceed farther, we mufl fee whe- ther thefe canals or cylinders are found in other parts of the animal, and whether they form a fyilem of vefTels and organs, hitherto unknown.

We firil obferved them in the external cellular membrane of the nerves, tendons, and mufcles. I have iince ihown how they rriay with eafe be found

Vol.. II. T in

274 F O N T A N A .

in all the cellular membranes of thefe organs • fo that their whole cellular fubflance is a web of wind- ing canals.

I have obferved that when the primitive nervous cylinder is covered with winding cylinders, its fize is more than double what it is when it is ilripped» A great number of thefe nervous cylinders form nerves, which are larger or fmaller, and feveral of thefe nerves ^re ufually united together, to form the very large ones. AH thefe nerves have proper cel- lular coverings and common ones, and thefe cover- ings are made of winding cylinders. If I now fup- pofe that the mafs of nerves is formed of two part s^ of winding cylinders, and of only one part of pri-' mitivc nervous cylinders, I do not think I am much ^miflaken. By applying the fame mode of reafoning to the tendons and mufcles, it will be found that the winding cylinders make up the greater part of thefe two fab fiances, becaufe the primitive ^teiidinou^ and fiefliy threads, are of the fame iize with the v^inding cylinders, and thefe encreafe their mafs by the numbeflefs windings- they m^ke round the- primitive cylinders- of thefe parts, over wdiich they heip^t'hemfelves.

Some hundreds of primitive threads, whether flefny or tendinous, form the primitive j^y^/^ ; and a great number of thefe at length form the mufcle or tendon; fo that I think 1 ihall not be led inta an errour by the belief, that out of fix parts, of j which the mufcles and tendons of an animal are , cotnpofed^, five of them are v/inding cylinders,

and-,

ON POISONS* 2

/:>

and - one only the primitive threads of thefe two fubftances.

We- already fee that -according to this^ a great '|)art of tile animal folids is compofed of winding cylinders ; it remai^$ to examine whethei- thefe cylinders are fo^iid ^ -other parts. This refearch^ which will thrbw a -great light into the knowledge "of anatditiy^ is very irripottant.

Firlt, it is natural to fuppofe, that, if thefe wind- ing cylinders are generally' found in the cellular membrane of the nerves, mufcles, and tendons^^ they ought likfewife to be found in the cellular fub-

ftatice of other parts : and as the membranes them- J. '

lelves are no other than cellular, the wdnding cy- linders liiould confequently be found in thefe mem- branes/ it would be tedious to give a detail here of my obfervations on thefe parts; I referve the doing this for another occafidn« It v/ill be fuffi-' cient to fay that I have found the whole cellulav fubilance to be formicd of winding cylinders, in whatever part of the body it is met with. 1 have found them in the membranes of the brain, in the pleura, the peritoneum^ the mefentery, the mediaf- tinum, the pericardium, the perioftium\, and the pericranium, and in the ligaments of the liver and other vifcera. The membranes of the arteries and veins are formed of thefe cylinders, and their inter- nal coats which feem fo compad, are woven w^ifh them. All the cellular fubilance, the facculi, and the veficles which contain the fat^ are a web of thefe winding cylinders. In a word, I know of no jpart in the body which has a cellular membrane.

276 F O N T A N A

and does not prefent thefe winding cylinders. 1 fhould except the membranes' of the vitreous and cryflalline humours, in which I was not able toob- ferve it ; and alfo the lamina of the tranfparent cornea, which did not prefent them to me with cer- tainty. If thefe membranes be deftitute of winding cylinders, they muft be diftinguilhed from the or- dinary cellular membrane, and are of another na- ture.

If it now be conlidered that the cellular fubftancc is found in all the organs of the animal body, and that all the folids are principally compofed of it, it will readily be concluded, that the winding cylin- ders form the greater part of thefe folids, and that all the reft is very trifling when compared with them.

The ufe of fo great a number of cylinders is without doubt of the higheft importance; but this is not the place to treat of it. The fubjedt requires new obfervations, and very many experiments, the greater part of which I have not yet made. I have indeed thought that the matter of which they feera' to be formed, is a glutinous fubftance fimilar in conliftence and colour to a gelly or a mucous mat- ter. I am fomewhat apt to fufped, that the gelati- nous matter which is drawn from the animal fub- ftance, is nothing elfe than the matter of which thefe winding cylinders are formed. But I repeat that I have not yet made a fufHcient number of experiments to determine with certainty, either their real nature, or the ufes to which they may be deftined in the living; body. It is enough for me at prefent to have Gftablilhed the exiftence^ fize, and extent of them.

REFLEQr

REFLECTIONS on the MOTIONS of THE MUSCLES,

The primitive nervous cylinder is abfolutely fim- ple^ is never found larger or fmalier in its progrefs^ and is not fubdivided into leffer branches. It appears befides to be filled with an homogeneous, tranfpa- rent, concrete, matter or fluid, which feems in dif- ferent cafes^ to form itfelf into irregular fpheroidal corpufcles, more or lefs elongated, and generally of a much fmalier fize than that of the red globules of the blood.

In animals, the nerves ramify much lefs than the arteries and veins, and their ramifications diminifh in fize much more than thofe of the blood-velTels ; obfervation has therefore eflablifhed this truth, that there is a lefs number of ramifications of nerves, in any given part of an animal whatever, a mufcle for example, than of veins and arteries ; it follows T 3 hence

27S F O N T A N A

hence, that the fpace occupied by the blood veflels mufl be much greater than that occupied by the nerves.

The primitive nervous cjlinder is about thrice as large as the primitive blood-veiTel, and this lafl is about four times as large as the primitive flefhy thread. Thus is the primitive nervous cylinder about tv/elve times the lize of the priipitiye flefhy thread, and when the primitive flefny fafci^ are at- tentively examined^ Vv^e can fcarcely fay that we ob- ferve blood- veiTels in them, and remain uncertain whether we really fee nerves in them or not ; and it is abfolutely impoilible in any circumflance, to fee either veffel or nerve proceeding to the primitive fiefliy threads. If there were any blood- vefTei or ilired of a nerve betwixt the primitive flefhy threads, thefe threads would not m.eet in contad:^ as they a^i-^ally do for their whole length ; their diflances w^ould be rendered four times greater by: the blood-veiTels, and tvx^elve times greater by the nervous cylmders. Theie would be. much more ^ilible to the microfcope, on acCQunt.of their flze ;. but vveobferve nothing of th^iT^^ The,fiMfl>y threads;, ci^ng to each other in fuch a way for their whole- length, • leaving fcarce any fpace betwixt, that., we can . fcarcely perceive the very ,fine cellular web, or ^glutinous principle, that faflens: them together,,

We^mayl think deduce from henco^ that a rnuf- cle is in the grcatefl part forrfjed of primitivte flefliy. threads, and, in the leafl of ■ priiTiitiv;e nervous cylin-

' ■ ders^.

ON POISONS. 279

ders. The blood veffels preferve a medium be- twixt rhefe two quantities.

We may likewife reafonabiy deduce, that the primitive fleihy threads are not accompanied throughout, nor environed on all fides, by blood- vefleis, and fliil iefs by nerves ; and I am almoft in- clined to think, that an entire fleihy fafcia, fcarcely receives any primitive blood- veffel, or primitive ner- vous cylinder. Hence it is fcarcely, probable, not to fay abfolutely impoffible, that every iieihy thread- can receive, either a venous canal, or a primitive nervous cylinder. Thefe feem to be the natural con- fequences of immediate obfeivation, and of the very great difproportion there is betwixt the fize of the primitive iieiliy threads, and that of the minuteil blood-velTels, and the primitive nervous cylinders.

It would be unaptly objedLcd, that the primitive flelliy threads could not vegetate, if there were not blood- veiTels to nourifh them ; that they could not contrad:, if there were not nerves throughout ; and that they would not be fenfible, if they were not .accompanied throughout by primitive nervous ca- nals. It is needlefs to remind, that to enable any part to vegetate or encreafe, it is fufficient that a fit humour be conveyed to this part; and that a hu- mour may reach a part, by other velTels than by thofe- of the blood, or by fimple tranfudation. The contradrion of the mufcles does not neceffarily lup- pofe that the nerves mufl penetrate into all the mi- nuteftpart of a mufcle, and that they ought to touch, furround, and envelope every one of its elementary

T 4 parts.

^8o F O K T A N A

parts, which could not even be combined by the or- dinary quantity of nerves. Senlibility is in the muf- cles in general, and no experiment can demonflrate that the primitive fleihy thread is fenlible, and much lefs, that it is fo in all its parts. Our fenfes are too blunt to reach fu far as this.

. The confequences v;e have jufl drawn from the primitive ftrudiure of the nerves and mufcles, not only do not favour the different hypothefes natural- ifls have imagined to explain the contraction of the ttiufcles; but likewife demonilrate that the greater part of them is abfurd. ' What however feems very clear is, that this undulated ftrudure of the primi- tive nervous cylinders, and of the fleihy threads and primitive tendons, ferves admirably well to refill very violent efforts in the machine ; thefe parts being able to bear a very great extenfion without breaking. An important queilion now prefents itfelf, w^hich is precifely occafioned by the very ftrudure of the primitive nervous cylinders. It is, to know whe- ther the nerves are irritable; that is to fay, whether they contracft when ftimulated by any fubftance, or when any of the mufcles are contracted at will. All the obfervations and experiments hitherto made by thebeft naturalifts, afTureus that the nerves are not aded on by any flimulus, that is to fay, that they do not diminiih in length, nor alter their fize, whether they are externally pricked, or whether the animal employs them in contrading the mufcles : but thefe experiments prove nothing, unlefs it be that the external co?.t of the nerves is in thefe cafes altoge-r t-her iifelefs ; they do nv)t prove that the internal

partj^

ON E O I S O N S, ^8|

parts of thefe fame nerves is motionlefs;, and that the primitive nervous cylinders are not capable of Hiortening themfelves. The external coat of th^ nerves is not fo formed as in any way to prevent an ofcillatory or contradting motion of their primi- tive canals, and the winding flrud:ure or progrefs of thefe cylinders would lead one to fufpedt the con- trary.

But it niuft be left to experiment to decide on all occafions when it can be confulted ; our reafon- ings very feldom exceed the limits of fimple con- jediure, even when they feem founded on the com-^ pleteii; analogy.

If the primitive nerv-ous cylinders change their iituation whenever the nerve is ilimulated^ the fpi- ral figure which refults from the pofition of thefe cylinders, ought neceiTarily to be more or lefs changed, and the fpaces betwixt one fpire and ano- ther, or betwixt one band and another, mufl be- pome greater or fmaller : it is at leaft certain, that ihe progrefs of the primitive nervous cylinders in a nerve cannot be deranged, without the fpires be^ ing deranged likewife. A common lens enables one to fee the fpires of the greater part of the nerves very vs^ell ; thus is the obfervation eafy, and the preparation of the parts for the experiment not at all difficult. 1 principally made my obferva- tions on the nerves of the diaphragm of fmall ani- mals, fuch as rabbits, and on the crural nerves of frogs. As foon as I had opened the animal, 1 em- ployed feme one to ftimulate the phrenick nerves

in

282 FONT A N A

in the thorax of the rabbits, and the crural nerves at their going out of the vertebrae. The diaphragm, and li-kewife the legs and feet of the frogs contracted themfelves. At this time I obferved the fpires of the nerves with fuch attention, that the fmalleil change in them could not efcape me. I examine4 the nerves of the diaphragm at their miiiuteil rami- lications, where the fpires are the moil fimple. I rcpeatedry examined the fmall nerves in frogs, that are fent to. the abdominal mufcles, and in which the fplres: are yet more vinble. But whatever diligence ♦jijd attention I bellowed on them, I never could perceive any alteration in their fpires. However violently I Simulated the nerves, and however great the Gontradion of the mufeles, i invariably found them motionlefs, and at the fame diilance from, each other as before.

Having loil the hope I had conceived, of feeing fome motion in the ipires of the nerves, I pro- ceeded to the iail experiment I had to make on tbefe organs, which was to examine in an im.mediate way, their primitive nervous cylinders themielves,_ This obfervation coil me a great deal of pains, and I cannot flatter myfelf with having fo nicely obfer- ved the abfolute immobility of thefe threads, as I did that of the fpires. But what 1 obferved in them did not indicate motion, and as they have always appeared to me at reil, I iliall invariably believe, till fome one ihall be more fuccefsful than myfelf, that thefe primitive nervous cylinders are in that fiate, when the nerves are ilimulated, and the muf-

4 cleS

p N P p I S O. N' S. 28

J

des contrad: ; and llliall believe it the more readily- as I cannot conceive how the cylinders can undergo afeniible change and vary their fituation^ v/hiift the fpires or bands remain quite motionlefs.

This lingular ilrudure of the nerves, and the re- gular progrefs of the primitive nervous cylinders^ which feemed to promife fome frelli difcovery as to mufcular motion, and fome new ufe of the nerves themfelves, leave us as much in the dark as before, and only ferveto diminiih the number of hypothefes that have been imagined to explain the contraction of the mufcles : fo true is it that before we can at- tain a knowledge of the truth, we mufl pafs through all the errours that furround it. The fyilem of the vibrations of nervous threads, for example, feems no longer capable of being fupported, after my ob- fervations. I fpeak of thofe vibrations that are ca- pable of being perceived by the microfcope, and I give up to metaphyficians the privilege of inventing invilible ones.

The pretended very great velocity of the nervous fluid feems to be contradicted by that inert, vifcous fluid or matter with which the primitive nervous cylinders appear filled. The conliderable iize of the nervous cylinders andblood-veiTels, when com- pared with the primitive flefhy threads, leads me to fufped: that thefe threads are not put in motion, in an immediate way however, either by the blood, or by the nerves. In a word, we ar& not only ignorant of mmfcular motion, but we cannot even imagine

t3'

anv

284 ' F O N T .A N A

any thing to explain it, and we fhall apparently be driven to have recourfe to fome other principle : that principle, if it be not common eledricity, may be fomething however very analogous to it. The ele&ical gymnotus and the torpedo, if they do not render the thing probable, make it at leail pofiible, s^nd this principle may be believed to follow the mofl cornmon laws of ele&icity. It may likewife be more modified in the nerves than in the torpedo and gymnotus. The nerves Ihopld be the organs defined to condud: this fluid, and perhaps alfo to excite it : but here every thing yet remains to be done, We muft firft aiTure ourfelves by certain ex- periments, whether there is really an electrical prin- ciple in the contracting mufcles ; we mult determine the laws that this fluid obferves in the animal body; and after all it will yet remain to be known what it is that excites this principle, and how it i^ excited. How many things are left in an uncertain llate^ to pofterity !

Microfcopical Err ours ; and Confequences deduced fron^ Microfcopical Obfervaiions,

Such have been my obfervations on tlie ftrudture of the nerves, tendons, and cellular membrane, and my conjediures on fome of the ufes of thefe parts, I have fo contrived as to give^ to my principal ob* fervatioiis 'at l6aft, all poffible certainty. I have en- deavoured

OK POISONS. 2?5

deavoured to render them as fimple as poflible, and have eftablifhed them by dired and diverfified expe- riments.

There is a great difference betwixt a microfcopi- eal obfervation, and a microfcopical experiment. The firil is no other than a fimple reprefentation of .an objedt, in the eircum^ances in which we obferve . it ; the fecond is the analyfis of the reprefentation of this objedfe, by which we are aifured that an ob- jed: of fuch a nature, and not of any other, does ac- tually exift. In the firft cafe, we fimply feel an im- predion of the light, or view at moil nothing more than an image ; in the fecond^ we judge of the na- ture of an object by the image it prefents to ns. Every one is capable of diftinguifning with the mi- crofcope ; but few know how to judge of the things they fee. Extenfiveknowdedge, and the greateil faga- city, are requifite to an obferver, to conceive the ex- periments that necelTarily condud: to a true ac- quaintance with a real objed:.

There is a fpecies of errour into which even the moft pradifed obfervers may eaiily fall. All our opinions on bodies are no more than fimple compa- rifons ; that is to fay, we judge that fuch a body, feen with themicrofcope, is of fuch a nature, and not of any other, becaufe it prefents itfelf to us under the fame forms or appearances, under which we are accuftomed to fee fome objed:, when we ex- amine it with a microfcope, that is already known. It is morally im*poirible that two images ihould be every way alike, and that the external objedls

thi^V

^^6 F O N T A N A

they reprefent ihould be every way different. An obferver of penetration, if two objects are not Si- milar, will at length find fome difference in the ap- pearance of them, and will avoid an errour* But how much induftry and attention mull he not ne- celfarily employ ? This however is not the mofl dangerous ihoal, although very enlightened ob^ fervers fometimes run aground upon it. It fome- times happens that we fee a certain objedl with a microfcope, which feems to agree i^ every refped: with the bodies we are befl acquainted with, parti- cularly when the ftrudlure of thefe bodies is not very common. It then feems impoflible to us that an image can have fo lingular and perfect an agree- m.ent with objed:s that we know, and that the objedl which furnilhes it can be notwithftanding of a per- fedily different nature ; it is not impoffible howe- ver but that this may happen. When, afterwards^ the images that are reprefented are irregular, and thefe irregularities are fomany Gonfequences refult- ing from fhe objed: v/hich we figure to ourfelves to ex ill, we have not a moment's doubt^ and yet m.ay Hill be deceived.

To prevent the fpringing up of thefe errours , it is abfolutely necelTary to analyfe the obfervation it- felf ; that is to fay, to make a microfcopical expe- riment capable of alTuring us, that the objed: is in reality fuch as the microfcope has figured it to us». This is the moll difiicuit part of the undertakings und this is what makes a difference betwixt obfer-

vatiot^

ON POISONS. 187

vatlon and obfervation, betwixt obferver and ob* ferver.

A fimple bare obfervatlon does not admit a full confidence, even although it be made by a cele brated obferver, becaufe it tacitly fuppofes that there is a necelTary and excluiive agreement betwixt the image reprefentcd by the microfcope, and the. real exterior objed: ; which is not always the cafe. The image reprefented by the microfcope may agree wdth feveral obje6:s at the fame timie, and it belongs to the induftrious obferver to determine which is the real exteriour objed: it reprefents and corref- ponds with. It is then not fufficient to fay, I have feen fo and fo. The circumftances muft be deter- mined, and the obfervatlon varied a thoufand diife- rent ways ; it muil in Ihort be analyfed, and the ex- periments rendered -deciiive.

Of all microfcopical obfervations, I knaw' of no one that can eafier lead the moil confummate and penetrating obferver into an errour, than the exter- nal ftrudure of the nerves, in all of which it feems impoffible for us not to dlilingullh, and that very conflvantly, a fpiral form of the utmoft regularity. The more we obferve them, whether they be large or fmall, limple or compofed ; whether w^e exa- mine their principal trunks, or their leall viiible branches ; we remain more and more perfuaded of theirhaving a conftant fpiral ftrudure. Their very irregularities ferve as proofs that they are all of this form, rather than they tend to undeceive us.

They

lS8 F O N *? A N A

They not only conciliate themfelves to this flrnc^ ture, but beome fo many luminous confequences of it.

The ftru(9:ure of the nerves I have examined,- tends greatly to a doubt, even of thofe obfervations that appear the moil conitant and certain, and Ihould at once infpire us with moderation and mif- truft. A haughty and confident tone only becomes an ordinary obferver, quite ignorant of the innu- merable circumilantes which may deceive him, and is frequently the character of a vifionary, who is more eloquent than judicious ; of a learned man who loves rather to divine nature in his ftudy, than to confult her where Ihe is ; or rather, of one who is fond of fubilituting dreams and vilions, to truths and matters of fadt. A fingle experiment, one lonely obfervation, has often reduced to vapour, whole libraries of fuch philofophical romances ; and to the ihame of our age be it faid, they are ilill mul- tiplied, and perfons are found who are fond of lof- ing their time in reading theni.

No part of what I havejuft nowobferved can be applied to the celebrated Dr. Monro of Edinburgh'.- He has not fought to divine the nature of the nerves, but has examined into it ; neither has he invented vain hypothefes, but has confulted nature herfelf. If he has been notwithflanding millaken,' it can only be obferved, that errour is more accef- fible than truth. I'ruth is fimple, errour is in- finite ; or rather, if truth exprefTes itfelf by unity^ efrour is capable of exgreffing itfelf by infinity, or

at

ON POISONS. 28^

at leaft in (o extenfive a way as nearly to approach it. It is certain, in relation to us, that errour af- fumes all the appearances of truth, and may feduce us a thoufand different ways. To be fatisfied of this, it will be fufficient to read the hiilory of hu- man errours. The greatefl philofophers have not been exempt from them, and the mofi: enlightened nations have fallen into errours that have conti- nued as long as themfelves.

The efforts then that man makes to come at the truth, are a kind of game of hazard, in which the probability of falling into an errour is very great, and that of attaining at a truth very fmall. Thofe who arrive the lateff are leaft fubjedt to err, iince they profit by the errours of others, by finding the number of cafes that lead to them diminiihed. Hence arifes the impoffibility of a work, comp- lete, and original in all its parts, being produced by one man, in a fingle age.

I hope the enlightened reader will pardon me this fmall digrefiion on microfcopical errours, and that he will look upon it as a kind of apology for my work itfelf, which, whatever care I have taken to bellow the attention of which I am capable, and which my circumftances have permitted me, on my obfervations, I do not think free from human imperfedions. And where is the obferver who can- ever affure himfeli of having fcen '"very thing, and •if I may fo exprefs myfelf, of having exhaufted nature, in the fi.rit trials he may have made, on fo many fmall and diilind: parts of the animal body !

Vol. II. U After

290 F O N T A N A

After a century of obfervatlons made on the blood by fo many good obfervers, from Lewenhoeck down^ to Father della Torre, we ftill feem ignorant of the figure, compofition, fize, and llrudiure of the corpufcles that give a red colour to this fluid : this will be feen in my microfcopical cbfervations, when I determine, imperfect as they are, to make them publick. It will now be fufficient to excite the attention of naturalifls on thefe fubjed:s, and to give a neceflary impulfe to the moil Ikilful obfer- vers, to the end that they may beflow their in- duilry on a fubjed: fo important to the under- flanding the mechanifm of the anim.al machine. When I fliall myfelf return to thefe matters, with a mind tranquillized and refrefhed, I may add many important things, that may have efcaped mc the firfl time; and m.ay corredt others which I now think have been well obferved. The true merit of a naturalift is in proportion to the number of dif- coveries he has m^ade, and to the dlfHculty and im- portance of them. Man is liable to errours, and they fhould therefore be pardoned him. They muft be confidered, to adopt the language of geo- metricians, as quantitates evanefcentes^ in comparifon to the difcoveries ; when thefe lafl: are many, ufe- ful, and original. Dices enimy (fays the great Haller) cum fide autorem ejfe, cum quo naturam fa- plus confentire videbis, &c. But when thefe difco- veries are not found in a book, errour entirely dif- credits the work, and its authour. The leaft blameabie is the man who copies truths already

publiihed^

ON POISONS. 291

publiihed;, without adding errours to them ; but his name will not be handed to poilerity, becaufe it will be indebted to him for nothing new, which may ferve to recall the recollediion of him.

Nothing but ignorance and envy can pollibly confound the merits of thefe two claiTes of writers, and unjuftly attribute to one, what the other alon^ is deferving of !

Obfervations on the Hairs, Epidermis, Nails, Bones^ and Fat,

The learned Edinburgh profeffor, after having examined the parts of animals that are moil com- pofed and moft interefting, thofe on which we have remarked above, extends his obfervations to many Other parts, lefs important if you pleafe, but which on that account are not better known : fuch as the nails, hairs, epidermis, &c.

He finds nervous fpires likewife in thefe parts, or pretends rather that they are compofed of ner- vous cylinders, although he agrees befides, that their nervous fubilance is not fenfibie* that is to fay, that the nerves woven in them are not organs of fenfation, as they are in general in all the other parts of the animal body. The opinion of Dr. Monro is by no means abfurd, although it may be falfe on the iide> of obfervation ; becaufe it is cer- tain that manp.€f the parts which are fenfible, and w\ U 2 provided

292

F O N T A N A

provided with nerves^ harden, offify, and lofc their fenfibility. But does obfervation clearly de- monftrate that all theie parts have been compofed of nerves ?

