64 



COMPARATIVE HYDROLYSIS OF GELATIN 



Days 



Fig. 3. Action of pepsin on gelatin partially hydrolyzed by alkali. 500 cc. 

 of 10 per cent gelatin containing 8 cc. of 3 N NaOH kept at about 80°C. 50 cc. 

 pipetted out at intervals and added to 50 cc. of 0.3 n HCl (pH = 2.0), these samples 

 kept at 2° until all had been taken and 5 cc. of 5 per cent pepsin then added to 

 each, and the samples placed at 38°. Formol titration was run on 5 or 10 cc. 

 The values plotted have been calculated on the basis of 10 cc. of 5 per cent gelatin. 



TABLE II. 

 Addition of Pepsin to Gelatin Partially Hydrolyzed by Alkali. 



