New York Agricultural Experiment Station. 321 



From the analytical data reported it appears that the substance 

 known as phytic acid or inosite phosphoric acid is either inosite 

 hexaphosphate, CeHisC^^e or else an isomer and that the formulas, 

 C 2 H 8 9 P2 or CeE^yOisPe heretofore used to represent this acid are 

 incorrect. 



CONCERNING THE ORGANIC PHOSPHORIC ACID OF 



COTTONSEED MEAL. II. 



In the last report 1 from this laboratory we described certain 

 crystalline barium salts of the organic phosphoric acid of cotton- 

 seed meal. We had also prepared and analyzed the free acid itself 

 and described its properties and we also showed that on cleavage 

 with dilute sulphuric acid in a sealed tube the substance gave 

 inosite as one of the products of decomposition. 



These crystalline barium salts and the free acid prepared from 

 them gave results on analysis which differed slightly from cor- 

 responding compounds calculated on the usual formula for phytic 

 acid, viz: CeHo-iOoyPe- The substance from cottonseed meal 

 appeared to be an acid of the formula C 2 H C 8 P2 or CeH^OiiPe- 

 The barium salts agreed closely with this formula but the percentage 

 of phosphorus in the free acid was found to be about 1 per ct. lower 

 than required. 



The reactions of the aqueous solution of the free acid, however, 

 were found to be identical in every respect with those given by 

 phytic acid. From the results obtained we concluded that the organic 

 phosphoric acid in cottonseed meal was very similar to phytic acid 

 but we were unable to determine whether it was identical with this 

 acid. 



Prior to our publication, so far as we are aware, no definite organic 

 phosphoric acid had ever been described as existing in cottonseed 

 meal; no pure salts of this acid had been obtained nor had the free 

 acid been prepared in pure form. 



However, some earlier work had been published by Rather 2 

 dealing with " The forms of phosphorus in cottonseed meal." This 

 author had isolated certain more or less impure substances from 

 cottonseed meal which undoubtedly contained some of the organic 

 phosphoric acid which we later isolated in pure form. He found 

 that these preparations gave reactions similar to those of meta- 

 and pyrophosphoric acids and he concluded that these reactions 

 therefore were not sufficient to prove that either meta- or pyrophos- 

 phoric acid exists in cottonseed meal as had been claimed earlier. 3 



l Joum. Biol. Chem. 13:311, 1912, and N. Y. Agr. Exp. Sta. Tech. Bull. 25, 1912. 



2 Texas Agr. Exp. Sta., Bull. 146. 



! Hardin. S. C. Agr. Exp. Sta., Bull. 8, N. S., 1892. 



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