Dr. Monro affures us that thefe organical parts are woven with cylinders entirely fimilar to thofe of which he believes the nerves to be compofed. This refemblance can only have a relation to the iize and refpe^^tive figures of the part, fo that the confequence he wifhes to deduce from it, is neither a demonllrated, nor an eflablilhed, truth. But though it fliould even be proved that all thefe parts are compofed of v/inding cylinders, in every refpedt like thofe that furround the primitive nervous cylin- der, it does not on that account follow, that they mud be compofed of nerves, nor that they muft ne- ceiTarily accompany the nerves in thefe parts; fince we have feen above that the cylinders which Ter- pentine and run along the nerves, although they form the coats of nerves, are not lb in themfelves* The cellular fubilance in the body is quite woven with thefe cylinders, and is neverthelefs not com- pofed of nerves.

But this does not render the Dodlor's obfervation unworthy attention. If all the parts in the body had the fame Urucfture, If they were all compofed of winding cylinders, and if thefe cylinders were in ail of them of the fame Iize, the knowing that there is a general primitive texture common to all the folid parts of the body, would however bean excellent difcQverv,

Let

ON POISON S. 2^J^

Let me examine then the reality of this particu- lar, and in the courfe of my obfervations, pay as fcrupulous an attention as I can to thefe fmaii.boclies, which can fcarcely be dlfiinguiiiicd with the llrongeil glalTes.

My firft obfervations relate to hairs. I iball 6nly mention a few of the principal of them ; as many as are necelTary to give a general idea. I took a hair, and cleanfed it feveral times by palling it flightly acrofs a piece of fine linen moiftencd with water ; I then examined it with lens' of diiferent llrengths, employing fome that magnified 400 times, and fo upwards to 700, and have invariably feen the fame ftrui^ture, and the fame compolition. Fig. I. Plate I. rcprefents an end of an hair, in which, towards its axis at a, a, I obferved a dark fpot, which was interrupted towards the middle, of its length. All the reft of the hair was of the colour of tranfparent amiber. It appeared to be woven, and formed, or covered, with fmall inter- rupted cylinders, winding in the manner of intef^ tines. Among thefe cylinders, there were here and there very fmall globules, the diameters of which did not exceed thofe of the cylinders themfelves, and thefe globules were in feveral places iituated betwixt the intervals of them. The figure men- tioned above reprefents all thi-; very clearly.

I bruifed the hair m, m, towards one of its ex- tremities, and it feemed to me to be formed of fe- veral irregular rugged trunks, compofed of groups, or bundles, of very fmall winding cylinders. Fig.

U 3 2. repre-

294 E O N T A N A

2. reprefents one of thefe trunks, which I bruifed more than I had done before. I found it as it is feen in the figure, that is to fay, formed of winding cylinders, with many globules or round bodies, difperled over them.

Fig, 3. reprefents a fmall portion of the hair of Fig. 2. feparated with the point of a needie ; in it are feen feyeral globules detached from the wind- ing cylinders.

Fig. 4. Ihows another fmall portion of the hair of Fig. 2. Vx^hich is pretty much like the other. How- ever v/hen 1 looked at it after 1 had wetted it well with water, it was become like an irregular tranfparent pellicle, in which there fcarcely remain- ed any traces of globules or winding cylinders ; but after I had left it to dry, it foon recovered its firfl fhape, appearing as it does in Fig. 4.

On the Tr.anfpiratioiu

The learned Father della Torre, who has bufied him.felf fo much in obferving the minuted parts of the anim.al body with very flrong lens', affures us of his having difcovered that wx tranfpire through the epidermis, an immenfe quantity of fmall, tranfparent, diiTerently fnapcd lamina. Thefe iamdna heaped fome over the others, compofe the fcales of the cuticule, which he fays is interwoven with iymphatick veflels. Laftly, he adds, that

thefe

ON POISONS, 295

/

thefe fmall laminse are even fcen with the naked eye, in the vifcous humour that covers the ildn of eels.

In imitation of Father della Torre, I wafhed one of my fingers well in feveral v/aters, and having re- _peatcdly dried it, applied it to a glafs, keeping it there for fome time, till the gla^s became foiled with it. On making ufe of a ilrong lens, which magnified upwards of 700 times, I could diftinguiili nothing befides very fmall tranfparent globules, which neither dried nor difappeared, as aqueous vapours do, but continued the fame on the glafs. Although there were feveral that touched each other, they did not unite their fubflances, to form larger ones. They were all of the fam.e fize and equally round, as is feen in Fig. 6. which induces me to believe that they are not a pure aqueous vapour, but rather a grofs oily fubflance. They are about four times fmaller in diameter than the red globules of blood. Fig. 7. reprefents the fize of a globule of blood, feen with the fame lens as the globules of Fig. 6.

I repeated thefe experiments a great many times, on the tranfpiradon of the epidermis of many other parts, and could only obferve the globules of which I have fpoken.

On the Gluten of Eels,

Being defirous of examining the gluten of the fkin of ^els, I had feveral brought me of different fizes,

U 4 and

296 F O N T A N A

and found, after taking the gluten in a very fmall quantity, and diluting it a little in water, that it was formed of uniform irregular bladders, filled with very minute fpheriodal corpufcles, as they are defcribed by Fig. 8.

I fufFered them to dry on the glafs, and they then appeared as they are feen in Fig. 9, that is to fay, more irregular than before, with large tranfparent edges all round them, with irregular corpufcles feat- tered in different parts within.

I broke two or three of thefe bladders or veficles, and a great number of very fmall corpufcles poured from them, as is feen in Fig. 11.

The veficle ^, of Fig. 10, reprefents one of the veficles of Fig. 9, in which an oviform body is ob- ferved, with a fpot in its middle. At its fide is placed a globule of blood, r, by way of comparing their re- lative fizes.

On the Epdermts.

After having repeatedly wafhed one of my fingers with great care, I detached from the epidermis feverai very fine lamina, which had fcarccly a fenfi- ble thicknefs, with a razor. Fig. 1 2, of Plate VIIL reprefc.ts one of thefe fragments examined with a very flrong lens. It appeared to be a web of winding cylinders v/hich approached each other, and retreat- ed, with great order and regularity : very fmall glo- bules were here and there diflinguiihed in it, I now

covered

ON POISONS, 297

covered one of thefe laminae with water, in which flate it appeared more tranfparent, and the cylinders and globules were feen more diftindlly than before. I employed glafles which magnified 70c times in dia- meter, but could perceive nothing more. Neither hole nor porofity could be diftinguifhed with the mi- crofcope, fo that I can venture to fay, that thofe who believe they have feen pores in the epidermis, are abfolutely deceived. Lewenhoeck was the firfl to lead other obfervers into this errour. Not that I wifh to affert that there really are none, I only fay that they are not obferved with the microfcope. It is very probable that the lymphatick velTels which Father della Torre fays he obferved in the epidermis, in the forni of net-work, are no other than my winding cylinders ; and I think them badly defcrib- ed in Fig. 7, of Plate XII. of his work, and that they do not form a net-work, as he wilhcs to believe*

On the Nails,

I detached a very fine lamina from one of my nails, with a razor, and on examining it with very ftrong lens', found it to be formed of the ufjal winding cylinders. They appeared here however a little clofer than ufual, and perhaps fomewhat fmaller. I found the ufual globules fcattered amongft them. Fig. 14. reprefents a fmall portion of a nail, which I examined. I then CQvered another portion with v/ater, and

obferved

298 F O N T A N A

obferved it in this ftate. It feemed to me that the -winding cylinders v/cre diminifhed in number, and were in fome meafure ftralghtened. Every thing ao- peared more tranfparent and homogeneous, as is re^ prefented by Fig. 15.

On the Bones and 'Teeth.

The very bones, and the enamel of the teeth it- felf> are compofed of the ufual winding cylinders. I have not thought it neceflary to defcribe them par- ticularly by figures. The only difference I obferv- ed was, that the winding cylinders which compofe the enamel of the teeth, are Ihorter and better united together.

On the Fat.

I wiflied likewife to examine the fat, and obferv- ed that of feveral animals in its natural ftate. I found betwixt the laminae of the cellular membrane an infinite number of fmall bags or bladders, which fiiffered in fize in different animals. Thefe veficles were filled with fat, or with an oily humour, either more or lefs concrete, or quite liquid. The vefi^ cles were heaped fome over the others, and covered and furrounded on all fides with winding cylinders, as is ktvi in Fig. 19, of Plate VIII. By the means of warm water, and a fe>v pricks of a needle, I conr

trived

ON POISONS. 299

trived to feparate from thefe veficles feveral of the winding cylinders, and I then perceived a bladder formed by a very fubtile, tranfparent, homogeneous, humour, filled with fat, as at Fig. 20. I could not obferve any thing fattened to it, nor any excretory or fecretory veffels, whatever attention I. paid to iu I compreiTed fome of thefe veficles belonging to fifhes, filled with oil, and obferved in thefe cafes, that the oily fubftance tranfudes on all fides, and regularly, through the fides of the veficle.

The fat of different animals, as well with warm blood as with cold, which I examined, appears to me to be feated in round bags or bladders, larger or fmaller, and more or lefs regularly fliaped, fituated in the cavities which the lamina of the cellular membrane leave betwixt them. I will not deny but that a quantity of the fat, not enclofed in the bags, but loofe, may be found betwixt thefe lamina. I only mention what I have obferved repeatedly in feveral animals. This obfervation has frequently furprized me, becaufe I knew it to be quite contrary to the re- ceived opinion, Thus I cannot determine whether the veficles of the fat are naturally defi:itute of par- ticular conduits intended for receiving it, and tranf- mitdng it elfewhere, according to particular cir- cumfi:ances and exigencies; I only remark, that al- though I have fought them very attentively, I have not yet been able to fee them. If it be true that thefe conduits do not exift, the veficles muft be fup- pofed to abforb and rejedt this oily matter, by means Qf porofities in the pellicles. This feems confirmed

by

3CO F O N T A N A

by the expmment on tranfudation I have related above.

On Ivory,

I feparated a fine fcale of Ivory, which had been previoully well polifhed, with a Iharp knife. I ob- ferved it in water in a refradled light, and in the fame light I viewed it dry. In the lad inftance it feemed to me far lefs tranfparent than in the water, but equally organized. Fig. 21, of Plate VIII. re- prefents this fcale or lamina, in which the ufual wind- ing threads are dillinguifhed.

On Sponges,

Curiofity led me to examine with fome attention, the fubftance of which fponges are formed. They are believed to be the work of animals. Fig. i, of Plate X. reprefents a branch of this fubftance. I viewed it in an obfcure, and in a refraded light. It feemed iikewife provided with the ufual winding threads, and was hollow in the middle.

This is all I have been hitherto able to obferve of the ftrudure of the animal body. I confefs that a great deal remains to be done, and am not altogether fatisficd v/ith the obfervations I have made. I flatter myfelf that at a future time I may be able to clear

up

ON POISONS, 301

up many doubts that ftill remain. The firft ad- vances are however made, and thefe are always the moft painful; when the pafTage is once cleared, it is no longer fo difficult to perceive the courfe we ought to take, and to avoid the precipices that may lie in our way.

It feems to me very likely that the primitive cylinders are abfolutely no other than what Dr. Monro calls nerves, and which he believes to be truly fo. He finds them indeed of go^oo of an inch' in thicknefs, whilft they appeared to me to be of ^_4,__, But as this relates to a very minute body, it is not impoffible but that the fame object may be judged i larger or fmaller by two different obfervers. Father della Torre, and Jacques Jurin, differ from each other, as twenty-feven to one, in determining the fize of the globules of blood.

The mlflake of the celebrated profelTor of Edin- burgh feems to me to confifl in his having taken thefe winding cylinders for the nerves themfelves, whilft they are only the coats or fheaths of them. They are common to the mufcles, tendons, and vifcera; and laftly, to the cellular membrane, with which all the organical parts of animals are woven or enveloped. They are diflinguifhed in the epi^ dermis, in hairs, in the nails, in the bones, and in the veficles of the fat 3 they are almoft uniform every where, both in their progrefs and fize, fo that I find no difficulty in believing that they are of the fame nature and quality in all the parts of a living body, and that they tend to the fame ends,

and

:02 F O N T A N A

and have the fame ufes s it mufl however be ob- ferved, that they may harden more or lefs, accord- ing to accidental circumflances, above all in the different organs, and different flates^ of the animal

n:iachinc»

iDn Vegetable Suhftances^

Dr. Monro is not content with examining all the parts of the body, but carries his refearches to ve- getable fubftances themfelves. He finds them to be formed of winding cylinders, exadly fimilar to thofe he obferved in animals, and of which he fuppofed the nerves to be compofed.

1 fhall relate in a few words fome of the very many obfervations I made on plants; and think they will be fufEcient to determine us ia what we ought to credit on the fubjed.

When in London, I examined the famous moving plant called hedyjarum movenSy and fought the in- terior mechanifm of that regular perpetual mo- tion which diftinguifhes it from all other plants, ^nd brings its nature fo near to that of animals^ Although I found nothing fatisfadory as to the objedl of my curiofity, I did not meet with any difficulty in difcovering canals or cylinders, and that principally in the flalks of the leaves, which feemed to be compofed of fpires or bands, as they arc defcribed in Fig. 13^ of Plate X. But I

foor>

ON P O I S O !4 S, 3OJ

foon perceived thefe to be veffeis formed of a fingf^ thread, which turned round a common centre, and^ doling on all iides, formed the coat of the large vei% fel itfelf. I fucceeded in unfolding great leDgthf of thefe, and then knew them to be the pipe§ (trachees) of plants, known before my time. The fpires or bands are here real, inftead of which the-/ are in the nerves only apparent, although in botJi they appear perfedily alike : fo true is it that ana^ logy is very fubjed: to lead us into errours/

Fig. 14. of Plate X. reprefents the pipe partif unfolded. The threads of which it is formed ^r§ tranfparent in their length, and their edges are p^s- fcure in fuch a way, that by rneeti.ng each otijef they form dark bands.

There is however in plants, another ilrudiur^ 'of parts ; a more general organization. This organic zation feems to compofe the. greater proportion <g|' their mafs, and is perfediy analogous to the windip ing cylinders we.have obferved in lb many p^art§ of the animal machine.

Fig. 15. of Plate X. reprefents a fmall h^gmmt of a rofe leaf, partly ilripped and torn, with tk§ point of a knife. The ufual globules and -winding threads are obferved in it. -

Fig. 2. of Plate X. reprefents a very fmail Mf of elaftick refni, in vv'hich are feen the v^ia4i?ig threads.

Fig. 2 7. of Plate VIIL. reprefents a cotton thre-M obfcryed dry.

4

304 P O N T A N A

The furface of the cotton thread feems inters fperfed as ufual with fmall cylmders. Fig. 23. of the fame plate iliows two of thefe '' cotton threads put in water : there are fewer of thefe winding cylinders on their furface, they are lefs regular, and feem to penetrate into the inner part of the threads.

Fig. iz, of Plate X. is a fragment of amber, which, like all other bodies, feems covered, with winding cylinders.

On Foffils,

Dr. Monro's obfervations on foilils are very lin- gular, and have the air of a true paradox. He be- lieves them to be all formed of winding cylinders. Earths, falts, metals, he finds them all made of cylinders, and even difcovers them in gold coin $ in guineas. He brings nothing but obfervations to fupport his opinion, and obfervations ought to be combated or confirm.ed by obfervations, and not by words.

I examined feveral of thefe Jubftances, and fhall only mention a few of them, intending to treat of them more at length in my microfcopical ohferva- tionSy when I fhall give my fentiments on this obr fcure matter, which I prefume will long divide the opinions of obfervers. Nothing lefs than the fee- ing the fmalleft conflituent parts of bodies is necef- fary to know whether there is an organical, fimple,

3 ^ole>

ON POISONS, 305

fole, primitive llrudture, common to animals, to vegetables, and to foiiils. Here fimple obfervation is not fufEcient, and it does not avail much to be Ikilled in the microfcope. The apparent objedl does not diftinguilli itfelf from the real one. Not to be deceived, obfervations muft be analyzed, and experiments made ; but the road in both is long and painful, and we do not always fee how we arq to fall into it.

I began my obfer^^ations by examining earths and marbles. Fig. 7, of Plate IX. reprefents feveral grains of calcined magnefia, which I obferved both wet and dry in a refradted light. They were in a greater or lefs degree of a cylindrical Ihape, and rounded at their extremities. The ufual winding threads were likewife very diftin6lly obferved in them. When in water every thing was very tranf- parent.

Fig. 9, of Plate IX. reprefents two atoms of white marble obferved dry. The ufual winding threads were likewife feen here.

Fig. 10, of Plate IX. reprefents an atom of hea- vy fpar, which I obferved in a refradled light. Nothing was difcernible beiides the winding threads, which were very regular.

Fig. II, of Plate IX, reprefents an atomof phof- phorick fpar, which difplays in every part of it t}\^ ufual winding threads.

F^g' 3^ of Plate X. reprefents an atom of com- mon fait. The winding threads^ are found in it, but not fo abundantly as elfewhere. Vol. 11. X On

306 t^ O N T A H A

On Gold.

From earths I proceeded to metals. I drew but. with the wire-drawing iron, a cylinder of very- pure gold, and after having fcraped and poliihed it well, I obferved it breadthwife. It appeared quite covered with winding threads, as is defcribed in Fig. I, of Plate IX. Fig. 2, of the fame Plate, is the fame cylinder obferved longitudinally. I ex- amined it both ways in a refledled light.

Fig. 3, of Plate IX. is a fmall piece of gold leaf. It appeared to be woven with iimple winding threads. I viewed it both wet and dry.

From gold I proceeded to the examination of iilver. The four fmall objed:s of Fig. 4. Plate IX* are atoms of very pure Iilver filings. They very much refembled hairs. In a refledted light the ufual winding threads were feen in them ; but in a re- fracted light all was obfcure, except at the very ex- tremities, where the winding threads likewifeihowed jhemfelves.

I examined a very thin plate of lead in a refledled light, and obferved the ufual winding threads, as they are feen in Fig. 10, of Plate X.

Brafs, likewife, in a refledied light, difcovered thefe winding threads, as they are reprefented by Fig. II, of Plate X*

Tin, obferved in a refleaed light, likewife fhowed

thefe

ON POISONS. 307

thefe winding threads. Fig. 7, of Plate X. is a fmall fragment of tin obferved in this way.

Antimony, as is feen in Fig. 8, of Plate X. has thefe winding threads. It was obferved dry, and in a refradled light.

Fig. 9, of Plate X. reprefents an atom of co- balt, in which are obferved the winding threads.

Fig. 6, of Plate IX. reprefents an atom of zinc, obferved dry, and in a reflected light ; it has wind- ing threads as ufual.

Fig. 8, reprefents an atom of bifmuth obferved dry in a refieded light ; the ufual threads are diflin- guilhed in it.

Fig. 12, fhows an atom of nikel, which, obferved wet, had the winding threads.

I pafsover in filence a great many other obferva- tions on foffils, which all agree with thofe we have hitherto feen, fo that it feems a truth eftablilhed by obfervation, that all bodies, viewed with very llfong lens', difplay the fame form^^or appearance,.

This is not the place to determine what is real, and what is only apparent. Simple obfervations are not fufficieht to decide with certainty. There is need of a very nice analyfis of all the circum- ftances ; it is neceiTary to prepare the fubilances for obfervation ; in a word, experiments are want- ed. I wilh to avoid the giving my opinion on this matter, I cannot do it with the brevity that is re- quiiite, and it will be thefubjedl of another v/ork. In the jnean time I ftiall be very happy to knov/ the

X z dif-

2o8 F O N T A N A

different opinions of obfervers on this fubje6l. The. mofl fkilful will be the laft to determine ; thofe who are pretty much fo will not find any great difficulty ; and the novices, and all thofe who do not obferve at all, will decide at once.

To retard a little at leafl, the judgements of all of them, I think it proper to fubjoin as briefly as I can two important particulars. I let fall into a bafin of cold water fome drops of melted filver. I afterwards examined feveral of the fmalleft of them, and inflead of finding the ufual winding threads, they appeared to me to be formed of fmall fhining grains, embof- fed at feveral parts of them. Fig. 4. Plate X. re- prefents a corpufcle of filver in which fome of thQ winding threads are however feen fcattered. The other parts feemed formed of unequal globules. I viewed it in a reflected light.

Fig. 5. of Plate X. reprefents another fmall bit of filver in which the very fmall fliining corpufcles are feen, without any winding threads. I examined it in a refledted light.

Fig. 6. of Plate X. is another fmall portion of filver, examined in a refradted light. It feemed for- med of points, pyramids, and very fmall diamonds, and I could obferve no winding threads in it. Thefe diflerent flrudtures in the fame body engaged me to try a few frefh experiments.

I fcratched, with the point of a needle, a fmall bit of talc, which was tranfparent and homogeneous throughout. I examined it with the lens, and it appeared to me in the way it is defcribed in Fig. 16.

of

ON POISONS. 309

of Plate VIII. There was a ridge in the middle of it, with winding threads, and globules. The threads did not vary much from thofe 1 had obferved before. I wet it with water, and poliihed it with linen, but it iliil remained in the fame ftate.

Upon this I fufped:ed, that probably the fimple contadl of very minute round bodies was capable of caufing this appearance of winding threads. In confequence of this fufpicion, I examined dry hair- powder, but could obferve nothing in fupport of it. Although the globules touched each other in feveral parts, they were very diftind: from each other, as is teprefented in Fig. 18. but fcarcely had I w^et them a little, when I obferved in fome places, continued, longitudinal, homogeneous, bodies, tranfparent throughout, as appears in Fig. 17. of Plate VIII. It is true that thefe winding threads were very few in number (a), when compared with the globules which furrounded them, and that they were fcatter- ed here and there without that regularity and paralel- Jifm which is fo conftantly obferved in other bodies. But we learn at the fame time by this obfervation, and by this experiment, that water is capable of fo infi- nuating itfelf and fettling betwixt the globules, that in certain inftances it imitates an homogeneous, tranf- parent, uninterrupted, thread, or cylinder.

I repeat, that good obfervers will be very fiOw in pronouncing any thing in a decided way ; but it is

(a) More of thefe threads are exprefled in the engraving of the above figure, than what I really obferved.

X 3 ro-

2IO F O N T A N A

proper at the fame time that obfervations fhould be made and varied in all poffible manners. Ob:erva- tions alone may fupply us with certain intelligences, after they have been well analyzed, and all the cir- cumftances of them well known.

A Letter

g

A Letter addrejfed to Mr, Adolphus Murray^ a ce- lebrated Profejfor of Anatomy at Upfal, in the Tear 1778,

X ENCLOSE you three defigns marked i^ 2, 3> (^), which I thought fufEcient to bring to your recollection the idea of the new canal I have dif- covered in the eye, and which I had the pleafure to ihow you when you paiTed through Florence. ^Twas on this occafion that I had the fatisfadtion of l?:nowing you, and of being favoured with your agreeable friendfhip.

To fo enlightened an anatomiil as yourfelf, it will be fufEcient to limply point out the priDcipal parts ; every thing elfe would be quite fuperflu- ous.

The three figures 8, 9, 10, (Plate VII.) exprefs the three principal fedions in the eye of an ox,

(«) Thefe are the three numbers annexed to the drawing fent to Mr. Murray ; but to preferve the order of the plates in this work, I have employed in their place. Figures 8,9, lo,

X4 which

212 FONTANA

which I fhowed yen when you was at Florence. I ftiall not mention to you the other fedtions, lince I confider thefe three as the moil effential and neceffary to fatisfy your enquiries.

Fig. 8. as you fee^ reprefents almoft half the eye, obferved in its inner part. Letter n^ points out the tunica fcierotis ; niy the ciliary body, likewife Called ligamentum ciliare ; e^ the proceiTus ciliares ; r, the uvea; a, the pupil. You fee by the deiign, that my canal of the eye anfwers to the circular band indicated by m^ which forms the corpus ci- liaris.

Fig. 9. is the half of the preceding figure. Let- ter n indicates the tunica fcierotis ; e the procelTus ciliares ; c the uvea ; a the pupil. Letter w, at the the right of the fame figure, exprelTes the corpus ciliaris divided ; the opening points out the hollow of the body, or canal rather, I have difcovered in the eye.

