Artificial immunity against toxins 387 



There is, therefore, no analogy of action between what takes place in 

 the nerve elements against tetanus toxin and against venom." Never- 

 theless venom, like diphtheria toxin and tetanus toxin in the frog, 

 exerts an undoubted action on the nerve centres. 



Again, the protective fixation of poisons to the cerebral sub- 

 stance is not the exclusive privilege of tetanus toxin. Kempner and 

 Schepilewsky 1 obtained the same result with the toxin of botulism 

 (produced by van Ennenghem's anaerobic micro-organism which sets 

 up intoxication of intestinal origin in certain cases of poisoning by 

 food). The brain and spinal cord of the guinea-pig, when triturated 

 with physiological salt solution and mixed with botulinic toxin, 

 prevents intoxication in susceptible animals, exactly as in Wassermann 

 and Takaki's experiments with tetanus. 



When Kempner and Schepilewsky wished to obtain some idea as 

 to the substance or substances in the nerve centres which fix the 

 toxin of botulism and thus prevent poisoning, they found that lecithin 

 and cholesterin, mixed with this toxin or injected separately and 

 simultaneously, protected mice just as completely as did the cerebral 

 substance. On the other hand, they found a difference as regards the 

 two substances when injected before the toxin was introduced ; they 

 were then unable to prevent poisoning, though the cerebral substance 

 exerted an undoubted protective influence. Kempner and Schepilew- 

 sky also showed that heating altered the preventive action of lecithin 

 and cholesterin less than it did that of cerebral emulsion. 



These observers extended their researches to the protective action [407] 

 of fats and demonstrated that olive oil when emulsified and neutra- 

 lised with soda and mixed with twice and even four times the lethal 

 dose of botuliiiic toxin, prevented the contraction of a fatal poisoning 

 by mice. Tyrosin also protected mice against this intoxication, not 

 only when injected simultaneously with the poison, but even when 

 introduced into the animal 24 hours before the poison was ad- 

 ministered. Kempner and Schepilewsky conclude "that not only 

 with the substance of the nerve centres, but also with various other 

 substances, they were able to obtain a certain protective effect against 

 the toxin of botulism" (p. 221). Their experiments with cholesterin 

 and tyrosin were suggested to them by the previous researches of 

 Phisalix 2 who demonstrated that the bile salts, as well as the two 



1 Ztschr.f. Hyg., Leipzig, 1898, Bd. xxvn, S. 213. 



2 Compt. rend. Acad. d. sc., Paris, 1897, p. 1053; and 1898, p. 431 ; Compt. rend. 

 oc. de biol., Paris, 1897, p. 1057 ; and 1898, p. 153. 



