H4 



Scientific Proceedings (49). 



equals within a fraction of a per cent, that of the co-group of the 

 lysine. It appears that the co-group of lysine constitutes prac- 

 tically all of the free amino nitrogen of the native proteins deter- 

 minable with nitrous acid. The albumoses show appreciably more 

 free amino nitrogen, which is to be expected from the fact that 

 the protein molecule is partially broken down in their preparation. 



82 (691) 



An experimental study of anti-anaphylaxis. 



By R. WEIL and A. F. COCA. 



[From the Laboratories of Experimental Therapeutics and Experi- 

 mental Pathology, Cornell University Medical School, 

 New York City.] 



If a guinea-pig be given a single injection of a foreign proteid, 

 it becomes, after the lapse of 10 to 14 days, actively sensitized 

 to that proteid, in such wise that the reinjection of the same, in 

 doses far too small to cause any symptoms in a normal animal, 

 produces almost immediate death with convulsions. If, however, 

 such a sensitized pig, after the sensitizing injection, be given a 

 second dose, too small to induce its death, it immediately passes 

 into a condition of anti-anaphylaxis, in which it is refractory to 

 the foreign proteid in question, and may manifest no symptoms 

 even after the injection of doses toxic to normal animals. This 

 refractory stage lasts for weeks or months. In the same way, 

 an animal may be passively sensitized by the introduction into 

 its veins or peritoneum of the serum of another animal, which has 

 been previously immunized or sensitized to a foreign proteid; in 

 this case, too, the injection of a relatively small, i. e., sublethab 

 dose of the same proteid into the passively sensitized animal 

 produces a condition of anti-anaphylaxis. 



By no experimental device hitherto employed has it been 

 possible to alter this condition of anti-anaphylaxis. The theories 

 offered to explain it are numerous. Friedemann, in his general 

 review of anaphylaxis, in 191 1, cites three hypotheses, those of 

 Gay and Southard, of Besredka, and of Friedberger, all of which 

 he proves to be untenable, and offers three other possible explana- 



