28o Report of the Chemical Department of the 



Table III. — Comparison of Acetic and Hydrochloric Acids for 

 Separation of Forms of Phosphorus. 



It will be noticed from these results that whenever there is a 

 large amount of total soluble phosphorus there is also a corre- 

 sponding increase in the amount of inorganic phosphorus. In 

 but one instance — that of the hydrochloric acid extract of bran — 

 did this fail to hold true. In all cases the character of the inor- 

 ganic precipitate was greatly different from that of an ammonium 

 phospho-molybdate precipitate. It was invariably of a flocculent, 

 proteid-like nature and only on standing did the characteristic 

 yellow precipitate begin to separate. This certainly indicated a 

 slow cleavage of the organic phosphorus in the solution which 

 was brought about by the excess of nitric acid in the molybdate 

 reagent. In the case of the acetic acid extract from bran this 

 cleavage was especially marked. Such conditions of manipula- 

 tion certainly lead to results altogether too high for inorganic 

 phosphorus. 



