proof of this being the genuine fmall pox; therefore I must be allowed to confider this fubject a little further, and fee how far all the circumftances correfpond or are fimilar to the true fmall pox. In the fmall pox we have a previous fever, in place of which, in the prefent cafe, we have no information but that of the mother's having had the fmall pox within fuch a limited time as may favour the poffibility of infection in the womb; yet we may prefume,

that the child must have had con. fiderable fever preceding fuch an eruption, of whatfoever kind it

was.

In the fmall pox the eruption goes through pretty regular tages in its progrefs and declenfion, which circumstances we know nothing of in the prefent cafe; but even this fever, the eruptions, and their progrefs, are not abfolutely proofs that the diforder is the fmall pox when it is caught in the common and natural way: and in proof of this affertion it may be obferved, that practitioners every now and then are mistaken.

It may be asked, what is the true characteristic of the fmall pox that by which it differs from all other eruptions that we are acquainted with? The most certain character of the fmall pox, that I know, is the formation of a lough, or a part becoming dead by the variolous inflammation; a circumftance which hitherto, I believe, has not been taken notice of.

This was very evident in the arms of those who were inoculated in the old way, where the wounds

were confiderable, and were dreffed every day; which mode of treatment kept them from scabbing, by which means this process was easily obferved; but in the prefent method of inoculation it is hardly obfervable: the fore being allowed to fcab, the flough and fcab unite and drop off together. The fame indiftinctnefs attends the eruptions on the fkin; and in thofe patients who die of, or die while in, the disease, where we have an opportunity of examining them while the part is diftin&t, this flough is very evident.

This flough is the cause of the pitt after all is cicatrized; for it is a real lofs of fubftance of the furface of the cutis: and in proportion to this flough is the remaining depreffion.

The chicken pox comes the nearest in external appearance to the fmall pox; but it does not commonly produce a flough.

As there is generally no lofs of fubftance in this cafe, there can be no pitt. But it fometimes happens, although but rarely, that there is a pitt in confequence of a chicken pock; then ulceration has taken place on the furface of the cutis, a common thing in fores.

In the prefent cafe, befides the leading circumstances mentioned in the cafe of the mother, correfponding with the appearances on the child, and the external appearances themselves, we have in the fulleft fenfe the third and real or principal character of the fmall pox, viz. the flough in every puftule; from all which, I think, we may conclude, that the child had caught the fmall pox in the K 4

womb;

womb; or at least a difeafe, the effects of which were fimilar to no other known disease.

In opening the bodies of thofe who had either died of, or died while under, the fmall pox, I always examined carefully to fee whether any internal cavity, fuch as the afophagus, trachea, ftomach, inteftines, pleura, peritoneum, &c. had eruptions upon them or not, and never finding any in any of thofe cavities, I began to fufpect, that either the fkin itself was the only part of the body fufceptible of fuch a fimulus; or that the fkin was fubject to fome influence to which the other parts of the body were not fubject, and which made it alone fufceptible of the variolous ftimulus. If from the firft caufe, I then concluded it must be an original principle in the animal œconomy. If from the fecond, I then fufpected, that external exposure was the caufe; and I was the more led into this idea, from finding that thefe eruptions often attack the mouth and throat, two expofed parts; add to which, that we generally find the eruptions most on the expofed parts of the body, as the face, &c.

With thefe ideas in my mind, I thought I faw the most favourable opportunity of clearing up this point. I therefore very attentively examined most of the internal cavities of this child; fuch as the periton um, pleura, trachea, infide of the afophagus, ftomach, inteftines, &c. but obferved nothing uncommon. I have already obferved, that in this child the face and extremities were the fulleft, fimilar to what happens in common; from all which I may be

allowed to draw this conclufion, that the skin is the principal part which is fufceptible of the variolous fimulus, and is not affe&ted by any external influence whatever.

The communication of the fmall pox to the child in the womb may be fuppofed to happen in two ways; one by infection from the mother, as is fuppofed in the above cafe; the other by the mother's having abforbed the fmall pox matter from fome other perfon, and the matter being carried to the child from the connection between the two, which we may fuppofe done with or without first affecting the mother.

Teftimonies and opinions are various with respect to these two facts. Boerhaave feems to have been led by his experience to think that fuch infection was not communicable for we find that he attended a lady, who having, in the fixth month of her, preg-, nancy, had the confluent fmall pox, brought forth at the regular period a child, who fhewed not the leaft veltige of his mother's difeafe.

