338 BACTERIOLOGY. 



In such a case the power of forming antitoxin 

 is present without a corresponding immunity. 

 According to Mosso, the blood of the eel 

 possesses poisonous qualities, and according to 

 Calmette, the blood of both poisonous and non- 

 poisonous serpents, of salamanders and of toads 

 is also poisonous ; the toxicity of the blood of 

 all snakes is approximately the same, whereas 

 snake-venom shows the greatest differences in 

 the different species. In contrast to snake- 

 venom, which, according to Fayrer and Ward, 

 can withstand a temperature as high as 75 

 and is weakened only at 8o-9O, the poison 

 of the snake-blood, like the generality of the 

 active bodies found in the blood, is destroyed 

 at 65-7o. These facts demonstrate the in- 

 dependence of the two poisons, 'one of another, 

 and this independence is substantiated by vari- 

 ous experiments. According to Sewall, whose 

 experiments have been extended by Calmette, 

 Phisalix and Bertrand, animals can be made 

 immune against snake-venom, and also against 

 poisonous snake blood (Calmette). Toxic 

 serpent blood kills animals which are immune 

 against serpent-venom, and conversely. In 

 spite of this difference of action, one active 

 poison does influence the other. Serpent blood 

 that is normally poisonous may become tem- 

 porarily non-poisonous in consequence of the 



