228 MICROBES AND TOXINS 



affairs, as in the experiment of Heymans and Masoin on the 

 neutralization in vivo of hydrocyanic acid by hyposulphite of 

 soda. 



In vivo the hyposulphite of soda acts as an antidote or 

 chemical antitoxin to hydrocyanic acid. Now no one has ever 

 succeeded in reproducing this experiment in the test-tube, 

 whereas in the body it is perfectly easy. " In consequence it 

 is legitimate to appeal to certain peculiar conditions in the 

 living animal, which, however, does not exclude the possibility 

 that the transformation of the toxic substance into a harmless 

 material may be due to a chemical reaction." 



Fresh nutrient broth possesses an antitoxic action towards 

 abrin intoxication (Calmette). The serum of an animal 

 immunized against certain toxins or venoms protects other 

 animals to a greater or less extent against the action of other 

 toxins or other venoms ; here there can be no question of a 

 specific direct antitoxic action. 



The fresh blood of the crayfish is capable of preventing the 

 fatal intoxication of mice by scorpion venom ; yet the crayfish 

 is killed by a dose of scorpion venom three or four times 

 smaller than that necessary to kill a mouse, and the blood of 

 the crayfish has no protective action for another crayfish. 



Roux and Vaillard observed long ago that animals might die 

 of tetanus although possessing an abundance of antitoxin in 

 their blood. There are certain horses originally good furnishers 

 of diphtheria or tetanus antitoxin which suddenly cease to 

 produce this in their serum although they remain immune. 



Rabbits may be immunized against tetanus by inoculating 

 them under the skin of the tail several times in succession 

 with tetanus spores along with a little lactic acid ; the animal 

 becomes resistant to the toxin and yet 100 volumes of its 

 serum fail to neutralize a single minimum lethal dose of 

 toxin (Vaillard). The antitoxic power of the body-fluids is 

 thus not sufficient to explain acquired immunity, since it is 

 not an invariable fact in animals rendered immune. 



The actions of the body itself have again to be reckoned 

 with in attacking the question of the origins of antitoxins. 



