R. H. Chittenden — Ferments of Pineapple Juice. 299 



solution of the proteid substance ; in fact, a single observation of the 

 manner in which blood fibrin is attacked by pineapple juice is suf- 

 ficient to give one a just appreciation of the energy of the ferment. 

 Thus in Experiment IV, it will be remembered that 50 per cent, of 

 the blood fibrin used in the experiment was converted into soluble 

 products in two hours, and that in Experiment V, with the proteid s 

 of muscle tissue, 58 per cent, of the proteid matter was dissolved 

 by neutral pineapple juice in half an hour at 40° C. Naturally, on 

 coagulated egg-albumin the digestive power of the ferment is less 

 quickly manifested, but the experiments already recorded show that 

 even with this more difficultly digestible proteid, the rate of action is 

 faii'ly rapid. The two experiments following give a general impres- 

 sion of the rate of action of the ferment, in the digestion of coagu- 

 lated egg-albumin. 



Experiment XVII. — The 10 grams of albumin coagulum used in 

 the digestions contained 1 -3944 grams of dry albumin. The mixtures 

 were warmed at 45° C. for the periods stated in the following table, 

 the amount of albumin digested during the periods being then detei'- 

 mined in the usual manner. 



Neutralized Undissolved Per cent, 



pineapple juice. Time. albumin. di^fested. 



A 100 c. c. A hour 1-3026 grams 6-6 



B 100 1 1-3073 13-5 



C 100 3 1-0837 33-4 



D 100 4 0-8814 36-8 



E 100 5 0-8531 38-9 



Ex])eriment XVIII. — The 10 grams of albumin coagulum used in 

 the digestions contained 1-4333 grams of dry albumin. The mix- 

 tures were warmed at 40° C. for the different periods stated, after 

 which the undissolved albumin was filtered off, washed and weighed. 



While the results of these two experiments differ somewhat from 

 each other in some respects, they are alike in showing that the fer- 

 ment commences to act upon the proteid matter at once, and that 

 this digestive action steadily continues, in the case of the above 

 proteid, for about four hours, after which time the action becomes 

 very much slower. 



Trans. Comn. Acad., Vql. VIII. 40 Jak., 1892. 