His commentator, however, Van Swieten, fupports a different opinion (fee his comment, vol. v.). He quotes a cafe from the Philofophical Tranfactions, vol. xxviii. N° 337. p. 165, of a woman, who, having juft gone through a mild fort of fmall pox, was, by means of a trong dofe of purging phyfic, thrown into a miscarriage, and brought forth a dead female child, whofe whole body was covered with variolous puftules full of ripe matter; but this history is founded only on the relation of a midwife to a clergyman, and therefore not

abfolutely

abfolutely to be depended upon as accurately stated: however, it is. more than probable, that there was a cafe as defcribed; and that there were really eruptions on the fkin of the child fimilar to the fmall pox.

Van Swieten likewife mentions what Mauriceau relates of himfelf. This author teflifies, that he had often heard his father and mother say, that the latter, when big with him, and very near her time of delivery, had a painful attendance on one of her children, who died of the fmall pox on the feventh day of the eruption; and that on the day following the death of this child, Mauriceau came into the world, bringing with him five or fix true pufules of the fmall pox.

It does not appear, however, from this recital, whether or not Mauriceau paffed through life free from any pofterior infection; but admitting that this eruption of Mauriceau's was truly the fmall pox, yet I fhould very much doubt his having caught it from the child who died of it: as it fhould feem that the puftules of Mauriceau were of the fame date with thofe of the child who died. Van Swieten appeals to a more recent cafe, which had been reported to him by perfons of great credit, and is recorded in the Phil. Tranf. vol. xlvi. p. 235.

"A woman, big with child, having herfelf long ago had the " fmall pox, very affiduously "nurfed a maid fervant during "the whole procefs of this dif"eafe. At the proper time the

brought forth a healthy female child, in whofe fkin Dr. Wat

performed on both children in "the fame manner; and the pus "ufed in both cafes was taken "from the fame patient. The

66

event, however, was different "for the boy had the regular eruption, and got well; but "the girl's arm did not inflame nor fuppurate. On the tenth day from the infertion of the matter, he turned pale fud"denly, was languid for two "days, and afterwards was very "well. In the neighbourhood of "the incifion there appeared a " puftule like thofe pustules that we fometimes obferve in perfons "who, having had the difeafe, "attend patients ill of the imall " pox.

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In the epiftles of T. Bartholinus, cent. ii. p. 682, there is the following hiftory. "A poor woman, "aged thirty-eight years, pregnant, and now near the time of delivery, was feized with the fymptoms of the fmall pox, and "had a very numerous eruption. "In this ftate fhe was delivered

womb; or at least a difeafe, the effects of which were fimilar to no other known disease.

In opening the bodies of thofe who had either died of, or died while under, the fmall pox, I always examined carefully to fee whether any internal cavity, fuch as the afophagus, trachea, ftomach, inteftines, pleura, peritoneum, &c. had eruptions upon them or not, and never finding any in any of thofe cavities, I began to fufpect, that either the fkin itfelf was the only part of the body fufceptible of fuch a fimulus; or that the fkin was fubject to fome influence to which the other parts of the body were not fubject, and which made it alone fufceptible of the variolous ftimulus. If from the firft caufe, I then concluded it must be an original principle in the animal œconomy. If from the fecond, I then fufpected, that external expofure was the caufe; and I was the more led into this idea, from finding that thefe eruptions often attack the mouth and throat, two expofed parts; add to which, that we generally find the eruptions most on the expofed parts of the body, as the face, &c.

allowed to draw this conclufion, that the skin is the principal part which is fufceptible of the variolous ftimulus, and is not affected by any external influence whatever.

The communication of the fmall pox to the child in the womb may be fuppofed to happen in two ways; one by infection from the mother, as is fuppofed in the above cafe; the other by the mother's having abforbed the fmall pox matter from fome other perfon, and the matter being carried to the child from the connection between the two, which we may fuppofe done with or without first affecting the mother.

Teftimonies and opinions are various with respect to these two facts. Boerhaave feems to have been led by his experience to think that fuch infection was not communicable for we find that he attended a lady, who having, in the fixth month of her pregnancy, had the confluent fmall pox, brought forth at the relar period a child, who fhe the leaft vettige of hi difeafe.

His commentator, Swieten, fupports nion (fee his co He quotes a c fophical Tran N° 337- p. having ju fort of fm of a trom thrown broug who wit ma