A. Calmette

“ By degrees the snake moves, extends itself, and then assumes an erect posture, but without quitting the basket. It begins to appear uneasy and endeavours to recognise its surroundings; it becomes agitated and irritated, expands and spreads out its hood, breathes hard rather than hisses, and frequently and quickly shoots out its slender forked tongue; several times it makes a violent dart as though to attack the juggler; it frequently trembles, or rather gives sudden starts. ”

“ It is very difficult to specify, even within broad limits, the dose of venom necessary to kill a human being. The quantity of poison introduced by the bite of a venomous snake depends, as has already been stated, upon a large number of factors, and, very fortunately, this quantity is not always sufficient to cause death. Thus in India, that is to say in the region in which snakes are most numerous and most dangerous, the mean mortality seems scarcely to exceed 35 to 40 per cent., so far as it is possible to judge from official statistics. ”

“ Its body is heavy and thickset, and the flanks and the sides of the tail exhibit a series of glandular crypts, which secrete venom.
“The mucus which flows from the mouth, and resembles milk, eats away human hair,” wrote Pliny; “the spot moistened by it loses its colour, which subsequently returns. Of all venomous animals the salamander is the most terrible; it is capable of annihilating whole nations by poisoning the vegetation over a vast area. When the salamander climbs a tree all its fruit is poisoned, and those who eat of it die as surely as if they had taken aconite. ”

“ In the case of young animals, venom is not modified by the digestive juices, and a portion of it is absorbed by the mucous membrane of the intestine. When the dose ingested is suitably reduced they withstand it, and when these ingestions are repeated every second or third day during the first weeks of life, the animals become perfectly vaccinated against doses certainly lethal for controls of the same age and weight. But it is always difficult to push the vaccination far enough for the serum to acquire antitoxic properties, and I have never been able to prove the appearance of the latter. ”

“ The lethal dose for a horse being, as I have ascertained by my own experiments, about 0·025 gramme, 1 gramme of dry Cobra-venom will therefore suffice to kill 20,000 kilogrammes of horse.
Assuming that man, in proportion to his weight, possesses a resistance intermediate between that of the dog and that of the horse, we may consider that the lethal dose for a human being is about 0·015 gramme. It follows, therefore, that 1 gramme of venom would kill 10,000 kilogrammes of man, or, let us say, 165 persons of an average weight of 60 kilogrammes. ”

“ The juggler keeps his eyes always fastened upon the snake, and gazes at it with a singular fixed stare. After some time, about ten or twelve minutes, the Cobra becomes less animated, grows quiet, and then sways as though influenced by the slow and monotonous rhythm of the musician; it keeps incessantly darting out its tongue. ”

“ If the blood of the dog remains non-coagulable when mixed with doses of venom which, on the contrary, are actively coagulant for the blood of the rabbit, the reason would be that the leucocytes of these animals are not equally resistant to venom.
This conception, however, does not conform to the facts that I have myself observed. I have always found that viper-venom, mixed with citrate- or oxalate-plasma of the dog, rabbit, or horse, coagulates these various plasmas when the venom is in weak doses, while with strong doses coagulation is not produced. ”

“ When the poison-fangs are folded back in their sheath, the poisonous secretion can escape freely into the buccal cavity by the slit situated at the base of the fangs.
At the moment when the animal is about to bite, when it throws back its head and opens its jaws, directing its fangs forwards, the muscles that come into action (masseters, temporals, and pterygoids) compress the glands on each side, and cause the venom to be expelled in a sudden jet, as if by a sort of ejaculatory process. In the case of certain species the venom may be projected to a distance of more than a yard. ”

“ But when the moon is at the full, then indeed, an excitement which is dangerous in another way takes possession of him. His cerebral faculties become over-excited, and he feels that his senses are deserting him; his eyes become bloodshot, and he is pursued and tormented by an irresistible impulse to bite. ”

