and Casein Peptone. 81 



dyscaseose were very small, but still sufficiently laro-e to enable us 

 to make out their general characters. Similarly, Dr. Thierfelder* 

 found in the purification of his protocaseose, or " propeptone I" as 

 he terms it, a small, insoluble residue each time he dissolved the 

 sodium chloride precipitate in water. It would appear, therefore, 

 that in a vigorous or long continued digestion there is a much greater 

 probability of the hetero body being formed than when the ferment 

 is allowed to act only a short time on the casein. This, however, is 

 contrary to Neumeister's views regarding the order of formation of 

 the proteoses. 



In order to free the precipitated protocaseose from salt and any 

 adhering heterocaseose, it was dissolved in water and dialyzed until 

 all chloride was removed. The neutral solution was then concen- 

 trated to a syrup, and the proto body precipitated by alcohol. 

 During the concentration of the fluid, a gummy-like mass separated, 

 similar tothe separation of protoelastose. This, however, dissolved 

 more or less completely as the mixture cooled. The precipitated 

 caseose, after being extracted several times with alcohol and with 

 warm ether, was partially dried, ground to a fine powder, re- 

 extracted with ether in a fat extractor and finally dried at 110° C. 

 until of constant weight. 



On analysis it gave the following results : 



Protocaseose A. 



I. 0-4947 gram substance gave 0-9794 gram CO„ = 53-98 per cent. C. 



II. 0-380-2 gram substance gave 0-2397 gram H.,O = 7-00 per cent. H. 



III. 0-3862 gram substance gave 0-2467 gram H.,O = 7-09 per cent. 

 H and 0'7670gram CO„i=54-15 per cent. C. 



IV. 0-4953 gram substance gave 64-8 c. c. N at 20-8° C. and 

 760-3 mm pressure = 15-72 per cent. N. 



V. 0-3764 gram substance gave 50-1 c. c. N at 22-5° C. and 760-6 

 mm pressure = 15-95 per cent. N. 



VI. 0-4599 gram substance gave 0-0046 gram ash = 1-00 per cent. 



VII. 0-4103 gram substance gave 0-0041 gram ash = 0-99 per cent. 



Percentage composition of ash-free substance. 



Average. 



C 54-53 54-69 ..- --.. 54-61 



H .... 7-1] 7-07 ' 7-11 



N .... 15-88 16-11 15-99 



* Zur Kenntniss der Cfiseinpeptone, Zeitsclirifit fur ph3'siologiselie Chemie, x, p. 577. 

 Tkans. Conn. Acad., Vol. VIII. 11 Nov., 1888. 



