330 M. H. Chittenden — Papoid- digestion. 



degree of activity ; both of which results clearly favor the action 

 of papoid in the stomach. 



Further, while the presence of 0-1 per cent, hydrochloric acid 

 lessens soniewhat the action of the ferment, the latter is not 

 destroyed ; hence, by neutralization of the acid the inhibitory effect 

 is overcome and the ferment springs into renewed activity when 

 brought in contact with an alkaline medium. By long-continued 

 warming of the bare ferment with 0*2 per cent, hydrochloric acid, 

 there is a pronounced destructive action. This destruction, however, 

 is accomplished by the free acid ; free, because of the lack of pro- 

 teids present for it to combine with, a condition of things not so 

 liable to occur in the case of a full stomach, which is naturally the 

 time when a digestive ferment would be administered. 



The above statements are illustrated by the following facts : Two 

 portions of papoid, 0'5 gram each, were warmed at 40° C, for 5^ 

 hours with 25 c, c, of 0-2 per cent., and O'l per cent, hydrochloric 

 acid, respectively. The two solutions were then neutralized and 

 eventually made slightly alkaline with sodium bicarbonate. Their 

 digestive action was then compared with that of a like amount of 

 fresh papoid, dissolved in the same quantity of fluid and of the 

 same reaction. 



The 10 grams of cooked beef proteids contained 3*4420 grams of 

 dry proteid (110° C). 



The mixtures were warmed at 40° C. for 6 hours. 



Conditions. 



Weiofht of 

 undigested residue. 



Proteid digested. 



Fresh papoid 



1-7930 grams 



47-8 per cent 



w:rnrdt^h|«lP™t-HCI 



1-8425 " 



46-4 



0-2 " " 



2-9260 " 



14-9 '' 



It is thus evident that, under the above conditions, O'l per cent, 

 hydrochloric acid may hinder the digestive action of papoid, but 

 will not destroy the ferment. With 0-2 per cent, hydrochloric acidj 

 however, when the acid is free and not combined with proteid 

 matter, there is a marked destruction of the ferment; not complete, 

 but doubtless sufficient to interfere somewhat with its action. In 

 the presence of an excess of proteid matter, this destructive action 

 is not so marked. 



The presence of pepsin does not appear, materially, to modify the 

 action of the dilute hydrochloric acid on papoid. I do not think 

 that gastric juice of a given acidity has any more deleterious effect 

 on the ferment, than acid of the same strength alone. In any event, 



