SNAKES AND THEIR USES.*
THAT snakes should be dreaded is not unnatural—they crawl on their bellies and carry poison in their heads—but that snakes should be generally bated and held up to opprobrium as emblems of evil, made in the devil's image, seems rather unrea- sonable. To urge on the snake's behalf that he cannot help being a snake, is perhaps not to the purpose ; every creature must accept the responsibilities of its position; but he is really one of the most helpless and inoffensive of animals, and, unlike the great felitke and many insects, he does not prey on man. A blow that would not harm a child kills him instantly ; and there is nothing he so much desires as to be let alone. It is true that when you tread on him he turns,—so does a worm,— the difference being that the snake, after turning, generally bites, and if he bites effectually, the aggressor is likely to pass a very mouvais quart d'heure. Yet, save when hurt or other- wise provoked, the snake seldom or never strikes an animal which he does not mean to eat ; and, being small himself, he must needs prey on such "small deer" as he can kill at a. stroke, for, being a slow mover, he is unable to run down a. wounded victim. To be of any use to him, it must die instantly, and for this reason the trigonaceFhalus is provided with a poison so potent that it kills creatures of the vermin class (on which the snake mostly feeds) like a flash of light- ning. Men who have studied the snake closely say that he is slow to anger, and would always much rather ran away than fight. M. Coutance, who has recently written a remarkably interesting and instructive book on the subject, tells a story of a West Indian negro affected with elephantiasis, who, being advised that a snake-bite might cure him, put his hand into a cage of rattlesnakes, which, however, heeded him so little that he had to tease and provoke one of them for severe minutes before it could be prevailed upon to render him the service which he desired. It was so effectually rendered that the experimenter died within twenty-four hours. There can be no question, moreover, that even in the countries where he is most redoubtable, the trigonacephalus has his uses; he helps to preserve the balance of Nature, and destroys creatures who are more dreaded or more noxious than himself. The French island of Martinique and the English island of Saint Lucia are infested by a snake known as the far de lance, which has acquired an almost world-wide repute. Its bite is not of
necessity fatal ; but the limb which it strikes gangrenes, and. unless it be amputated, the patient dies. Strangely enough,,
the fer de lance is found nowhere else, not even in the neigh- bouring islands of Guadeloupe and Saint Vincent, and seems incapable of living anywhere else,—why, is a mystery, all the • Venins et Poisons tear Prodnction et tears Fonetions pendant Is Vier; Dangers et UMW pour PHomme. Par A. Coutanoe. Paris : J. Rothschild. 1888. islands of the Antilles being as nearly as possible identical in soil, climate, and vegetation. Fers de lances are so numerous in Martinique, that it is not safe to venture into the "high woods" or " cane-pieces " unaccompanied by a guide who can at a glance distinguish a snake from the foliage and fallen leaves, in which he often reposes; and after dark the highways are as dangerous as the high woods. Neverthe- less, the people of Martinique set great store by the fer de lance ; he is so much thought of, indeed, that the planters of Guadaloupe have made several unsuccessful attempts to acclimatise him in that island. For this snake is a great devourer of rats, and rats are great devourers of sugar-cane. Were there no destructive rodents in Martinique, the planters would probably be glad to dispense with the fer de lance; but believing that it is better for a few coolies and negroes to be occasionally sacrificed than for the entire popu- lation to be eaten out of the island by rats, they hold him in respect. Nature generally knows what she is about. If it were possible to destroy the fer de lance, the result would probably be more calamitous for Martinique and Saint Vincent
than the introduction of rabbits has been for Australia and New Zealand. But such an enterprise is neither possible nor likely to be attempted, and M. Contance (who spent four years in the Antilles) tells us, and the fact is very significant,
that the trigonacephalus increases with cultivation, and abounds more in the cane-fields than the forests. The same
rule probably obtains in India, for Bengal, where poisonous snakes are the most numerous, is also the most thickly popu- lated part of the country, and the majority of their victims are bitten while working in the fields.
