VACCINATION AGAINST SNAKE-VENOM 



245 



cutnb in course of treatment from endocarditis or acute nephritis ; 

 in the case of others, each injection of venom leads to the forma- 

 tion of enormous aseptic abscesses, which have to be opened 

 and drained. It may be said that on an average an interval of 

 sixteen months is necessary in order to obtain a serum sufficiently 

 antitoxic. 



Fig. 94. — Aseptically Bleeding a Horse Vaccinated against Venom in order 



TO OBTAIN AnTIVENOMOUS SeRUM AT THE PaSTEUR INSTITUTE AT LiLLE. 



When a horse is well vaccinated and tolerates without a reaction 

 2 grammes of dry cobra-venom in a single subcutaneous injection, 

 it may be bled on three consecutive occasions in the space of ten 

 days, and in this way 20 litres of blood may be drawn from it 

 (fig. 94). 



