PROTEIN SENSITIZATION OR ANAPHYLAXIS 253 



devoid of peptone action, and there may be peptone action 

 without peptone. They think that in the peptic digestion 

 of proteins there is formed in small amount a highly poison- 

 ous body for which they propose the name peptozym. 

 Popielski, 1 who has made a chemical and physiological 

 study of Witte's peptone, states that the albumose con- 

 tained in it is without effect, and that peptone prepared 

 from it by the method of Pick has the same, but less marked, 

 action as the original Witte's peptone. From this he con- 

 cludes that the active agent is not peptone. He also con- 

 cludes that, in peptic digestion, a highly poisonous sub- 

 stance is formed along with the peptone, and on account 

 of its action he proposes the name "vasodilatin." This 

 he obtained in an impure state by fractional precipitation 

 of aqueous solutions of Witte's peptone with hot, absolute 

 alcohol. This substance is highly active and contains 

 relatively small amounts of albumose and peptone, and no 

 cholin. This agrees well with our own work. As has been 

 stated, we have prepared our protein poison from Witte's 

 peptone, but Nicolle and Abt 2 could not obtain it by our 

 method from Defresne's peptone, and we subsequently 

 confirmed this. Gastric digestion is a progressive process, 

 and it progresses through its successive stages at widely 

 differing rates. When it is arrested as in the manufacture 

 of peptones, the product may contain the poisonous group, 

 either in combination or free, or the digestion may have 

 continued to the destruction of the protein poison. This 

 seems a simple and rational explanation of the above- 

 mentioned findings, and reconciles their apparent contra- 

 dictions. If this be the correct explanation, one batch of 

 peptone may contain the poison, while another from the 

 same manufacturer may contain no trace of it. The protein 

 poison is a group in the protein molecule; at each successive 

 step in the digestive process it exists in a smaller and more 

 labile molecule, and finally it itself is broken up and rendered 

 inert. 



1 Arch. f. Exp. Path., Ivi; Pfliiger's Archiv, cxxxvi. 



2 Ann. d. 1'Institut Pasteur, 1907. 