“ When the quantity of venom introduced into the organism is insufficient to cause death, the phenomena that precede and accompany recovery differ very greatly according as the snake from which the venom was derived belongs to the Colubridæ or Viperidæ.
After a non-lethal bite from a Cobra or Krait, for example, convalescence usually takes place very rapidly, and, apart from the local œdema of the subcutaneous tissue surrounding the wound, which in very many cases leads to the formation of a suppurating abscess, no lasting injury to health is observed. ”

“ The animal withstood the injection, but I am inclined to think that this is not a case of true immunity; it is probable that the pig owes its resistance to venom to the fact that its skin is lined with an enormous layer of adipose tissue, which is but very slightly vascular, and in which absorption takes place very slowly. This opinion is corroborated by my discovery that the serum of this animal is entirely destitute of any antitoxic substance. I mixed a dose of Cobra-venom, lethal for the rabbit, with 3·5 and 8 c.c. ”

“ It has often been asserted that scorpions kill themselves with their own venom if enclosed in a circle of fire. This is an absolute myth, for it is easy to prove by experiment, as was done by Bourne at Madras,120 that these animals cannot be intoxicated by their own poisonous secretion, nor by that of other individuals of the same species. Moreover, it has been established by Metchnikoff,121 in very definite fashion, that the blood of the scorpion is antitoxic. ”

“ Thanks to the long and sharp spines by which their bodies are protected, they avoid being bitten and contrive to catch the reptiles very cleverly, but it occasionally happens that they do not escape being struck. However, even in these cases they rarely succumb.
Inoculation with fairly large quantities of venom does not make them ill: the dose of viper-venom lethal for these small animals is about forty times greater than that which kills the guinea-pig. Their power of resistance is therefore beyond doubt. ”

“ The liver is more affected than any other organ. In cases in which death has quickly followed the injection of the venom, the protoplasm of the cells is merely cloudy, or granular, and the granulations readily take a stain in their periphery, though the interior remains uncoloured. If, on the contrary, the animal has survived for some hours, the protoplasm becomes condensed in certain parts of the cell, leaving vacuoles, the limits of which are not well defined. ”

“ Moreover, venom acts not only upon microbes of the same kind, but also on very different species which are not affected by rat-serum, especially upon B. pestis, for which, on the contrary, this serum, when fresh, proves a favourable culture medium. The bacteriolytic power of Cobra-venom therefore constitutes a special property of venom.
“In their work on the cytolysins of venom, S. Flexner and Noguchi have shown that animal cells, when heated to 55° C. and rendered inactive, do not undergo complete dissolution under the influence of venoms which destroy the fresh cells. ”

“ On making an autopsy of an animal which has succumbed to intoxication by snake-venom, we find that the blood in the heart and large vessels is sometimes coagulated into a mass, sometimes entirely fluid, and that, in certain cases, it is as black as prune-juice, while in others it is of a fine transparent red colour. ”

“ The fresh flesh of the pigeon and the swallow, and owls’ feet burned, are good against snake-bites.
“If one has been bitten by a snake or by any venomous animal, another method of cure is to take salt fish and wine from time to time, so as to vomit in the evening. This remedy is chiefly 260 efficacious against the bite of the Chalcis, Cerastes, Seps, Elaps and Dipsas.”
In Equatorial America, and especially in India, a multitude of plants are credited with marvellous properties, which they possess only in the imagination of the snake-charmers or medicine-men by whom they are employed. ”

“ Venomous fishes almost all belong to sedentary species, as in the case of the genera Trachinus, Cottus, Scorpæna, and Synanceia. This fact suggested to Dissard and Noë142 a very hazardous theory in order to explain the existence of a poison-apparatus in these animals. The venomous fishes being sedentary, say these authors, have no need of a poison-apparatus; their prey offers itself to them without effort on their part, and, on the other hand, they escape destruction by their enemies. ”

