and Casein Pejitone. 83 



wholly insoluble. This residue, whicli by analogy should consist of 

 hetero and dyscaseose was somewhat soluble in salt solution and 

 wholly soluble in dilute sodium carbonate and dilute acid, both acetic 

 and hydrochloric, even dissolving in 0-2 per cent, hydrochloric acid. 

 It was dissolved in sodium carbonate, the fluid neutralized without 

 giving any precipitate, and dialyzed until the sodium chloride was 

 entirely removed. The neutral and clear fluid was then concentrated 

 to a syrup, precipitated by alcohol and the precipitate dried at 110° C. 

 On treatment with cold water, it was now found soluble to a large 

 extent, though a certain amount of gummy matter was still insolu- 

 ble. The soluble portion showed all of the reactions of the proto 

 body ; the solution being rendered turbid by heat, clear again on 

 cooling, and giving in the cold a heavy precipitate with nitric acid, 

 soluble when heated. This behavior of the insoluble heterocaseose 

 towards dilute sodium carbonate would seem to imply a conversion 

 of this substance into protocaseose, or perhaps a reconversion of the 

 coagulated heterocaseose dyscaseose, into heterocaseose proper. 



Acetic acid precipitate. 



On adding a little 30 per cent, acetic acid to the oi'iginal salt- 

 saturated filtrate from the first sodium chloride precipitate of proto- 

 caseose, etc., a heavy, flocculent precipitate settled out, which in 

 amount far exceeded the protocaseose and which on standing, soon 

 became gummy. Excess of acid was avoided, as the precipitate 

 was somewhat soluble in a large amount of the reagent. The 

 gummy mass, after being washed as thoroughly as possible with 

 saturated salt solution, was treated with cold water, in which the 

 greater portion of the substance dissolved, the solution made neu- 

 tral, dialyzed, concentrated to a syrup, and the substance precipitated 

 with alcohol. It was then thoroughly extracted with ether and 

 finally dried at 110° C. 



In reactions, it diftered decidedly from protocaseose; in water 

 it was quickly and completely soluble and the solution when heated 

 gave no coagulum whatever, or at the most only the slightest ap- 

 proach to a turbidity. 



Dilute nitric acid, in the cold, gave no precipitate ; when heated, the 

 acid fluid changed to a reddish yellow color, which quickly turned 

 yellow. 



With acetic acid, an aqueous solution of the substance remained 

 perfectly clear. Potassium ferrocyanide, however, when added to 

 the acid fluid gave a heavy precipitate. 



