THE PITCHER LIQUOR OF NEPENTHES. 



119 



determination proper, but it always was decidedly less voluminous 

 than the precipitate in the corresponding control experiment ; there- 

 fore digestion of the substrate had occurred, though less rapidly 

 than when liquor from stimulated pitchers was used. 



TABLE V. 

 Digestion of Edestan by the Pitcher Liquor. 



Liquor from 



Volume 



of 



Pitcher 



Liquor, 



C.c. 



Precipitate on Neutral- 

 ization of Experiment 

 Proper After Incubation. 



Non-stimulated pitchers . 



Stimulated pitchers. 



Precipitate one half 



as great as in 



blank 

 Precipitate one half 



as great as in 



blank 

 No precipitate 

 No precipitate 



Digestion of the Protean of Castor Bean Globulin. 



A 2 per cent, solution of castor bean globulin in 5 per cent, 

 sodium chloride solution was used. This solution was filtered, if 

 necessary, then mixed with the pitcher liquor; 0.1 N hydrochloric 

 acid was next added ; a cloudy precipitate of the protean derived 

 from the globulin formed. The presence in the pitcher liquor of 

 a proteolytic enzyme, active in the presence of hydrochloric acid, 

 was shown by the digestion or solution of the protean, the cloudy 

 precipitate gradually becoming less dense, and finally disappearing 

 completely. Liquor from a separate pitcher was used in each ex- 

 periment; the details are recorded in Table VI. The protean was 

 usually dissolved by the liquor from both non-stimulated and stimu- 

 lated pitchers. 



Digestion of Jacoby's Ricin. 



The reagent was prepared by dissolving i gram of Jacoby's 

 ricin and 1.5 grams of sodium chloride in 100 c.c. of water, and 

 filtering, if necessary. The test was carried out by mixing i c.c. 

 of pitcher liquor and 3 c.c. of ricin solution, adding i c.c. of 0.56 

 per cent, hydrochloric acid, then incubating. A cloudy precipitate 