The three letters, r, m^ 0, not only Ihow the ca- nal, but likewife the upper fide of it divided in two. Letter m, is the body of this new canal opened, and r, 0, are the two extremities or lips of the incilion made in the upper part of its coat.

You muft perceive hence, that this new canal is formed of the ligamentum ciliarCj which is wrapped in its fubflance ; you will underfland this fliil bet- ter by throwing your eye over Fig. 10. which is the other half of Fig. 9.

Letter ^, in this figure, ihows the tunica fcierotis flripped of the tunica choroides. Letter f, indi- cates

ON POISONS, 313

cates the ridge in which the ciliary ligament is faflened by. means of the cellular filaments. Let- ter r, points out the tranfparent cornea. The three letters, ^, 0, s, belong to a membranous fubilance formed by the m.eeting of the tunica choroides, e, the ligamentum ciliare 0, and the uvea s. Letter 0, Ihows that part of the ligament which is inferted into the ridge c, of the tunici fclerotis.

A very fmall crevice is difcovered in the fide of this canal at 0 i this part^ or this fide, of the canal is white and cellular, and is fattened very flrongly to the tunica fclerotis through the whole of the circular ridge m, of Fig. 8,

I have paiTed water, quickfilver, 8cc. from one fide to the other of this new canal, without the fmallefi: -laceration being caufed by the paifage of thefe fluids. Its coat within is very fmoth and equal. The part 0, can very eafily be detached from the tunica fclerotis e, even by forcing it a little with a fmall fcale of ivory ; and the detached membrane, without being at all torn, is then feen to form the new canal as it is obferved at 0,

I fend you the drawing of this new canal of the eye, not becaufe I wiih you, as you tell me you are defirous of doing, to publiihit in the adisof theaca- demy at Upfal, but fimply becaufe you afk it of me. It is enough for me that 1 am perfuaded of my great efi:eem for you, and of the pleafure 1 receive from the correfpondence of a man of your merit. Do what you will with it, for I am totally indifferent. You muft certainly have perceived when you was

here

3^4

F O N T A N A

tere how little I valued this difcovery, now grown out of date with me ; I fay difcovery ^ lince you will liave k called fo.

I ihall however fay nothing to you on the ufe of -this new canal, and of the tranfparent liquor with ^hlch it is found moiftened. I have at prefent no obfervation fufficiently fure, nor experiment fufE- ciently decilive, to render me certain thereupon. I will not advance imaginary hypothefes, nor fim- jile probabilities. I abandon and fubmit this diffi^ cult fubjed: to your genius, leaving to you the glory of clearing it up.

SUPPLE'

SUPPLEMENT.

ADVERTISEMENT

OF THE

FRENCH EDITOR.

X HE impreffion of the two volumes of this work was quite finiihed, when I heard that our authour, always indefatigable^ and always millrull- ing his own labours, had, in the fhort intervals of leifure, which his painful and multiplied occupa- tions afforded him, made a great number of experi- ments relative to the different matters he has treated of

in the prefent work. He has very freely confented to the deiire I teilified to him of making them pub- lick, by inferting them here under the form of a fupplement. He has likewife communicated to me an extrad, or rather, the dernier confequences,

and

2l6 FONT A N A

and moll general concluiions, of a treatife on opium he has jufl finiihed, and which, if it were pub- lilhed entire, would alone form a work apart. It is a real pleafure to me to be able to enrich this edi- tion with fo many new and interelting truths, which together concur to render it more complete, and to give to fo extenfive a fubjedt-matjer, a perfediion which would be in vain fough , in the works of the moft renowned naturaliils of the twq laft centuries.

The learned and impartial reader will readily agree with me, that this work cannot fail of form- ing an epoch in experimental philofophy ; and I care but little what the ignorant, and above all the \ envious, the number of whom is however but too confiderable, may think of it. I Ihall reply to thefe, with the Latin poet, Odi prophanum vulgus et arceo.

Although I have inferted this fupplement at the end of the fecond volume, the reader is begged to read it before the article that treats of ^' the toxico- *^ dendron, and fome other vegetable fubftances ;'* or rather, to read the different parts of it jointly with the chapters to which they relate. The au- thour has contrived it in this form, for the fake of brevity.

He has difcovered an important truth, by render- ing himfelf certain that the venom of the viper is a poifon, when fimply fwallowed by animals; and that, contrary to the opinions of the beft authours till this day, it kills in this way very fuddenlf.

The

ON POISONS* 317

The Oil of the cherry-laurel, and the reffified fpirit of this plant, which when injedied into the veins of animab, inftantly kill them, furnilh atlo- thei truth which removes the myftery and embar- raffment as to the adion of this poifon, that had obliged our authour to make an exception to the common laws he had eftabliilied, of the other poi- fons.

But what deferves the greateft applaufe is, hk having found, when there did not feem the fmall- eft hope or probability of it, having found, I {s^fy a matter, which when united with the venom of the viper, renders it innocent ; a matter, which may now be regarded as the true fp&ciiick againft this formidable poifon. This important and unexpe<^-. ed difcovery, which we owe entirely to the inde- fatigable genius of our authour, has been managed with an extent and depth of inveiligation that arc proper to him ; and with that delicate analyfis of experiments, which forces nature to unveil her moft hidden fecrets. Pofterity will judge of the remedy, and of the merit of this difcovery. In the mean time, I exhort naturalifts to follow his fteps in the road now open to their refearches ; to mul- tiply experiments on the largeft kinds of animals, according to the wifh of the authour of this new re- medy himfelf ; and to determine the circumftan- ces with the niceft exadlnefs, in v/hich it may be moft ufeful and moft certain. The remedy feems fure if given in time, and the fpecifick is difco- vered ; it remains to eftablifh the mode of applying 3 it

3l8 • F O N T A N A

it with the greatefl fuccefs, and the leafl pain and inconvenience.

The authour ends his fupplement by fetting in the cleareit light, the adiion of opium applied to the different parts of a living body ; he proves demonflratively, that the proper vehicle for opium is no other than the blood ; that opium adts in- ftantly on the blood ; and that in whatevej way it is applied to the nerves, it produces no changes in them : three experimental truths of the greateft importance, and which oblige the reafoning philo- fopher to form a new theory on this fubjedt, lince they muft caufe almofl all that has been faid on opium, by the majority of other writers, to be re- garded as errours and iimple imaginations.

SUPPLE-

ON POISONS. 319

SUPPLEMENT.

1 H E experiments I had made on the fpirit oF the cherry-laurel, which, notwithilanding I had found it innocent when applied to the eyes of qua- drupeds, fuch as guineapigs, rabbits, &c. (in the quantity however in which I had tried it) was ca- pable of killing .pigeons in a few minutes, when ap- plied to their eyes : thefe experiments, I fay, made me fufped: that the oil itfelf of the cherry- laurel would be a poifon to thefe animals, that arc fo fenlible to the flighteft impreflions* Here fol- low the experiments I made on the fubjed:.

I let fall into each of the eyes of a young pigeon three drops of the oil of the cherry-laurel ; in the fpace of a minute it became flightly convulfed ; in two minutes the convulfions v/ere become violent and general, and it then fell on its breail without the power of fupporting itfelf. In two minutes more it died. Neither of its eyes nor eyelids were fenlibly enfiamed ; there were circular red velTels however in the uvea, at fome diftance from the

pupil

320 F O N T A N A

pupil. Two other pigeons treated like this one, died, one in five minutes, the other in lefs than fe- ven. It is certain then that the oil of the cherry- laurel, as well as the fpirit, is a violent poifon when applied to the eyes of pigeons.

Thefe experiments induced me to think that the eyes of pigeons were formed in fuch a way, or were delicate and fenfibleto fuch a degree, that the venom of the viper, which I had found innocent when ap- plied tpthe eyes of other animals, wouldmake violent impreffions on them* Although neither of the pi-^ geoiis died to which I applied this poifon, my fufpi- Cion was not altogether vv'ithout ground; for having repeatedly covered the eyes of two of them with the venom, I foon found their eyelids to fwell confiderably, infomuch that the eyes themfelves were fcarcely perceptible, and feemed as if funk in a hollow. In feven minutes their eyes were no lon- ger vifible, and the pigeons were feveral hours be- fore they could open their eyelids. The uvea and tranfparent cornea were not inflamed, but the inner part of the eyelids was very much fo. The venom of the viper then is not altogether innocent, when fimply applied to the eyes of certain animals ; al- though in fome others it is not hurtful when appli- ed in the fame quantity. I am however perfuaded that if it were applied for a long time to the eyes of thefe lail, its effed:s would be perceived ; and that it might even occafion death, or fome violent de- rangements at leall.

Thefe

ON POISONS. 321

Thefe experiments on the eyes of pigeons, which become inflamed when the venom of the viper is ap- plied in abundance to them ; and thofe I had made on the ticunas, which does not occaiion death when fwallowed, unlefs it be in a large quantity ; confirm- ed me fliil more in my fentiment {a), that the vi- per's venom itfelf might kill animals when fwallow- ed plentifully. Chance having thrown a good number of very large vipers in my way, and thofe in full vigour, I v/as determined not to lofe the op- portunity of ellabliihing for pollerity, fo important a point of natural hiflory. As it is not the place here to enter into a detail on this fubjed:, I Ihall for the prefent content myfelf with relating, in a few words, an experiment I made on a pigeon, young ic is true, but very lively and in found health,

I cut off the heads of eight vipers, and received the venom exprefled from them, in a tea-fpoon ; it was almoil full, and mJght contain thirtf drops or more. I introduced the whole of this into the oefo- phagus of a pigeon that had failed for eight hours. In lefs than a minute it became very weak, two mi- nutes after it began to reel, and at length fell on it^ fide in violent convulfions, dying in lefs than fix minutes. The beak, oefophagus, and crop, to the very gullet, were inflamed and livid, and the blood v/as blacker than ufual; thefe parts were fo difco- loured, that they feemed to tend to gangrene and Sphacelus.

(^) Page 1C5 of this volume*

Vol. II. Y It

322 F O N T A N A

It can no longer then be doubted but that the ve- nom of the viper, contrary to what Redi and many other famous obfervers after him Lave written, is a violent poifon. This venom, like the ticunas and feveral other poifons, when taken in a fmall quantity, either does not produce, or does not feem to produce, any efFedt; although it is notwithiianding true that it kills very-'fuddenly, and that in very fmall quantities, when introduced into animals by the medium of wounds, and of the blood. It is certain that the famous Jacques, the viper-catcher Francois Redi fpeaks of (a) venturoufly offered to fwallow whole fpoonfuls of it ;: but we do not read in any part of the works of that celebrated writer, that the good Jacques had after- wards fulfilled his promife, and he vv-as certainly for- tunate in not having done fo. The greatefl proof Redi gives of the courage or temerity of this man, is his having fvvallowed the venom of three vipers in half a glafs of wine ; that is to fay, that he fwal- lowed a few drops of it, perhaps three or four only, coniidering the imperfed: method he muft have em- ployed to extrad: it. I am perfuaded that the venom of even a more conliderable number of vipers, mixed with fo large a proportion of wine, would not be dange- ious to the perfon who fhould fwallow it ; but on the Qi\\tr band I am of opinion, that a whole fpoonful of thispoifon, unmixed with other fubilances, would be very capable of killing a man himfelf. The expe-

{a) Obfervadons onVipers, publilh^d in Italian^ at Florence, i&644page 17,

riijisnt

ON P' O I S O N S«

323

linient Redihimfelf made, proves ilili lefs than the other. He fqueezed the venom of four vipers into a glafs of water^ and gave it to a kid without any ill confequences. The water vs^as in a much larger quantity than the wine I have mentioned^ and con- fequently the venom ought to have been far lefs ac- tive, lince it was more diluted and more divided. But, as Redi pretends, it does not follow from all this that the venom of the viper, introduced in abun- dance into the ftomaeh, would be neither mortal nor hurtfuL It is both hurtful and mortal when taken in a large quantity. This* errour is indeed common to the ancient phiiofophers, who believed that the venom of fnakes was only a poifon when in- troduced into wounds : Nonguftu^fed in vulnere, no- cent, fays Celfus ; and Lucan before him, puts intp the mouth of Cato. Morfu virus hahent, & fatum dente Minantur ; pocula ntorte carent.

The venom of the viper, as is faid in the firil volume, although feparated from the animal, re- tains its hurtful qualities for feveral months ; but ^ well determined experiment has latterly induced me to believe, that its faculty of killing, if indeed it laft fo long, does not continue beyond the ninth month. This is the experiment,

I wetted four pieces of thick brown paper, each of them with about tv/enty drops of venom, and enclofed them feparately in glalies. At the end of nine months, I forced thefe papers into the wounds , of the legs of four young pigeons. Neither of the animals died, nor gave any fymptoms of the

" y ;^ ' ' ' difeals

3^4 F O N T A N A

difcafe of the venom. The venom thus preferved then had lofl the faculty of killing even pigeons^ that are fo readily deilroyed by it when frefh.

On the Lunar Caujlick.

Although, as has been feen in the firft volume, I iiad fatisfied myfelf that the fluid volatile alkali 15 not a fpeciiick againfl: the bite of the viper, and that it does not deprive the venom of this animal of its noxious quality when mixed with it, I had how- ever-the curioiity to examine likewife the lunar cauftick, and began my refearches by mixing the venom of the viper with this cauftick fab fiance, to fee whether it would flill preferve its original ve- nomous quality, as it preferves it when it is united with the fiuid volatile alkali. I made my experi- ments by mixing equal quantities of the venom and lunar cauflick, adding a few drops of water ta render the pafle, which I applied to the wounds of animals, fomewhat more liquid. And as fmal! birds are eafiefl killed by the venom, I wifhed to try on fuch the effedis of this pafle, and procured fpar* rows and pigeons for that purpofe.

Experiments on Birds*

J wounded the legs of five birds with the ve-

fiomous teeth of vipers, making fearifications im*

S Gjediatel/^

O IT POISONS. 325

mediately, and applying the above pafle. Neither of them died, nor feemed affected with the difeafe of the venom ; and there was no gangrene in either ,of their legs, although the mufcles were much burnt by the cauflick.

I repeated this experiment on five other birds, and in addition, walhed the parts v/ith water, after having applied the paile. Here again neither of them died, and I found that the mufcles of the legs were lefs corroded and burnt by the cauftick.

As thefe animals are fo fmall that an atom of venom fuffices to kill them, it appears that it can be no longer doubted for a moment, but that the lunar cauHick renders the venom of the viper inno- cent when it is fcarcely mixed with it ; for I ap- plied the paile to th^ wounded mufcles, the mo- ment I had blended them together.. I wiihed however to try it on ten other birds ; and to my great furprife, they all recovered very readily. Still I could not determine as to the unexpected novelty of thefe confequences ; and fearing that accidental circumilances might have prevented the adtion of the venom, I refolved to m^ake frefh ex- periments on the fame animals. I wounded the legs of fix others, multiplying the incifions to in- troduce a good deal of the yenom, of which I am fure the quantity of pafte I employed in each muft have contained a drop at lead. In thefe experi- ments two of the birds adually died, one in the fpace of fix hours, the other in twenty-eight. On the mor- row I repeated this experiment, with the fame cir- Y 3 cumHances^

326 F O N T A N A

cumftanccs, on ten other birds ; one only of theni died, and that at the end of twelve hours. Fearing that the wounds aione might have brought on death, particularly as they were irritated by the cauflick, I tried ten birds, on the legs of which I made wounds as ufual, and applied the cauftick by itfelf. One of them died at the end of eight hours. So that it feems at lead very probable, if not very certain, that the three birds before men- tioned, died likewife of their w^ounds, and not of the effedis of the venom. I wounded ten other birda in feveral places, in the perioral mufcles, to vv^hich in a ihort fpace I applied the pafte. Not one of them died.

Experiments on young Tlgeons.

The pigeon, next to fniali birds, particularly if very young, is the animal killed with the fmalleft quantity of venom. I chofe four of thefe for a trial, and operated on all of them in the fame way. I made feveral tranfverfe wounds v/ith fcifTars, in the mufcles of their legs, and introduced the venomous paile abundantly into the wounds, which although pretty deep, did not bleed conliderably. Neither of thefe pigeons either died, or feemed to have the difeafe caufed by the venom of th^^ viper. The next day I repeated this experiment on twelve, pigcpnS;,^ the legs of which I wounded in feveral

placeSj

© N POISONS. 3IJ

places, and again applied the pafte; neither of them died. I varied the application of the venomous pafte, which I fometimes forced into the wounds with fmall bits of wood, fometimes with pieces of flout thread, fmeared with it. Neither of them died in thefe trials. I proceeded to the mufcles of the bread, which I wounded in different ways, and diveriified the application of the paile : but it was in vain that I multiplied my experiments ; neither of the pigeons died.

It cannot now be doubted but that the lunar cauftick, when mixed with the venom of the viper, renders it innocent ; and thus every thing concurs to make us regard it as the true and only fpecifick againil this poifon. I can now flatter myfeif with having at length difcovered a certain remedy againft the bite of the viper ; a remedy that fo many peo- ple have hitherto fought in vain. But does the viper's_ venom lofe its deadly qualities, when mixed with the lunar cauflick, becaufe its nature is chan- ged, or rather, becaufe ^being unite4 with this ftrong cauilick, in the way with acids when they are faturated by alkalies, or by abforbent earths, it can no longer exercife its original qualities ? May we not fufped: that the lunar cauftick, by crifp- ing , the blood-veifels, prevents the poifon from inlinuating itfelf in this way into the blood ? This lafl fufpicion does not feem fupportable, iince the mineral acids, which likewife crifp the veifels, are however not capable of rendering th^ venom in- nocent, and fince the fluid volatile alkali itfelf has

Y 4 no

328 r O N T A N A

110 , fuch property : this muft appear ftrange to tfs when we conlider the great agreement there ia betwixt the fluid alkali, and the lunar cauftick,

I muil confefs that I felt a real fatisf action, when I flattered myfelf that my labours had been crown- ed with fuch great fuccefs i and the knowing that the venom of the viper does not lofe its hurtful qualities when united to other very adtive fubflan- ceSj fuch as the mineral acids^ concurred to infpire me with confidence. But I well recollected the errour I had fallen into in France, when I thought I had found a certain remedy againll the bite of the viper, becaule I was able to recover fmall birds and pigeons that had been bit, Simple analogical proofs had no longer any weight with m^e, and in the prefent cafe only ferved to make me recur to imm.ediate and irrefiflible experiment, v/hich alone ought to be confulted in philofophical refearches, This is the. only purpofe to which a prudent philofopher/ if he does not wifh to be deceived or led into errour, ought to apply thefe proofs ; and 'tis to this appli- cation of them that the penetrating naturalift owes his mofl: important difcoveries.

JEx^eriments on Birds,

I wounded the mufcles of the legs of four fmall birds with venomous teeth, and after having made flight fcarifications, I applied the lunar cauftick^

waihing

ON POISONS. 329

wafhing the wounds foon after. Neither of them died, nor had the difeafe of the venojn.

I wounded four other birds like the preceding ones, in the legs, with venomous teeth, and after^ wards waihed and fcarified the wounds, but did not apply any remedy. They ail died, one in a fingle minute, one in four minutes, one in feven, and the fourth in eight.

I wounded the mufcles of the legs of four others with fciffars, and applied the venom to them. Im- mediately after, I fcarified the wounds, applied tq them the remedy, and w^afned them. They all four recovered.

I treated four other birds in the fame way with the laft, and neither of them died.

I thought it proper to repeat the fame experi- ment on ten others. I wounded their legs, ap- plied the venom, icarified, and medicamenced, and ^11. ten of them recovered.

I muft not however conceal that of five other birds 1 had wounded in the legs with venomous teeth, three died, although they had been fcarified and dreffed with the lunar cauftick in the way de- fcribed above. Two of them died at the end of three hours, the third on the twentieth.

Two other birds died in the fame w^ay, out of four, of which the pedioral mufcles had been wounded with venomous teeth, and had been dreffed in the ufual way, after the fcarifications had been made. One died in three minutes, the other in three hours,

Anotl;^

33<^ F O N T A N A

Another time I wounded the pectoral mufcles cf three birds with a lancet, and applied the venom. 1 drefTed the. wounds with the lunar cauf- tick, aiid the three birds all died, one in half an iiour, a fecond in eight hours, and a third in nine.

I feared that the wounds made in the pectoral iBufcies, joined with the cauftick, were alone fufficient to occafion death; and •• therefore wounded thefe Biufcles in three other birds, and applied the lunar cauilick to them : neither of the birds died.

We may I think conclude from the experiments related above, that the lunar cauilick, when applied m the way I have defcribed, deftroys the effects of tlie viper's venom, in birds. If it however does Bot prevent fome of them dying of this venom, it may be believed, either that the remedy has been applied too late, or, which is more probable, that it cannot always reach the envenomed parts by in- troducing itfelf as far as where the venom has pe- netrated. Every one muft perceive that in thefe cafes it cannot have corred:ed the deadly qualities of the venom, as it certainly does corred: them., in the way we have feen, when they are united to- gether.

Be that as it may, the lunar cauftick being capa- ble of recovering bh'ds, is not a iufficient aiTur- ance to us that it would recover other creatures in the fame way : and even thou.o-h this cauftick ihould

CD

be the true antidote againft the venom, of the viper, as k incontcfiibly appears to be, it does aot .follow

01

OH POIGQT5JS* 331

of neceffity, that it ought to cure the larger kmd of animals. Circumfta;ices may vary, the fcarifica- tions iiiay be more dangerous, and the application of the fpecifick to the envenomed parts^ either more difficult, or lefs certain.

Experiments on Pigeons.

I wounded the mufcles of the legs of four pigeons with venomous teeth, made the ufual fcari- fications, applied the lunar cauilick, and covered the wounds with linen. Two of the pigeons died in a few hours, the other two furvived. I walhed the wound of one of the two firll, after I had dref- fed it, but did not walh that of the other ; and I obferved the fame treatment to the two that furviyed.

I repeated thefe experiments on four other pi- geons, to which I applied the venom taken from the animal, and did not walh either of their wounds. Keither of them died, nor had any appearance of the difeafe of the venom.

I made the fame experiment on iix others, and applied the venom to the mufcles, after having wounded them. They all furvived.

I returned to my iiril experiments, fearing that the remedy had not reached all the parts where the venom had penetrated, in fpite of my having made large and deep fcarifications. I operated on the legs

of 4

||2; F O N T A N A

of feven pigeons, three of which died in lefs than an hour, the other four had no complaint.

1 paffed on to the peftoral mufcles. I wounded thofe of four pigeons in feveral places, and applied the lunar caufiick. They all four recovered.

On repeating the fame experiment on four other \ F%^^^s, neither of them died, no?: became ill. I got ready twelve other pigeons as above, and ap- plied, firfl the venom, and immediately after the lunar cauftick, to the wounds in their pedioral muG ^les. They all twelve recovered.

I wounded the pecftoral mufcles of four others with venempus teeth, and immediately fcarified the wounds, and applied the cauftick^ Two o£ ^them died in lefs than an hour.

It cannot be doubted after this, but that the deaths, of the animals to w^hich the lunar caufticl^ was applied, w^ere occalioned by its not being in-: variably able to reach all the parts envenomed • and not becaufe it is no true fpecifick againlt this poifon.

I muil again confefs ing^enuouiiy, that having^ one day applied the venom to wounds made in the mufcles of the legs of two pigeons, one of thern (died at the end of four hours, notwithilanding I j had treated it with the cauilick. Another time I wounded the mufcles of the legs of two pigeons, with venomous teeth, and one of them died in eighteen hours. But unlefs I am deceived, all thefe cafes only tend to prove Hill more, either that the remedy does not always come in time,

or

ON POISONS. JJJ

or does not always unite with itfelf the venom ; this feems to be fufficiently demonilrated by the tioia that thefe animals continue to live, whilil they in general die in a very fliort fpace, when the re- medy is not applied.

I was deiirous of making a trial ©n ten other pigeons, and having wounded their legs vvdth ve- nomous teeth, I fcarined them, and applied the cauiilck a little after. Five recovered without having had any complaint j a fixth died in my hands^^ and the other four died, one in three, one itfixtee% one in eighteen, and one in nineteen hours^-

I think it quite fuperiiuous to give a detail of feveral experiments I made on the mufcks of the" legs and breails of fowls. I wounded them in fe- veral places, applied the venom abundantly, and treated them in the ufual way with the eauUick* Neither of them died. This may readily be ac- counted for, fince pigeons, which are much more tender, and which fink more readily under the ef- fecfis of the poifon, have in the fame circ-umllaiiceB efeaped death.

