dog, and the fox, purfue their prey with intelligence and addrefs.

In Senegal, the oftrich fits upon her eggs only during the night, leaving them in the day to the heat of the fun. At the Cape of Good Hope, where the heat is not fo great, the fits upon them day and night. Rabbits, when domefticat. ed, are not inclined to burrow. Bees augment the depth of their cells, and increase their number, as cccafion requires. A wafp carrying out a dead companion from the neft, if he finds it too heavy, cuts off the head, and carries out the load in two portions. In countries infefted with monkeys, birds, which in other countries build in bushes or clefts of trees, fufpend their nefts at the end of flender twigs. The nymphæ of water-moths, which cover themselves with cafes of ftraw, gravel, or fhells, contrive to make their cafes nearly in equilibrium with the water: When too heavy, they add a bit of wood or ftraw; when too light, a bit of gravel. A cat, when hut into a clofet, has been known to open the latch with

its paws.

The third clafs of inftincts comprehends all thofe that are improveable by experience and obferva

tion.

The fuperiority of man over the other animals, feems to depend chiefly on the great number of inftincts with which he is endowed. Traces of every instinct which he poffeffes are discoverable in the brute-creation, but no particular fpecies enjoys the whole. On the contrary, moft animals are limited to a small number. This appears to be the reason why the inftincts of brutes are ftronger, and more steady in their operation than thofe of man, and their actions more uniform.

Moft human instincts receive improvement from experience and obfervation, and are capable of a thoufand modifications. One inftinct counteracts and modifies another, and often extinguishes the original motive to action. The inftinct of fear is often counteracted by ambition and by refentment: The inftinct of anger, by fear, by shame, by contempt, by compaffion. Of modified, compounded, and extended inftincts, there are many examples. Devotion is an extenfion of the inftinct of love, to the first Cause or Author of the univerfe. Superftition is the inftinct of fear extended to imaginary objects of terror. Hope is the inftinct of love directed to future good. Avarice is the inftinct of love directed to an improper object. Fear is likewife an ingredient of this attachment. Envy is compounded of love, avarice, ambition, and fear. Sympathy is the inftinct of fear transferred to another perfon, and reflected back upon ourselves. In this manner all the modified, compounded, or extended paffions of the human mind, may be traced back to their original inftincts.

The inftincts of brutes are likewife improved by observation and experience. Of fuch improvement, the dog, the elephant, the horse, the camel, afford numerous and ftrong inftances.

From thefe and other examples, given of the different claffes of inftincts, Mr. Smellie argues, that inftinct is an original quality of mind, which, in man, as well as in other animals, may be improved, modified, and extended, by experience.

Senfation implies a fentient principle or mind. Whatever feels, therefore, is mind. Of course, the F 3 lowest

loweft fpecies of animals is endowed with mind. But the minds of animals have very different powers; and these powers are expreffed by peculiar actions. The ftructure of their bodies is uniformly adapted to the powers of their minds; and no mature animal attempts actions which nature has not enabled it to perform: The inftincts, however, of animals, appear often previously to the expanfion of thofe inftruments which nature intended they should employ. This view of inftinct is fimple: It removes every objection to the existence of mind in brutes, and unfolds all their actions by referring them to motives perfectly fimilar to thofe by which man is actuated. There is perhaps a greater difference between the mental powers of fome animals, than between thofe of man and the most fagacious brutes. Instincts may be confidered as fo many internal fenfes, of which fome animals have a greater, and others a smaller number. These fenfes, in different fpecies, are likewife more or lefs ductile; and the animals poffeffing them are, of course, more or lefs fufceptible of improving, and of acquiring knowledge.

The notion that animals are machines, is therefore too abfurd to merit refutation. Though not endowed with mental powers equal to thofe of man, they poffefs, in fome degree, every faculty of the human mind. Senfation, memory, imagination, the principle of imitation, curiofity, cunning, ingenuity, devotion, or refpect for fuperiors, gratitude, are all difcoverable in the brute creation. Every fpecies too has a language, either of founds or

understand in part the language of man. The language of infants is nearly on a par with that of brutes. Brutes, without fome portion of reafon, could never make a proper ufe of their fenfes. But many animals are capable of balancing motives, which is a pretty high degree of reafon. Young animals examine all objects they meet with, and in this investigation they employ all their organs. The first periods of their life are dedicated to ftudy. When they run about and make frolicfome gambols, it is nature fporting with them for their inftruction. Thus they gradually improve their faculties, and acquire an intimate knowledge of the objects that furround them. Men who, from peculiar circumftances, have been prevented from mingling with companions, and engaging in the different amufements and exercises of youth, are always awkward in their movements, cannot use their organs with eafe or dexterity, and often continue, during life, ignorant of the most common objects.'

