94 M. II. Chittenden — Caseoses, Casein Di/speptone, 



Percentage composition of ash-free substance. 



Average. 



C 55-90 56-50 56-20 



H 7-07 7-09 .... .... 7-08 



N --.- -..- 15-40 15-31 15-S6 



Alter being dried at "110° C. the substance dissolved with diffi- 

 culty in water, leaving a large residue, but was readily and com- 

 pletely soluble in 0-2 per cent, hydrochloric acid and in 0*2 per cent, 

 sodium carbonate. From the alkaline solution it was reprecipitated 

 by hydrochloric acid, and not readily dissolved by an excess of the 

 acid. Aqueous solution of the substance was rendered turbid by heat, 

 the turbidity disappearing as the solution cooled. With dilute nitric 

 acid, a white precipitate was formed, readily soluble on warming and 

 I'eappearing as the solution cooled. Acetic acid and potassium ferro- 

 cyanide gave a heavy precipitate. 



Thus in many respects this body resembles protocaseose formed 

 by pepsin-hydrochloric acid, but is apparently characterized by a 

 somewhat higher percentage of carbon. 



The filtrate from the original sodium chloride precipitate, treated 

 with salt-saturated 30 per cent, acetic acid, gave a flocculent, chang- 

 ing to gummy precipitate which was readily and completely soluble 

 in water. The solution made exactly neutral was dialyzed without 

 showing any evidence of a hetero-like body, finally concentrated and 

 precipitated by alcohol. After being dried at 110° C, the substance 

 was only partially soluble in water. The aqueous solution was ren- 

 dered turbid by heat, clear again on cooling, and gave with nitric 

 acid a heavy white precipitate as also with acetic acid and potassium 

 ferrocyanide. 



Analyzed, it gave the following results : 



Acetic acid precqntate of easeose (a deuterocaseose ?) formed hy 

 dilute sidphnric acid. 



I. 0-4056 gram substance gave 0-2383 gram H„0 = 6-52 per cent. 

 li and 0-7733 gram CO^=5l-99 per cent. C. 



II. 0-4697 gram substance gave 0*2740 gram H,^0 = 6-48 per cent. 

 H and 0'8910 gram CO„ = 51-73 per cent. C. 



III. 0-5379 gram substance gave 66-5 c. c. N at 14-9° C. and 752-1 

 mm pressure= 14-58 per cent. N. 



IV. 0*4150 gram substance gave 0-0210 gram ash = 5'06 per cent. 



V. 0*5136 gram substance gave 0*0247 gram ash=4*80 per cent. 