ExperlmeHts on ^iadrupeds»

I wounded two guineapigs, each of them repeat^ edly in the mufcles of one of its legs, with venom- ous teeth, and after having made the fcarifications, I drelTed the wounds with the lunar cauiiick : one recovered, the other died at the end of f.ve hours.

I. trcatc*^

J24 F b N t A N A

I treated four other guineapigs hi the fame way^ and only one of them died, and that at the end of five hours.

I wiihed to try whether on applying the venoni drawn from the animal, to the wounded mufcles, the temedy would be more certain. I wounded the mufcles of the legs of fix very fmall rabbits in fe- veral places, and applied the remedy ; neither of them died. I treated the pedtoral mufcles of fit other rabbits in the fame way, and all of them re» covered.

I proceeded to fmall guineapigs, on fix of which I tried this remedy. To three of them I api:>lied the venom to the mufcles of the legs, to the other three to thofe of the brdail, each of which I had previouily wounded : I then applied the caufiick. Neither of the guineapigs died.

I returned to the venomous teeth, with which I wounded eight very fmall rabbits in the legs. A little after i fcariiied and medicamented the parts. Two of the rabbits died ; the other fix reca- yered.

It can no longer be doubted but that the lunar cauftick is a true fpecifick againfl the venom of the viper. But the mode of applying it to the en- venomed parts is not certain, and it is natural to conceive that the difficulty will become miich greater, when the application of it is attempted on the immediate bite of the viper ; particularly if the creature may have bit feveral times, and if the traces of the bites can fcarccly be diilinguifiied. In thefe

cafes

ON POISONS. 335

cafes ttere will be always fome uncertainty, and if the remedy fail in correding the venom, too exten-^ five and multiplied fcarifi cations may be extremely hurtful.

Bites of the Viper treated with the Lunar Caujikh

The latter part of my experiments is the more im- portant, in having for its objedl the fecuring us againil the bite of the viper. My experiments arc too few in number, and too little varied, either to dlow the drawing from them all the pradiical utiilt/ that may be hoped, or to render the method I have propofed perfed:. Owing to the feafon, I have ex- perienced a fcarcity of vipers; and the circumftances in which I have found myfelf, and the obligations i have had to fulfill, have prevented my applying myfelf more attentively, and in the way Ilhould havewifh* cd, to this fubjedw Ifhallforthe prefent publifhthe refultof fuch experiments as I have been able to make, intending to return at a more convenient opportu- nity, to an enquiry that has the good of my fellow creatures for its objed:. In the mean time, I hope that philofophers and naturalifls wdll pay every at- tention to this brancli of medicine, and will fpare no pains to render it more ce rtain and ufeful.

I had a middle iizcd rabbit bit five times fuceiliVe- ly in the leg-, by a large viper, and, after m.aking icarlfications, ap plied the eauHick, and wafhed and

bound

2^6 F O I^ T A N A

bound the wounds. The rabbit died at the end of twelve hours.

I had another rabbit bitfeveral times in the leg bj a viper. It died in the fpace of an hour, although it was treated like the preceding one.

I had two guineapigs bit in the legs b)^ a viper^ each one three times, and after making the fcarifi- cations^ I applied the cauflick. Both of them died in a few minutes.

I repeated this experiment with the fame circum- flances, on a large guineapig, which died in the fpace of twenty-ft)ur hours.

Thefe five unexpetfled deaths convinced me hovi)^ cafy it is to be deceived, even in matters of obferva-^ tion and experiment^ and how little truil is to be re- pofed in analogy. The minuteft circumftance fuf- fices to render what in itfelf would be very ufeful^ tDoth ufelefs and hurtful. Every one may perceive, that in the prefent cafe the whole difficulty lies in making the eauftick penetrate into all the parts to which the venom has found its way. But how cart this difficulty ever be furmounted ? The holes made by the teeth of a viper are very fmall, and often in- vifiblei They run in different directions within the Ikin, and have different depths^ according to a thou- fand varied circumftances. The fwelling or inflam- mation that fucceeds, augments the difficulty fiill more, fo that the fcarifications are made almofl at hazard.

I mufl not hovvreve omit that I have cured {ivq ©ther larger rabbits by this method^ after they had been

repeat-

ON POISONS. 237

repeatedly bit by vipers ; as alfo feveral guineapigs that I had had bit in the fame way ; all of which would probably have died, if they had not ^been' treated with this new remedy. But I recovered a much greater number of thefe animals, when ihey had been bit a iingle time only, although even in this inftanee fome of them died ; and this was un- doubtedly occafioned in the way related above ; that is to fay, not by the inefficacyof the medicament, but be« caufe it cannot always reach the parts where the poi- fon has penetrated and lodged. There are likewife other eircumilances which elude the new method I have propofed, and thefe are when the difeafe, by accidental circumilances, is more internal than ex. ternal ; that is to fay, when the venom is fuddenly introduced in a large quantity into the blood of the animal, by the means of fome vefTel that the teeth may have penetrated. And I do not think it impoffibk but that the bite of the viper may kill even inilan - taneouily, provided it ihould ever happen (which is not abfolutely impoifible) that the teeth ihould pierce a large venous veiTel in fuch a way, that a quantity of the venom would be inftantly carried to the heart* In this cafe, which differs little or not at all from the artificial injedlion of the venom, the difeafe may be incurable, and obviate all remedy.

The lunar cauflick, J repeat it, renders the ve- nom of the viper innocent, and is its true fpecifical remedy ; but much remains to be done, to apply it with the greateft advantage in the bite of this ani-

VoL^ IL Z nuh

338 Montana

riiaLl. It would perhaps be ufeful to fwallow it di- luted with w^ater, even in pretty ftrong dofes.f If the venom of the viper derange the blood, and be fatal when it is introduced into the torrent of the cir- culation of humours, the lunar cauftick, taken in- ternally in a liquid form, may weaken its noxious qualities, and corred: it in the velTels themfelves, ta fuch a degree as to deilroy, or diminilh, the inter- nal difeafe that this venom produces.-

After my having difcovered that the lunar cauf- tick renders the venom of the viper innocent, it is natural to conceive that I ought to make fome trials on the lapis infernalls ; I have indeed made fever al.

I found that a pafle formed of this ftone, and of the venom of the viper, might be applied with im- punity to the wounded mufcles of birds ; on ehoof- ing ten of them for thefe experimeftts, not one died- But of three which I envenomed with the teeth, and drefTed with the lapis infernalis fcraped to a pow- der, two died, one at the moment of the applica* tion, the other at the end of two hours. I had four pigeons bit in the legs by vipers, and treated them with the fame cauftick. One died in my hands im- mediately after I had applied it, another in the fpace of an hour, and the two others recovered.

Notwqthfianding that the feafon was becoming un- favourable, and that I had no longer a hope of finding any vipers, I met with thirty-four of them by acci- dent, in an excellent ftate and very vigorous. The firft purpofe to which I applied them was that of

3 veri-

o .N POISONS. 339

verifying my new remedy, and of feeing at the fame time whether a folution in water of the lunar cauf- tick given internally, would be at all efficacious to animals bitten by the viper.

I deilined four very fmall guineapigs for this ex- periment, and made them drink a teafpoonful of the above folution : it was rather weak, but flill dif- aereeable to the taile. I wounded the femoral m.uf- cles of three of them with venomous teeth, made immediate fcarifications, and applied the lunar cauf- tick as ufual ; neither of them died.

I made another fmall guineapig fwallow tVN^o tea- fpoonfuls of the above folution, and it died in my hands. I conclude from this that the quantity I employed was too great. I afterwards gave aiingle teafpoonful, as in the firfl experiment, to other four fmall guineapigs, and had them immediately bit by as many vipers, making fcarifications inilantly after. They all four died. One when fcarce bitten, ano- ther in ah hour, a third in three hours, and the laft in five. The refult of this experiment fhows that the bite of the viper is far more dangerous, than wounds that may be made artificially with its teeth, although filled with venom. One reafon per- haps is, the difficulty of conveying the remedy nice- ly to all the parts where the teeth of the viper pene- trate when it bites at its will. I iikewife imagined at the time that the fmallnefs of the animals I made choice of might partly have caufed this, and deter- mined in confequence to make trials on larger and ilronger ones, better able to refill the effeds of the Z 2 poi-

340 F O N T A N A

poifon ; particularly the internal malady^ which is communicated much quicker in fmall animals. I had fix fowls bit in the thigh by as many vipers. Five of them fwallowed three teafpoonfuls each of the folution of the cauftick, the other did not fwal- low any. I applied the lunar cauftick in the fame way to each of their wounds ; the laft died, the other five all recovered.

I had fix rabbits of a middling fize bit in the thigh by as many vipers. I immediately applied the lunar cauftick to their wounds, and made them all drink the folution of it. Four of them reco- vered ; the other two died, one in three hours, the other in eight.

I repeated this experiment on fix other rabbits, fomewhat larger than the above, and neither of them died. On having four others bit, and treated exadily in the fame way, they all likewife reco* leered.

The number of thefe experim.ents Is ftill too cir- cumfcribed to render us certain that the lunar cauftick is a never failing remedy againft the bite of the viper ; and this is owing to the difficulty or conveying it to all the parts into which the venom has infinuated itfelf : three or four hundred experi- ments would fcarcely fuffice to fully clear up this important matter ; I however have no doubt of the efficacy of this remedy, and can affirm that the lunar cauftick is the true fpecifical remedy againft thi^ dreadful poifon.

ON POISONS. 341

On the Poifon called 7^1 c mas.

The fmgular and unexpedled effedis of the lunar, caullick, which, when united with the venom of the viper, renders it innocent, made me fufped: that the efFed: might be the fame if it Vvere united with the ticunas, I mixed them then in equal quantities, and formed a fomewhat foft palle. I now made feverai w^ounds in the mufcles of a pigeon's leg, and applied this paile to them. The pigeon died in lefs than two minutes. I repeated this experiment with the fame circumftances on another pigeon, v^hich died in lefs than three mi- nutes. I again repeated it on two others, one of which died in lefs than two minutes, and the other foon after the end of the third. The lunar cauftick then does not correct the deadly quality of the ti^ cunasy and confequently is not its fpecifical remedy. The paile formed of it does not even retard the death of animals to which it is applied ; iince two pigeons, to the legs of w-^ieh I had fimply applied the ticunasy died in three minutes, and not fooner. I pafs over in iilence many other analogous confe- quences which I obtained on making like experi'- ments on guineapigs and fmall rabbits.

Having procured fevcral fnakes, limilar to thofe the examination of which is mentioned in page 139 of this volume, for the occafion^.I ihad the curio-

Z 3 fity

342 FONTANA

lity to fee whether the poifoning them witl^ the iicunaSy in the mufcles of the tail, would be attended with the confeqiiences I had before obferved ; and whether thefe creatures would continue in an ap- parently lifelefs Hate, for as many hours as they did on the former trials. I introduced then into the mufcles of the tail of one of thefe fnakes, an American arrow which 1 had previouily fteeped in the iicunas, liquified by the heat of boiling water. I made a confiderable wound along the vertebra, that the poifon might penetrate well into the mufcles, At the end of an hour the fnake fcarcely ftirred, and in an hour more fecmed dead, and quite de- prived of motion and irritability. In this appa- rent flate of death, I examined the motion of the heart attentively through the fkin, and could per- ceive a feeble and Hov/ contradion of this mufcle. This contrad:ion continued for twenty-feven hours, conflantly diminiihing in force, and in this inter- val every one would have looked on the creature as dead, for fetting afide the motion of the heart, it was quite ilill and free from irritability. At the end of twenty-feven hourf the motion of the heart gradually became quicker and more confiderable i and I then thought I perceived, on giving the creature a violent blow, a fmall undulating motion. In forty hours, I obferved a motion, fometimes of one extremity of the body, fometimes of the other, but very feeble. In ten hours more this motion, and the return as it were to life, were manifeil and certain, notwithftanding the fnake could nei- ther

ON F O I S O N S,

343

ither crawl nor hold up its head. I left it in this ftate during the night, and the next morning found it very lively, in good health, and able to crawl ^ but fix hours after, it died.

The event was exadtly the fame on treating two other fnakes in the fame way. Another much fmaller one died in lefs than two hours ; its heart continuing to move three hours after its lofing alj apparent figns of life.

It cannot then be doubted but that tl>e ticunas is ^ mortal poifon, even to animals with cold blood, •although it be true that it is far lefs fo to them, than to thofe that have the blood warm. But that which well merits our attention, i^ the apparent fuf- penfion of life, and of the voluntary motions of all the animal's mufcles, except that of the heart, the irritability of which is indeed diminifhed, but not totally deftroyed.

We cannot aftervv^ards but admire, that a long continuance of this ifolated motion of the heart, is capable of relloring by degrees to the animal, that life, and that motion of all its other organs, which it had entirely loil. Without the ad:ion of this muf- cle, all mufl irrevocably have eeafed.

Ori ihe dangerous Confequences of the Oil of the Cherry Laurel.

The following experiments on the oil of the

cherry-laurel, will not only ferve to complete thofe

Z 4 I have

344 F O N T A N A

I have already made on this fubjedl, but to fhow in a clearer way, that this oil, whether given internal- ly or applied to the wounds of animals, is one of the moll terrible and deadly poifons known. This important truth will, I hope, deflroy once for all, the abufe that has crept into feveral places in Italy, of felling the oil of the cherry- laurel publickly inthe ihops, to all thofe who afk for it. It is eafy to fee how dangerous this cuftom may be to fociety ; and this danger is encreafed again by the method adopt- ed in felling it. It is ufuajly maiked under the title of EJJence of hitter Almonds, and is found under this name in the printed lifts of diftillers, who fell it with other effences, oils, and liquors, that may be drank with the greateft impunity. Nay, what is more, this dangerous poifon enters into the compo- iition of a liquor for the ufe of the publick, which is made and fold without any ceremony ; and to prevent all fufpicion of the true nature of this poi- fonous mixture^ it is vended under the title of Li- quor of hitter Almo?ids, or of Peach flowers, and is even put into milk, and into ragouts. It is true that a fmall quantity of this poifon is employed in them, and that thefe liquors are not drank like wine and v>'ater ; but a poifon is always a poifon ; and v/e do not bendes know but it may be hurtful when ufcd a long time, -although in very fmali quantities ; and whether it may not give a difpofi- tion to certain difeafes. I have heard fomc perfons fay^ that when fwallowed it myft be an excellent

cordial.

ON POISONS. 345

If

cordial, which its truly agreeable and aromatick fmell may eafily induce them to believe. ' Tufcany owes to a philofophick fovereign, the knowledge of this pretended oil of bitter almonds^ and the advantage of being fecured from the abufe that may be made of it : fo true it is that philofophy is ufeful even to fovereigns, and that, according to the wifh of one of the ancients, they ought all to be philofophers, or at leaft to know how to philofo- phize on occafion !

The Oil of the Cherry-Laurel is a Foifon to Vipers.

Having had an opportunity of providing a quan- tity of the oil of the cherry-laurel, I wiihed to fee what eifedis it would have on vipers, and accord- ingly made a large one fwallow about ten drops. In lefs than two minutes it could fcarcely drag itfelf along, and at the end of feven feemed quite dead. In two minutes more it was perfectly infenfible to the flimulus of a needle. However on obferving at- tentively, its heart was feen to move, and to rife and fink alternately : it continued this motion, which regularly diminiflied, for three hours. In thefe ani- mals we may judge extremely well of the total re- pole of this mufcle, without opening the thorax ; an obfervation that in many cafes may be highly important. We may likewifc obferve this motion of

the

F O N T A N A

the heart externally in other animals- with cold bloody even in frogs^ but with greater difficulty.

I have found in general that the oil of the cherry- Jaurel is a very fhrong poifon^ even to vipers, the fuddennefs of its effects on which, is proportioned to the quantity fwallowed. I have feen thefe crea^ tures die in a very few minutes on giving them thirty or forty drops, in which cafes they have iick- €ned and become motionlefs inflantly ; and I have found it mortal even when given to them in the fmail quantity of a drop, or at mofl of two. It is true that in thefe lall inftances, the difeafe difcovers itfelf very late, and that the viper lives many hours after. 'Tis obferved that the mufcular irritg.- bilityis in general very foon deftrqyed, notwith- llanding which the heart continues to move for a very long time, even after the animal ceafes to give any iign of life, or fenfation. The heart, I do not here fpeak of the inteftines, is an exception to the general rule of the other mufcles, and this interefting point of animal phy licks deferves Hill more the atten- tion of philofophers, as having been hitherto totally negled:ed.

^he Oil of the Cherry- Laurelis a Poi/on to Snakes,

I made a fnake fwallowfive drops of the oil of the cherry-laurel, which it had fcarcely taken, when I ob- ferved it to crawl with difficulty j in lefs than two mi- nutes

^^ng^l^^^

q H POISONS. 347

nutesit appeared to be almofl dead, fince it only pre- ferveda fmall motion of its tail, which ceafedalittle after. Iftiniulatedit in different parts of its body with- put any effed:. On opening the thorax, I found the heart and auricles motionlefs ; but when I pricked them with a needle, they began to move, and this motion continued feveral hours. At length I fepa- rated the heart from the thorax, and it inllantly eeaitd to move. However on touching it repeat- edly, with the point of a needle, it each time con- tracted itfelf once, and continued to do fo for feve- ral hours. It never had a fpontaneous motion, and never contracted itfelf more than once on being pricked with the needle.

fhe Oil of the Cherry- Laurel is a Foifon to Snakes ,

when applied to their Mufcles,

I made a wound of about an inch in length, in the mufcles of the tail of a young fnake, and ap- plied to it about forty drops of the oil of the cher- ry-laurel. It died in lefs than ten minutes, without having been convulfed, and without the fmalleft iign of irritability remaining in its whole body.

I laid bare a great length of the mufcles of the tail of an ordinary iized fnake, and wounded them in feveral places. I applied an abundance of the oil of the cherry-laurel to the wounded parts throughout, and a moment after repeated this again.

In

348 F O^ N TAN A

In lefs than a minute the fnake moved languidly and with difEculty, and the motion of the different parts was feeble, in proportion as they approached the tail. In an hour after, however ^ it had in a great meafure recovered its former vivacity. I then applied frefh oil to the fame wounds, and in lefs than a minute it could fcarcely flir itfelf, re- maining twilled in the form of a zigzag; however, in half an hour it became as lively as ufual,

I applied the oil of the cherry-laurel twice, to the mufcles of the tall of another fnake^ which although it had appeared dead, and remained in that flate far feveral hours, both times recovered itfelf. How- ever, after reviving the fecond time, and becom- ing very lively, it died of itfelf in a few hours.

This oil then, when it is applied to the mufcles of fnakes, incontefLibly produces violent derange- ments in a very little tim.e, but is not, however, capable of killing them v/hen they are very large; Deither does it, in the circumftances at leail in which I have obferved it, kill the fmaller ones very fuddenly, notwithftanding it is otherwife certain, that fnakes without difiin<fLion die readily, when made to Uvaliow it, even in a very fciall dofc.

It is a FcJfon to Vipers, when fimply applied to their Mufcles.

I wifhed to fee whether the oil of the cherry- .laurel would be mortal, when applied to the wounds

of

4

ON rojsoNS. 34P

of vipers purpofely made, and whether it would be Jefs fo in thefe cafes than in thofe I have related, of their fwallowing it. It has been found by a long fucceffion of experiments 1 have made for that pur- pofe, thkt both the fpirit and oil of this plant pro- duce violent derangements when applied to the mufcles of vipers, but not to fuch a degree as when they are taken internally. In thefe cafes the heart continues to move in the fame way that it does in the other animals with cold blood, whilil: all the other parts remain motionlefs and infenfible to the mofl adtive ilimulants. In like manner I have ob- ferved, that on introducing a few drops of the oil into the natural aperture that is found towards the tail of the viper, the creature died in the fame \vay as in the cafes related above, that is to fay, with a lofs of mufcular irritability, but with a conti- nuance of the motions of the heart.

I bathed the mufcles of a vipers tail, ftripped of the fkin for a great length and wounded in feveral places, with the oil of the cherry-laurel ; an inilant after, it had loft the motion of the part of the body towards the tail ; it twifted and wrapped itfelf up, fwelled confiderably, and was violently convul- fed. — I likewife bathed the mufcles of another viper towards its tail, w ith this oil, and in twenty feconds it could fcarcely move itfelf. It was contradied and wound up, was fwelled to twice its fize, and numbed.. L: died in lefs than three hours.

It

§50 t ON T A N A

it aBs likewlje as a Foifon^ when applied to the Muf- cles of Pigeons.

It will be fufficlent to relate here fome of the ex- periments I made on the mufcles of pigeons, to ihow in what way the oil of the cherr3^-laurel adis in thefe cafes.

I flripped the whole of the ikin from the leg of a young pigeon, and wounded the mufcles in feve- ral places, without dividing any perceptible blood- vefiel. 1 then applied about twenty drops of the oil to the part, which was more than a fquare inch in fuperhcies. In fix minutes the pigeon was no longer well able to fupport itfeif on its feet. In thriee more it was feized with convullibns, and at length fell on its brealt. In fix minutes m.ore it had loft its ftrength, but flill breathed, and kept open its eyes. After fix other minutes it began to ftir a little, and remained quiet for the fpace of twenty more; It at length recovered, and became as well as ever.

I laid bare the breaft of a very young pigeon^ ivounded the perioral mufcles in feveral places, and applied to them about twenty drops of oil. Five minutes after, the pigeon became very feeble, and almoft incapable of fupporting itfeif; it however furvived, and had no other fymptoms. The wound was very large, and well covered with oil;

Ire-

ON POISONS. 351

i repeated this experiment on another pigeoii, ap- J)lying twenty drops of the oil, as above. In the fpace of three minutes it could no longer fupport it- felf, and died in five more.

Tw6 other pigeons, fomewhat larger^ recovered, although treated precifely in the fame way with the laft.

I returned to my experiments, on the legs, t laid the leg of a middling fized pigeon entirely bare^ and wounded the mufcles in feveral places. I then fucceffively applied to the wounds more than thirty- drops of the oil : in thirty minutes it could no longer Hand, but foon revived, and recovered per- fedly.

This experiment made on two other pigeons^ was attended with the fame fuccefs 1 neither of them died, but on the other hand foon recovered from the feeblenefs that feized them : however having re- peated it on two much younger ones, they both died in violent convuliions in lefs than three minutes,/ notwithilanding I had not laid their legs fo bare as ufual, and had applied a lefs quantity of the oil.

From all thefe experiments, it appears that the oil of the cherry-laurel is in reality a poifon to ani- mals, when applied in an immediate way to the muf- cles, by the means of w^ounds; but that it is in this way far lefs deadly, than when fwallowed>

//•

35^ MONTANA

It is a Foifon when applied id the Eyes of Figeons.

I omit the mention of feveral experiments I made on the eyes of pigeons ; it will be fufficient to know that the oil of the cherry-laurel is a violent poifoa when applied to thefe organs, and that it caufes a fpeedy death to thefe animals, in the fame way with the fpirit itfelf of the plant.

Applied to the Hearty it renders it m&tionlefsi

The faculty poffelTed by the oil of the cherry-laurel of deftroying the irritability of fleihy fibres, indu-^ ced me to try whether, on being immediately applied to the heart, it would render it motionlefs, even to external ilimuli. I therefore let fall a few drops on the hearts of feveral frogs, the motions of which foon ceafed, and could not be reilored by the pricks of a needle. The fpirit of the cherry-laurel produces the fame effect, but lefs fuddenly and more imperftdtly than the oil.

i

It

b N POISONS, 2^^

it kilhy when applied to the Bram

1 was afterwards defirous of feeing whether this hA would be mortal when applied to the brain of frogSj and a few minutes after the application of it Obferved that the creatures could fcarcely crawl : in lefs than fix minutes they died. The heart how- ever continued to move. The brain being ftimula- ted, no contraction of any part enfued, but on for- cing a pin longitudinally into the fpinal marrow^ the feet fprung up violently. This would lead one to believe that the nervous fubilance, when put in eontadt with the oil of the cherry-laurel, lofes its power of contradting the mufcles ; but that this poifon notwithftanding, is only capable of removing It in the'nerves or nervous produdlibns tliat it im- mediately touches.

