New York AGRICULTURAL EXPERIMENT STATION. 241 

Concentration HCL in Case 
7 2 3 4 S~ G 7 
Hours Contact} ———> 
Fic. 8.—Showing relation (curves A and B) of amounts of acid fixed 
at 25° to the concentration of acid in surrounding solution. Curve C 
shows rate of extraction of acid from casein that had taken up acid, and 
attainment of practically same equilibrium as when casein takes acid from 
solution (curves A and B). See tables IX, X, XI, 
16 