From the time of Fontana, the first writer on the subject (1767), to the present, a multitude of theories have been broached as to the composition and nature of snake-poison. This being the age of microbes, it was natural that its lethal qualities should be ascribed to the presence of microscopic organisms, —a theory, however, which has been disproved by actual ex- periment. The venom of the cobra di capello and the fer de lance, enclosed in a sterilised vessel and exposed for three hours to a temperature of 125° Centigrade, still retains its peculiar properties. It is effective even when mixed with alcohol or ammonia, and resists the action of the most powerful acids, such as caustic potash, and nitrate of silver: Snake-venom in its natural state, though somewhat like ordinary saliva, is less fluid and more gummy, its colour varying from amber to clear yellow. It dries rapidly on exposure to the air, when, while retaining its natural colour, it becomes glassy and shining. The latest authority on its chemical composition is M. Armand Gautier. After analysing many specimens, he has come to the conclusion that the active principle of all snake-venom is an animal alkaloid analogous to that which is found in a putrefying body; and how deadly that is, many an unfortunate surgeon, accidentally inoculated while making an autopsy, has found to his cost. The venom is neither a virus nor a ferment. It is a septic principle like strychnine and digitalis, and, like strychnine and digitalis, it acts always in the same way, other things being equaL Hence (assuming the correctness of M. Gautier's theory), the venom of the English viper and the cobra are practically identical, the bite of the latter being more fatal simply because Nature has provided him with a greater abundance of septic matter. According to Dr. Weir Mitchell, and other authorities, the glands of the viper contain ten centigrammes of venom, those of the rattlesnake from forty- eight to eighty-one centigrammes, of the Indian naga 1.30 grammes. The virulence of the venom, or rather the vigour of the serpent, is, moreover, modified by climate and temperature. In the higher parts of Martinique, for instance, dangerous bites are much leas frequent than in the valleys and plains. The greater freshness of mountain air lowers the snake vitality, and though his store of venom may be the same, he strikes his enemy or his prey with diminished energy. Snakes only enjoy the full- ness of their powers in low latitudes. Cold stupefies them. The European viper becomes torpid in winter, and menagerie snakes are roused with difficulty from their habitual languor. On the other hand, cold-blooded animals—molluscs, fishes, frogs, turtles, and snakes themselves, are impervious to the poison which the latter secrete. The only warm-blooded creatures proof against it are pigs, an immunity which they owe to the thickness of their adipose tissue.
As we have seen, snake-poison is unique, and, as yet, a poison without an antidote. Permanganate of potash may, if applied promptly, arrest its action by destroying the tissue, but there is no drug, or lotion, or embrocation known by which the venom, after it has been introduced into thehuman economy, can be rendered innocuous. Perhaps the best thing which a person bitten by a snake can do is to enlarge the punctures with a lancet or knife, and suck out the poison ; for the punctures themselves are so small that they do not bleed, and the affected part generally swells so fast that a few minutes after the bite they are invisible.
The existence of venomous snakes side by side with non- venomous, is a fact for which the theory of evolution does not seem satisfactorily to account. If all were non-venomous to begin with, how has it come to pass that some have acquired the power to poison and others have not ? If, on the other hand, the faculty was once common to all ophidians, by what process have so many lost it? Surely not by allowing it to become dormant, for all observers agree that venomous snakes invariably poison their prey as a preliminary to eating it. Then, again, assuming that all snakes were once harmless, how long did it take them to acquire the power of secreting a deadly poison, and the exquisite mechanism whereby they are enabled to inoculate their victim, and how did they live in the meantime? And if they did contrive to live, why should Nature have taken the trouble to endow them with the most wonderful lethal apparatus in her wide domain? Either hypothesis involves us in a difficulty; but it seems more in accordance with. the fitness of things to suppose that all serpents were originally venomous than that they were the reverse. If we adopt this theory, we must regard the harmless snake as a foolish creature who has neglected his opportunities, and gone backward in the world; while the other is a snake of progress and energy who, by assiduous practice, has perfected his faculties and made himself widely respected.
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