lbSl.J and Proteolytic Activity of Pancreatic Extracts, 



159 



Curve illustrating the effect of temperature on the tryptic digestion of milk. 



the vanishing point of the reaction was employed for the same purpose. 

 The results brought out by these experiments correspond pretty 

 closely with those given in Table VII. 



Table VEIL 



Showing the effect of temperature by the length of time required to 

 reach the metacasein reaction, when constant quantities of pancreatic 

 extract are used. 



I Set. 



0'4 cub. centim. pancreatic extract 

 with 100 cub. centims. diluted milk. 



II Set. 



4 cub. centims. of pancreatic extract 

 with 100 cub. centims. diluted milk. 



Temperature. 



Onset point of the 

 metacasein reaction. 



Temperature. 



Vanishing point of the 

 metacasein reaction. 



2 to 5° C. 

 10 

 15 

 20 

 30 

 40 

 50 

 60 

 65 



70 | 



312 minutes. 

 168 

 120 

 70 

 25 

 12 

 6 

 4 

 6 



action suspended, but 

 resumed on cooling. 



10° C. 



20 

 30 

 40 

 50 

 60 



180 minutes. 



75 

 26 

 12 



6 



4 



An examination of the table shows how very nearly the results 

 correspond, whether the onset point or the vanishing point of tne 

 metacasein reaction be taken as a measure of tryptic activity. This 

 correspondence substantiates the conclusion that the onset point of 

 the reaction furnishes a trustworthy index of the activity of tryptic 

 digestion. The proportionate quantity of pancreatic extract added to 

 the milk in the experiments recorded in Set II of Table VIII was ten 