It deprives the Ner-ves with zvhich it is put in co^itaB, of the faculty of contraBing the Mufcles,

To alTul-e myfelf of this I applied it to the crural nerves of frogs, and in leCs than two miniltes obfer- ved that one of thefe creatures on which I tried it^ had loil the faculty of contradling its feet, and that when I Simulated thefe nerVes, at the part where

Vol. IL a % the

354 F O N T A N A

the oil had touched, with a needle, they no longer put the mufcles in adiion. But every time I flimulated them towards the legs, where the oil had not reach- ed, the feet contraded themfelves forcibly. The nerves then are not the organ or inflrument by which the oil of the cherry-laurel communicates its delete- rious qualities to the other parts of the machine, and are themfelves only fufceptible of them at the pre- cife part to which the oil of the cherry-laurel has been immediately applied. The fpirit of the cher- ry-laurel, when applied to the nerves, produces efFedia analogous to thofe of the oil, but not fo violent. It is very probable that this adtion of both oil and fpi- rit is limply mechanical, and that they alike operate in the way with fubllances that corrode and crifp.

I'he Oil of the Cherry-Laurel, admlntjlered to Leeches j deadens the Fart it immediately touches,

I injeded the oil of the cherry-laurel into the bellies of fever al leeches, which immediately dead- ened, and were no longer fufceptible to external ffcimuli. The fame thing happened when I tried the fpirit. I injeded fome of them for almoft half their length, preventing the oil from paffing further by a ligature, and faw with furprize that, the injeded half was deadened, and no longer fen- fible to any ilimulus, whilft the other part was alive, and continued iivthat ftate for many hours. This

very

ON POISONS, 355

very fingular phenomenon is not found either in fnakes or vipers^ every part of which becomes in- fenfible almofl at the fame time; and this difference may be principally caufed by the diverfity of mo- tion in thefe animals, when compared with the others.

I bathed the part of a leech towards the head, with the oil of the cherry-laurel. In lefs than three minutes there was no motion in this part, whilfl the other half was Hill living and in full adiion fix hours after.

I bathed the part of another leech towards the tail, and in lefs than two minutes found it motion- lefs ; the other part continued to move for fix hours.

I rubbed a part of a fnake's tail that I had cut, with the oil of the cherry-laurel; in lefs than half an hour it had loft all motion.

The Oil of the Cherry -Laurel is deJlruBive to Animals^ when injecled by the Jugular*

The multiplied examples I have related above, of the deleterious powers of the oil of the* cherry- laurel, induced me to think (notwithftanding I had two years before in London, injedted the fpiric of this plant into the jugular veins of rabbits without its caufing their death) that it might kill animals, when injeded into the blood. I prefumed that the

A a ;2, oil

356 :f O N T A N A

oil being much more pungent and burning than the fpirit, would adt on the blood with far greater energy. In confequence of this I made feveral ex- periments.

I injed:ed into the jugular vein of a large rabbit, ten drops of the oil of the cherry-laurel, with which I had mixed five or fix drops of water. At the moment the Hquor pafTed through the fyringe in- to the vein, the animal fell into convulfions and died. I opened the thorax, and found the blood blacker than it is in its natural ftate. The left ventricle and left auricle of the heart were almoft empty, and the littk blood that remained in them coagulated. The right ventricle and auricle were fvvelled, and filled with coagulated blood. There was no motion, neither could any be excited by llimulations. The lungs were covered throughout with large dark fpots, and all their veliels filled with coagulated blood, fome of which was like wife extravafated in feveral places. From the part of the liquor that remained in the fmallfyphon, I judge that fcarcely feven drops had entered the vein.

I tried the oil on another rabbit in a lefs quan- tity, only injecting five drops with as many of wa- ter. The rabbit became convulfed and died inflant- ly. I like wife opened the thorax of this one, and found the heart and auricles in motion. The right ventricle and auricle were fwelled, and the oppofite cavities contained a little blood. In a Ihort fpace the heart ceafed to m.ove, and I found the blood in the light auricle and ventricle fomewhat vifcous

a-c>d

0 K POISONS. 357

and black. In the oppofite cavities lay a little blood of a red colour. The lungs were flained with blood all over, but not fo much lb as in the former cafe^ and the blood in the veiTels feemed to be flagnant.

I do not think that more than three drops of the oil entered the jugular vein, and yet we fee that the animal died inilantly. It cannot here be doubted but that the eaufe of the death lay in the lungs, and in the blood that was found llagnant in their veffels. It isfuperfluous to remark that the fuddennefs of this event, and the certain marks of a general coagula- tion of blood in t4ie lungs, diredlly exclude the pre- tended action on the nerves, and furniih a certain proof to the contrary.

I have fince found that if the oil be injedred in a much fmaller quantity, either death does not enfue, or happens much later ; in this cafe there are very violent convulfions, which are certainly produced by the anxiety in the animal, caufed by the blood's becoming by degrees llagnant in the veiTels.

fhe Spirit Ukewtfe of the Cherry -Laurel^ kills when it is injcBed into the Ftffels,

On making thefe latter experiments it was natu- ral to fufpedl that the fpirit of the cherry-laurel, when injected into the veffels, would likewife bring on death, and that the experiments I made in Lcn- doa were not concluiive, becaufe they were too few

A a ^ in

358 F O N T A N A

in number, or perhaps likewile, becaufc I em- ployed a weak fpirit. Be that as it may^ I wifhed to aflure myfelf afreih by experiment, and I do not blulh to oppofe my own trials to new ones, more deciiive, more precife, and more numerous.

I prepared then a fpirit of cherry-laurel three times diHilled, and having put about fifty drops into the fyphon, I injed:ed them into the jugular vein of a rabbit. A fhort time after the injed:ion, perhaps in iefs than forty feconds, the creature died in con- vulfions, which were however not violent. Hav- ing opened the thorax, I found the lungs quite fpotted ; the fpots were very fmall, and refembled fo many dots of a darkilh red colour. The blooc} in the pulrnpnary velTels appeared quite vifcous and ilagnant, and I found it in the fame Hate in the heart.

This experiment, repeated on three other rabbits, varied but little in the refult ; one of them died at the moment of the injedion.

The fpirit I employed was highly adiive, an4 killed the animals very fuddenly to which I gave it in an exceedingly fmall dofe. I fhall not enter into a detail of any further experiments, becaufe thofe I have juft defcribed are fufficient for my purpofcj however I met with a cafe of a middling lized gui- neapigthat particularly deferves to be noticed. I made itfwallowateafpoonful of the fpirit ofthecher- ry-laurel of the third diftillation, which had fcarcely reached its flomach, when it fell as if dead, and re- mained in this flate for fix minutes ; it then fud- denly

ON POISONS. 355>

denly fprang up and began to run, although with fome difficulty. In a few minutes it appeared as flrong and lively as it was before it had fwallowed the -Jiquor ; I however found it dead two hours after.

It is then beyond a doubt that the fpirit of the cherry-laurel itfelf, given in fufficient dofes, and rendered more active by re-diflillations, is a violent poifon when introduced into the blood by the jugu- lar vein/ and that it kills inilantly ; fo that it is no longer an exception to the law I have eilabliilied of the other poifons^ which when introduced imme- diately into the blood, without touching either the nerves or the wounded folids, kill in an immediate way, and in a few inilants after bringing on con- vulfions. It is not only abfurd to have recourfe to the nerves to explain the action of the pOifon in thefe cafes, but this imaginary hypothefis is quite Superfluous, lince its violent efFecls on the blood are fo very evident.

^he Lunar Caujlkk does not render the OH of the Cherry-Laurel Innocent.

I wifhed to know whether the lunar cauflick, blended with the oil of the cherry-laurel into the form of a paile, would not ferve to correal it.

I made feveral fmall wounds in the pefioral muf- cles of a pigeon, and applied the pafle to them. In lefs than a minute it was feized with convuliions, and died an inftant after.

A a 4 I re-

360 F O N T A N A

I repeated this experiment on another pigeon^ which in fix minutes fell into violent convulfions, and died in a very Ihort fpace.

I made a comparative experiment, to fee what ef- fedtthe lunar cauftickalone would have, applied to the pedtoral mufcles of a pigeon. It was a little difordered by it, but foon recovered itfelf perfectly, without having been at all convulfed.

I applied the pafle I have fpoken of, to four other pigeons prepared in the ufual way. They all died convulfed in lefs than five minutes.

It is evident then that the cauflick alkali does not correct the deleterious qualities of the oil of the cherry-laurel ; neither does it corredt thofe of the fpirit, as I have found by feveral experiments, the relation of which I here omit.

On Opium.

I Vv'as a long time defirous of rendering myfelf acquainted by e:?:periment, with the effefls of opium applied to the living body. The little uniformity found in the authours who have treated on the pro- perties of this fubftance, was a flrong incentive to my applying myfelf ferjoufly tq fo interefljng a fub- je(5t. The experiments I had tried of the imme- diate application oT opium to the nerves, of which mention has been rn^d^ in the fecgnd volume of this work, were too few in number, and too little

varied^

ON POISONS. 361

varied, to enable me to fpeak with affuranee, and without the rifk of having myfelf been mifled by them, on this matter. A little leifure when I leail expedted it, at length enabled me to make a great number of experiments on opium, of which I Ihall at prefent content myfelf with giving the moil ge- neral confequences, with a fmall detail of neceflary particulars, to enable my readers to form a clear judgment on the fubjecft.

I had announced feveral years ago, that opium^ diflblved in fpirit of wine, and applied to the crura! nerves of frogs, deprives them of the faculty of con- trading the mufcles ; and that this effedt ought foljsly to be attributed, not to the opium, but to the fpirit in which it was dilTolved ; fince experiment had demonftrated that opium, fimply diiTolved in water, did not in any way derange the nerves to which it was applied. The farpous Haller availed himfelf of the experiments and conclufjons I have mentioned, in feveral parts of his publications againft the Englifh phyfician Robert Whytt, who every where fupported the immediate action of ppium on the nerves themfelves.

The various experiments which other naturalifls have made iince me, and which are not very con- formable to mine, and the different hypothefes which authours have latterly fupported on the adion of opium, have obliged me to repeat feveral of the experiments I made a long time ago, and to give them a greater extepfion and certainty.

I thought

^6z F O N T A N A

I thought it proper "^to begin with animals that have warm bloody and to apply the opium to the different organs and parts of the living body. And as fpirituous fubilances are one of the beil diffol- yents of opium^ I wiihed in the firft place to ex- amine all the effedis of a folution of it in fpirit of wine. I employed an ounce of opium and three of the fpirit well united together, and heated in balnea mari£. I likewife made a folution of opium in water without a drop of fpirit of wine, employing the fame proportion of water that I had done of the fpirit^ inixing it well with the opium in a mortar, and keeping it feveral minutes in a jar in balneo mari^ ; I then added frefh water according to the exigen- cies of the different experiments.

Refv.lt of the Experiments.

Guineapigs which I made fwallow a fpoonful of fpirit of wine, inltantly became motionlefs, and died in lefs than 20 minutes. Thofe that fwallowed the fpirituous folution of opium, became motionlefs in a few minutes, and died in lefs than twenty-feven.

Thofe into the bellies of which the fpirituous fo- lution was injedled, became motionlefs in an inftant, and all without exception died in lefs than half an hour.

Thofe beneath the fkin of which I injeded the | fame preparation of opium, died in lefs than half

an

O t^ P O I S O N S» 363

an hour ; and I had fcarcely made the injedion, when they could no longer flir their hinder feet.

Thofe into the anus of which I injedted it, at the jEnd of half an hour could no longer fupport theni- felves, and died in an hour.

Thofe that drank the fpirituous folution died 111 three hours ; they had fcarcely fwallowed it when they became infeniible and motionlefs.

Thofe into the bellies of which the aqueous folu- tion was inje(?Led, died in lefs than two hours ; they loft the greater part of their motion in lefs than half an hour, and were violently convulfed.

Thofe, beneath the ikin of which the fame folu- tion was injedied, died in three hours. In the fpace of half an hour they had iofl; all m.otion, par- ticularly that of their hinder feet.

Thofe that I made fwallow this aqueous folution, were very foon incapable of moving ; but only two died, of tenon which I tried the experiment..

Thofe into the anus of which the aqueous folu- tion was injed:ed, died in lefs than three hours ; in the fpace of half an hour they could no longer fupport themfelves on their feet.

It is then a fadt, confirmed by all my experiments, that opium, when limply diffolved in water, kills animals with warm blood ; although it is belidea true, that when diffolved in fpirit of wine, its ef- fects are much quicker and more violent ; but they then proceed, in a great part however, from the fpirit itfelf, fince we have feen that this fpirit is ^lone capable of producing all theie eiFejfts,.and that

it

364 F O N T A N A

it even produces more violent ones, and that more expeditioufly.

My experiments on bpium, either dilTolved in fpirit of wine, or limply in water, have been hither- to made on animals with warm blood. I was d^.^li-. Tous of repeating them, varying them, and render- ing them general, on thofethat have the blood cold, and prefumed that I Ihould obtain confequences equally new and important, lince I was about to operate on creatures much more irritable than th.6 Others, and in which life is of longer duration, and more tenacious. *

I chofe turtles and frogs, in preference to fe- veral other animals, and likewife made fome trials on leeches; a very lingular creature, and one which differs, as well in its organs as in its vital fundlions^ pom all other known animals*

Refiilt of feveral Experiments made on Leeches^

Leeches immerfed in fpirit of wine, died in two or three manures.

Leeches immerfed hi a folution of opium in fpi- rit of wine, died nearly in the fame fpace of time.

Leeches immerfed In a folution of opium in water, died pretty nearly in the fame fpace of time.

I plunged half the body of a leech into fpirit of wine, and found in a little time that this part had loft ail motion, vvhilil the other half continued in

adion^

%

ON POISONS, 365

adtion* The experiment fucceeded in the fame way, whether the part of the leech towards the head was plunged, or that towards the tail.

The fame confequences enfued on plunging a leech into the folution of opium in fpirit of wdne, or into the folution of it in water ; and I looked upon it as fomething very' extraordinary, that one half of the creature ihould become dead, whilft the other half continued in the flate of not having undergone any change, or fuffered any injury. As to the adtion of opium on thefe animals, it appears certain that it iliould be confidered as that of a very violent poifon.

Experiments on Turtles^ made to fwallow different Suhjiances*

A turtle which fwallowed fpirit of wine, died iii iefs than 20 minutes.

Another turtle which fwallowed the folution of opium in fpirit of wine, died in the fpace of an. nour.

Another, after having fwallowed the aqueous fo- lution, preferved its vivacity for four hours ; it died at the end often.

I repeated tuefe three experiments with the fame circumftances on fix other turtles, and the con- fequences were perfedly analogous to the preened-

366 IF O N T A N A

It is eafily feen that opium, although diflblved in water, a6ts violently on thefe animals, fo as even to kill them ; but that its ad:ion is but triflings when compared with that of fpirit of wine.

InjSions made into the Anus of Turtles.

^ I injedled three turtles of the fame fize, at tBe anus, by means of a fmall glafs fyringe. On the firft of them I tried fpirit of wine, and in a few minutes it could fcarcely Itir. At the end of an hour, it was quite dead.

I injedied the fecond with an equal quantity of a ftrong folution of opium in fpirit of wine, and in half an hour it fcarcely feemed alive or able to flir : it died at the end of the feventh hour, but the mo- tions of the heart continued for an hour after.

I injedied the third with the fame quantity of the < aqueous folution : it was very lively at the end of the fixth hour, and furvized the fixteenth.

I have however obferved in general, that turtles do not die when injedred at the anus with the folu- tion of opium in water. Thofe I injedied with the fpirituous folution, all died in lefs than three hours : the injedlion was fcarcely made when they loll their ftrength and vivadty, and in half an hour they almoft ceafed to give any figns of life.

The adlion of the aqueous folution of opium, when Introduced by the anus^ is clearly proved ; but it is

very

ON POISONS. '^d'j

very flow and weak, when compared with that of the fpiritof wine.

InjeBlon made beneath the Skin of Turtles^

1 made an opening with a lancet in the Ikin be- twixt the legs and belly of a turtle, and injed:ed within it fpirit of wine. In a few feconds the tur- tle became motionlefs, and died in lefs than an hour.

I injeded another turtle in the like way, with an equal quantity of the fpirituous folution of opium. In feven minutes it became without motion, and died at the end of four hours.

I injected a third with the aqueous folution of opium. It continued lively for two hours, but died at the end of the eighth.

The refult of a repetition of the fame experiments on nine other turtles, was perfectly analogous to that of the foregoing ; fo that there can be no longer any doubt of the adiion of an aqueous folution of ©pium, injedled beneath the fkin of turtles.

Turtles in which the Heart was laid bare.

I wifhed to fee what changes would be wrought in the heart of a turtle, on applying to it opium, and fpirit of wine.

0^ I ftrip-

368 - F O N T A N A

I ftripped the pericardium from the heart of a turtle, and applied to it fpirit of wine feveral times fucceflively. In twenty minutes it had loft all mo- tion, notwithftanding the animal continued alive- It died however in lefs than an hour, when no part of Its body was any longer irritable.

I applied the fpirituous folution of opium to the heart of another turtle, prepared as above. In half an hour it was become motionlefs^ even to ftimula- tion. The animal died at the end of three hours,

i applied the aqueous folution of opium to the heart of another turtle, and it continued its motion perfedtly w^ell for two hours : it ftill ftirred a little at the end of the iixth* The turtle lived eight hours*

I applied an aqueous folution of the cortex to the heait of a fourth turtle ; it had ftill retained a little motion at the end of the fixth hour^ The turtle died on the eig-lith.

I laid bare the heart of another turtle, and fprink- led it fucceflively with feveral drops of fpirit of w'ine. The two auricles inftantly ceafed to move, and the heart in lefs than two miniites had no longer any motion, even when ftimulated. The turtle liv= ed a long time in this ftate.

1 opened the thorax of three turtles, on the heart of one of which I poured the aqueous folution of opium., on that of another the fpirituous folution, and on that of the third the liquid laudanum of Sy- denham. That en vvhich the fpirit of wine was poured ccnthiued to move feveral hours longer

4 thari

ON POISONS. 3O9

than the other two, which ceafed their motion as if it had been by concert. The contraftions of the auricles of the heart on which I had poured the laudanum, were for fome time two by two, they then became three by three, foon after which the animal was quite dead. The heart continued a longer time contraded, in proportion as the inter- vals betwixt its contractions were of greater dura* tion; a new and lingular phenomenon, which cannot be readily explained by the common theo^ Ties.

Thefe experiments are not fufficient to deter- mine that a folution of opium in water has no ac- tion on the heart ; particularly as ^ when it is applied during the time this vifcus remains in the thorax^ there are veffels and blood that may ferve to intro- duce it into the torrent of the circulation, and carry it to the other vifcera, by v/hich a derangement of the animal economy may be brought on ; fo that we cannot in this cafe attribute what may perhaps be the effed: of a change in the blood, or of fome other unknown caufe, to. its immediate application to the heart : to render the experiment deciiive and unequivocal^ it mufl be made in fuch a way, that all the other parts being excluded, the heart may alone feel the adion of the opium. It ftruck pie then to purfue the following method ;

Vol. II. Bb Turtles,

27<^ J O N T A N A

furtks, the Hearts of which were detached from the-

Thorax,

I removed the heart of a turtle from the thorax, and covered it with fpirit of wiae* Its- motion ceafed in a few minutes.

I put the fpirituous foiution of opium on the heart of another turtle. In the fpaee of a quarter of art hour there was fcarcely any eontraftion of it, and in twenty-fix minutes it no longer flirred, even when fiimulated,

I plunged the heart of another turtle into the aqueous folution.^ It ftiil continued to move, but not forcibly, at the end of half an hour. In two* hours alliiMS at reft. * -

I plun^n another heart into fimple water, and it ftill retained a little motion at the end of the third- hour.

Another: plunged into the aqueous folution of the cortex, ceafed to move at the end of two hours.

I made three other experiments on the heart, feparated from the thorax, and plunged into the fpirituous folution of opium, and could not perceive any fenfible difference in the diminution and lofs of its motion, when compared w^ith that of three others, two of which I had immerfed in the folu^ tion of the bark, and the third in water.

o i^ p o 1 s o i^ s. 371

it. feems then very probable, if not very certain, at leaft from the few experiments I have related, that a folution of opium in water has no imme- diate adion on the hearts of turtles : a new and itii- portant truth, contrary t6 the opinions of the greateft naturalifts of this age, and which Ihould induce others that have more leifure than myfelf, to invefligate this important matter, by multiply- ing their experiments, varying them many different ways> and guarding themfelves as much as pof- iible againft all accidental circumftances. Care iiiuft be taken that the opium may not form a glu- tinous fluid, and that it may not dry fpeedily when applied to the part. I avoided this inconvenience by Wetting the part from time to time with water.

Frogs that have heeh made to /wallow Opium*

1 made a frog fwallow about forty drops of fpi- i-it of wine. In forty minutes after I found it dead.

I made a fecond fwallciw forty drops of the fpi- rituous folution of opium. At the end of forty minutes it was deadi *-

I made a third fwallow the fame quantity of the

aqueous folution^ twenty-five minutes after which

it fcarcely flirred. It was then lying on its back

' with its legs ftretched out. It died in fomewhat

lefs than three quarters of an hour^

B b 2 ' On

^yi F O N T A N A

On repeating thefe experiments on twelve other frogs, I found a very feniible difference, but not fuch as to enable me to fay to a certainty, that the aqueous folution of opium itfelf, kills frogs in a little fpace, and that it caufes convulfions and a^ drawing back of the mufcular parts*

Frogs injeBed heneath the Skin.

I injefted a frog beneath the fkin with fpirit of wine. It died a minute after.

I injedted a fecond witfi the fpirituous folution of dpium, and in a ihort time it could not fupport it- felf on its feet. It however was able to crawl a little at the end of thirty-five minutes, and died on the fortieth.

I xnjefted a third with the aqueous folution of opium. In the fpace of ten minutes it fcarcely ftirred, and had its legs flifFand extended. It died in forty minutes.

I repeated the fame experiment on feveral other frogs, and the confequences were pretty much the fame. It is certain then that the aqueous folution of opium kills animals, when injedted beneath the ^in.^

"The.

O N P O I S ON S. 373

fbe Hearts of Frogs laid hare^ hutjlill remaining in the

Thorax,

I covered the hearts of three frogs with the aqueous folution of opium, and a fourth with water alone, by way of a comparative experiment. I could perceive no great difference in the ceiTation of the motion of the four hearts.

In fix other frogs I found that the motion had ceafed fomewhat fooner in the hearts to which I had applied the opium ; but having again repeated the experiment on fix others, I found on the con- trary that the motion of thofe hearts to which I had applied the opium, ceafed much fooner thai> thofe to which I had applied the folution of the cortex ; fo that I cannot conclude from thefe ex- periments, that opium, in frogs however, dimi- niihes the irritability and motion of the heart.

To enable me to ellablilh fomething more cer ^ tain, I made the following experiments.

Hearts of Frogs feparate^ from the fhara.\%,

I put the heart of a frog into fpirit of wine. Its motion ceafed in two feconds*

I put a fecond heart into the fpirituous folution of opium. It ceafed to move in twenty feconds.

• Bb 3 I put

274 ^ ^ ^ "^ ^ -^ -^ '

I put a third into pure water. It continued in motion for forty minutes.

I put the hearts of three frogs into pure water. The motion of one of them ceafed in twenty-one minutes ; hut it fpontaneoully recovered its ofciU lations^ and that repeatedly.

The fecond lofl its motion in ten minutes, but recovered it of itfelf.

The third ceafed to move at the end of fifty minutes.

I repeated thefe experiments on upwards of fifty hearts feparated from the thorax. I endeavoured to obferve the fame circumftances in all of them. I put feveral of them into the folution of the corteXj^ others into pure water, and others again into the aqueous folution of opium. The confequences have been very diver fified, and very inconltant ; I could not however conclude that opium has a real aStion on the hearts of thefe animals, when applied in the above manner. Such at leafl: is my prefent opinion, and it is my defign to make at a future period a greater number of experiments.

