NA TURE 



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THURSDAY, FEBRUARY 28, 1878 



SNAKE POISON 



EVERY now and again the British public is horrified 

 by accounts of the famines which periodically 

 carry off myriads of our fellow-subjects in India, but 

 comparatively few have the least idea of the enormous 

 destruction of human life which occurs there from the 

 ravages of wild animals and venomous snakes. In a 

 most interesting lecture recently delivered at a meeting of 

 the Society of Arts by Sir Joseph Fayrer, the lecturer 

 estimated the loss of life at no less than 20,000 human 

 beings and 50,000 head of cattle annually. Wild animals 

 destroy most of the cattle, but venomous snakes kill more 

 human beings than all the wild animals put together. 

 The bites of these reptiles caused the death of 17,000 

 persons, and over 3,000 cattle in the year 1875, and these 

 figures very probably understate the facts, as the returns 

 upon which they are based are incomplete. The desira- 

 bility of obtaining an antidote to snake poison is thus 

 evident, and many attempts have been already made to 

 discover one. Another has been added to the already 

 numerous investigations on this subject by Mr. Pedler, 

 who has lately published the results of his research in 

 a paper read before the Royal Society. Before proceeding 

 to seek for the antidote, he endeavoured to analyse the 

 poison chemically, and thus discovered several facts 

 of great interest. The venom of snakes seems to 

 contain very much the same proportion of solids at all 

 times, even under such different climatic conditions as 

 during the wet and dry seasons. It may be kept for two 

 or three months without alteration, but if preserved for a 

 year or eighteen months, it becomes insoluble, and, to a 

 great extent, loses its poisonous qualities. Its composi- 

 tion is very like that of albumen, and, indeed, the dried 

 poison, which looks very like gum arable, contains about 

 sixty per cent, of albumen, and only forty per cent, at 

 most of the poisonous principle. By the use of solvents, 

 Mr. Pedler endeavoured to separate a crystalline principle, 

 such as Lucien Bonaparte affirmed to be present in the 

 poison of the rattlesnake. His attempts were unsuccess- 

 ful, and he therefore tried to obtain it by dialysing the 

 poison through parchment paper. Part of the poison 

 dialysed, and part did not. On evaporating the fluid 

 inside the dialyser, the residue formed a gummy mass, 

 with a poisonous action. The water outside the dialyser 

 also gave a similar result, but in it a few crystals could 

 be detected. It was, if anything, rather more poisonous 

 than the ordinary virus. He did not succeed, however, 

 in obtaining any very definite crystalline substance. 

 Ammonia, which has lately been highly recommended as 

 an antidote in snake poisoning, he found, as did Fontana 

 two hundred years ago, to be useless, and indeed its addi- 

 tion to the poison before injection seemed really to hasten 

 death. 



Some organic poisons may have their physiological 

 action greatly altered by changing their chemical consti- 

 tution. Thus strychnia has its action completely altered 

 by combination with iodide of methyl, so that instead of 

 producing convulsions, it causes complete paralysis, like 

 Vol. xvii.— No. 435 



curara. At the same time its deadly power is greatly 

 diminished, and it occurred to Mr. Pedler that the poi- 

 sonous properties of cobra virus might be diminished in 

 a similar way. On testing this supposition, he found it to 

 be correct, as the poison, after digesting with ethylic 

 iodide, took five times as long to kill an animal as fresh 

 cobra poison would have done. Hydrochloric acid also 

 diminished the activity of the virus, and platinum chloride 

 had a still more powerful action. This salt seems to 

 combine with the poisonous principle of cobra virus, form- 

 ing with it a yellow amorphous precipitate, which is very 

 insoluble in water, and which has little or no poisonous 

 action. This result of the action of platinum chloride on 

 cobra virus out of the body is most satisfactory ; but this 

 apparent antidote has not the -same power when the 

 poison has once entered the system. When the poison is 

 injected under the skin and the platinum chloride ir. 

 injected shortly afterwards into the same spot, death 

 appears to occur even more 'quickly than when no anti- 

 dote whatever is used, the second injection seeming to 

 drive the poison before it and to cause it to act more 

 rapidly. When the platinum chloride, however, is injected 

 at the same point, but somewhat more deeply than the 

 virus, so that in passing inwards the poison might come 

 in contact with the platinum, life is considerably pro- 

 longed. If a short time elapses between the injection 

 of the poison and that of the platinum, death ensues, 

 even though the interval be only one or two minutes. It 

 would thus seem that when the platinum chloride is 

 brought directly into contact with the poisonous principle 

 of the cobra venom it renders it insoluble and prevents 

 its poisonous action, but that it is not a physiological anti- 

 dote, and will not counteract the deadly action of the 

 virus after it has once entered the circulation. It may be 

 useful as a local application, but cannot be regarded as 

 an antidote. Every means hitherto tried of counteracting 

 the effects of cobra venom has thus proved ineffectual. 

 Artificial respiration, proposed by Sir Joseph Fayrer and 

 Dr. Lauder Brunton, gave fair promise of success, 

 and by its use the heart may be kept beating for 

 many hours. Indeed in one case an animal appa- 

 rently dead for many hours has been partially revived 

 by it, yet on no occasion has afatal issueeverbeen averted by 

 its use. The experiment just mentioned was performed 

 by a commission appointed by the Indian Government, 

 at Sir J. Fayrer's suggestion, to examine into the modes 

 of preventing death from snake bite. A dog was bitten 

 one afternoon by a water snake, and apparently died 

 about three o'clock. Artificial respiration was at once 

 commenced, and the heart continued to beat, but the 

 animal seemed to be perfectly dead, and the limbs no 

 longer responded to electrical stimuh. Early next morn- 

 ing, however, an alteration took place. The limbs again 

 answered to electricity, voluntary movements occurred, 

 and the eyelids closed not only when the eye was touched 

 with the finger, but when the hand was simply brought 

 near it. This showed that the animal could see the 

 approaching hand, and closed its eyes in order to protect 

 them from the expected touch. The dog seemed to be in 

 a fair way to recovery, but about noon it began to get 

 worse, and finally died at three o'clock on the second 

 day, twenty-four hours after its first apparent death. 

 Whether a combination of artificial respiration with 



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