300 PROTEIN POISONS 



toxicity. (2) By evaporation and resolution in smaller 

 volume it can be concentrated. (3) It cannot be extracted 

 from the serum by ether or chloroform. (4) It can be 

 precipitated without loss of toxicity by alcohol. 1 (5) Ana- 

 phylatoxin is not a globulin. (6) It can be obtained by the 

 action of complement upon heated (as well as unheated) 

 precipitates. 



Biedl and Kraus claim that anaphylatoxin cannot be 

 the true anaphylactic poison because it does not induce 

 anaphylactic shock when injected into the brain, and 

 Besredka has shown that with serum the reinjection of a 

 very small dose into the brain causes the shock. To this 

 Friedberger very properly replies that the only form in 

 which he has obtained the poison is in solution in guinea- 

 pig serum, and he cannot introduce a large enough quan- 

 tity of this into the brain without doing mechanical injury, 

 and, moreover, the minimum reinjection dose in the brain 

 is not smaller than that required intravenously. It should 

 always be borne in mind that Friedberger's anaphylatoxin 

 is a solution of a poison whose physical and chemical 

 properties are not known in blood-serum. 



Friedberger 2 states that after death from anaphylatoxin 

 the blood does not coagulate. This seems to complete the 

 identity of the action of this poison with that formed in 

 anaphylaxis. The symptoms and all the postmortem 

 findings seem to be identical. 



Friedberger 3 and his students showed that various bacteria, 

 such as the vibrio of Metchnikoff, the prodigiosus, the 

 typhoid and tubercle bacillus, when incubated with normal 

 guinea-pig serum, furnish a soluble poison which, when 

 injected into normal animals intravenously, causes anaphyl- 

 actic shock and death. The poison obtained from these 

 diverse bacterial proteins as well as that obtained from 



1 It will be understood that the proteins of the serum were precipitated 

 by the alcohol and the poison carried down with the precipitate. It does 

 not mean that the poison would necessarily be precipitated from aqueous 

 solution by alcohol. 



2 Zeitsch. f. Immunitatsforschung, 1910, viii, 239. 



3 Ibid., 1911, ix, 369. 



