and Casein Peptone, 99 



concentrated giving a gummy , deposit as the heating continued. 

 Further, the reaction with heat was the only respect in which this 

 body differed from the preceding ammonium sulphate pi-ecipitate. 

 Owing to insufficient quantity it was not analyzed. 



In the filtrate from the first sodium chloride precipitate, a second 

 caseose was precipitated by addition of a little 30 per cent, acetic 

 acid. At first it separated as a flocculent precipitate, but on stand- 

 ing changed to a gummy mass, which dissolved more or less readily 

 in water, and completely so when a little sodium carbonate was added 

 to neutral reaction. After reprecipitation, the aqueous solution of the 

 substance was neutralized, dialyzed, the solution concentrated without 

 separation of any gummy matter, and the substance finally precipitated 

 with alcohol. The precipitate was boiled repeatedly with alcohol and 

 finally dried at 110° C. The dried substance was readily soluble in 

 water and also in dilute acetic acid, potassium ferrocyanide producing 

 in the latter solution a slight turbidity only. Added to an aqueous 

 solution of the substance, acetic acid produced a heavy white pre- 

 cipitate readily soluble in excess of the acid. Nitric acid, likewise, 

 produced a heavy white precipitate not so readily soluble in excess. 

 Cupric sulphate also gave a heavy white precipitate. The aqueous 

 solution of the caseose gave no turbidity whatever, when heated. 



Analyzed it yielded the following results : 



Acetic acid precipitate of caseose {a deuterocaseose f) formed by 



trypsin. 



I. 0-5594 gram substance gave 0-3300 gram H.p = 6-55 per cent. 

 H and 1-0924 grams CO^=53-25 per cent. C. 



II. 0-3670 gram substance gave 0-2157 gram H„0 = 6-53 per cent. 

 II and 0-7158 gram CO^=53-19 per cent. C. 



III. 0-3811 gram substance gave 44-4 c. c. N at 12-8° C. and 

 765-1 mm pressure =14-07 per cent. N. 



IV. 0-2848 gram substance gave 33-0 c. c. ISl at 13-4° C. and 

 765-5 mm pressure =13-98 per cent. N. 



V. 0-4351 gram substance gave 0-0230 gram ash =5-28 per cent. 



VI. 0-4033 gram substance gave 0-0210 gram ash =5-26 per cent. 



Percentage conqwsition of ash-free substance. 



Average. 

 C 56-20 56-14 .-. ..-- 56-17 



H 6-91 6-89 .... 6-90 



N .... .... 14-85 14-75 U'SO 



