iQisl Charles J. Robinson and J. Howard Mueller 113 



filtrate gave a heavy precipitate, consisting almost entirely of in- 

 organic phosphate, since, after being converted to the barium salt, 

 it failed to precipitate with alcohol. 



Preparation of the alcoholic precipitate (2). Two and one-half 

 k. of wheat-bran were extracted as before with 0.2 percent hydro- 

 chloric acid sol. over night, and the extract, after filtering, precip- 

 itated directly with 3 vol. of alcohol, without previous purification 

 with tannic acid, which would have interfered with the copper pre- 

 cipitation of the filtrate. The precipitate, after settling, was filtered 

 out, dissolved in 0.2 percent hydrochloric acid sol., and tannic acid 

 added in excess. The resulting precipitate was filtered out, and the 

 filtrate precipitated with alcohol. The precipitate was then purified 

 by four more alcoholic precipitations, and was finally washed with 

 alcohol and ether, and dried. Yield : 40 gm. ; free f rom inorganic 

 phosphates and slowly but perfectly soluble in water. 



Copper acetate precipitation of filtrate (i). To the alcoholic 

 filtrate was added a conc. sol. of 100 gm. of copper acetate. A very 

 heavy precipitate was produced. This was filtered and washed, 

 suspended in water, and decomposed with hydrogen sulfid. The 

 filtrate from the copper sulfid was made alkalin with barium hy- 

 droxid sol., after the addition of a sol. of 100 gm. of barium chlo- 

 rid, a heavy white precipitate resulting. This was filtered out, dis- 

 solved in 0.2 percent hydrochloric acid sol., and 3 vol. of alcohol 

 added. Only a faint turbidity was produced, and after long Stand- 

 ing a slight precipitate formed which, after filtering and drying 

 without further purification, weighed only about 0.2 gm. It was 

 discarded. It is possible that the copper precipitate at first con- 

 tained more organic material, but it stood in the laboratory at 20° C. 

 — 25° C. for 2 or 3 days and may have undergone decomposition, 

 although this does not seem probable. 



Preparation of the barium salt by direct precipitation with barium 

 hydroxid. Twelve gm. of the crude material were dissolved in 

 water to which a small amount of hydrochloric acid was added, and 

 the Solution boiled. Barium hydroxid sol. was now added to strong 

 alkalin reaction. The precipitate was filtered out, dissolved in dil. 

 hydrochloric acid sol., and reprecipitated with barium hydroxid sol. 

 It was then purified by three alcoholic precipitations in the usual 



