SNAKE-CHARMERS 235 
I have submitted this hypothesis to the test of experiment. 
I succeeded in making adult rabbits, guinea-pigs, and pigeons absorb 
enormous doses of Cobra-venom by way of the alimentary canal. 
In this manner I have administered doses as much as a thousand 
times greater than the lethal one, yet I have never been able to 
prove that the serum of these animals became antitoxic. 
On the other hand, I have succeeded in vaccinating very young 
guinea-pigs and young rabbits which were still being suckled, by 
making them absorb, every second day, minimal and certainly in- 
nocuous doses of very dilute venom. In the case of young animals, 
venom is not modified by the digestive juices, and a portion of it 
is absorbed by the mucous membrane of the intestine. When 
the dose ingested is suitably reduced they withstand it, and when 
these ingestions are repeated every second or third day during the 
first weeks of life, the animals become perfectly vaccinated against 
doses certainly lethal for controls of the same age and weight. But 
it is always difficult to push the vaccination far enough for the 
serum to acquire antitoxic properties, and I have never been able 
to prove the appearance of the latter. 
I think, however, that it ought to be possible to arrive at this 
result by experimenting upon animals such as lambs, kids, calves, 
or foals, the intestine of which remains permeable to toxins for 
a sufficiently long period. 
It may be that certain snake-charmers, who claim to possess 
family secrets which they transmit from father to son, employ an 
analogous method in order, in their infancy, to confer immunity 
to venoms upon those of their male children who are to inherit 
their strange and lucrative profession. 
In Mexico, certain Indians called Curados de Culebras know 
how to acquire the privilege of being able to be bitten by poisonous 
snakes without the least danger to life, by inoculating themselves 
several times with the teeth of rattle-snakes. 
Dr. Jacolot,! a naval surgeon, while staying at Tuxpan, made 
l Archives de médecine navale, 1867, p. 390. 