It now remained for me to make a new kind of experiments, which are perhaps the molt impor- tant, and the objed: of which is to examine whether opium afts on the nerves.

Fr^ih

ON POISON s. 375

FrvgSy the Brain of which was laid hare.

I laid bare the brain and fpinal marrov^ of a frog, and applied to them *fpirit of wine. In ten mi- nutes the frog could fcarcely move, and was dead in thirty-five.

I applied pure water to the brain of another frog prepared in the way with the preceding one. It was flill lively twenty-four hours after.

I applied the aqueous folution of opium to the brain of a third, which at the end of twenty mi« nutes moved with difficulty.

I applied to another the fpirituous folution of opium, and thirty minutes after, it was Hill able to move a little.

I applied the aqueous folution to another, which in forty ipinutes was drawn together, and llirred but little. It died at the end of the fifty-feventh.

I applied the fame folution to another, and thirty minutes after found it contradled, with the body drawn backwards, and the hinder feet liretched out and lengthened.

I applied fpirit of wine to another, which died at the end of ten minutes. The heart however con- tinued Hill in motion.

Another treated in the fame way died in twenty- feven minutes, and another again in forty-five ; both of them after a few minutes moved with difficulty.

On repeating this experiment on another frog, it died in fifty- four minutes ; at the end of thefeventh it fell into convulfions, and could neither walk nor fupport itfelf,

B b 4 Another

376 F O N T A N A

Another treated in the fame way was feizQd with very ftrong convulfions, and after four minutes was no longer capable of walking.

^he erural Nerves of Frogs laid bareS

I opened the belly of a frog, laid bare the crural nerves, and applied the fpirit of wine to thofe on the right fide. At the end of four minutes I repeat-? edly flimulated the right foot, which renlained con- ftantly motionlefs.

To thofe of another I applied the fpirituous folu- tion of opium. After eight minutes I found that the right foot could no longer fupport itfelf^ in what way foever 1 flimulated it ; but fcarcely did I fli- mulate the nerves of the left fide, when the left foot contrad:ed itfelf perfedtly well.

I applied to the crural nerves of the right fide, in a third frog, the aqueous folution of opium. At the end of two hours, the right foot flirred on flimulating thefe nerves, but not fo well as the left foot did, on flimulating the nerves of that fide.

1 applied the aqueous fplution of opium to the <prural nerves of the right fide, in three frogs, and fimply applied water to the correfponding ones of the left ; the motions as well of the mufcles of the right fide, as thofe of the ieft^ geafed indifferently.

rhi

O K T- K7 T S O 2^: S. 377

The crural Nerves of Frogs, to which a partial Ap" plication zvas made,

I applied fpirit of wine to one fide only of the crural nerves. At the end of nine minutes, they could no longer contrad: the feet when llimulated on that lide ; but flimulations on the other fide had a contrary efFecft.

I again applied the fpirit of wine to one of the crural nerves only. At the end of four minutes they no longer contracted the feet, which moved however when Simulated at the part where the fpirit of wine had not touched. On touching the other nerves, the mufcles every where contraded themfelves very well ; a proof that the adibn of this fluid does not extend to beyond the parts that are touched by it.

I got ready a frog for a comparative experiment^ to the nerves of which I applied nothing ; at the end of forty minutes it flill contradted its feet.

The foot of another frog, four minutes after I had applied fpirit of wine, no longer contradted itfelf, unlefs when the part of the nerves towards the legs and thighs, where the fpirit had not reach- ed, was Simulated,

The

57$ • F O N T .A N A

The Crural Nerves of Frogs detached from ikti Vertehr^e,

I cut the crural nerves at their going out of the Tertebrse^ and applied fpirit of wine to thofe of the right iide. At the end of two minutes the light foot, although itimulated, and its nerves prick- ed, no longer contracted itfelf; whilfl the nerves cf the oppolite fide w^ere fcarcely touched, when the left foot contracted itfelf forcibly.

I applied the aqueous folution of opium to the Tight fide of another frog prepared in the fame way* At the end of thirty minutes I found on irritating the nerves, that the correfponding foot moved, but not fo forcibly as the left foot on ir* ritating the nerves of that fide.

I plunged the crural nerves of another on one Iide into the above folution of opium, and thofe on the other fide into pure water, and found each of them, when irritated, to contrail the feet alike, even at the end of fifteen minutes.

Thefe experiments are not at all decifive ; they may however furnilh matter to a variety of re- flediions. Notvvith (landing it appears indubitably that opium, even when'fim-ply dilTolved in w^ater, whether it is introduced into the ilomach by the cefophagus, or into the inteilines by the anus; whether it is injeded beneath the fkin, or into the

abdomen i

OH POISONS, ^y^

abdomen ; whether it is applied to the brain, or to the medulla oblongata ; aS:s on the anhnal body : yet a doubt remains whether its ad:ion and energy are wrought on the nerves, or whether it needs the vehicle of the blood and circulation, and the mo- tion of. the humours, to give it adivity. We have feen that the venom of the viper ads in no other way than by the medium of the blood ; and the two vegetable poifons of the ticunas and cherry- i laurel appear to ad: in the fame manner. It is ' certain that all poifons, as well as opium, kill when 'fwallowed; but this does not prove that their ac- tion is wrought immediately on the nerves, and that they do not employ the medium of the blood* There are many paffages open in the mouth, in the oefophagus, in the flomach, and in the inteflines, \ through which the mofi nimble and adive parti- cles of thefe poifons may introduce themfeives I readily into the blood. Thus the difficulty which i arifes from the mortal effeds of opium when ta- ken internally, does not prove that it ads imme- diately on the nerves ; and we have befides de- monftrated that the three poifons, the venom of the viper, the ticunas, and the cherry -laurel, have no immediate adion on the nerves themfeives.

To be enabled to make fome very probable af-- fertion on this difficult matter, an experiment muft be imagined in which opium may ad freely againfl the nerves, without the fmalleft introdudion of it I into the blood, or rather, without its touching the Hood-veiTels, Such an experiment, coniidering

the

580 F,0 N T A N A

tjie dexterity and preclfion it requires, is not one of the ealieil to make, and can be only well tried on very fmall animals, and on a very few of the ijerves. I could think of nothing th^t would an- fvver my purpofe better than the crural nerves oi frogs. To obtain certain confequences, and fuch. as do not proceed from deceitful and variable ex- periments, it was neceffary to make a great many trials,, to exclude all the preparations that acci- dental circumitances might have rendered imper- feift, to compare the different confequences with each other, and to weigh them in each cafe, with thofe of the experiments intended to ferve as com- parative ones.

The following is the plan I have purfued in mak^ ing thefe experiments. As the number of theni already exceeds 300, I fhall regard the inferences I have drawn from them as certain, till fome one fiiall be able to demon ftrate to me the contrary. - I open the belly of a frog, and lay bare the cru* ral nerves, by means of fmall pincers and fcifiars, in fuch a way that they are entirely freed from every other part. I then cut the vertebra and body of the animal in two, precifely at the place from whence thefe nerves go out, which, by gently agi- tating the neighbouring parts, fall betwixt the thighs of the animal. In this Hate, I remove the thigh bones, and totally clear the nerves for the. length of eight or ten lines, and in very large frogs t>f even more. I let fall the nerves of each thigh into a fmall hollow glafs, which receives them iu

fuch

OK FOISONS. 2^i

fuch 1 way, that I can fill each glafs with a fluid of any kind without its touching the adjacent muf- cles ; the nerves are not only freed from eacll other, but llkewife from all contad: with the thighs^ I ufually put into one of the glafles, fuch a pro- portion of whatever I wifh to try on the nerves, a^ to cover the greater part of them with it, without its being poffible for any of the liquor to End its way to the thighs, and mix with the blood. I take the precaution not to leave any veflel faflened to the nerves, and^to put a little \^ater into the other glafs, to keep the contents of it wet like thofe of the firfl. In this way I can make a comparifon betwixt the nerves that are enve- nomed, and thofe that are not, compute the time that they continue to contract the mufcles, and judge of the vivacity of the motions.

I deitined 300 frogs for thefe experiments, and divided them into ten elafies, according to the dif- ferent intervals of time that I kept them under trial. Thus I kept the crural nerves of the firft clafs, whicil as well as all the others was compofed of thirty frogs, in contadt for ten minutes, with an aqueous folution of opium on one fide, and with water on the other. Thofe of the fecond remained in the fame Hate for twenty minutes, and fo on to an hundred, after which time the nerves were no longer capable ot contradting their mufcles. It is true, that in fome other experiments I have found that 100 minutes were not fufficient for the nerves to entirely loib the power of contrading the mufcles; but thcfe

dilTerenl'.

^82 I? O N T A N A

different confequences depend upon a thoufand particular circumftances, and do not invalidate the law of effects that I have cbferved in this feries of 300 experiments*

This is the refult of the trials I have made. At the end of the firil ten minutes, I Simulated the medicated nerves ; 1 Ihall dillinguilli in this way thofe to which I applied the opium, and thofe which were not medicated, and found that the two feet,, light as well as left, eontradted with the fame force and vivacity.

At the end of twenty minutes, I tried the Simu- lation on the fecond clafs of frogs, and could per- ceive no fenfible difference betwixt the motions of the two feet, which were almofl as lively as thofe in the firfl experiment.

At the end of thirty minutes the motions of the two feet were feebler, but alike in both.

At the end of forty minutes, the het fcarcelv con- tracted; but their diftindt mufcles were clearly feeii to contrad, when the crural nerves were Simulated; and the motions of thefe mufcles were equally lively in each foot.

At the end of fifty minutes^ the mufcles were dif- tindly feen to move, but not fo much as before^ The motions were however equal in the mufcles of both feet.

At the end of iixty minutes the rndtidns were very fmall, but alike on both fides.

At

ON POISONS* 3^3

At the end of ieventy minutes a great deal of atten* tion was necelTary to diflinguifh them to a certain ty,, t3ut I could find no difference betwixt the motion of the mufcles of . the right foot, and that of thofe of the left.

At the end of eighty minutes there was no longer any motion to be obferved in feverai of the frogs^ in whatever way I fllmulated either their crural nerves that were medicated, or thofe that were not fo. But in the others of this clafs, I could not find that the medicated nerves were lefs ready to contract the mufcles, than the others.

At the end of ninety minutes, very few of the frogs retained any m.otlon, on their crural nerves being flimulated ;" and in the thirty that formed this clafs of the experiments, I could not find that the opium had wrought any greater change on the nerves^ than the fimple water.

. At the end of loo minutes the mufcles of the legs were immoveable, in whatever way they were {l:lmu- lated on either fide.

I can conceive nothing more declfive and more certain than the ferles of experiments I havejull re- lated, from which it feems of neceffity to follow,- that the circulation of blood and humours in the machine is the vehicle for opium, and that without this circulation it would have no- adlon on the living body*

the

384 F O N t A N A

l^he aqiieou^ Solution of Opium injeHed into the Bloocl' vejfels of Rabbits.

It now remains to be fecn whether opium, when injedied into the veiTels, caufes death, and whether it produces the fame derangements in the animal economy, when introduced into the circulation of the blood, as it does when fwallowed, or injedled into the different organs and vifcera.

1 injedted about eighteen drops of the aqueous folution of opium into the jugular vein of a large rabbit. It was fcarcely inje<fted when the creature could no longer fupport itfelf, or walk, and its legs were bent and drawn afide. It recovered in a few hours. I conceive that fcarcely eight drops of the folution entered the vein. -

1 repeated this experiment on a fecond rabbit, the legs of which, as in the firil inflance, v/ere bent and drawn afide. At the end of two minutes, it fell on its breaft, moving itfelf a little now and then. Af- ter half an hour it ran about freely, and became per- feftly well.

The injedtion tried on another rabbit did not fuc- ceed, fince the opium, inftead of entering the jugu- lar vein, pafTed wholly into the cellular membrane. This rabbit had no ailment*

1 en-

ON P O I S O N g. 3S5

I mjefted into the jugular vein of another rabbit a tea-fpoonful of the fame aqueous folution^ and it died inftantiy,

I ^repeated this experiment on another rabbit, with the fame quantity of the folution, that is to fay about forty drops ; the creature died at the mo- ment of injedlion.

I repeated this experiment on another rabbit, with the fame dofeof the folution, a great part of which, however, flowed back during the injedlion. Theani- mal could no longer walk, nor fupport itfelf on its feet, which were flretched out. It died at the end of two hours.

I conceive it to be altogether fuperfluous to re- late, for the prefent however, a greater number of experiments on opium, injed:ed into the jugular vein, and introduced into the circulation, without its touching any of the wounded folids. When once it is received into the velTels, I do not fee how it can communicate itfelf in an immediate way to any of the nerves, fince anatomy afTures us, that the inner membrane of the blood- vefTels is not furniihed with what can properly be called nerves; andalthougli this fhould even be the cafe, opium, on touching a nerve, does not act on it in any -way, nor produce any derangement in the anim.al economy, in what- ever way it is applied to a nerve, whether that nerve is entire, or cut ; whether it is covered with its proper coats or fheaths, or its medullary pulp itfelf is put ia contadl with the poifon. In Vol, IL C c ail

^M F O N T A N A

all thefe cafes, without any exception, opium haS been found innocent.

Thus then, opium injedted into the veins, pro- duces heavinefs, convuUions, and, at length, as has been feen, death itfelf. Wine produces pretty- nearly the fame efFedls. Spirit of wine diluted with water, likewife produces heavinefs and con- vulfions, and if genuine and rediified, kills in an in- flant* The blood is then found congealed in the vena cava, in the auricles, in the right ventricle, and in the lungs ; certain efFed:s, and fure caufes of death, without our being driven to any recurrence to the nerves.

Emeticks and purgatives when injefted, bring on vomiting and ftools, as if they had been taken by the mouth ; a proof that their adiion conveys itfelf unaltered, to the flomach and inteftines, without the concurrence of the nerves, and in the fame way as if thefe fubflances had been fimply fwallowed. And why not fay as much of opium, when it is fwallowed too ? If there is no recurrence ^ the nerves in the cafes of emeticks and catharticks, and there can be no reafonable recurrence to them, why ihould the nerves be employed to explain the adtion of opium, whilft this fubflance, when applied imme- diately to the naked nerve, does not adt on it in any manner, and produces neither change nor derange- liient in it ? I do not however think, that any one will recur to the nerves, in the cafes in which opi- um, injedted into the jugular vein, kills, as has beea feen, inftantly.

Ida

ON POISONS. 3§5?«

i do not pretend to exclude by my reiterated ex* periments, any other than the immediate action of opium on the nerves ; and my aim is to prove, at the fame time, the immediate adiion of opium on the blood, independent of the nerves, without per- plexing myfelf with the imaginary hypothefes that neurologifls may invent to fupport old errours and prejudices, and to make them agree with ^he princi- ples 1 have jufl eftabliihed. Real phyficians have now a bafis of certaiil experiments on which they* may for the future found their theories on opium^^ which has been the fubjedi: of fo much difcuffion^ and which is fiill fo little knov/n ; and I flatter my- felf that they will refolve to fet afide the hypothefes and received opinions they have imbibed in the fchools, and refied: maturely on the circumitances I have jufl related. I know the power of a prejudice in favour of old erroneous dodtrines, and how great the refiflahce is even to the moli certain and lumi- nous experiments. The man w^ho is at length con- vinced of the truth of fadis^ which are always irre- fiftible, will not liilen to the mofl dired: confe- quences. Prejudice has certainly a great fhare in this repugnance ; but it is, above all, our felf-love that dreads to adopt new truths^ becaufe they carry with them a tacit avowal of our ignorance ; hence arifes the difficulty of bringing thofe who are ad- vanced in years, and men of learning who have al- ready acquired a reputation, to admit of new difco- veries,

Cc 2, Ltt

^SS F O N T A N A

Let not the fuddennefs of the efFefts of opium, and the infenfible diminution of its weight, be brought in favour of the nerves, againft the blood : fince it has been feen that the venom of the viper, the Ticunas, and the Cherry-laurel, when injected into the jugular vein, aft inflantly, fo as to occaiion death, even when employed in very fmall quanta- ties ; and'ilnce it has been found by experience chat the ad:ic'i or €fiQ&: of thefe poifons is wrought on the blood, and not on the nerves. Oil of vi- triol kills, v/hen injected into the blood, even in a very fmall quantity, and no one, I apprehend, will fay that this liquor ads on the nerves, and not on the blood. Common oil, and many other innocent fubftances, Vv^hen injeded in the fame way into the? blood, kill even very fuddenly, and produce very Urong convuliions. Every one muft perceive, that all the derangement thefe bodies can bring about in the animal economy, is ifim ply mechanical, and de- pendant on the floppage or diminution of the circu- lation in the different vifcera, and not on an affedtion of the nerves. We mull not even be afloniihed at obferving very great derangements produced by ve- ry fmall quantities of matter, fnice the adlive part of bodies, and particularly of medicaments, is abfo- lutely confined to very fmall maffes, I can almoft fay, to atoms. And I cannot conceive how any force can act on the nerves, and occafion the greatefl difordersin them, and can yet in no way adton the blood, whilft we fee that the --oVo part of a grain of the venom of a viper is fufficient to kill a bird,

when

ON POISONS. 389

when mixed with its blood; and perhaps that which renders this animal gum poifonous, may ftill again fee no more than the t^W part of this fradion of a grain.

Dr. Robert Why tt ftarts, as an argument againft the blood in favour of the nerves, that when the heart of a frog is removed, the opium it is made to fwallow adls equally againll fenfation and motion ; but that when the head is cut off, and the fpinal mar- row deflroyed, the opium operates flower and lefs violently. The firil part of this reafoning is, as has been feen, altogether falfe, and the other part, even if it were true, would prove nothing ; becaufe when the brain and fpinal marrow are deftroyed, the ani- mal economy may be fo changed, that th€ opium can no longer adl, as- it previoufly did, in a ilate of health. Indeed purgatives, emeticks, and poifons in general, only ad: on living animals. But in the prefent caf«, Whytt's experiment is not conforma- ble to mine, which I have however repeated feveral times with the utmoil attention. Here again, a few experiments can decide nothing, confidering the great diverfity that attends the event of them.

To render the experiment m.ore fimple,* and fub- je6t to fewer difficulties, I did not cut off the head of the frogs, but made afmall opening in the cra- nium, through which, with a large pin, I deftroyed the whole of the brain and fpinal marrow. In this [ way I avoided the great lofs of blood that the ani- mal fuflains on its head being cut of, and facilitated the comparifon with the frogs that had been made

C c 3 to

^go F O N T A N A

to fwallow opium, without the brain and fpinal mar- row. I noted the duration of the heart's motion, and from time to time llimulated the crural nerves pf all of them. I can certify, that having pre^. pared forty- eight frogs, twenty- four in one way, and twenty-four in the other, I could not perceive the opium to ad: later, or more feebly, in one cafe than in the other,

I however deduce from thefe confequences two very important corollaries ; the firft of which is, that the motion of the heart neither depends on the perves, nor on that chain of fenfations that con- flitutes animal life. The fecond is, that the ^dtion of opium is independent of the nervous fyilem.

I find in feme authours a flrong argument againft the bloqd, in favour of the nerves, in the cafe where opium is injedied into the veiTels : it is, that the ad:ipn of this fubflance is fuddenly carried to the nervous extremities of the blood-veflels them- felves, and from thence to all the other parts of the nervous fyftem. It cannot be denied but that flefhy fibres are obferved in the large blood-velTels, whence it is certain, that there are likewife nerves in thefe parts, fince there is no mufcle without a nerve. But thefe fleiliy fibres are only obferved in the large trunks, and not elfewhere ; and it would be abfurd to imagine a flrudture that is belied by obfervation, with the only view of fupporting an hypothefis which is combated on fo many fides. It is cer- tain that no nerves are feento go towards the blood-

yefiTelS;,

ON POISONS. 291

vefTels, to unite themfelves with them, lince the greateil anatomills have not been able to find any. On another hand, the fenlibiiity of thefe vefTels is in no manner demonftated, and I have fucceeded in tying them many different ways, without the ani- mal's giving any fymptom of uneafinefs. Indeed very great attention mull be paid in mailing thefe experiments, which are exceedingly nice, that the velTel at the place where it is tied is well cleared of all the neighbouring parts ; that it is not tied at a part which may be accidentally crolfed by a nerve in its paiTage el fe where ; and that in tying it, neither the velTel itfelf, nor the adjacent parts, is dragged. I muft likewife recommend the not ope- rating on very large velTcls, lince I have fometimes obferved, that if a large torrent of blood is fud- denly flopped, the animal appears to faffer from it. It is, in Ihort, a thing known to all the world, that the internal membrane of the veffels is neither muf- cular nor nervous, and therefore opium cannot ad: immediately on the nerves, from the fole caufe of its being put in contadt with the inte,rnal coats of the veffels. •

Iwiihed to fee whether opium^ when fwallowed, would diminilh the force and velocity of the contract tions of the heart, fmce it appears to have no ad:ion on this mufcle, that relates to the duration of its motions. I mull confefs, that I could eftabliih nothing certain on this point, notwithftanding I diredied upwards of one hundred experiments to this objeft alone. I found a great variety and in- C c 4. conflance

29^ F O N T A N A

conilance in thofe on the frogs, on which I princi- pally operated. I obferved in general that opium given to animals with warm blood, in moderate dofes, increafes the force and motions of the heart ; but that if it is given in a great dofe, it feems at once to diminiih the vigour of the animal, and the force itfelf of the heart : in this it refembles many other fubilances that tend to dellroy life, and to abate the vital powers. The adlion of opium is thus found to be quite comformable to the fymp- toms that we obferve in man, when it is taken in- ternally. The ofcillations of the heart, far from being diminifhed, are mofl frequently increafed ; and the few contrary inftances that may be found, do not in any way change the general law of the aclion of opium on animals.

I made twelve frogs fwallow each about twenty drops of the aqueous folution of opium, and in- ilantly feparated the heart from the thorax. I opened the thorax in twelve others, but did not re- move the heart ; all of thefe, as Vvell as the others, had previoufly fwallowed opium. I noted the time of its adion on all the twenty-four, and found that the effedts of the opium difcovered themfelves much fooner in the frogs, the heart of which remained in the thorax, than in thofe from which I had removed it. The difference in time was more than one- half. By the efFeds of opium, I mean the faculty it pofTefTes of rendering the limbs paralitick ; that is to fay, of depriving the animal of the power of exercifing its mufcies. I do not here fpeak of the 3 heart

ON POISONS. 293

he^rt itfelf^ which continues to move for a very long fpace of time^ even after the animals are dead; nor of the nerves, which, on being Simulated, are yet capable of contracting the mufcles, although the creature can in no way move them of itfelf.

We muil diflinguifh, then, the voluntary motions of the animal, from thqfe that are excited by an ex- ternal Himulus ad:ing on the nerves, the fpinal mar- row, and brain. The latter are not always wanted, when the former no longer exift ; but in all cafes where the latter are not obferved, the former are in- fallibly w^anted.

There is another thing to be diftlnguifhed in fpeaking of the nerves, and of motion ; this is the fenfation, of which the nerves are the only organ in animals. In the courfe of my experiments I have frequently obferved, that when the animal could no longer move any of its parts, if 1 llimulated its nerves with needles, or applied pincers to them, it gave very certain fymptoms of fenfation. It is be- fides equally true, that the mufcles frequently con- trad: on Himulating the nerves, notwithflanding the creature has been a long time dead. So that the motion of the heart, and the power the nerves poilefs of contrad:ing the mufcles v\'hen llimulated, decay much later than the voluntary motions and fenfations.

I have likewife obferved, that opium, on being applied immediately to a nerve, not only does not deprive it of the faculty of contracting the mufcles, but likewife does not dellroy Its natural fenlibility; '

and

394 ' F O N T A N A

and It has been feen, that its effects are quicker when animals have been made to fwallow it without their heart having been taken out, than when they have been deprived of that mufcle. It feems to follow from all thefe particulars, that opium does not aQ: immediately on the nerves, but has need of the circulation of the blood and humours, in exer- eiiingitfelf on animals.

