300 R. a. Chittenden — Papoid-digestion. 



moses and globulin can be precipitated together, while the peptone 

 can be detected in the filtrate by the biuret test, viz: by potassium ' 

 hydroxide* and dilute cupric sulphate solution. 



From the foregoing simple reactions, it is evident that papoid is 

 composed essentially of a mixture of globulin, albumoses and pep- 

 tone, with which is associated the ferments characteristic of the 

 preparation. This is essentially in accord with what is known re- 

 garding the vegetable ferments in general, and indeed, the animal 

 ferments as well. Thus even pepsin, in its general chemical reac- 

 tions, behaves like an albumose, and the best known methods of 

 isolating vegetable ferments result simpty in the separation of one 

 or more albumoses, or a glodulin-like albumose, with which the fer- 

 ment appears to be inseparably connected. In addition to the above 

 proteid constituents, papoid appears to contain a small amount of 

 indifferent material, probably added to counteract any tendency 

 which the peptones or other like bodies have towards the accumula- 

 tion of hygroscopic moisture. 



2. The Proteolytic Action of Papoid. 



As early as 1874, Royf had called attention to the fact that papaw 

 juice had the power of dissolving both animal and vegetable 

 albumin, although he apparently did not clearly recognize the pro- 

 cess as one of digestion. Later, AlbrechtJ experimented in the 

 same direction, and since then many experimenters have added their 

 testimony to the power of papaw preparations as solvents for pro- 

 teid matter. 



Papoid, so far as my observations extend, has the power of digest- 

 ing to a greater or less extent all forms of proteid or albuminous 

 matter, both coagulated and uncoagulated. Furthermore, papoid is 

 peculiar in that its digestive power is exercised in a neutral, acid 

 and alkaline medium. These statements are amply illustrated by 

 the following experiments : 



a. Action on Coagulated Egg-albumin. 



The albumin was prepared for this experiment by taking the 

 whites of several eggs, cutting the transparent membranes with 

 scissors, adding an equal volume of distilled water and straining 

 the mixture through fine muslin to remove the meshes enclosing the 



* The potassium hydroxide solution must be added in large excess, sufficient to 

 decompose all of the ammonium salt present. 



f Glasgow Med. Journal, 1814. J Schmidt's Jahrbuch, vol. 190. 