EMPHIGUS is a disease of very rare occurrence, and many phyficians in extenfive practice have never met with an instance

of

of it. However, fix have fallen within my obfervation, three in Scotland, one in England, and two in this kingdom. I mention this circumftance as an apology for writing on this fubject: had the fame opportunities occurred to men of more enlarged experience, I fhould have been filent. I am also aware that uncommon cafes are not the best fubjects for medical inquiry; but they often ferve to reflect light on those which are more ufual; and befides, whatever affects human nature muft naturally conciliate our attention.

nera.

Our best nofologift, Dr. Cullen (to whom, by the by, no inftance of this difeafe ever occurred) has claffed Pemphigus in the order of Exanthemata. This claflification will certainly appear fufficiently proper to those who grant this Nofologift the latitude he allows himfelf in the arrangement of his geWhen the plague and petechial fever are allowed to be claffed under different heads, and the thrush and fcarlet fever under the fame head, we need not contend about the place of Pemphigus, even though we fhould find it not to be contagious, fometimes commencing and continuing without fever, and affecting perfons more than once in the courfe of their lives. Dr. Cullen defcribes this diforder as follows: "A contagious fever, vefi"cles about the fize of an almond appearing on the firft, fecond, or "third day of the disease, remain ing for many days, and at length pouring out a thin ichor." I propofe to amend his defcription in the following manner: A fever, accompanied with the fucceffive eruption, from different parts of the body, internal as well as external, of veficles

about the fize of an almond, which become turgid with a faintly yellowish ferum, and in three or four days fubfide. I fhall only obferve at prefent, that I am by no means convinced of this disorder being contagious; that new veficles arife, not only on the first, fecond, or third, but on every day of the difeafe; that I have never known them remain for many days; that the fluid they contain does not appear in general to be an ichor or fanies, but a bland, inodorous, infipid ferum; and that inftead of being poured out, it is most commonly abforbed into the fyftem.

No traces of this disease are difcoverable in the writings either of the Greeks, Romans, or Arabians.

Bontius, in his account of the medicine of the Egyptians, mentions the cafe of his friend Caval lerius, who was feized with the epidemic dyfentery that prevailed during the fiege in Java, by Tommagon Bauraxa, in 1628. His diforder was accompanied with the eruption of cuticular veficles, which were filled with a greenish pus, that eroded the skin underneath, even to the flesh. The patient died. It is evident that little can be concluded from this brief account.

Carolus Pifo, in his 149th obfervation,accurately depicts the genuine Pemphigus, as it appeared in the cafe of Egmont de Rinach, about 150 years ago, at Nantz. He terms it hydatids, and fays it occurred to him frequently. But I have reason to fufpect that he confounds under the fame name the chicken-pox, a flight diforder, in which the skin is affected, not with fpreading veficles, but with fmall puftules. He feems alfo to confound with Pemphigus fome other erythematous afF 4

fections;

fections; for he fays that these watery puftules frequently precede the eruption of the itch; that they fometimes occur without fever, fometimes accompany continued fever, and fometimes appear in the beginning of intermittents. The truth is that Pifo, though an induftrious obferver and a candid man, was by no means an acute nofologift. His account, however, of the cafe of Egmont de Rinach deferves attention, not only as being the first accurate and authentic defcription of this disease on record, but as pointing out a diverfity in the habit of body then accompanying this difeafe from what has been fince met with; for though Pifo declares that the veficles in this cafe fupervened on a purid fynochus, yet he says that he let blood in the beginning with great advantage, and earnestly recommends the fame practice in fimilar cafes. In every inftance, however, that I have' feen of this disorder, fuch a practice would have been plainly improper, if not pernicious.

The next author who mentions Pemphigus is Morton. Speaking of the difeafes which prevailed in London between 1682 and 1692, he mentions, among other fevers of a malignant type, fome in which watery veficles were fcattered over the head and chest. These fevers however, he fays, were merely fporadic, and not propagated by contagion, as in the peftilential conftitution.

