108 ANAPHYLAXIS AND ANTI-ANAPHYLAXIS 



resist. However, before announcing it, they wished 

 to find out how a dog sensitised with serum, then 

 " vaccinated " with peptone, would behave at the 

 trial injection made with the same serum. 



The experiment thus performed shewed that the 

 peptone did vaccinate — that is to say, that it con- 

 ferred a state of anti-anaphylaxis at the time of the 

 second injection of serum; the dog shewed none of 

 the above-mentioned symptoms. In the same way 

 a dog sensitised to the serum, then submitted to anti- 

 anaphylactic vaccination by means of a small dose 

 of serum, became refractory to the injection of 

 peptone . 



From all these facts, Kraus and Biedl have con- 

 cluded that anaphylactic intoxication is brought 

 about by a poison which, physiologically speaking, 

 is identical with peptone (de Witte). 



In our opinion, Kraus and Biedl ought, before 

 formulating their theory, to have tried other animals 

 than the dog. That these things take place in the 

 dog, as they say, nobody doubts; but what is argu-^ 

 able is their interpretation of them. 



For the theory of Kraus and Biedl to be true, it 

 should apply equally to the guinea-pig — the ana- 

 phylactic reagent par excellence. Even if the symp- 

 toms of anaphylaxis may slightly differ in the dog and 

 the guinea-pig, the mechanism of anaphylaxis should 

 always be the same, and should not vary with the 

 animal species. 



Starting from this idea, we have asked our col- 

 laborator Werbitzki^ to sensitise guinea-pigs to horse 

 serum, next to inject peptone as anti-anaphylactic 

 vaccine, and then to make the trial injection by 

 introducing horse serum subdurally. 



If the peptone is equivalent to the serum, as Biedl 

 and Kraus think, what is true of the dog must be true 

 ^ Comptes rend. Soc. de Biol., Ixvi., p. 1084, 1909. 



