“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 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. None of them stand the test of experiment, any more than the more or less compound drugs, numbers of specimens of which from all sources have passed through my hands.
It cannot, however, be denied that certain chemical substances, of well-defined composition, are very useful, not as physiological antidotes to venoms, but as agents for their modification or destruction in the poisoned wounds, when they have not yet been absorbed. In this way permanganate of potash, chromic acid, chloride of gold, and the alkaline hypochlorites, especially hypochlorite of lime, may be extremely useful under many circumstances.
Permanganate of potash was recommended in 1881 by Professor de Lacerda,[104] of Rio de Janeiro, as the result of experiments made by him with venoms of Brazilian snakes. When a few cubic centimetres of a 1 per cent. solution of permanganate of potash are quickly injected into the actual wound caused by the bite and around the point of inoculation, there can be no doubt that the venom not yet absorbed is destroyed. When mixed in vitro with venom, permanganate renders the latter innocuous.
Here, however, it is a case of actual destruction by direct contact. If we inject a lethal dose of venom into the right thigh of an animal, for example, and several cubic centimetres of permanganate solution into different parts of the body, or beneath the skin of the left thigh, neither the general intoxication nor the local effects of the venom are modified.
The same may be said with regard to chromic acid (1 per cent. solution), recommended by Kaufmann[105] for the bite of the common viper.
No other effect is produced by a 1 per cent. solution of chloride of gold, or the alkaline hypochlorites, which I have shown to possess a strong oxidising action on the different venoms, even on those that are most rapidly diffusible, such as cobra-venom (see Chapter V.). They possess, however, owing to their slight causticity, the advantage of not producing severe local disorders, and in this respect they are to be preferred.
The chemical reagent most to be recommended is hypochlorite of lime, in a fresh solution of 2 grammes per cent., and containing about 90 c.c. of chlorine per 100 grammes. It immediately and surely destroys the venom by simple contact, and the chlorine gas that it gives off, owing to its great diffusibility, acts at a fairly long distance from the point of inoculation on the venom which is already beginning to be absorbed.
Professor Halford, of Melbourne, advises the direct injection into the patient’s veins of from 10 to 20 drops of ammonia, diluted with an equal quantity of distilled water. This is a means of reviving nervous excitability in certain subjects at the commencement of intoxication; but torpor soon reappears, and, if the dose of venom inoculated is sufficient to cause death, a fatal ending takes place notwithstanding. Experimentally the effects of ammonia are nil.