34 Literature on Inosite-Phosphoric Acid [Sept. 



radicles. This may be illustrated by these two graphic represen- 

 tations : 



.HO: OH^^^* \ /OH«-^ 



\ / 0=:P OH 



0=P— OH ^ -f— ua. 



The idea of this type of reaction for ortho and pyro-forms 

 is in harmony with the fact that when inosite-phosphoric acid is 

 precipitated in acid Solutions by divalent metals, the tri-metal salt is 

 the more readily formed. The activity of the hydrogen ions is 

 relatively greater in the inosite-phosphoric acid than the sum total 

 of the ions of the ortho-forms would be, probably due to the influ- 

 ence of increased negative electric charges in the many phosphorus 

 atoms held in one molecule, so that, altho six having been eliminated 

 in the assumed ester formation, the very reactive ions are eight 

 in number. The last column in Table 2 is interesting in this con- 

 nection. Finally, the Statement that the inosite-phosphoric acid 

 is decomposed by dry heat has been shown to be erroneous by both 

 Anderson and the writer. 



That phytin is a salt of inosite-phosphoric acid seems to be con- 

 clusively demonstrated by the synthetic work of Contardi, whose 

 preparations from rice bran gave analyses identical with a synthetic 

 preparation obtained by heating anhydrous inosite with ortho- 

 phosphoric acid (sp. g. 1.7). Other workers have attempted to 

 substantiate this result, but so far without success. Carre could 

 obtain only a mixture of the two chemicals ; Anderson was able to 

 produce tetra-ortho and di-pyro-phosphoric acid esters. 



It does not follow that these preparations of inosite-phosphoric 

 acid are identical in form with the organic phosphorus Compound 

 occurring in plants. The writer calls attention elsewhere to a differ- 

 ence of behavior between the phytophosphate in seeds and in prepa- 

 rations.^ Certain data, not as yet published, as well as differences 

 in the products described in the literature, fall in with those 

 suspicions.^ 



What inosite-phosphoric acid is, in terms of a definite chemical 



'Rose: Technical Bulletin 20 of the New York Agricultural Experiment 

 Station. 



' Cf . Preparations analyzed by Patten and Hart, Winterstein and Schulze, 

 and Levene, in table 2, p. 29. 



