2/8 Report of the Chemical Department of the 



tate, accordingf to Araki, should contain any free phosphoric acid 

 spHt ofif by the action of the enzyme. In our hands, as we shall 

 show later, tannic acid in dilute mineral acid solution and tannic 

 acid with sodium acetate both fail to precipitate completely the 

 soluble nucleins contained in certain of our feeding materials. 

 We do not assume to deny the accuracy of the results of these 

 authors, recognizing the important fact that the constitution and 

 consequent reaction of the nucleic acids with which these investi- 

 gators worked may be entirely dififerent from those that occurred 

 in our materials. 



Our preliminarv work was done on whole oats, ground and air- 

 dried. Five-gram samples were treated with 125 cc. of the ex- 

 tracting reagent for varying lengths of time with occasional vigor- 

 ous shakings. The mixtures were then allowed to settle and the 

 supernatant liquid was decanted through dry filters into 500 cc. 

 flasks. The residue was washed by decantation with several por- 

 tions of water until 500 cc. of filtrate had been collected. To 

 200 cc. of this filtrate 10 grams of ammonium nitrate was first 

 added, and after heating the solution to 65° C. 50 cc. of ordinary 

 ammonium molybdate solution was added, the whole kept at 

 65° C. for 15 minutes, then removed from the bath and allowed 

 to stand for i hour. The precipitate was then filtered ofT, washed 

 with a small quantity of water and the phosphorus estimated as 

 magnesium pyrophosphate. This was supposed to be the inor- 

 ganic phosphorus. The total soluble phosphorus was determined 

 in another aliquot of 200 cc. by the Neumann method. The 

 phosphorus in the insoluble residue, representing a mixture of 

 nucleo-proteids. nucleins and lecithins, was also determined and 

 designated as insoluble organic phosphorus. Tannin, with acetic 

 and hydrochloric acids, under the conditions shown in the table 

 below, was also tried. The molybdate solution used was one pre- 

 pared according to the method adopted by the Ofificial Agricul- 

 tural Chemists. (^^ 



(1) U. S. Dept. Agr., Bur. Chem. Bui. 46, rev. ed. 



