98 M. H. Chittenden — Caseoses, Casein Dyspeptone, 



VI. 0-4804 gram substance gave 0-0365 gram = 9-59 per cent. 



VII. 0-4272 gram substance gave 0-0405 gram ash=9-43 per cent. 



VIII. Ash from 0-8070 gram substance gave 0-0181 gram BaSO^ 

 =0-03 per cent. S, 



Percentage composition of ash-free substance. 



Average. 



53-36 



6-70 



15-07 15-07 



0-95 0-91 0-93 



23-74 



100-00 



This sample of /5 deutero shows very close agreement in composition 

 and reactions with the like body formed by dilute sulphuric acid ; 

 both being characterized by the reaction with acetic acid and show- 

 ing, by their reactions and composition, a closer relationship to the 

 proto-like bodies than their non-precipitation by ammonium sulphate 

 would appear to warrant. In composition, however, this body 

 shows a much smaller percentage of cai'bon than the caseose precipi- 

 tated by acetic acid. 



For separation of the other caseoses formed in this digestion, 

 the first ammonium sulphate precipitate was dissolved in water 

 and protocaseose precipitated by saturation of the solution with 

 sodium chloride. The precipitate, which was not very heavy, was 

 purified by reprecipitation and dialysis. On dissolving the first salt 

 precipitate in water quite a little residue was noticed, soluble in 

 dilute sodium carbonate, but readily precipitated by the least trace 

 of acid. The final neutral solution was concentrated, giving when 

 heated a heavy coagulum which finally came together as a gummy 

 mass. The clear fluid, separated from the gum, gave still another 

 coagulum as the heating was continued. On cooling, the gummy 

 matter readily dissolved. As the evaporation continued and the 

 fluid became concentrated the gummy matter dissolved even in the 

 hot fluid, and the caseose was finally precipitated while hot with 

 alcohol, and the precipitate boiled repeatedly with alcohol for the 

 complete removal of leucin and tyrosin. 



In reactions, this body was apparently identical with protocaseose 

 formed by pepsin-hydrochloric acid, except that with acetic acid and 

 also with hydrochloric acid it yielded a heavy white pi-ecipitate, sol- 

 uble in excess of acid. In water it dissolved almost completely, 

 the solution, however, becoming turbid when heated and if sufficiently 



