H. H. Chittenden — Papoid-digestion. 309 



checked in its digestive action by contact with the alkaline fluids 

 of the intestinal tract. 



Another very noticeable action of papoid was seen in connection 

 with this experiment. Sodium carbonate, especially the larger per- 

 centages, tends to produce a very noticeable and pronounced swell- 

 ing of the coagulated proteid. Thus, in the control experiment 

 without papoid, where 10 grams of the cooked beef proteids were 

 warmed at 45° C. with 2*0 per cent, sodium carbonate, the proteid 

 matter was quickly swollen to an almost solid jelly, but in the 

 presence of papoid this swelling of the proteid was wholly absent, 

 even when the alkali carbonate was increased to 4*0 per cent ; in 

 the presence of papoid, the undigested residue was thoroughly dis- 

 integrated and pultaceous. Papoid thus counteracts the swelling 

 action of the alkaline fluid in the same manner as it counteracts the 

 swelling action of dilute hydrochloric acid, already referred to. 



Influence of JBoracic Acid on Papoid Digestion. 



a. With raw beef proteids, — 10 grams contained 2-8508 grams of 

 dry proteid (110° C). The digestions were warmed at 45° C. for 7 

 hours. 



Boracic Acid. Weight of undigested residue. l^roteid digested. 



(Neutral) 0-8988 gram 68-4 per cent. 



2-0 per cent. 0-8210 " 71-2 



h. With cooked beef proteids, — 10 grams contained 3-7438 grams 

 of dry proteid (110° C). Digestions were warmed at 45° C. for 

 51 hours. 



Boracic Acid. Weight of undigested residue. Proteid digested. 



(Neutral) 1-7.82 grams 52*5 per cent. 



3-0 per cent. 1-5950 " 573 



c. With boiled blood-fibrin, — 10 grams contained 3-692 grams of 

 dry proteid (110° C). Digestions were warmed at 45° C. for 9 hours. 



Boracic Acid. Weight of undigested residue. I'roteid digested. 



(Neutral) 2-6397 grams 28-5 per cent. 



2-0 percent. 2-7705 " 24-9 



d. With coagulated egg-albumiii, — 10 grams moist coagulum con- 

 tained 1-5143 grams of dry proteid (110° C). Digestions, were 

 warmed at 45° C. for 12 hours. 



Boracic Acid. Weight of undigested residue. I^roteld digested. 



(Neutral) 0-6503 gram 57 per cent. 



2-0 per cent. 0-6012 " 60-3 



