30 Professor Halford. 



that previous inoculations save, or greatly modify, 

 the effects of other organic poisons. This brings us to 

 a remarkable statement by C. J. Martin* which is : 

 " A previous injection of small doses of black snake 

 venom confers an immunity, so far as in tra- vascular 

 clotting is concerned, against further injections of the 

 venom. This immunity is very speedily produced ; 

 how long it may last 1 am at present not in a position 

 to say." 



I have introduced these facts stated by Dr. C. J. 

 Martin, as they may be considered side by side with 

 the facts I have recorded about Shires. 



The Indestructibility of the Toxic Powers of 

 Snake Venom. 



Dr. Weir Mitchell, in 1860, speaking of the poison 

 of the rattle snake, says : " Freezing has no effect ; 

 boiling has no effect ; strong nitric acid, strong muriatic 

 acid, strong sulphuric acid each of these strong acids, 

 after mixing with the venom arid acting upon it for 

 twelve minutes, was neutralised with liquor potassse 

 each mixture, when injected into the subcutaneous 

 tissue, produced death. When mixed with ammonia, 

 chlorine water, iodine, soda, potash, and each mixture 

 injected, no effect was found to have been produced on 

 its virulence." 



I repeated all these experiments with the poison, of 

 the Australian tiger snake, and found the results 

 actually similar. 



* Journal of Physiology, Vol. XV, No. 4, 1893. 



