450 HEPBURX— BIOCHEMICAL STUDIES 



phane was made in the usual way with dilute acetic acid and bromine 

 vapor; the production of a red color showed the presence of free trypto- 

 phane, and cleavage of the dipeptide. 



In the first experiment, the period of digestion was nine days in the 

 incubator; the test for free tryptophane was negative. 



In a second experiment, the period of digestion was 21 days in the 

 incubator, followed by 7 days in the room. A distinctly positive test 

 for free tryptophane was obtained. 



General Summary 



The following conclusions may be drawn from the experiments re- 

 ported. 



The formal titration showed that the Hquor from stimulated pitchers 

 produced proteolysis of ovalbumen, fibrin, ovomucoid, Nahrstoff-Heyden, 

 and Witte peptone, while the liquor from non-stimulated pitchers lacked 

 proteolytic power. This method also showed that, in the presence of 

 very dilute hydrochloric acid, edestan was digested by the hquor from 

 stimulated pitchers, but not by that from non-stimulated pitchers. 



Carmine fibrin was dissolved by the Hquor from both stimulated and 

 non-stimulated pitchers, in the presence of 0.2 percent, hydrochloric 

 acid. This substrate was not dissolved by Hquor from non-stimulated 

 pitchers in the absence of acid. 



In the presence of very dilute hydrochloric acid, the pitcher liquor 

 produced proteolysis of edestan; digestion proceeded more rapidly in 

 Hquor from stimulated pitchers than in Hquor from non-stimulated 

 pitchers. 



The protean derived from the globulin of the castor bean was usuaUy 

 dissolved by the liquor from both stimulated and non-stimulated pitchers, 

 in the presence of very dilute hydrochloric acid. The same statement 

 may be made concerning Jacoby's ricin. 



The Hquor from stimulated pitchers apparently hydrolyzed glycyl- 

 tryptophane, provided the period of incubation was sufficiently long. 



The liquor from stimidated pitchers possessed proteolytic power in 

 both the absence and the presence of acid. 



The Hquor from non-stimulated pitchers exerted no proteolytic power 

 in the absence of acid, but possessed such power in the presence of acid. 



Further study is required to determine the manner in which stimula- 

 tion imparted active proteolytic power to the pitcher Hquor. Possibly 

 stimulation gave rise to a change in the reaction (hydrogen ion concen- 

 tration) of the Hquor and thereby created a favorable environment for 



