M. H. Chittenden — Papoid-digestion. 323 



a heavy white precipitate, of what was later proved to be an albu- 

 mose-like body, readily soluble in a little 10 per cent, salt solution. 

 Addition of 0*2 per cent, hydrochloric acid, likewise, produced a 

 heavy precipitate of the same body, easily soluble in a slight 

 excess of the acid. Boiling the neutral solution also gave rise 

 to a heavy precipitate or coagulum, apparently the same body 

 as that precipitated by water and by dilute acid, slowly but com- 

 pletely soluble in w^arm 0*2 per cent, hydrochloric acid^ and in warm 

 0*5 per cent, sodium carbonate-solution. Hence, this body is a solu- 

 ble albumose and not a coagulable globulin. It is completely pre- 

 cipitable from a neutral solution by heat, and partakes of the general 

 character of heteroalbumose, being insoluble in water but com- 

 pletely soluble in salt solutions, as well as in dilute acid and alkali. 

 In addition to this peculiar primary product of digestion, there was 

 also found a large amount of more soluble primary and secondary 

 albumoses, together with true peptone, leucin and tyrosin. 



Raw blood-fibrin, digested with a weak hydrochloric acid (0'05 per 

 cent.) solution of papoid, yields the same products as those just 

 described ; the peculiar primary albumose making its appearance here 

 in fully as large quantity as in the neutral digestion and apparently 

 taking the place of acid-albumin, which in the single experiment 

 tried appeared to be entirely wanting. 



In the digestion of cooked beef proteids with a neutral solution 

 of papoid, as likewise with an alkaline solution of the ferment, the 

 peculiar heteroalbumose-like body above described was wholly 

 absent ; only the ordinary primary and secondary albumoses w^ere 

 observed, together with a large amount of peptone and some leucin 

 and tyrosin. 



The above results, therefore, plainly warrant the statement that 

 the power possessed by papoid of dissolving various forms of pro- 

 teid matter is dependent upon an ordinary digestive action akin to, 

 or identical with, that of digestive ferments in general, whether 

 animal or vegetable. 



5. — Action of Papoid on Milk. 



The action of papoid on milk is twofold. First, under suitable 

 <;onditions, it brings about a curdling of the milk or separation of 

 the casein, more or less complete according to the circumstances. 

 This is followed by the ordinary digestive action of the proteolytic 

 ferment, in which the precipitated casein is gradually converted, 

 wholly or in part, into soluble products. 



