Auguste Lumière and Joseph Nicolas, of Lyons, conceived the idea of studying the effect upon venom of the prolonged action of the intense cold produced by the evaporation of liquid air.[13] The Cobra-venom employed by these investigators was in solution at a strength of 1 in 1,000. It was submitted to the action of liquid air, partly for twenty-four hours and partly for nine days at -191° C. Its toxicity was in no way diminished.
Lastly, I must mention the recent researches of Hideyo Noguchi,[14] with reference to the photodynamic action of eosin and erythrosin upon the venoms of the Cobra, Vipera russellii, and Crotalus. It was found by the scientist in question that the toxicity of these various venoms is more or less diminished in the presence of these aniline colours, when the mixtures are insolated. Cobra-venom is the most resistant, just as it is in regard to the other physical or chemical agents. That of Crotalus, on the contrary, is the least stable.
CHAPTER VI.
THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS.
A.—Physiology of Poisoning in Man and in Animals Bitten by the Different Species of Poisonous Snakes.
(Colubridæ; Viperidæ; Hydrophiidæ.)
The bites of poisonous snakes produce very different effects according to the species of snake, the species to which the animal bitten belongs, and according to the situation of the bite. It is therefore necessary to take these various factors into account, in describing the symptoms of poisoning in different animals.
When the quantity of venom introduced into the tissues by the bite of the reptile is sufficient to produce fatal results—which is happily not always the case—the venom manifests its toxic action in two series of phenomena: the first of these is local and affects only the seat and surroundings of the bite; the second, or general series, is seen in the effects produced upon the circulation and nervous system.
It is remarkable to find how great is the importance of the local disorders when the venomous reptile belongs to the Solenoglypha group (Viperidæ), while it is almost nil in the case of the Proteroglypha (Colubridæ and Hydrophiidæ).
The effects of general intoxication, on the contrary, are much more intense and more rapid with the venom of Proteroglypha, than with that of Solenoglypha.
In considering the usual phenomena of snake-poisoning in man, we must therefore take this essential difference into account, and draw up separately a clinical description of the symptoms observed after a bite from a Cobra (Colubridæ), for instance, and another list of those that accompany a bite from Lachesis or Vipera berus (Viperidæ).