“ Because of it no one can carelessly lie down to rest in the shade of a tree; no one can walk in the woods or enter unconcernedly into the pleasures of the chase.” It is especially abundant in coffee and sugar plantations, and is met with from the sea-level up to the summits of the highest mountains in Martinique and St. Lucia. It not infrequently makes its way into human habitations, and is not uncommon in gardens, even entering those of the town of Fort-de-France.
It does not seek its prey by day, but remains on the alert, always ready to bite. ”

“ Pursuing the same order of ideas, I have observed that bacteria killed by heating for one hour at 60° C. do not undergo total disintegration as do living bacteria. But, while Flexner and Noguchi infer the plurality of the cytolysins in venom for different animal cells, I have not been able to prove the same thing with regard to the bacteriolysin; venom saturated with cholera vibrios to such an extent that vibrios added at repeated intervals are no longer dissolved, is incapable of dissolving another highly sensitive species of microbe, such as the asporogenous bacterium, and vice versâ. ”

“ It will be understood from what has been already stated, that a man weighing 60 kilogrammes, if bitten by a snake which injects, let us say, what would amount to 20 milligrammes of venom if collected in the dry state (the mean quantity that a 268 Naja is able to inoculate in a single bite) , would only require, in order to escape death, to receive the quantity of antivenomous serum sufficient to neutralise the portion of venom in excess of the amount that he could tolerate without dying. ”

“ In hot countries, on the other hand, they attain large dimensions, their venom is much more active, and, although they hardly ever attack man, and in most cases avoid him, they cause a considerable number of fatal accidents.
It is sometimes a rather difficult matter to recognise from the mere appearance of a snake whether it is poisonous or not. Naturalists themselves are occasionally deceived. It is therefore useful to learn to distinguish the most dangerous species by their external characters, and to know in what countries there is a risk of their being encountered. ”

“ Those of man, the guinea-pig, and the rat, on the contrary, are more so.
On experimenting with washed corpuscles, it is found that venom alone is incapable of dissolving them. In order that dissolution may take place, we are obliged to add to the mixture either a small quantity of normal horse-serum, preferably heated, and, consequently, deprived of alexin (Calmette) , or 1⁄2 c.c. of a 1 in 10,000 solution of lecithin in physiological saline water (P. Kyes) .
Venom, therefore, is capable of hæmolysing red corpuscles only when it is quickened, either by heated normal serum, or by lecithin. ”

“ We know, in fact, that common snakes suffer without danger many bites from 219 vipers (Phisalix and Bertrand78) , and that the Cobra is relatively little affected by inoculation with its own venom or with that of other Colubridæ, such as Bungarus, or even of Viperidæ, such as Vipera russellii.
This immunity, however, is far from being absolute; I have killed common snakes (Tropidonotus natrix) with doses of viper-venom ten times greater than the lethal one for the rabbit, and Lachesis lanceolatus (from Martinique) with 0·02 gramme of the venom of Naja tripudians. ”

“ In the monkey, the first apparent sign of the absorption of Cobra-venom, or of the venom of any other species of Colubridæ, is a sort of general lassitude; the eyelids next become half closed. The animal appears to be seeking a suitable spot in which to rest; it gets up again immediately, and walks with a jerky action; its 171 limbs have a difficulty in supporting it. It is soon attacked by nausea, vomiting and dyspnœa; it rests its head upon the ground, raises it, trying to get breath, and carries its hand to its mouth as if in order to pluck a foreign body from its throat. ”

“ The venom extracted 283 from a couple of bees, by crushing the posterior extremity of the body in 1 c.c. of water, is sufficient to kill a mouse or a sparrow.
Death supervenes in a few minutes, from respiratory asphyxia, as in the case of intoxication by the venom of Colubrine snakes (Cobra) . In the blood-vessels and in the heart the blood is black and remains fluid. It therefore appears that this venom contains a very active neurotoxin. ”