314 PROTEIN POISONS 



decrease takes place rapidly at high temperature. We 

 showed this by making aqueous solutions of the poison 

 alkaline with sodium bicarbonate and keeping them in the 

 incubator for varying periods. Friedberger finds that 

 when he heats the alkaline serum containing anaphylatoxin 

 to 65, its toxicity decreases, but when the serum is made 

 acid it may be heated to 100 without appreciable loss in 

 toxicity. It will be seen, therefore, that the two substances 

 behave in the same manner when heated in alkaline solution. 

 We never supposed that the heat destroyed our poison, 

 but that on combination with alkali, which combination is 

 hastened by heat, it becomes less poisonous, and Friedberger 

 has failed to show that this is not true of anaphylatoxin. 



There is another striking point of similarity between our 

 poison and Friedberger's anaphylatoxin, and in this par- 

 ticular both substances show a close relationship to peptone. 

 It has long been known that when an animal is quite fully 

 under the influence of peptone the further administration 

 of peptone has but little effect. This is true of both our 

 poison and anaphylatoxin. We have designated this as 

 tolerance, but it must be admitted that it is an unusual 

 form of tolerance and it needs further investigation. 



Besredka, Strobel, and Jupilli 1 refuse to accept anaphyl- 

 atoxin as the true anaphylactic poison because its adminis- 

 tration to sensitized animals does not induce the so-called 

 anti-anaphylactic state. Of course it does not and should 

 not be expected to do so. The anti-anaphylactic state is 

 due to the partial exhaustion of the specific proteolytic 

 ferment, and the retarding effects of the products of digestion 

 on the remaining ferment. Administration of the poison 

 itself, already formed, uses up none of the ferment, and the 

 other products of the cleavage action, besides itself, are 

 not present. Another reason the French investigators 

 give for concluding that anaphylatoxin is not the true 

 anaphylactic poison is that the former is not specific in 

 origin and may be obtained equally from diverse proteins; 



1 Zeitsch. f. Immunitatsforschung, 1913, xvi, 250. 



