There is another kind of infects which are hurtful to man by mere touch. Such is the Scolopendra marina, which caufes a pricking in the skin, and a heat fimilar to that which one feels after having touched the common nettle. Among thofe which render themselves formidable by their prickles, fome have the hair so acute that they wound almost imperceptibly, occafioning an inflammation which quickly brings on fever; others, as the hornet and bee, ftrike with their fting, and though the wounded part does not bleed, it does not fuffer the lefs, and a fenfible fwelling fucceeds. Befides thefe different infects there are others which like the gad fly have ftings fo fharp and strong that they can pierce the fkin through gloves and ftockings; others are remarkable by their bite like fpiders; and fome attach themfelves to our bodies and fuck the blood. The East Indies fwarm with leeches, to which the Dutch have given the name of Snygers. They lurk in general among the grafs, when the dew has moistened the ground, and as the country, which is interfected by rivers, torrents and fwamps, obliges travellers to walk for the most part with naked feet, it happens that thefe animals cling to the legs and gorge themselves fo with blood, that they fall off spontaneously. There are fome fo greedy that they thrust their head into the fkin as far as the neck, and the only method of making them quit their hold, is by furrounding them with moistened gun powder, when they will come away of themselves in about a quarter of an hour or thereabouts. If a perfon ignorant of this expedient fhould think of employing force to detach these animals fuddenly, he would pay dearly for his imprudence. Not only would he experience violent pain, but a part would remain in the skin, engender an abfcefs, and corrode the flesh to a great depth. I appeal for the truth of this to the fad experience of many perfous who for feveral years have been fubject to

fuppurations

fuppurations fimilar to thofe formed by the cautery, from having torn away these infects inconfiderately from their legs.

Let us proceed to other infects which like moles glide under the skin, and vex and torment us without the fmalleft remiffion. In the Eaft Indies there is a fort of worm known by the name of Culebrilla; its head and tail are extremely flender and acute. It is nearly a yard in length, aud its body is as fmall as the firing of a guitar. This animal gets between the skin. and the flesh, and there occafions a tumour, of the fize of a small bean. Although it causes neither fever nor pain, it is exceedingly troublefome. At every time it ftirs the perfon feels fomething difagreeable to which it is not poffible for him to accuftom himself. The inhabitants of Brazil fuffer much from a fpecies of infect called Nigua, which pierces the Ikin, penetrates deep into the flesh, and there infallibly causes gangrene, unless by fuitable remedies, applied in time, these dangerous effects are prevented. The itch is caufed by infects as well as other cutaneous difeafes. Lice caufe a difeafe which in the opinion of Blancard, happens generally to perfons to whom fome other has communicated a great number of these infects at once. In proportion as they feed they excite an itching; the hand fcratching the place where they are makes wounds which fuppurate, and become fo many receptacles proper for nourishing the young vermin, which penetrate further and further, and entring at one place go out at another. Their immenfe multiplication convinces me that they can penetrate every part of the human body, and fo infinuate themselves, that it is impoffible to get rid of them, at least, there have been infiances where' many people have been delivered from them only by death. But I fee nothing fupernatural in this difcafe, although Hiftory would teach us that it has

Ff

always

always been a chastisement referved for monfters of cruelty and avarice.

