612 EFFECT OF ACIDS ON DIGESTION OF PROTEINS 



SUMMARY. 



1 . At equal hydrogen ion concentration the rate of pepsin digestion 

 of gelatin, egg albumin, blood albumin, casein, and edestin is the 

 same in solutions of hydrochloric, nitric, sulfuric, oxalic, citric, and 

 phosphoric acids. Acetic acid diminishes the rate of digestion of all 

 the proteins except gelatin. 



2. There is no evidence of antagonistic salt action in the effect of 

 acids on the pepsin digestion of proteins. 



3. The state of aggregation of the protein, i.e. whether in solution 

 or not, and the viscosity of the solution have no marked influence on 

 the rate of digestion of the protein. 



The author is indebted to Drs. Van Slyke and Cullen for placing 

 their apparatus for the hydrogen ion determination at his disposal. 



