90 TOXINS AND ANTITOXINS. 



nucleo-albumins, as we have already stated; there 

 are also found in venoms alkaloidal bases, but 

 these principles are present only in very slight 

 quantity. These bases are but very slightly toxic 

 compared with the toxins that accompany them. 



Natural Immunity towards Serpent-venoms. 

 Certain animals exhibit a natural immunity toward 

 snake-bites; among them are the snakes them- 

 selves, the hog, the hedgehog, and the mongoos 

 (an Egyptian rat) ; the blood of these animals con- 

 tains apparently an antitoxin.* 



Fontana f had remarked that snakes were quite 

 unaffected by the bite of the viper, even when 

 inoculated with the venom hypodermically. Phy- 

 salix and Bertrand t confirmed these statements, 

 and showed that the snake perfectly resisted quan- 

 tities of viper-venom capable of killing at least 

 20 guinea-pigs. According to these scientists, 

 this natural immunity is due to the existence in 

 the blood of toxic principles analogous to those of 

 viper 's venom principles that exist in the labial 

 glands of the snake, and pass into the blood and 

 the fluids via the internal secretions. These writers, 

 and also Calmette, have shown that the blood of 

 venomous serpents becomes antitoxic when heated. 



* Compt. rend, de I'Acad. des Sciences, cxxi, p. 745; JACODOT: 

 Arch, de Medecine Navale, vn, p. 390. 



f Traite sur le Venin de la Vipere, Florence, 1781. 

 j Archives de Physiologie^ 1894, p, 423. 



