SNAKE VENOMS AND THEIR ANTIDOTES. 17 



is tli3 least poisonous of all, its venom being about half the strength of 

 the poisons of the two common Indian Vipers. 



I have now to say a few words on the venom of the common Sea- 

 Snake (Enhydrina valakadien) , 



This snake is very abundant along the coasts of India and Burma to 

 the Malay Archipelago and New Guinea. 



The poison, as we have just seen, is very deadly, being about eight 

 times stronger than cobra venom. 



There are no authentic cases on record of bites in the human subject, 

 so that any description of symptoms and of physiological action must be 

 taken from animal experiments. The symptoms observed are very 

 similar to those of cobra venom intoxication. The local reaction is, 

 however, very slight, and further no symptoms pointing to any action 

 of the poison on the coagulability of the blood or on the red cells 

 occur. There is progressive paralysis, accompanied by difficulty in 

 'breathing, which latter symptom is much more marked than in cases of 

 cobra venom poisoning. The heart goes on beating for several minutes 

 after the respiration has ceased. While, however, the action of this 

 poison is similar to that of cobra venom there are slight differences 

 which show that the two poisons are not identical. These differences 

 are too technical to enter into here. Suffice it to say that the respira- 

 tory mechanism appears to be the part of the organism which is chiefly 

 affected by Enhydrina venom, while some of the actions which cobra 

 venom has on the circulatory apparatus are wanting in the case of the 

 poison under consideration. These differences are clearly brought out, 

 as we shall see later, when the two poisons are tested against a serum 

 prepared with one of them. 



I have little to say about the viperino poisons, which now claim our 

 •attention. I have already given you a description of the symptoms 

 and of tho physiological action of the venom of Vipera RusselUi. The 

 venom of Echis carinata has to all intents and purposes a similar action 

 but again shows slight differences, which we shall see are of great 



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importance in connection with the problem of serum-therapeutics. 

 This poison has a much more powerful action on the coagulability of 

 the blood than any other venom with which I have worked. A very 

 small quantity injected directly into the blood stream of an animal 

 causes solid ©lotting throughout in a few seconds. This action of tho 



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viperine poisons, an action which is also exhibited by those poisons ot 

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