VACCINATION AGAINST SNAKE-VENOM 251 
the first quality that an antivenomous serum ought to exhibit, 
in order to be capable of being used in the therapeutics of 
poisoning, is the possession of an antinewrotoxic power as high 
as possible. This antineurotoxic power is easily obtained by 
employing cobra-venom for the fundamental immunisation of the 
horses destined for the production of the serum. 
Antineurotoxic serum thus prepared shows itself perfectly 
capable of preventing all effects of intoxication from cobra-bites, 
which are much the most frequent in India. In the same way 
it shows itself quite sufficiently efficacious with regard to CoLu- 
BRINE and VIPERINE venoms, the neurotoxic activity of which may 
cause death. But it does not possess any preventive action upon 
the local effects of hemorrhagin, to which the noxiousness of 
certain VIPERINE venoms—such as those of Lachesis—are almost 
exclusively due. 
In countries in which VIPERIDÆ are very common, we must 
therefore not confine ourselves to vaccinating the animals that 
produce serum solely against the neurotoxin of cobra-venom, for 
instance ; we must prepare these animals, after having immunised 
them to cobra-venom, by injecting them with progressively increas- 
ing doses of the various venoms derived from the snakes that are 
most frequently met with in the district. 
Nothing, moreover, is easier than to train animals vaccinated 
against cobra-venom to tolerate strong doses of the venoms of 
Lachesis, Vipera russellit, Crotalus, Hoplocephalus, or Pseudechis. 
In a few months we succeed in obtaining serums very active 
against these different venoms. 
Utilising the horse as producer of antitoxin, I have prepared by 
this method polyvalent serums capable of preventing the local 
action of VIPERINE venoms, and of suppressing in vitro their 
coagulant and proteolytic effects upon the blood. 
Unfortunately, great as has been the kindness of the many 
persons who have most obligingly given me their assistance in the 
course of the fifteen years during which I have studied this ques- 
