370 PROTEIN POISONS 



of our poison and of Friedberger's anaphylatoxin. As we 

 have stated more than once, parenteral digestion is a 

 normal, physiological process, and in this process the 

 protein poison is liberated. There are many proteins, not 

 all, which are digested by the normal, non-specific proteo- 

 lytic ferment of the blood and tissues. In this, in our 

 opinion, lies the explanation of the results obtained by 

 Szymanowski, 1 who has found that the intravenous injection 

 of varied protein-precipitating agents, such as copper 

 nitrate, c6pper sulphate, mercuric chloride, lead acetate, 

 phosphomolybdic acid, tannin, and picric acid in small 

 doses, may cause all the symptoms of acute anaphylactic 

 shock and death. In our opinion, the most probable explan- 

 ation of this is that the precipitates formed in the blood by 

 these substances act like foreign proteins and are digested 

 by the non-specific proteolytic ferment of the blood with 

 the liberation of the protein poison. 



There has been some difference of opinion as to the 

 source of the protein poison in anaphylaxis. At one time 

 H. Pfeiffer thought that it must come from the proteins of 

 the body. He was led to this conclusion by the smallness 

 of the dose of the anaphylactogen necessary to induce 

 anaphylactic shock on reinjection, but in his latest paper 

 he states that the poison comes from the anaphylactogen 

 (antigen). For like reason Friedemann 2 was inclined to 

 the opinion that the poison is furnished by the serum of 

 the sensitized animal, but he seems now to think that it 

 comes from the anaphylactogen (antigen). Wassermann 

 and Keysser 3 thought that the source of the poison is in 

 the ferment (amboceptor) . They shook horse serum with 

 kaolin and then separated the kaolin from the horse serum 

 in a centrifuge and digested the kaolin with guinea-pig 

 serum and obtained a poison. They explained this by 

 supposing that the kaolin absorbed the amboceptor from 

 the horse serum, and when this was acted upon by the 



1 Zeitsch. f. Immunitatsforschung, 1912, xvi, 1. 2 Ibid., ii, 591. 



3 Folia Serologica, 1911, vii. 



