1912] 



Grover Tracy and William J. Gies 



469 



was 0.008 per cent. (o.i gram per 1,200 c.c). The mixtures were 

 kept at room temperature for two hoiirs before filtration was 

 Started. The exact nature of each mixture in the group, and the 

 experimental and calculated data, are summarized in Table i. 



TABLE I. 



The data of this experiment show that pepsin markedly in- 

 creased the water-combining power of fibrin under the imposed 

 conditions. The striking power of the pepsin in this experiment is 

 fully appreciated when the active proportion of the enzyme is con- 

 sidered. The concentration of the commercial pepsin product in the 

 liquid that exhibited the greatest bloating power was 0.000,014 pc 

 cent. The proportion of pure pepsin in that liquid must have been 

 very much less. 



2. Conditions of the second experiment: Same as those of 

 No. I, except that the concentration of the pepsin product in the 

 enzyme Solution was 0.05 per cent. (0.1 gram in 200 c.c). See 

 Table 2. 



3. Conditions of the third experiment: Same as those of Nos. 

 I and 2, except that the concentration of the pepsin product in the 

 enzyme Solution was 0.1 per cent. (0.1 gram in 100 c.c). See 

 Table 3. 



In the second and third experiments the heights of the columns 

 of bloated fibrin indicated that the enzyme accelerated the swelling 



' Slight digestion. 



* The differences in the volumes of the filtrates in all the experiments were 

 less striking than the differences in the heights of the columns of bloated protein 

 materials. 



