BY JAMES M. PETRIE. 



107 



The nitrogen-curve, A, indicates the existence of more than 

 one distinct protein. The first and least soluble protein 

 has begun to precipitate with 5% alcohol, and, at this low 

 concentration, nearly one-third of the total protein in tha 



B 



5 10 10 30 



^ Alcohol per cent. 



liO 



50 



60 



70 



80% 



extract is precipitated. From the initiation, iip to 40% 

 alcohol, the amount of this protein precipitated is roughly 

 proportional to the concentration of the alcohol. At the 

 limits of 40 and 60%, distinct changes in the solubility are 

 observed, and practically the same amount of nitrogen is 

 precipitated. At the latter stage, both curves rise suddenly, 



