Mr. Boag on venemous Serpents.

while pretending to restore the dead snake to 1805. life.

They exhibit innumerable other tricks with venemous snakes, which they have perfectly tame, and pretend to charm by their music but they take care to have the poison-bags cut out from their jaws, although they pretend to the contrary.

SERPENTS.

From a number of ingenious and useful experiments made on the poison of serpents, by Mr. William Boag, Surgeon on the Bombay Establishment, I cannot help extracting the following curious particulars, which must gratify the curiosity of most readers.

Mr. B. begins by observing, "that by far the greatest number of serpents are not venemous. Gmelin describes 219 different kinds of snakes, of which Linnæus informs us, that only about one in ten are poisonous. We likewise know, that many snakes are not poisonous to man, though they may be destructive to lesser animals.

"It would be a desirable thing to be able to ascertain, from the appearance of a snake, whether it be poisonous or not; but these animals so nearly resemble one another, that it is impossible, without great experience, to distinguish them. The skin on the belly and tail of serpents is composed of scales, which vary in number and arrangement, in different serpents; and the colour, which is most attended to, is a very fallacious mark, for it commonly changes with age. A serpent with a large head is generally suspected to be venemous; but the mark which is chiefly to be depended on, is the large

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Venemous Serpents.

1805. canine teeth or fangs, fixed in the upper jaw, May. which are commonly two in number, but sometimes more. These teeth are covered with a membranous sheath; and are crooked, moveable, and hollow, to give passage to the venom, which they receive from a small reservoir, that runs along the palate of the mouth, and passes through the body of each fang. This reservoir contains but a small quantity of venom, which is forced out of it when the animal attempts to bite, by a strong muscle, fixed on the upper jaw for that purpose. It has been well observed by Linnæus, that if nature has thrown them naked on the ground, destitute of limbs, and exposed to every misery, she has in return supplied them with a deadly poison, the most terrible of all weapons!

The symptoms which arise from the bite of a serpent, are commonly pain, swelling, and redness in the part bitten; great faintness, with sickness at stomach, and sometimes vomiting, succeed; the breathing becomes short and laborious; the pulse low, quick, and interrupted. The wound, which was at first red, becomes livid, black, and gangrenous; the skin of the wounded limb, and sometimes of the whole body, takes a yellow hue; cold sweats and conyulsions come on; and the patient sinks sometimes in a few hours, but commonly at the end of two, three, or four days.

"This is the usual progress when the disease terminates fatally; but happily the patient will most commonly recover; a reflection which should moderate the fears of those who hap pen to be bitten by snakes; and which, at any rate, should, as much as possible, be resist

Various Opinions respecting the Poison.

ed, as the depressing passion of fear will in all cases assist the operation of the poison.

"With respect to the manner in which the poison acts upon the human body, it must be allowed, that this is a very interesting question; a great variety of opinions have arisen, and hardly any subject is less understood.

"Late physicians, supported by the respectable authority of Dr. Mead, observing how suddenly death ensues after the bite, have concluded that the venom must act through the medium of the nerves only.

"But the celebrated Fontana has combated this doctrine, by demonstrating, from a variety of experiments on different animals, that the venom of the viper is perfectly innocent, when applied to the nerves only; that it produces in them no sensible change, and that they are incapable of conveying the poison to the animal. On the other hand, he has shewn distinctly, that it acts immediately upon the blood; and through the medium of this fluid, it destroys the irritability of the muscular fibres, and produces death."

After some observations on the nature of the blood and atmospherical air, Mr. B. advances a conjecture, that the poison of serpents acts upon the blood, by attracting the oxygen, which it receives from the air in its passage through the lungs, and upon which its vitality depends.

In support of this opinion he adduces the following arguments:-"ist. Man and other warmblooded animals, exposed to an atmospheric air deprived of oxygen, quickly expire. The poison of a serpent, when introduced into the blood,

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Cure of the Bite.

1805. also causes death; but carried into the circulaMay. tion by a wound, and in very small quantity, its operation is comparatively slow.

"2d. The appearances, on dissection, in both cases are very similar; the blood becomes of a darker hue, and coagulates about the heart and larger vessels; the irritability of the fibres is destroyed in both cases, and the body has a strong tendency to putrefaction."

Mr. B. observes, that the venom of serpents has a much greater effect on warm, than on coldblooded animals; the reason of which he supposes to be this: " that cold-blooded animals do not require so large a proportion of oxygen, to preserve them in health, as warm-blooded animals do."

After enumerating the variety of opinions, and various remedies in use among the older physicians, he proceeds to take notice of the modern remedies; and first of the volatile alkali.

"This is the remedy most commonly used by physicians, both here and in Europe. But the belief which formerly prevailed, that it possessed some specific power, which corrected the poison, seems now exploded. It seems to have no other effect than that of being a stimulus."

METHOD OF CURE.

"A ligature should as soon as possible be tied above the bitten part, so as to impede, but not entirely to stop the circulation of the blood; for the bite of a serpent is for the most part superficial, and the poison is carried into the circulation by the smaller vessels on the surface. The wound should next be scarified and washed with a solution of lunar caustic, in water. I would

1

Experiments on the Cobra Capello.

prefer for this purpose a weak solution; as it may be used more freely, and frequently repeated: the same medicine should likewise be given internally, and repeated at intervals, as circumstances may point out.

"I know, from experience, that half a grain of lunar caustic, dissolved in two ounces of water, may be taken two or three times a day, and its use be persisted in for several days with safety. To these means might be added, (if the symptoms are not relieved,) a warm bath, acidulated with nitrous acid. In this bath, which should be made sufficiently strong to produce a very sensible irritation on the skin, the wounded limb, and a great part of the body, might be placed for half an hour, and repeated, as circumstances might direct."

EXPERIMENTS.

Having procured a snake, a large Cobra de Capello, with the venemous teeth and poisonbag entire, the following experiments were made.

"Er. 1. The snake was made to bite a young dog in the hind leg, and for which no medicine, either internal or external, was made use of. The dog upon being bit howled violently for a few minutes; the wounded limb soon became paralytic; in ten minutes the dog lay senseless and convulsed: in thirteen minutes he was dead.

"Er. 2. A dog of a smaller size, and younger, was bitten in the hind leg, when he was instantly plunged into the warm nitre bath, prepared on purpose. The wound was scarified and washed

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