390 Chapter XII 



antibodies. Again, certain mineral poisons, quite unexpectedly, gave 

 rise to the development of the counter-poison in the animal body. 

 This fact forced itself upon Besredka^ in his researches on the 

 adaptation to arsenic made in my laboratory. His experiments were 

 undertaken for the purpose of studying the mechanism of the re- 

 fractory condition against a poison, apart from any antitoxic action 

 whatever, which, according to previous investigations, seemed excluded. 

 This action, however, was exhibited in such a degree that it could not 

 be ignored. The serum of animals immunised against arsenious 

 acid was found to possess both protective and antitoxic properties 

 against a dose of this poison killing a rabbit in 48 hours. It is true 

 that Morishima^, in a research carried out in Heyman's laboratory at 

 Ghent, has thrown doubt upon these results. His objections, how- 

 [410] ever, cannot refute the statements of Besredka which rest on very 

 precise and numerous experiments which I witnessed. Morishima 

 left out of account several important circumstances and carried out 

 his experiments without any continuous check by means of control 

 animals. It must be said also that the resistance of the rabbit 

 against arsenic depends on many different factors and that, at certain 

 seasons, it is much more difficult to adapt them to the poison than at 

 others. It is only by numerous researches extending over a very long 

 period that we can arrive at precise and conclusive results. 



From these observations there is every inducement for us to 

 attempt to ascertain whether, by subjecting animals to repeated 

 injections of saponin, it is possible to augment the antisaponic power 

 of their blood-serum and whether, if this takes place, the antitoxic 

 action is due to a rise in the amount of cholesterin in this serum. I 

 therefore requested Besredka to carry out some experiments bearing 

 on this point. Guinea-pigs, injected with progressive doses of saponin 

 for more than two months, at the end of this period showed no 

 increase in the antisaponic power of their serum. They followed the 

 rule established by Ehrlich ; they developed no antitoxin against a 

 glucoside. Moreover, they gave us no new information as to the 

 origin of these antibodies. 



In his first memoir in which the theory of side-chains is treated, 

 Ehrlich insists on the nervous origin of antitetanin as an example of 

 the production of antitoxins by animals susceptible to poisons. Now, 

 however, that he has come to distinguish haptophore and toxophore 



1 Ann. de VInst. Pasteur, Paris, 1899, t. xiii, p. 465. 



2 Arch, inter nat. de Pltarmacodyn.^ Gaud et Paris, 1900, vol. vii, p. %6. 



