New York Agricultural Experiment Station. 331 



percentage of the phosphorus in the dried preparations is present 

 as inorganic phosphoric acid. 



The analyses of the barium salts on the other hand agree very 

 closely with the formula C2H 4 08P 2 Ba or CeH^C^PeBaa. It will 

 be shown also that the barium salts suffer but very slight hydrolysis 

 on drying at a temperature of 105°. Evidently, therefore, it is 

 safer to calculate the formula of the free acid from the barium salts 

 rather than from analyses of the free acid itself. 



EXPERIMENTAL PART. 

 ISOLATION OF THE SUBSTANCE. 



Whole ground oats, including grain and hull, were digested over 

 night in 0.2 per ct. hydrochloric acid in porcelain percolators covered 

 on the inside with a double layer of cheesecloth. The next day 

 the substance was percolated with the same strength hydrochloric 

 acid until the extract gave no appreciable precipitate with barium 

 chloride. The extract was then filtered through paper and precipi- 

 tated by adding a concentrated solution of barium chloride in liberal 

 excess. The precipitate, after settling, was filtered on a Buchner 

 funnel and washed in 30 per ct. alcohol. It was then dissolved in 

 sufficient dilute hydrochloric acid, about 1 or 2 per ct., filtered and 

 the filtrate precipitated with barium hydroxide solution. After 

 settling, filtering and thoroughly washing with water the precipi- 

 tate was again dissolved in the same strength hydrochloric acid as 

 before, filtered and the filtrate precipitated by adding an equal 

 volume of alcohol. After repeating these operations alternately 

 a second time the substance was twice precipitated from dilute 

 hydrochloric acid, same strength as above, with barium hydroxide 

 (Kahlbaum) which had been recrystallized. It was then further pre- 

 cipitated three times from the same strength hydrochloric acid 

 with alcohol. The final precipitate was filtered and washed free 

 of chlorides with dilute alcohol and then in alcohol and ether and 

 dried in vacuum over sulphuric acid. 



The crude precipitate obtained by adding barium chloride to the 

 acid extract of oats contains large quantities of impurities, inorganic 

 phosphates, colored substances, etc., which during the above opera- 

 tions are gradually eliminated. The precipitates obtained at first 

 do not dissolve completely in dilute hydrochloric acid. It is there- 

 fore necessary to filter such solutions repeatedly in order to free 

 them from suspended insoluble matter. Finally, however, a prod- 

 uct is obtained which is readily and completely soluble in the dilute 

 hydrochloric acid, in which it gives a perfectly colorless solution. 



When prepared as mentioned above, the dry substance is a 

 snow-white, amorphous powder. It is very readily soluble in 

 dilute hydrochloric and nitric acid, less so in acetic acid. It is 