We cannot reasonably doubt that infects are the cause of many difeafes. Some phyficians have even carried the matter fo far as to fuppofe that worms were the cause of all the diforders mankind are liable to. Sturmius maintains that the air is filled with an infinite number of the germs of man, and other animals, fo that at each infpiration we inhale a prodigious quantity of them; and unless they transpire through the pores, they engender corruption which is the origin of all difeafes. A physician of Paris maintains, that the gout and other difeafes which attack the patient in different parts are owing to cer'tain worms which puncture the nerves, fometimes on one fide, and fometimes on another. He has not thought it enough to publifh his fyftem, but in a particular treatife has pointed out fpecific remedies, and among the reft mentions another fort of worms which, he fays, are an excellent antidote. He avers that they are to be found in plants and minerals, that they must be extracted by means of water, and that after the patient has drunk of this water, the worms it contains will devour those which had produced his disease, and thus cure him. On this fubject there is only one defideratum, and that is to know precifely what worms fo happily contribute to rid us of thofe that are fo noxious. This Phyfician boasts of having obtained the fecret from a man who profeffed his art at Ifpahan. He affures us that he has ftudied it with much care, and that after forty years of observation he had reduced it to practice, to the great relief of the afflicted. He adds that this univerfal me-. decine has not only acquired a great reputation, by the marvellous effects it has produced in many def perate difeafes; but that this precious treafure has coft him a million of livres. If we confult Borrel

lus

lus, we fhall be told that the itch proceeds from infects. A phyfician of Brellaw refers to the fame caufe, the origin of the venereal difeafe. But let us return to the French physician, and follow him in the explanation he gives of the origin of ague. He lays it down as a principle that it ariles from a minute febrile animalcule which infinuates itself into the body, either by refpiration or with the food: that fo long as it remains quiet, the perfon enjoys eafe: but no fooner does this plague awake, than the fits return, and end not till exhaufled with fatigue he falls again into lethargy. It is the fame with measles, and fmall pox; both confift in a fermentation caufed by worms corrupting the whole mafs of blood. Even the plague is not an exception from this doctrine: it is maintained that this contagious disease take its origin from the fame caufe, and that animalcules multiplying to excess in the air, neceffarily become a general poifon..

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Although this fyftem be countenanced by feveral phyficians, I confels it is with difficulty I fubfcribe to it as a fettled truth. I would rather take the fide of of the celebrated Kundmann, whofe words I fhall here ufe. "What prodigies might we not expect to see happen from such an hypothefis! There must then infallibly be worms of every different fpecies, and "each difeafe would have its own; worms for fever, "worms for the cramp; worms for hysterics; "worms for flatulency, which probably would not ❝ resemble thofe for tumour, and which undoubtedly would difcover themselves by the noife they "would excite in the bowels; worms for confump ❝tion, for apoplexy, for epilepfy, for madness, which

66

I imagine fhould be exceedingly alert, if we may "judge by the extravagancies they occafion; and " and laftly, how do we know but there may be worms of every calibre, worms of every fhape.

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"and of every difpofition? This is truly a most ingenious doctrine, pity it had not more folidity, For does it not confider human nature as a foetus "on which worms operate difeafes as unhealthy mo"thers do on their children? Perhaps it will be faid "that thefe worms cause diseases by the corrupted hu"mours they produce, or because they attack or in

..

jure our inteftines. But the bad temperament of "our humours alone, independent of worms, may "furely produce the fame effects, and may not this "bad temperament take place without being occa"fioned by infects? Befides, of how many meta"morphofes must not these infects be fufceptible? It " is certain that they ought to change their figure according to the different changes that take place in difeates, and to the different events that may fol"low from those that are ill cured. Further, I wish "to know whether in the human body, worms beget indifpofition, or are the confequence of it. In "the laft cafe, the caufe of the indifpofition not be66 ing from worms, another caufe must be fought; "in the firft, all diseases would originate from in"fection, which is not at all probable. For be"fides that in fwallowing feveral forts of worms "each of which is preparing for the patient its own

66

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particular difeafe, he fhould at the fame time la"bour under apoplexy, confumption, tenia, small' pox, and a thousand other evils which I need not 66 name, I am not perhaps fingle in reprobating a fyftem which I take to be the idea of a vifionટ્ ary, or of a quack, as defpicable in the eyes of an "experienced phyfician, as the very worms are on "which the fyftem is founded,"

Although I think in the fame manner with this author in general, I do not go fo far as to deny the poffibility of finding worms in perfons afflicted with abfcefs, measles, fmall pox, and other infectious dif

eafes.