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SNAKE VENOM AND ANTI-VENOMOUS SERUM.

Two species of poisonous snakes are usually recognised— the viperines (viper, rattlesnake, etc.) and the colubrines (cobra, bungarus, etc.).

The venom, which is secreted by a gland in the region of the parotid, is a yellowish albuminous fluid, and in the dried state can be preserved for long periods. It contains two albuminous bodies, one of which acts locally on the tissues, and the other produces the general constitutional symptoms due to bulbar intoxication. By being heated to 85° C. for fifteen minutes the first-mentioned poison can be removed, when it is found that the venoms of different species produce the same effects, differing only in the degree of their activity. Although the poisonous substances are contained in venoms in different proportions, Calmette holds that the physiological action of the venoms of colubrines and viperines is, in essence, alike. Thus, the venom of the French viper is forty times less toxic than that of the Indian cobra, but the active substance of both varieties is essentially the same.

The mongoose and hedgehog can tolerate large doses of snake venom, but the immunity is not absolute, for they readily succumb when the dose is still further increased.

The so-called immunity enjoyed by the Indian snakecharmers is easily explained. In many cases the poison fangs are removed, but when these are intact the jugglers so familiarise themselves with the movements of the reptile

When the snake

that they mostly escape being bitten. attempts to bite, the juggler looks at it with a strange fixed gaze and plays an instrument, so that it becomes spellbound by the gentle and plaintive cadence of the musician.

Professor Fraser has shown that normal bile possesses an antidotal effect against snake venom. This is probably due to a digestive power of the bile, and for its exhibition a

certain interval of time is necessary. Thus, if a fatal dose of the venom is injected directly into the gall bladder of a rabbit, death supervenes in exactly the same time as when the injection is made in the subcutaneous tissue. Evidently in this case the venom is absorbed into the circulation before it has had time to be modified by the bile.

According to Calmette, antitetanic serum and normal bouillon have a preventive action similar to that possessed by the bile. These substances, therefore, do not act specifically, but merely cause a transitory stimulation of the leucocytes, which normally fix the venom and convey it to the central nervous system.

That the leucocytes play an important rôle in the fixation of venom is evident from the fact that the introduction of this poison into an organism is always accompanied by a hyperleucocytosis. Further, if we inject into a normal animal a fatal dose of venom, diluted in a fresh leucocytic exudation, we invariably observe a retardation in the poisonous symptoms, and very often the animal actually survives.

Antivenomous Serum or "antivenine is derived from horses that have been immunised by gradually increasing doses of venoms obtained from the cobra and other poisonous snakes. The introduction of several kinds of venoms is necessary in order to obtain a serum which shall be equally protective against all species of serpents. Several authorities, however, deny this universal efficacy of Calmette's serum, and they urge that there should be a special

serum for each kind of snake. Such a suggestion is scarcely practicable, considering the difficulty and length of time (over fifteen months) involved in the preparation of any effective serum. Perhaps a satisfactory compromise would be to prepare different antisera for the colubrines and the viperines.

Lamb has recently asserted that antivenine does not keep well in India, but, on the other hand, Calmette affirms that flasks sent to Indo-China and India, and returned to him after eighteen months, have preserved their antitoxic properties "absolutely intact". It is necessary, however, to keep the bottle in a cool place and in the dark.

The ordinary dose of antivenine is 10 c.c. (i.e., a whole bottle) for children and adults. But in the case of bites from the cobra and other highly poisonous snakes it is advisable to inject 20 c.c. (or even 30 c.c.), and to make the injection intravenously, instead of in the subcutaneous tissue. Intervention must take place immediately after the bite and should never be delayed beyond an hour.

Along with the serum, the application of a tight ligature close above the wound should never be forgotten. In order to neutralise any venom remaining in the wound, the latter should be bathed in a fresh solution of hypochlorite of lime (1 in 60) or in a solution of chloride of gold (1 per cent.).

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Agar-agar as nutrient medium, 129.
Agglutination, 82.

Agriculture and soil bacteria, 44.

Alcohol, 8.

bacteria and, 33.

Alcoholic fermentation, 12.

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Bacillus, Eberth-Gaffky's, 80.
fluorescens liquefaciens, 34.
influenza, 100.

lepræ, 89.

mallei, 98.

pestis, 102.

phosphorescens, 28.

prodigiosus, 23, 34.

pyocyaneus, 35, 62.

pyogenes fœtidus, 31.
saprogenes, 34.
subtilis, 28.

tetani, 107.

thermophilus, 28.

tuberculosis, 28, 84, 134.
typhosus, 80, 83.
violaceus, 35.

Bacteria, association of, 30.

as scavengers, 36.
classification of, 24.
cultivation of, 129.
definition of, 18.
denitrifying, 39.
disease and, 57.

fermentation and, 13.

form of, 19.

heat and, 28.

light and, 30.

locomotion of, 22.

microscopic examination of; 131.

multiplication of, 21.

nitrifying, 6, 38.

nitrogen-fixing, 25, 42.

oxygen and, 28.

power of selection of, 27.

relation to vegetable kingdom,
18.

reproduction of, 19.

size of, 20.

spore formation of, 21.
structure of, 19.

temperature and, 28.

thermophilic, 29.

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