TACCINATION AGAINST SNAKE-VENOM 245 
cumb 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 
a 4 
sixteen months is necessary in order to obtain a serum sufficiently 
antitoxic. ‘ 
Te oe Be Or 
Fic. 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). 
