In a paper, read some time ago before this Society, by Mr. Pedler, he mentioned his discovery of the fact that the activity of cobra poison was completely destroyed by admixture with perchloride of platinum. This substance, however, could only be regarded as a chemical and not as a physiological antidote to the poison, inasmuch as it had no power to modify or prevent the action of the venom after its absorption into the blood. Mr. Pedler expressed his opinion that the proper method of pursuing the investigation was to investigate separately the action of platinum salts and of cobra poison upon the animal body. In the discussion which followed we stated that the method proposed by Mr. Pedler was in the present instance not likely to lead to any results, and that as the action of the substance employed by him was in all probability due to its simply forming an insoluble compound with the cobra poison and not to any action of the platinum
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, certain other metallic salts would have a similar action to the perchloride of platinum. Experiments have confirmed the opinion we then expressed, and we find the action of chloride of gold is precisely similar to that of perchloride of platinum, the cobra venom being rendered entirely inert by admixture with the gold salt before its injection into the body. Chloride of gold, however, like perchloride of platinum, is merely a chemical antidote, and does not modify the action of the venom after its absorption into the circulation. Permanganate of potash, which has been recommended as an antidote, also destroys its activity completely. Chloride of zinc, chloride of mercury, nitrate of silver, and carbolic acid all diminish the activity of the poison, and prolong life when mixed with it before its injection; but they do not prevent death, nor do they pro long life to any great extent. Perchloride of iron has very much less action upon the poison than one would expect, and it prolongs life to a very slight extent. Liquor potassæ impairs the activity of the poison very considerably, and prolongs life for several hours. When a large dose of cobra poison is injected, none of these substances prevent death even when applied immediately to the wound. The reason of this probably is that they do not come into such perfect contact with the poison as to destroy the whole of it, and the portion which escapes destruction is sufficient to kill. It is possible, however, that when minimum doses only are injected, the local application of one or other substance may turn the balance between life and death, but this point we must reserve for a future paper. Our first. experiment was made in order to compare the action of chloride of platinum alone with that of cobra poison alone, and of chloride of platinum injected after cobra poison.