SNAKE VENOMS AND THEIR ANTIDOTES. L9 



venom one is able to produce an anti-toxic serum. I have already indi- 

 cated to you how such a serum is won and the use to which it can be 

 put. I have told you that Calmette was the first to prepare a serum 

 for therapeutic use and that this serum, claimed by Calmette to be effica- 

 cious against the venoms of all species of snakes, was soon shown to be 

 practically specific for cobra poison, the venom which preponderated in 

 the mixture with which it was prepared. Dr. Martin was the first to 

 show that tliis serum was of little or no value for any of the Australian 

 snakes against which it was tested, and in India it was soon demonstrat- 

 ed that Calmette's serum, while anti-toxic to cobra venom, had no neu- 

 tralising effect for the venoms of the following snakes : — Bungarus fas- 

 c/atus, Vipera Riissellii and Echis carinata. 



I have already indicated that Calmette's serum was at first prepared 

 with a mixture of venoms, the constitution of which mixture was uncer- 

 tain, -but in which cobra venom greatly preponderated. You will, 

 tberefore, understand that in order to test thoroughly this question of 

 specificity it was necessary to prepare different serums, each with a 

 single pure venom. This has now been done in Australia, in America 

 and in. India, and the results obtained are in complete harmony with 

 each otber. Lat me in a few words summarise these observations. 



Dr. Frank Tidswell in Sydney has prepared a serum with the pure 

 venom of the Australian Tiger Snake (Notechis rcutatus). Tins 

 serum was found to be active for the corresponding venom, lint 

 failed to neutralise the poisons of three other Australian snakes, namely, 

 the brown and the black snakes and the death-adder. Further, this 

 serum was found to be inactive against the venoms of the followino- 

 Indian snakes: — cobra, king cobra, krait, banded krait, Enhydrina 

 valakadien, Kussell's viper, phoorsa, green pit-viper and also the 

 Californian rattle-snake. 



Two pure serums have been prepared in India, one with the venom of 

 the cobra and the other with the venom of the Russell's viper. 



The cobra venom anti-serum was found to be strongly anti-toxic for 

 the venom used in its preparation ; in large quantity it has a neutra- 

 lising power for the venom of Enhydrina valakadien; further, it delays 

 death in cases of intoxication with the venom of the king cobra, a 

 species belonging to the same genus as the cobra, and also in cases of 

 intoxication with the venom of Bungarus fasciatus. It does not, how- 

 ever, even when used in large quantities, completely neutralise these 



