the fkin, and the other is abforbed by the lymphatics back into the body.

It is always a difficult task, and fometimes a needlefs one, to investigate the true caufes of things. But as the public may perhaps expect, that I fhould account for the above-mentioned differences in this dif eafe; I fhall fay, that the principal reafons of thefe differences, which have occurred to me upon mature confideration, are, the almoft infinite variety of temperaments in various individuals; the feafons of the year and their changes, and in fine, many accidents which befal the body, between the time of catching the infection and the appearance of the disease. For inoculation fhews, that the fmall-pox does not break forth before the eighth or ninth day from receiving the infection.

Poffibly it may be thought ftrange, that, in enumerating these caufes, I have not mentioned a word of the nature of the infecting particles. But, befides that the knowledge of this is not attainable by us, it feems to have no great influence on the production of this or that particular fort of the diftemper. For we frequently obferve, in the fame family, where one person catches it from another, that fome have a favourable, and others a bad fort.

But fuch is the power of temperaments of body, that they defcend to thofe of the fame blood by a fort of hereditary right: whence fome difeafes are found to be familiar and fatal to certain families.

As to the feafons of the year, we find, by daily experience, that fome of them are fitter to produce certain difeafes than others; that they are the caufes of epidemic fevers; and that thofe chiefly, in which

fome

fome fluid is to be thrown off by the skin, are the most remarkably liable to be affected by their changes.

But numberless are the things comprehended in the third article, to wit, all thofe accidents which happen to the body from the time of taking the infection to the eruption of the puftules. For the poifon is far from lying quiet all this while, but is conftantly and gradually exerting its malignity, by first corrupting the animal fpirits, and then the whole mafs of blood and humours. Wherefore, if bodily exercise, diet, or the affections of the mind (which have great power in this cafe), should happen to make any particular alteration in the fermenting fluids, they may ea fily occafion various forts of puftules, poffibly in the manner I am going to explain.

The fimple fmall-pox are fuppurations made, while the blood is not fo far vitiated, but that the derivations of the humours into the proper parts may be effected tolerably well, and the natural functions are not entirely hurt. But in the malignant fort the cafe is quite different. For the whole mafs of humours is corrupted more or lefs, according to the nature of the difeafe; and the blood is in fuch confufion, that the purulent matter cannot be thrown upon the skin. Now, in this cafe, fometimes a thin fluid is thrown out, which, when watery, makes cryftalline puftules; when thick and vifcid, warty; and filiquofe, in fine, when the fluid has been reforbed by the lymphatics into the blood, and has left the puftules quite empty. Befides, the texture of the blood is too frequently broken to that degree, that it is obftructed, and ftagnates in the fmall veffels: whereupon, the

fkin is ftrewed with black fpots, which are fo many real gangrenes, and hemorrhages enfue through all the outlets of the body; whence this is called the bloody fort. That these horrid fymptoms are the effects of an acrid poifon, a pears plainly; becaufe the fame happen to those who have been bit by the hæ morrhois, a Lybian ferpent, according to Lucan's beautiful defcription:

A fierce hæmorrhois ftruck both his fangs
Deep into Tullus; a brave valiant youth,
And fond admirer of great Cato's worth.
And as Corycian faffron, when 'tis fqueez'd,
Pours forth its yellow juice through all the holes
Of the hard preffing boards; fo from the pores
Of all the parts flow'd ruddy venom'd gore.
His tears were bloody; nature's paffages,
For their own humours, were all fill'd with blood.
His mouth, his nofe, chok'd up with filthy clots:
Red fweats tranfpir'd from all the skin inflam'd.
His body feem'd one univerfal wound *.

But from these objects of terrour, it is time to pafs to those which may afford comfort,

IT

Of the methods of cure in the fmall-fox.

T is most evident, that all peftilential diseases are accompanied with the highest inflammation of the blood and humours, and therefore they all require emptying and cooling. I begin with the fimple fmall* Lib. ix. ver. 8c6.

pox, and fhall afterwards defcend to the treatment of the malignant fort in its feveral varieties.

But in this place it feems proper to clear up two material points. The one regards the management of the fick, and the other, the diet proper for him.

With refpect to the firft, ferious attention fhould be given both to the feafon of the year, and to the ftrength of the pacient. For the fame things that are done with fafety in fummer, may be attended with danger in winter; and young lads or robuft men eafily bear what might destroy infants, or weakly women. But let this be a general rule, to keep the pa tient in bed during the first days of the diftemper, taking care to defend him from the inclemency of the winter by proper means, and to moderate the exceffive heat in fummer by cool air. But to chill and as it were to freeze up the fick in winter, is not the part of a prudent phyfician, but that of a fool-hardy empiric, trying experiments at the expenfe of unhappy people's lives. Wherefore a mean is to be obferved herein, by managing the patient in fuch a manner, as neither to stifle him with heat or cloaths, nor check the eruption and perfpiration by cold. However, great care ought to be taken in general, to fupply him with pure and cool air, which he may take in plentifully becaufe a hot air caufes difficulty of breathing, checks the fecretion of urine, and increases the number of puftules on the internal organs of the body; the confequences whereof we may justly apprehend to be inflammations, and, towards the end of the difeafe, gangrenes.

:

With regard to diet, it ought to be very flender, moistening, and cooling; fuch as oatmeal or barley

gruel,

gruel, &c. Nevertheless, as the food is to be adapt ed to the feveral ftages of the difeafe, the best regimen in the beginning is that which will keep the body open, and promote urine. These advantages are obtained by boiling preserved fruits with their food, efpecially figs, damascene plums, and tamarinds; and giving them fubacid liquors for drink; as fmall beer acidulated with orange or lemon juice; whey turned with apples boiled in the milk, or with wine; emulfions made with barley-water and almonds; Mofelle or Rhenish wine plentifully diluted with water; ON any other things of this kind.

66

When this fort of diet did not keep the body open, the Arabian physicians added manna to it; but this they did sparingly, and with caution. "For it is quite neceffary," fays Avicen, "that the body be open in "the beginning." Which is one of the most important advices that can be given in this disease, if to it be added, that urine must be made plentifully. For there is a wonderful correfpondence between the fkin and the kidneys; whereby, whatever fluid is wont to be fecreted by the cuticular glands, may with great ease be evacuated by the urinary passages. Wherefore it is very proper to draw off as much of the matter of the disease as can be done, by these paffages, in or der to prevent the overloading of the internal parts.

Now let us país on to medicines; and, in the first place, blood-letting is neceffary. But as diffenfions frequently arife on this fubject, fome rules are to be laid down concerning it.

It is agreed on all hands, that this remedy is not very fuitable to the tenderest age. But yet, as the *De variolis & morbillis.

blood