I here conclude the principal confequences of my refearches into opium, and I wifh I had been able to have entered into a circumftantial detail of the experiments, in the way I have made them. I do not now regard the fubjed: as exhaufted, and am as far from fuch a belief, as I am from thinking that there is nothing to corred: in my prefent work, and that nothing can be added to it. This very Supplement itfelf demonilrates the contrary, and if I could in any way retard the publication any longer, I might probably be myfelf able to add many new particulars, to fee many others in a clear- er light, and perhaps to corred: feveral of them. I fhall therefore lend a willing ear to criticifms, and to the objediions that may be made againfl my work, and ihall take a real pleafure in corred:ing and ren- dering it perfedt for a new edition, fhould fuch an one ever become necelTary. But I protefl at the fame time, that I will anfwer none of thofe pretended philofophers, who oppofe words to fadts, fophifms and cavils to experiments, poffibilities to obferva- tions, and prejudices and fcholailick errours to natural, direft, and luminous, confequences. Thus

I Ihall

ON POISONS,

395

I fliall not think myfelf obliged to repeat my expe- riments, already repeated fo many times, and to fancy myfelf in an errour, on account of a few ifolated experiments which feme one may wifh to oppofe to me, limply becaufe they are not exad:ly comformable to mine. A fimple glance thrown on my work itfelf, will ihow how eafy it is to be de- ceived in matters of experiment, even when many of them have already been uniform, and when one would the leail exped: the poffibility of being led aftray. My experiments, on the fide of truth, ex- ceed the number of fix thoufand, and the obferva- tions I have interfperfed through the work are at leaft as numerous. I know very well that the quef. tions I have propofed and examined are likewife very numerous, and that there may be fome few in the number, as I have obferved on a former occa- fion, that have not been difcuiTed with as many ex- periments as were necelTary. But in fpite of all this, I firmly maintain, that a few experiments will not be fufficient to deilroy the great number I have rnade, and varied in fo many ways, and that like contradidiions will not be capable of making l?ie change my manner of thinking.

F J N I S.

1 N D E X

TO THE

SECOND VOLUME.

• Academy Royal of Sciences at Paris % experiments made by two of its members on the eiFefts of common oil againfl the bite of the viper - - 3^

A<:idsf blended with the venom of the viper, do not deprive

it of its deadly qualities - - 8

I ■ they render the ticunas innocent - 115

^-« '- but are not a remedy when applied to wounds poi-

foned by this fubllance - - 117

Air is one of the moft adive principles in awakening irrita- bility - - - - 142 Albinus ', his opinion of the ftruclure of the brain - 217 Alkali 'volatiley recommended as a fpecifick againfl the ve- nom of the viper, and particularly brought into vogue hy Juffieu - . „ - ^ ■ experiments on its effeds againll the venom of the viper - - - 3 does not feem to penetrate through the ikin

to the mufcles - - - 4

— — — when blended with the venom df the viper

it does not render it innocent - - ^

' it is not a fpecific againfl this poifon ia man 5 j

Alkalies

ti Index.

Alkalies caufe no change in the ticunas * ii6'

Alexipharmick of M. Zecmeyer - *' 78

Amber obferved with the microfcope - - ^04

Amputation', its efFefts as they relate to thedifeafe caufed by the bite of the viper . - - 16

*■■ very ufeful to guineapigs that have been ve- Bomed, provided it is made within fix minutes after the tite _ - - - 19

*■ of the comb of fowls after they were bit, and

its efFefts - - - 24

Animals with cold blood ; the eiFedl of the ticunas on them

121, 139

B

Bark Perwvtan ; is inefficacious in the bite of the vipeJr I5

Birds ; the fmaller ones die of the bite of the viper 34

Bifmuth obferved with the microfcope - 307

Bite of the Viper ; its efFe£ls on the ikin - 2Z * its efFe6ls are more violent in proportion

is the animal is fmaller - • - 36

it is not fo dangerous as was believed 46

it is in reality not mortal to man - 47

Blood', the change wrought in it by the ticunas - 129

- is not coagulattd in animals poifoned by the ticunas 134

jPo^r^^^o'^ admits of nervous difeafes - 192

Bones ; their ftru£lure obferved with the microfcope 298

Brain ; its internal ftrufture - ■* 241

Canal^ difcovery of a new one in the eye - %\l

Cantharides, the effe£ls of thefe infedb, either applied to a

part bit by the viper, or taken internally - J I

Cats, the larger ones make an obllinate refinance to the

bite of the viper, but are at length killed by it - 41

Centipedes ;

N D E X.

lit

Centipedes 5 inie£ls, the bite of which is thought to be mortal 43

Cherry -laurel Water, is a very llrong poifon - 143

. ■— — its eiFeds on wounds - 146

■ ' its efFeds on the blood when injefled

into the vefTels - - - 14^

■ does not aft on the nerves - 148

Cherry-laurel y the empyreumatick oil of, experiments on its

effedls - ^ . . « 177

Cherry-laurel, the ejjential oil of, tz.hQniD,ttvn2MY - 169

■-*—---—--—----— — is a very violent poifon^,

both to warm and eold animals - - i^t

■ " — ' eiFeds it produces when ap- plied to wounds - - - - 173 ■'- _ experiments with this oil

dried in the fun - - - 175

Cherry-laurel, experiments on the water and oil of this

plant - - - - - 143 169

«' the different produ6lions it yields by diHil-

lation - - - - - 157

— — — in what part of it the poifonous qualities

feem to reiide - - - 179

Cherry 'laurel, the phlegm of, its effects on animals - 161

Cleahy, experiment he relates in his journals, on the fubjed

of the ticunas fwallowed by animals - 103

Cobalt, obferved with the microfcope - - 307

Cobras-Jione, Kempfer thought it of ufe againft the bite of venomous animals - - -» 51

what it is thought to be - - 77

'' experiments made with artificial ones- - 84

«-. 1 . .—..-.««-..-_ — on quadrupeds -»- 86

Common Oil, has been fuppofed a fpecifick againll the vencnl of the viper - - - - 3S

— experiments made on this fubjefb by the Royal

Society of London, and the Academy of Sciences at Paries - _ - - 3^ 39

— found inefficacious by two of the French Aca- demicians, and afterwards by Mead « 39 4»

Condaminf.

INDEX.

Condamine M, de, his account of the jprocefs employed in

America, in making the ticunas - - lo©

Cottony obferved with the microfcope - - ^03

Cruikjhanks Mr.y his difcovery of the reproduction of nerves 203 Cy/zW^r^, primitive winding of the animal' body . 272

D

Diaphragm^ analyfis of the teridinous part of it - 261

Dogs and CatSy recover of the difeafe of the venom with a

facility proportioned to the violence of their vomitings 10

Dogsy the eiFedls of tartar emetick on thefe animals venomed

by the viper - -

— amputation of their ears, after the latter had been bit

by vipers - - - . zy

— — fmall ones are eafily killed by the venom of the viper,

but thofe of a larger kind make a very powerful refiflance

to it - - - - 36

E

Eau de luce, employed agalnft the bite of the viper - 43

^^/y, their gluten obferved with the microfcope - 295

Ele£irlcity, tried againlt the bite of the viper - 14

Emetic^, feenis to be of fome efficacy againft the bite of the

viper - - - - 10

Epidermisy obferved with the microfcope - 296

Erroursy thofe are liable to who obferve with the microfcope 284

Eat of the Viper y received by Mead as a remedy againft the

bite of that animal - - - ^5

Fat, obferved with the microfcope - - ^9^

Fomentation,

t N D E X. ^

^cmetttation, is fome relief to a part bit by the viper - lo FoJJilsy general microfcopical obfervations on thefe fubftances 304 Fo-ivls, amputation of their comb* &c. after they have been

bit by the viper - - _ ^ 24.

. the ticunas occafions'no difeafe when applied to the

comb - - - - II

'' the effeds of the venom of the viper on thefe animals

not fo violent as thofe on pigeons - - 3^

— — fingular difeafe that attacks them ^fter they are bit

in the comb - - « - 2^

— ^-^ — inefficacy of the ligature on thefe animals after they

are bit - - - -. 60 ^ eiFe£ls of the ticunas on them - - 1 11

/'ro^/, experiments made on them vvith the ticunas - 121

t^e/ner, his opinion of the compofition ot the retina 24^

Goldy obferved with the microfcope - - 306

Guineapigs, the fmaller ones infallibly die when bit effecl-

ually, but many of the larger ones recover . 35

z — : -1. Utility of cutting off their legs after they have

been bit by the viper ^ - . - 16

'' in what time it oiight to be donCj to be ef-

feftual - _ » - i(^

eiFecls of the ligature tried inflead of ampu-

tation _ i. A. » 64

^ — ■• ■ ■ eifecls of the ticunas introduced into the

wounds of thefe animals - - iiz

fwal lowed by them 10^

efFeds of the fpirit of the cherry-laurel fvval-

lowed by therii - - - 160

efFeds of the eiTential oil of this plant fwallovv-

ed by them ~ « a « i^-o

Vol, II. J} I H^rs,

vi I N r> E

H

Hairs, obferved with the microfcope - . 2^j

Nailer, his opinion of the flru6lure of the nerves Uartjhorn burnt y its efFefls againft the bite of the viper 83

Heart the, is, of all others, the organ firfl aifedled in paflions

of the mind, and in nervous difeafes - 194.

■' does not contrad when the nerves that are fent to

it are ftimulated - ' - - ibid

Hedyfarum mo-vens, obfervations on this plant _ - 302

Hoffman, affirms that all difeafes derive their origin from the

nerves - - - - 186

Hunter, does not feem to allow a true reprodudlion in

nerves that have been cut - ^- 204

Journal Britijh, what is related there on the fubje«!l of the

ticunas taken internally - - - 103

/r/j, its motions are voluntary - - - 189

Irritability, is deilroyed by the ticunas - ■ • 142

and is awakened by the air - ibid

Juice the milky, of the toxicodendron, its effefls on the human

Ikin - - - - 182

Jujjieu, from the authority of Mead, believed the venom of

the viper to be acid - - _ 2

' reply to the cure wrought by the means of this pre-

tended fpecifick . _ . 4.3

i'l/ory, obferved with the microfcope - - 300

K

Kempfer, advifes and pradifes the ligature in the bites of venomous fnakes - - . - 49

Kempfer,

INDEX. til

Ke?npfery his treatment of people bitten - « 50

.r experiments made according to his plan •* 8s

Lead, obferved With the microfcope « • * 306

^f-ec^^-j, employed againft the bite of the viper ^ ■ - i^

Ligamentum ciliare, the new canal of the eye formed of it 312

Ligature y its eifedls when tried on the legs of pigeons 27

* ■■ when made immediately after the bite of the

viper> and fufFered to remain a certain time, feems to be

an efFedual remedy - - - 3^

was tried by Kempfer _ . ^o

— ' experiments to determine its utility - 53

* ■■ on fparrows - - 54.

' . —'■ on fowls » - 57

__- ____ — — . on guineapigs - 60

— — — — on rabbits -- «. 65

« ^ tried in conjunfllon with fcarificatlons - 6j

* tried againft the ticunas - - n8

Lmtgs, the change wrought in them by the ticunas - 126

M , <' ^

Magnefia calcined, obferved with the microfcope »- ,305

Malpighiy his idea of the ilrudlure of the brain - 241.

Marble nx>hite, obferved with the microfcope - 305

Mafcenai de, cure he made with the volatile alkali on a per-

fon bit by a fnake - - "" 43

iVf(frif/, his definition of fneezing - *. 18^

MemLrahe cellular ohCerv'diiGtiS on - * 272

Microfcope y the errours to which the bbfervatlons made with

this inftrument are fubjed - . ^ • 2S4

Monro Dr.f his difcoveries that relate to the nerves 218 222

D d a Monro

vni INDEX*

MoHfo Dr,y his opinion of the primitive compofition of fe-

veral bodies * - - 301303 ^c,

ilf«/f/^/, aftion of the ticunas on them - - 112

■ of animals killed by the ticunas become pale 126

■ their general primitive ftrudure - 263 ■" reflexions on their motions - - 275 Mu/gra'w Dr.y was of opinion that all difeafes had their

origin in the nerves - - - 18$

N

Nails human i their primitive flrudure - - 297

Nefves, microfcopical examination of thefe parts 220 224

»■ ' ' '■■■ their ftrudlure may eafily be miftaken - 287

t their elements - - 228, ^r.

■^* reproduXion of them after they are cut - 203

■» »-« an enquiry into their irritability - 280

«- — thoughts on their influence in difeafes - 1 86

'•* effeds of the ticunas applied to the furface of them 130

«— effeds of the water of the cherry-laurel applied in

the fame way - - - - 148

iWif/, obferved with the microfcope • - 307

Oihy blended with the venom of the viper, do not deflroyits

poifonous qualities » - _ ^

Oil of Tobaccoy its eiFefl on animals - -185

•' Turpenti?iey feems to poflefs a degree of efficacy, if

the part bit by the viper is plunged in it - 9

0//»»/, various opinions of its effedls ■» - 199

Oxy the new canal of the eye iirft difcovered in the eye of this animal - - ♦ 311

Pigeons,

N D E X,

IX

Pigeons, are readily killed by the venom of the viper = 35

. the application of leeches is ineffedual to thefe ani-

mals after they have been bit by the viper - 15

.- what may be expedled from a well-managed liga-

ture, in the cafes of thefe animals bit by the viper 32

— - — " confequence of making the ligature before the

part is bit - - - - 29

— — not endangered by the amputation of the leg 20

— efFefts of theticunas fwallowed by thefe animal3 '104.

■ ' "' - ■ introduced into wounds, pur-x

pofelymade - - lio

" effe6ls of the fpirit of cherry- laurel fwallowed by

thefe animals - - - 159, ^f,

f ^ — ' ^^^ ' applied to

mechanical wounds - - - 116

Toifomy have no immediate adion on the nerves 15^ 15?

Poifon Indian, brought from the banks of the river of the Amazons -^ - ^ ^98

' of the arrows brought from the Eaft-Indies - 138

Portenjield, his ideas of the ftrudure of the retina - 247

"Pringle Sir John, his opinion of nervous difeafes - 201

Prochajka, his obfervations on the ftruifture of the nerves 217 ^--— -, — . -L. ..." . .-." ' . ■.. ' ; . I J of the nm.fcles 264

P^ahhits, the venom of the viper a6ls on them in propor- tion to their fize - - «. 35

• ^-— eiFeds of the ligature made on the limbs of thefe

animals _ ^ -. *, 65

what may be expected from the cutting oiF of

their ears, after the latter have been bit by the viper ao

D d 3 Rahhitt,

^ INDEX.

^ahbits ; their ikin is not penetrated by the effluvia of the , volatile alkali - . - - 4

>. efFe£ls of the Ticiinas on them, taken internally 103

^ -^ — —^ —«..-.=- introduced into

mechanical wounds - - - 1Q7

„. . ^ ^ «. applied to the fur-

face of the nerves \ - - - 131

'■— " ■• ■ introduced into

the fubftance of the nerves - , ^ 132 ' effeds of the water of the cherry-laurel on thefe

animals - - - ^144

nerves ^ ^ - 148

— • efFedsofthe fpirit of the cherry-laurel fwallowed

by thefe animals ,. - 160 161

of the eflential oil of the cherry-laurel 170

obfervations on the reproduflion of their nerves

after they have been cut - . - 206 microfcopical obfervations on the retina of the

eyesof thefe animals -^ - . 248

'Rattle-fnake ', an enquiry whether its bite is always mortal 44 ^edl, does not fpeak of the ligature, in enumerating the re- medies againft the bite of the viper - - 48 Jie?nedies ; a great variety of them employed by the country

people againft the bite of the viper - 37

j^efift elafiick obferved with the microfcope - 303

'Retina ; its primitive fl:ru6lure - - 246

^0/^-/^^ obferved with the microfcope » ^ 303

^ alt common, obferved with the microfcope » 305

tabs, neutral, united with the venom of the viper, do not

deprive it of its poifonous qualities - 9

tannini ; the cure^ie effefted with the volatile alkali on a

perfon bit by the viper - - 45

Scarifications. \

INDEX,

XI

Scarifications ; an examination of their eiFeds againil the bite of the viper - - - 12

. — tried by MeiTrs. Geoffroy and Hanauld 40

. by Kempfer - - 50

,__ . are more dangerous than ufeful - ibid,

combined with the ligature are equally dan-

gerous - - - 67

<^/7T:;^r obferved with the microfcope - - 306

^««i^; is not aded on by'theTicunas - 121

»" when wounded with feveral poifoned arrows was

iimply benumbed- by them - - 140

Sneezing, a voluntary motion - » j88

^par phof-phorick obferved with the microfcope - 305

Sparro^-ws, are recovered after they have been bit by th.Q vi- per, by the immediate application of a ligature - 54 Sponges; their Ilrufture obferved with the microfcope 300 StruSlure, the primitive, of the animal body - 215 Su'^ion ; its eiFed on animals that have been bit by the vi- per ^ - » » 15 — prafllfed in the bite of the rattle-fnake - 44

Sympathies newous ; what opinion fhould be had of them i 8^

Tartar fiihiated I of fome efficacy againfl: the bite of the viper la Tecmeyeri his alexipharmick - - 77 his opinion of the nature of the venom of the vi- per „ - _ X _ yg Teeth human ; their enamel viewed with a microfcope 298 Tendons 'y their ftrudure - » » 257

' do not receive nerves - - 262;

Theriaca ; its effedls in cafes of the bite of the viper 13

— employed by the country people for thispurpofe 37

"■ recommended by Kempfer - - 50

Ticunas, the American poifon ; an enquiry into its effefls, 96 D d 4 Tunica;^,

xn

INDEX.

Ticunas, the American poifon ; the vapours of it have been

thought deilruflive - * - oS

. ' ■ ■ ' ' » but are not fo * ^n

* charafterifticks of this poi-

foa - - - - loi

... > J -

'■" — ___. It IS innocent to the eyes \oz

it is likewife thought to be

innocent when fwallowed

experiments made on tfc

103

fubje^ - - - ihid,

■ ■ ' v/hich prove it to be a poi-

fon when fwallowed - - _ jq-

■ ' its eiFe£ls when introduced

into the wounds of quadrupeds - -. io5

— ~ , ^-^.., »-_ into thofe of birds 109

* — ' ■ '- the quantity of it required

to kill an animal - - - n®

"■ — ^ ' ' ^ has no effe6l on the comb of

fowls - - . _ III

• — ^ ^ i— the time in which it pro-

duces its eifeds on animals - - 118

■ — ■ — — -= has been deemed a poifon to

all fpecles of animals - - - 120

„., — , «-^ , — ^ — ^ it is however innocent to

adders and vipers - - - 122

■ - — '■ feems to excite a nervous

difeafe - - - -12^

— ■ its eifefts on blood drawn

from the veifels - -^ - 124

» —. ■ has no aftlon on the furface

of the nerves - - - 130

«— ^s — '■ ' — - nor when it is introduced

into their fubflance - - - 132

.— „ — -— . ^-, il5 aftion is on the blood

alone ^ ^ * - - 134.

Tin obferved v/ith the microfcope - - 306

5l?^^tc«?, 0// ^j its eiFects on animals * - 185

Torre

INDEX.

xa

Torre della\ his examination of the Aibftance of the brain 216

^^ , , of tranfpi ration - 294.

Toxicodendron ; experiments made with this plant - 182

. . >■- efFeds of the milk of this plant ihid^

————— its juice is innocent - ibid„

Tranfpiration\ microfcopical examination of the materia

perfpirabilis - - - 29^

Turpentine^ oil of ^ feems to poflefs a degree of eiHcacy, If the

part bit by the viper is plunged in it - 5

Turtles ; effeds of the ticunas on thefe animals - 140

. ii -w — -^— of the oil of cherry-laurel on them 170

f^enom of the Viper was thought by Tecmeyer to be acid 7^ • is a poifon to all the fpecies of animals

with warm blood . _

ads with greater violence on fmall and

40

delicate animals, than on the larger ones - 35 ' ■ is not innocent to man - 41

-1 caufes no change in blood drawn from the

veflels r - - 125

— - not even iri the fhape of its globules ihid.

• -r is not rendered innocent by the volatile

alkali - - - %

Vinegar does not counterad the deadly qualities of the ti- cnnas - - - 115

Viper is fcarcely aded on by the ticunas - 122

a fingle one notfufficient to kill a man - 36

< three of thefe animals did not kill a dog of nearly fixty

pounds weight _ - - ihid,

» feems to have difTcrent degrees of adivity in diffe- rent climates r - - 94

Water,

INDEX.

W

fTnisrf when warrR;, is©f fome stiilty tc the part bit by the

•Tjper - - ' - JO

Wrise of Burgimdjy %\^tTi to people bit by the viper 4c?

Whjtt^ Hs opinion of nervous difeafes - • J9r

Zint obfer^ed with the microfcop© - - 5^'

2^7.^ 1

H^m

K^ m

F,<, ip- c

^s^.F^l^(^

T^/-m.

^^^^Mi^^H

Fi^ VT

WkXMW'^MWrWJmr

Wmmmmm

Ftqvnr

a. at £^ a

d c c C

m^^^

faill

--liTff'it-trTitTiil^

Fiq \

Fa^VU

Fcg.lX

niy )n

y,r

T,:^ir

T^iV

MI

J^

FtflZ T^m ^[z^,

FtyJ

^m

2:./ . T7

1'U7 VI

JI^IVZ

F^^yVm

ly

Fri/ K

Fcyjor^

y S\

^T?u

^

^- „^§3

(S	(»	^
(m	^	^
s	^	-
^ i^ ^
	^"9: *

^^.;^^:7^

lu:^l

mm

r^ryJK

T./.VJ

I'fa XT

ri^.vnr

iy<j.n

F/^.IV

%-^^,

y,^ Ji

F'9,^

j'a/:\^ii

\a. TV

I'l </ 12.

Fi:i/ij

Fia.J4i^

*=N^;

^

Fi^is

t\ O^ ^° "-.

if n „J-> CO Oc.o'^ l-'

i^ %0

oj'a O

o c Oo

p^r-

'F,'/..7() .

T^f21

IV^AK

T^/ IC

:F/a./J

#'

Jf?^. /s

^/^./,5

7^^.x^

#

^^7. /d

^?^^1

EXPLANATION

OF THE

PLATES.

Explanation of the firjl Ten Figures of Plate the Firjl, Taken from Mead's Work on Foifons.

J^ IG. I. offers the lateral view of the cranium and J4ws of a viper, a, reprefents two venomous teeth on each fide, fixed in a folid bon-e, by the mecha- nifm that will be defcribed hereafter. Thefe folid bones at h, are articulated by ginglymus, as if they adhered to each of the procelTus zygomatici. By means of this articulation they have two mo- tions ; by the firft the teeth fhow themfelves, and prepare to bite ; by the feccnd they retire, and are carried within, bending themfelves 'towards the ^oot of the tongue, fo as to approach the two jaws.

In Fig. 5. thefe teeth arc fcen on a larger fcale.

Thefe motions are produced by a gentle depref-

fion of the bone e^ and in Fig. 5. d^ which, fafiiened

:; to

( n )

to the bone b, above its articulation, forces it to unite with it, and to affiil in thefe motions, by which it is either driven without or carried within ; they are communicated to it, both by its connection with the low^er jaw, and by virtue of the mufcles w^hich belong to it, and which are deftined to this purpofe.

Fig. I./, fhows the lower jaw, and e, d, the two axes or points of fupport, by the means of which it performxS the motions necelTary to the devouring of its prey.

In Fig. 6. thefe two axes, or fupporters, are feen ^t a^ and ^, as they ferve to conned: the lower jaw with the finciput and temporal bones,'

To fully comprehend the mechanifm the viper em_ploys in fwallowing its prey, it mull be obferved that the jaws, both upper and lower, on the fame Jidcy are capable of moving at the time the oppofite ones remain fixed and motionlefs ; fo that both jaws oa one ilde may be carried without, or brought within, whilil thofe on the oppofite fide either have con- trary motions, or continue fixed and immoveable. Now thefe jaws are provided with fmaU teeth. Fig. I, g, and Fig. 5. r, which adhere very flrongly to their fuperficies, and which, from the purpofe K) which they are applied, may be called hooks. It is in confequence of thefe alternate motions of re- traction, that the prey is driven into the ftomach.

