mid Casein Peptone. 95 



Percentage composition of ash-free substance. 



Average. 



C S4-68 54-42 54-55 



H 6-86 6-81 .... 6-84. 



N ---- 15-33 15-33 



This caseose, instead of being a pure cleutero boclj^, appears to be 

 a mixture of proto and a deutero as indicated by its behavior towards 

 heat and nitric acid ; indeed, the behavior of this acetic acid precipi- 

 tate resembles the acetic acid precipitate of caseose obtained in our 

 previous work, where the two bodies were plainly precipitated to- 

 gether. In composition, while it agrees closely with protocaseose 

 formed by pepsin-hydrochloric acid, it has a higher content of carbon 

 than the corresponding a deutero, but bears about the same relation 

 to the sulphuric acid protocaseose as the a deutero formed by pepsin 

 to its corresponding protocaseose. 



On boiling the original ammonium sulphate-saturated filtrate, a 

 second gummy precipitate gradually separated from the hot fluid. 

 This caseose, after purification by the usual methods and drying 

 at 110° C, was entirely soluble in hot and cold water, and 

 was especially characterized by yielding with acetic acid a heavy 

 white precipitate, soluble in excess of the acid. With nitric acid it 

 also gave a white precipitate, soluble in excess of acid. Cupric 

 sulphate likewise gave a heavy precipitate. The cold water solution 

 was not rendered turbid by heat. 



Analyzed it gave the following results: 



yS deuterocaseose, formed hy dilute sulplmrlc acid. 



I. 0*3952 gram substance gave 0-2308 gram H.,0 = 6-49 per cent, 

 H and 0*7282 gram GO^=bO-2o per cent. C. 



II. 0*3518 gram substance gave 0*2064 gram H.,0 = 6*51 per cent. 

 H and 0*6440 gram CO„ = 49-92 per cent. C. 



III. 0*4727 gram substance gave 59*2 c. c. N at 15-0° C. and 

 754*9 mm pressure = 14*81 per cent. N. 



IV. 0-4279 gram substance gave 0*0233 gram ash = 5*44 per cent. 



V. 0*5184 gram substance gave 0*0219 gram ash = 5*38 per cent. 



Percentage composition of ash-free substance. 



Average. 

 C 53*10 52-77 .... 52-93 



H 6-86 6-89 .... 6-87 



N 15.66 15-66 



