62 Chemical Basis of Genus and Species 



laxis, was able to produce this phenomenon, and later 

 he showed that it was generally impossible to produce 

 anything resembling anaphylaxis by non-protein sub- 

 stances, e. g., cocain or apomorphin. I Wells isolated 

 from egg-white four different proteins (three coagulable 

 proteins and one non-coagulable) which can be distin- 

 guished from each other by the anaphylaxis reaction, 

 although all come from the same biological object. 2 

 Michaelis as well as Wells found that the split products 

 of the protein molecule are no longer able to call forth 

 the anaphylaxis reaction. Since peptic digestion has 

 the effect of annihilating the power of proteins to call 

 forth anaphylaxis, we are forced to the conclusion that 

 the first cleavage products of proteins have already 

 lost the power of calling forth immunity reactions. 



A pretty experiment by Gay and Robertson 3 should 

 be mentioned in this connection. Robertson had shown 



that a substance closely resembling paranucleins both in 

 its properties and its C, H, and N content can be formed 

 from the filtered products of the complete peptic hydro- 

 lysis of an approximately four per cent, neutral solution 

 of potassium caseinate by the action of pure pepsin at 

 36 C. 



He considered this a case of a real synthesis of proteins 

 from the products of its hydrolytic cleavage. This 



1 Quoted from Wells, H. G., Jour. Infect. Diseases, 1908, v., 449. 



a Ibid., 1911, ix., 147. 



3 Gay, F. P., and Robertson, T. B., Jour. Biol. Chem., 1912, xii., 233. 