The number of thefe hooks is more coniiderable in the upper than in the lower jaw.

Fig. 5, c, reprefents thefe teeth, or hooks, of the upper jaw ; Fig. 6. //, thofe of the lower.

Fig-

( 111 )

Fig. 4. Ihows the upper part of the head. The finciput at a, which in men is formed by the con- jundtion of the two parietal bones, is here formed of a (ingle one ; whilfl the os frontis b^ which is a lingle bone in men, is formed in this animal of two bones united by a future.

c, the anteriour entry of the orbit of the eye, hol- lowed in the frontal bone.

dy the bones of the nofe.

e, the maxillai'y bone, which in this animal is entire.

But before we leave the bones of this part, I mufl not forget to obferve, that the venomous teeth differ from the others, not only on account of their iize and motion, but in having very diflind: qualities. In the iiril place, it mull be remarked, that although two of them are found at each fide, they are very rarely faflened with equal flrength to the fockets that contain them. Sometimes the exteriour tooth on each fide is the loofefl, and at other times this i$ the cafe with the interiour ones. At others again, the internal on one fide, and external on the other, are the loofeft. When the teeth jut out or projed:, that which is the befl faflened rifes more than the loofer one, which appears longer.

By weighing all thefe circumflances, and fome others that remain to be mentioned, we fee that the viper, in biting, only employs one of thefe teeth on each fide. Nature has made this difppfition, to the end that the acflion of one alone may fufEce to con« vey into the animal the viper preys upon, all the 3 renom

venom prepared on one fide, and which is ihed with as much efficacy to the reptile itfeif^ as if both teeth had aded equally. '

The tooth of the viper, in wounding, defcribes a fegment of a circle, and this crooked Ihape, which makes it refemble in a degree the claws of a bird of prey, Fig. i. a, and Fig. 5. a, gives it a much greater ftrength than it would otherwife have. But this fliape prevents the tooth from difengaging it- felf, whence it fometimes happens that the animal preyed upon, in making efforts for its deliverance, plucks it out, particularly as the viper, perceiving itfelf dragged by a variety of motions, applies its tail to the earth, till it finds itfelf well fixed. If by this means it cannot preferveits tooth, the latter is broke in the weakeft part of its articulation. Na- ture, to "remedy this evil, has contrived' that the tooth which was before loofe, fuddenly acquires a great degree of firmnefs, and that in the place of the one which fell, another, which is detached at pleafure, immediately fucceeds : a tooth broken or plucked out, is foon fupplied by the fmall rudi- ments of young teeth that are concealed in the focket betwixt the roots of the venomous teeth, and which, by degrees, at length become perfeci:.

In the rattle-fnake I have remarked fix teeth of this kind, growing on the fame fide. 1 fhall not hazard any conjecfiures as to the caufe of thefe aux- iliary teeth falling into the empty focket ; but from all that has been hitherto faid, there is great reafon to believe that their true ufe has been afligned

to

( V )

to tlicm, iince the prefervation of thefe anir'nah rcTi* ders fiich a fuppiy indifpenfably necelTary.

The venomous teeth are hollow, from where. they are iixed in the focket to the point. This hollow begins at the top of the orifice placed at the anteriour part of the tooth, Fig, 2, a, and ends at ibm€ diik2LU.cCy near the fummit L The rell of the tooth is iirm andfolid, and cut like a tooth-pick.

Fig. 3^ fhows the hollow of this tooth cut in the middlco

- The venom is prepared and fupplied bv a gland iituated at each fide of the cheeks* It is attached fey a ligament (a, Fig« 9.) to the iinciput, where it proceeds to faften itfelf to the occiput and lower jaw, by means of another ligament k^ A flrong white membrane which goes out of thefe ligaments, ferves to bind it ^11! faHer^ and to fecure it from too great a compreffion, to which it would otherwife be fub- jed, either by too great an accumulation of the ve- nomous fluid, or by too violent a preffure made b3^ the aoimai to expel this fluids The 'excretory con- duit Cy is formed by a continuation of this fame to-- nick. This conduit is carried from the gland to the cavity of the tooth, by means of the bag or fheath {Fig. 7. 8.) which enclofes the teeth on each fide.

fy Fig. 9. is a fmail white gland, the proximity of which to the teeth caufed is to be taken, for the fe- cretcry organ of the venom, though it feems to be nothing more than a lymph atick or falivary gland, and to be abfolutely wanted in the rattle -fnake. All

the

( vi )

the mufcles that concur towards the act of biting^ are iituated in the viper in fuch a way, that when they ad they made a llrong compreffion on the gland that contains the venom, and thus affift the ejaculation of the latter.

That which of all of them contributes the molt to this ejaculation, is the mufcle dy Fig. 9. After riling out of the lower ja^.v, it extends obliquely below the gland that contains the venom, till hav- ing palTed betwixt the two ligaments, a and b^ it is returned back upcJn the outer furface of the gland, and is flrongiy faftened to it in a diredion parallel to its length, by the ligament a^ w^hich ferves it as a tendon. This mufcle may likewife affift in clofing the jaws. Its greatefl adion however confifts in making a llrong compreffion on the venomous gland it fo exadly furrounds ; and this compreffion is made nearly in the way we employ in expreffing the juice from an orange. The difpofition of this xnufcle, (which extends over the whole furface of the gland, and takes the fame diredtion as the ex- cretory conduit) and the very end of this conduit (which appears tendinous, and terminates at the root of the teeth) gave rife to the opinion of this mufcle ferving for the retradtion of the latter. But it is eafy to be convinced of the contrary, by mace- rating a viper's head, the ikin of which has been re- moved, in w^arm water, when the mufcle feparates ealily, and ihows the naked gland*

Fig. 7. prefents an entire viper's head. At a are feen the two venomous teeth on each f^le, enclofed

as

( vii )

their proper flieath. The different degrees of erec« tion and diiteniion are readily obferved.

h Ihows the entrance of the trachea placed in fuch a way, that it is as little as pollible expofed to compreflion at the time of deglutition.

c Ihows the tongue of the viper, which ferves it in fucking up the dew. It is this perhaps that places the auxiliary teeth in the empty fockets, as exigencies may require.

Fig. 8. fhows the bag or fheath that enclofes the two teeth. It is drawn large, that its fringed aper- tures a^ may be the readier dillinguifhed.

Continuation of the Explanation of Plate the Fir/l.

Fig. I. mm, is a bit of hair, in which are feen, in the middle and internally, feveral brown fpots ; its whole furface feems to be covered with fmali winding cylinders, in fome meafure parallel to each other.

Fig. 2. reprefents a fmall portion of the fame hair, which had been flrongly comprefTed on a glafs port-objed:, with an iron plate.

Fig. 3. is a fragment of the above figure, in which very fmall globules, detached from the winding cy- linders, are diflinguilhed.

Fig. 4. is another fragment of Fig. 2. which, having been fteeped in water, takes the appearance of a tranfparent and irregular i^ellicle as it appears in Fig. 5.

Ee- Fig,

( viii )

Fig. 6. fhovvs the globules of tranfpiration.

Fig. 7. is a globule of blood, obferved with the fame glafs that was employed in the obfervation. of Fig. 6. .

Fig. 8. is a mafs of the globules which form the gluten of the ikin of eels. They appear like fo many bladders filled with infinitely fmall globules.

Fig. 9. is the fame mafs of globules as in the preceding figure, but which have been a little dried. A fmall body is feen interiourly, lituated in each globule in a different part.

Fig. 10. reprefents one of thefe globules of Fig. 9. which contained in its middle part a fmall body likewife fpotted in the middle, c, which is one of the globules of blood, has been placed at the fide of it^ that their refpedtive fizes may be compared.

P L A T E II.

Explanation of the Drawings marked with fmall Figures.

Fig. I. reprefents the two canine teeth of the viper.

Fig. 2. ihows the bag or fheath that covers them. 5 5. are the edges of this bag or fheath which has been divided with fcifTars. n e, are the two ellipti- cal holes that are found at the bafis of the tooth. r a. are two equally elliptical clefts, which are iitu-

ated

( i^ >

ated almoil at the point of the fame tooth, m. is the receptacle of venom : this receptacle opens in its upper part in a conduit, and this conduit pro- ceeds to 0. where it opens at the part in which the two teeth are faftened in their focketSe

Fig. 3. fhows the fame receptacle of venom, ob- ferved with a lens ; its Ihape appears to be nearly triangular.

Fig, 4. is this fame receptacle in its natural fize. Fig. 5. is a tranfverfe fedtion of the above recep- tacle, which appears to be formed internally of fe- veral cavities filled with venom, and feparated by partitions, s 0 c, ; the venom, as is indicated in the figure, flows out by drops.

Fig. 6. reprefents one of the canine teeth with all its cavities and apertures, s s. fhows the ellip- tical cleft near the point of the tooth ; and c a, the hole found at the bafis. i i i. are a cavity of the tooth, clofed at r, and only open at e. The tranf- verfe fediion of it feen at the fide of the figure, and marked m. and the other fmall drawing at the fide of the figure, a r 0 d. exprefs another fedion of the fame tooth, made in a dired:ion with a h. of the figure itfelf.

Fig. 7. reprefents the gum in which the two canine teeth are fixed, and at their bafis are feen fix fmall teeth, which are not yet altogether formed, and which are deftined to replace the canine teeth, when the viper chances to lofe them, a c r, are three of thefe fmall teeth fituated at the left fide.

E e 2 Explanntioti

Explanation of the Drawings of this Plate marked %oith Numerals.

Fig, II. reprefents a drop of the venom of the ^iper, fuch as it- appears when it begins to dry a lit- tle on the microicope.

Fig, It reprefents the fame 4rop when entirely dry.

Fig. III. is a heap of feveral fragments of dried venom. The letter a. ihows a lingular cleft turned in a fpiral form. The letter c, Ihows one of thefc clefts, which feparates the fragments froni each other.

Fig, IV. Hiov/s a drop of venom t^ken from the inouth of the viper^ rnd left to dry on a bit of glafs, ^t 0, the fpiall globules and kjiots are feen, which are nothing more than fmall air bubbles. Letter m» Ihows one of the clefts that feparates th? frag- niepts.

Explanation of Plate the Third.

Fig. I. reprefents a nerve feen with a lens that jnagnified fix times. The letters c c c» fhow the white bands, which are of the fame fize, and fitu- ated at equal diflances. The letters oo, oo, o o, are the intervals, the colour of which is not fo pale ; they are likewife of the fame fize^ and equidiftant.

Fig.

( xi )

Fig. III. IS a nerve enlarged about eiglit times ty a microfcope. Its bands are not fo regular as thofeof the former figure, and in feveral places feeni to crofs each other.

Fig. IL is another nervcj the bands of which are more diflindl, and approach each other in dif- ferent parts with a degree of irregularity, but with- out crofling*

Fig. VI. reprefents ^ nerve, feveral of the bands of which approach, and others crofs each other.

Fig. VII. is a nerve in which feveral of the bands crofs each other at different angles.

Fig. V. Ihows a double range of bands in a nerve examined with a lens that magnified fix times ; the bands of the two ranges^ ar, o c, are equally large, and are all fituated at equal difiances : they enter into each other, as the band o. is feen to' enter into the band a> and the band c, into the band r.

The nerve of Fig. Vllt* is compofed of two nerves : r a^ r a, ftiow one of thefe nerves; and a Oy a Oy the other. The line a a^ Ihows the union of the two nerves*

Fig. IV. fhows a nerve feparated into four, a h^ € e^ 0 r, s m^ In neither of thefe the bands eitheif crofs each other, or meet*

Fig. XI. reprefents a nerve enlarged by a very llrong lens, and covered with its cellular membrane. a a, are the two extremities of the nerve, m m, are the ©viform globules that are obferved in the ceU

E e 3 lular

( Xli )

luhr membrane, r r r r* are the filaments of this membrane, floating hi water.

The figures IX. X.- reprefent the way in which thefe bands appear and difappear, as they are ob- ferved with a greater or lefs degree of light, and with lens of different Hrengths. c c c c, are the white bands of the nerve of figure X. and a a a a, the dark fpots. In turning the reflecting glafs of the microfcope the bands difappear, and the winding fi- bres of Fig. IX. are feen in their place. The bands c c c, of Fig. X. become the convex winding fi- bres, c c c, of Fig. IX.; and the opake intervals a a a a, of Fig. X. take the appearance of the con- cave fibres a a a a, of Fig. IX,

Explanation of Plale the Fourth,

Fig. I: reprefents a primitive nervous cylinder v\diich feems to have here and there on its coats fe- veral fragm.cnts of winding threads, and fome round corpufcles in its interiour part.

Fig. II. reprefents another cylinder, which feems filled with very fmall globular corpufcles, immerfed in a gelatmcus tranfparent humour.

Fig. III. reprefents three primitive nervous cy- lindei^§.

Fig. IV. reprefents a heap of primitive nervous cylinders, o m, is one of thefe cylinders entirely flrippcd of its external membrane. The cylinder rtprefen'c-ed by n c» is bare, except its extremity n e,

which

( xlii )

Xvhicih is covered. The outer cylinder a c, is almoft entirely covered with its membrane. The cylin-^ der r 5. is perfedly covered with its rugged mem- brane.

Fig. V. reprefents another of thefe primitive nervous cylinders.

Fig. VI. reprefents a primitive nervous cylinder, one half of which, a c. is formed of a tranfparent and uniform thread ; and the other half, m a. is al- moft twice as large, iefs tranfparent, and irregular and rugged.

Fig. VII. reprefents a primitive nervous cylin- der, in which 0 r, the thickefl part, is covered with a cellular network, formed of very delicate fila- ments. The part r s. is Gripped of this cellular net-work.

Fig. VIII. reprefents a primitive nervous cylin- der covered with its exteriour coat. This is com- pofed, as it appears to be, of very fmall winding threads, which proceed for the length of the cylin- der itfelf.

Fig. IX. reprefents a primitive nervous cylin- der, covered with its external coat.

Figures X. and XI. reprefent two lingular canals found in the fubftance of the brain.

P L A T E V.

Fig. I. reprefents feveral oviform bodies, found in the cellular covering of nerves.

E e 4 Fig*

( XIV )

Fig. 11. reprefents very fmall corpufcles found in the medullary fubflance of the nerves.

Fig. IIL Ihovvs the apparent fize of the globules of the blood of a rabbit, obferved with the fame glafs that was afterwards employed in Fig. IX.

Fig. IV. reprefents feveral winding cylinders of the cellular membrane of fat.

Fig. V. reprefents two threads, m, a, placed one at the fide of the other, that their relative fizes may be the better feen. The thread m, belongs to the cellular membrane of fat, and the thread a. to the external cellular membrane of a nerve. They are both perfectly cylindrical, and pretty equal in fize.

Fig. VI. r r. is a lamina cut from the cortical fubflance of the brain, and obferved with a very flrong lens, r a, are fmall rotind corpufcles, which appear to be filled with a gelatinous humour.

Fig. VII. m a. Ihows the windings and inteflini- form circumvolutions that are feen in the cortical fubflance of the brain, r r. are the above corpuf- cles.

Fig. VIII. r r. reprefents a thin lamina of the me- dullary fubflance of the brain, which, obferved with a microfcope, feems to be formed of an heap of inteftines r r.; at their fide, at a a, are feen fe- veral corpufcles detached from the cortical fub- flance.

Fig. IX. reprefents a part of the retina where it is not radiated. It feems to be compofed of a very fine cellular membrane, interfperfed with fmall glo- bules^ r r.

Fig*

( 3:v )

Fig. X. fliows thefe globules of the retina of their apparent fize, relatively to that of the globules of blood of Fig. XIII.

Fig. XI. is another fmall portion of the retin.-^, with the globules, and cellular membrane.

Fig. XII. reprefents the hollow of the eye, or the internal flrudure of the retina, of a rabbit. Ac r r. are feen the nervous rays, which proceed from the centre, and go on Xx<!0 oppofite fides as far as the edges. The two oppofite parts of the retina, m m. do not extend fo far, and are not furnifhed with fuch coniiderable rays. Thefe rays, or ner- vous fibrils, feem to be cut by knots or diaphragms placed at very fmall diftances. The engraver has not been fo happy in the execution of this figure as in the others. It is not poflible to meet Vv^lth an en- graver who can exprefs with the graving tool, all thefe little indeterminate flrokes, which characte- rize the truth of the objed:, and which are not ne- gled:ed by the perfon who at once delineates the ob- ject, and obferves it with the m.icrofcope.

Fig. XIII. fhows globules of blood obferved with the lens employed in viewing the retina abovco This is done that a comparifon may be formed of their relative lizes.

Fig. XIV. reprefents a portion of the cellular net-work of the retina, Vvhich is iimply a web of winding veiTels, to which the globules are attached.

Fig, XV. reprefents a Hired of the retina^ after it has been a little macerated. Several of the glo- bules that compofe it appear to be detached ; the

print

C xvi )

print of them however remains, and the hollow in which they were funk.

Fig. XVI. ihows feveral irregular bodies that were detached with the point of a needle from the medullary fubilance of Fig. IX.

PLATE VI.

Fig. I. reprefents a tendon magnified only fix times.

Fig. II. reprefents another tendon^ likewife ob- ferved with a very weak lens.

Fig. III. reprefents a primitive tendinous fafcia, which appears to be formed of feveral primitive and parallel tendinous threads, a r, are two of thefe threads detached from the others.

Fig. IV. reprefents another tendinous fafcia ftripped of its cellular membrane, and compofed of primitive threads, r r r.

Fig. V. is a fmall portion of the cellular mem- brane of a tendinous fafcia, which appears to be formed of feveral w-inding cylinders, r r r r. are the ends of thefe cylinders.

Fig. VI. reprefents four primitive flefliy fafcia? in contact with each other, and covered with their cellular membrane. The two marked m m, s s. have their fmall furrows in a circular form ; in the other two. a a, r r. they are notfo regular.

Fig.

( xvii )

Fig. VII. reprefents a primitive flefhy fafcia,. paitly covered with its cellular membrane.

a, e, are the primitive fleihy threads, feparatcd and bare.

Fig. VII. reprefents a primitive flefhy fafcia co- vered with its membrane.

Fig. IX. is the fame fafcia deprived of its mem- brane. Its threads are united at a, and are dif- perfed at the other end at r, r^ r. • Fig. X. reprefents a fmali portion of the cellular membrane of the mufcles^ formed of winding threads r, r, m^ m.

P L AT E VII.

Fig. I. reprefents a portion of the diaphragm oi a rabbit, The letters a, p, q, r, fhovs^ the fielhy part. ^7, m, c, Ty the tendinous part, n, is the trunk of the nerve that goes to the diaphragm, a, r, are a vein. /, /, are branches of the nerve n, a, r, r, j, are branches of the vein, and ii, u^ ii, u, are ahnoft im- perceptible ramification of the vein a, r.

Fig. 11. reprefents a very fmall portion of the tendinous part of the diaphrcigm, obferved with a very ftrong lens.

Fig. III. reprefents a nerve of the eighth pair of a rabbit, which had been divided twenty nine days before. It is drawn about twice as large as it na- turally is. The Ic-ters r^ r, fliow the part v, here ir was reproduced.

Fig.

( xvlli )

Fig. IV. is a repetition of Fig. III. magnified in a greater degree, that the fpiral bands may be better feen.

The letters n^ n^ n, n, of thefe two figures, indi- cate a part of the reproduced nerve, where is feen a white annular fpot.

,Fig. V. reprefents the fame nerve feen with a very Urong lens, a, a^ is the body of the nerve, m^ m, niy m^ the cellular membrane that covers its fides.

Fig. VI. is the fame nerve dripped of its covering. The progrefs of the primitive nervous cylinders is feen in it, and the point of reunion or reprodud:ion, where the diameter of the nerve, as well as that of the fibres, diniiniihes confiderably, is marked r, r. Fig. VIL is the fame nerve, but a good deal torn with a needle, particularly at the part where it was reproduced, to determine the continuity of the pri- mitive nervous cylinders. ^, a, are the two ends of this nerve, c, n^ c, Uy feveral of the primitive cy- linders that were torn.

Fio-. VIII. reprefents the anteriour half of the bulb of the ox's eye, obferved at\ the concave fide.

The letter n^ points out the tunica fclerotis. m^ the ciliary body, likewife called ligamentum ciliare. e^ the proceflus ciliares. r, the uvea, and a^ the pupil.

Fig. IX* is the half of Fig. VIII. in which the, ciliary body, as well as the new canal (?, is partly detached from the reft of the figure* r, is the tu- nica

* ( XIX )

nica fclerotis flripped of the tunica choroides. c, the fmall hollow in which the ciliary body, or liga- ment, is attached to the tri'^fparent cornea. The letters, e^ o, 5, indicate a memoianous fub {lance formed by the meeting of the tunica ch,: oides e, the ciliary ligament o, and the uvea s. The letter 0, ihows the part of the ligament that is failened in the hollow c.

PLATE Ylll

Fig. 12. reprefents a very fine lamina of the epi- dermis. Very frn^ll globules are obferved in dif- ferent parts of it.

Fig. 13. reprefents another lamina of the epider- mis, covered with water. It is not ditferent from the firft.

Fig. 14, reprefents ^ fmall bit of human nail ob- ferved dry.

Fig. 15. ihows the fame portion of nail, but fteep- fd in water.

Fig. 16. fhows the appearance of a fmall hollow made with a pin in a lamina of talc ; both edges are interfperfed with winding threads and globules.

Fig. 17. reprefents a pinch of hair-powder, or powdered ftarch, wetted, and afterwaras obferved with the microfcop?.

Fig. 18. Ihows the appearance of th^ above powr der obferved drj^.

Fig,

( XX )

Fig. 19. reprefents the veficles of fat as they are feen betwixt the laminae of the adipofe membrane ; they are filled either with an oily or fatty humour, riccording to the animals to which they belong, and are covered with winding cylinders.

FigT 20. fhows one of the above veficles deprived of i"s v;inding cylinders.

Fig. 21. reprefents a lamina, or rather a fcraping, of ivory.

Fig. 22. reprefents a piece of cotton thread ob- ferved dry.

Fig. 23. fhows the appearance of the fame thread, ficeped in water.

PLATE IX.

' Fig. I. reprefents a cylinder of very pure gold, obferved breadth wife.

Fig. 2. is the fame cylinder, obferved longitudi- nally.

Fig. 3. is a fmall bit of gold-leaf.

Fig. 4. iliows four atoms of very pure filver filings.

Fig. 6. fliows an atom of zinc, obferved dry.

Fig. 7. reprefents feveral grains of calcined mag- nefia, the furface of w^hich is covered with winding cylinders..

Fig. o. iliows an atom of bifmuth, obferved dry.

Fig. 9. reprefents tvv^o atoms of white marble.

Fig.

C XXI )

Fig. 10. is an atom of heavy fpar.

Fig. 1 1 . is a fragment of phofphorick fpar.

Fig. 12. h an atom of nikel.

P L A T E X.

Fig. I. reprefents one of the branches, or branched cylinders, of which fponges are formed.

Fig. 2. reprefents a very fmall fragment of elaf- tick refin.

Fig. 3. is a grain of common fait.

Fig. 4. is an atom of iilver, in which the winding threads are feen interfperfed here and there as ufuai.

Fig. 5. fhows another fmall bit of filver, in which, jnflead of the w^inding threads, fmall Ihining grains are obferved.

Fig. 6. is iikewife another fmall bit of filver, which appears to be formed of points and pyramids.

Fig. 7. reprefents a fmall bit of tin, Iikewife furniili- ed with the ufual winding threads.

Fig. 8. is a bit of antimony.

Fig. 9. is an atom of cobalt.

Fig. 10. is a very fine lamina of lead, covered with the ufual winding threads.

Fig. II. is a bit of copper, which, like the other bodies, Ihows on its furface the winding threads.

Fig. 12. is a fmall fragment of rofe-leaf, partly torn with the point of a knife.

( xxii )

Fig. 13. fnows a pipe, formed b^^a fpiral band, found in the ftalks of the leaves of the hedyfarum movcns.

Fig. 14. is the fame pipe, partly flripped at its in- feriour end.

Fig. 15. is a fragment of amber, which like all other bodies, appears to be covered with winding ipylinders.

^1

^1 COUNT WAY LIBRARY OF MEDICINE

r- QP

9lil F73^E3