8NAKE-CHABMEB8 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 Co6ra-venom by way of the ahmentary 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 v^hich 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 



' Archives de medecine navale, 1867, p. 390. 