For the next authentic * account of Pemphigus we are indebted to the obfervations of Sauvages. He firft obferved it in the hofpital at Montpellier in 1725, in a foldier

who fell a victim to it. Afterwards he faw five other cafes, chiefly of beggars, or other poor people, in all of which acute febrile fymptoms were pre'ent. Twice, however, hé faw it unattended with fever.

Laftly, Dr. Stewart, of Aberdeen (in a letter to Dr. Duncan, which is inferted in the Medical Commentaries for 1778) mentions a cafe of Pemphigus, which occurred to him in the hospital in that town. A foldier had been ordered to march foon after he had been feized with the measles; the eruption was driven in by the cold, and in ten days afterwards the Pemphigus appeared. The veficles (the largest of which were fnipped) poured out, at firft, a femipellucid ferum, but in the course of the difeafe difcharged a bloody ichor. In this cafe the tendency to putrefaction was very strong, but the patient recovered by the liberal adminiftration of bark and wine. this cafe I think we are justified in inferring that the nature of the fluid contained in the vesicles (however accurately it may be afcertained to be a pure ferum in the beginning) may be fo altered in the course of the disease, by its own fermentation, or by admixture with other fluids of the body, from their veffels being broken down, that it may at length cease to be a diag. noftic fymptom of this disorder.

From

But no author who has written on the fubject of Pemphigus has mentioned an extraordinary peculiarity of this diforder, which I have obferved in two inftances; namely, that the vehicles have taken poffef fion of the internal parts of the body, and proceeded in fucceffion

(fome rifing while others decayed) from the mouth downwards through the whole furface of the alimentary canal.

The firft cafe in which I had the opportunity of obferving this fin gular and diftreffing tymptom, was that of a woman under the care of Dr. Gregory, at the infirmary of Edinburgh, in 1783. This woman's menfes had been obftructed for two years and an half. During that period fhe had been thrice before attacked with the fame diforder, which had each time fupervened upon a vomiting of blood. Her skin was generally cool; and her pulfe (though weak) never much increafed in frequency. Peruvian bark and wine were administered to hér liberally. By thefe and other occafional remedies fhe recovered.

The other cafe, in which veficles appeared to have been formed internally, occurred to me lately in this town. I fhall relate the particulars of it, as I think it worthy of obfervation.

-aged twenty-three, of a delicaté form and fanguine temperament, the wife of a man in tolerably good circumftances, and who had been about a fortnight ill of a low fever, was feized (after having fuffered much fatigue in attending her husband) with pains in her back, head-ach, and tendency to vomit. As I was attending her husband I saw the first approaches of her diforder, and on the evening of the day fhe was firft attacked directed her to take an emetic, and to bathe her feet in warm

water.

The next morning her skin was very hot; pulfe frequent; headach not better; fhe had not flept, and complained of a fore-throat;

on infpection the uvula and tonfils appeared inflamed, and fome mucus was collected in the back of the fauces; he had no ftool for two days. I ordered a clyfter immediately; afterwards a gentle purgative; tincture of roles for a gargle.-In the evening all the symptoms were milder. The phyfic had operated twice. I ordered the pediluvium to be repeated.

Third day. She complained of a fmarting, itching, and (as fhe expreffed herself) tingling pain in her tongue, and through the whole infide of her mouth. Her tongue was of a bright red colour and dry, but clean. She was thirty, but complained that her drink was unpalatable, though acidulated with lemon-juice. She had no moisture on her skin. Had gone to tool once. Slept tolerably well the night before. The febrile fymptoms were mitigated, but the cynanche unabated. I ordered nothing but the faline julep.

Fourth day. There appeared on her tongue a pellucid veficle of about an inch long, and near half an inch broad, turgid with a faintly yellowish ferous fluid. A imaller one of the fame kind appeared on the infide of the left cheek. The feniation which they occationed the defcribed as being fimilar to that which the had experienced before their eruption, but greater in degree, and fomewhat as if they were full of fcalding water. This day her skin was cooler, but her pulfe very weak, irregular, and about ninety in a minute. She had had two loo ́e flools. I prefcribed half a drachm of the red l'eruvian baik, very finely powdered, to be taken every two hours in a goblet of wine and water. Imperial for

common