68 (Jhittexden — Caseoses, Casern Di/sjyeptone, and Casein Peptone. 



fluid, and washed with water uutil the washings gave no reaction for 

 chlorides. It was then treated in the cold with one litre of one per 

 cent, sodium carbonate, in which it appeared to dissolve completely. 

 On filtration there appeared a small whitish residue, which on treat- 

 ment with ether, dissolved in great part, thus showing its fatty 

 nature. There remained, however, a very small residue of a heavy, 

 browiiish substance too small in quantity to be considered other than 

 as an impurity. On adding dilute hydrochloric acid to the alkaline 

 fluid, no precipitate was obtained until the fluid was made distinctly 

 acid, when the dyspeptone was thrown down as a heavy flocculent 

 precipitate. In the filtrate, the biuret and Millon's test showed only 

 a faint trace of an albuminous body. The precipitate of dyspeptone 

 was washed with water until the washings gave no reaction with 

 silver nitrate, after which it was dissolved in one per cent, sodium 

 carbonate, the fluid made exactly neutral with dilute hydrochloric 

 acid, thymolized, and then dialyzed in running water until all chlo- 

 ride was removed from the fluid. 



The neutral fluid of dyspeptone so obtained, was concentrated to a 

 thick syrup on the water-bath, and then while still warm, it was 

 treated with 95 per cent, alcohol and a little absolute alcohol. 

 A moderately heavy precipitate of dyspeptone resulted, but appar- 

 ently not all of the substance was precipitated. On standing for 

 forty-eight hours, the fluid was found in a thick, gelatinous condition. 

 The coagulum was insoluble in 95 per cent, alcohol, but readily and 

 completely soluble in water. It was therefore washed thoroughly 

 with alcohol, allowed to stand under absolute alcohol for several 

 days, then treated with cold ether, after which it was dried, pow- 

 dered and placed in a fat extractor and extracted with boiling ether 

 as long as any fatty matter Avas dissolved, a process which took sev- 

 eral days. About nine grams of the pure, dry substance were 

 obtained. 



A portion was then dried at 110° C. until of constant weight, 

 for analysis. Its composition is shown in the accompanying table. 



The methods of analysis employed were the same as those previ- 

 ously described. Phosphorus was determined by fusing the sub- 

 stance in a silver crucible with potassium hydroxide and potassium 

 nitrate, acidifying the mixture with nitric acid, evaporating to dry- 

 ness, dissolving the residue in water acidified with nitric acid and 

 precipitation of the phosphoric acid, first with raolybdic solution, and 

 lastly with magnesia mixture and final weighing of the phosphorus 

 as magnesium pyrophosphate. 



