72 Chittenden — Caseoses, Casein Dyspeptone, and Casein Peptone. 



Digestions C and D. 



These digestions were conducted in much the same manner as the 

 preceding. In C, the casein was first subjected to the action of four 

 litres of vigorous, but purified, artificial gastric juice containing 0-4 

 per cent, acid, for four consecutive days. The undigested residue 

 was then filtered off, washed, and again treated with a vigorous pep- 

 sin-acid mixture for three days longer, in both cases at 40° C, The 

 residue still undigested was washed thoroughly with water and then 

 dissolved in one per cent, sodium carbonate, after which it was treated 

 exactly as pi-eparation A, 



In 2>, the casein was warmed for three days with six litres of a 

 similar pepsin-acid mixture, when the undissolved residue, after being 

 filtered and thoroughly washed, was dissolved in diluted sodium 

 carbonate and reprecipitated by dilute hydrochloric acid. Then, as 

 in B^ the washed precipitate was redigested with a vigorous gastric 

 juice for several days and the residue again dissolved, after thorough 

 washing, in one per cent, sodium carbonate and treated exactly as 

 the preceding preparation. 



For analysis, both products were freed entirely from fat, and ulti- 

 mately dried at 110° C, until of constant weight. Their composition 

 is shown in the accompanying tables. 



Three other distinct preparations of dyspeptone were made in man- 

 ner similar to the preceding, except that in all, larger quantities of 

 pepsin-hydrochloric acid were employed and the mixtures warmed 

 for a longer time at 40° C. Tims in digestion E, 1562 grams of 

 moist casein were warmed with 9-5 litres of 0*4 per cent, hydrochloric 

 acid and pepsin for two days, and the undigested residue again treated 

 at 40° C. with 3 litres of a like pepsin-acid for seven days, and finally 

 treated a third time with pepsin and acid for four days, before solu- 

 tion in sodium carbonate, etc. Likewise in digestion 6^, 2000 grams 

 of moist casein were warmed at 40° C. with 11 litres of 0*4 per cent, 

 acid and pepsin for 21 days and the residue warmed again at 40° C. 

 for several days, with a fresh pepsin-acid mixture. Ultimately, all of 

 the three products Avere treated as previously described, and finally 

 dried at 110° C. prior to analysis. The analytical results are shown 

 in the accompanying tables. 



