that salts of inosite phosphoric acid exist in all seeds. In the cereal 

 grains the outer layers or bran are particularly rich in organic phos- 

 phorus which is largely composed of inosite phosphoric acid. The 

 substance is also present in various roots and tubers, such as potatoes, 

 radishes, turnips and dahlias, also in clover leaves a*nd in flowering 

 millet. This list will undoubtedly be extended through further investi- 

 gations, but it shows that inosite phosphoric acid is very extensively 

 -distributed in the vegetable kingdom and that it is present in practi- 

 cally all of the material so far examined. 



AS TO THE NOMENCLATURE AND CONSTITUTION OF 

 INOSITE PHOSPHORIC ACID 



Winterstein, as mentioned above, found that inosite and phos- 

 phoric acid were produced on hydrolyzing the substance in a sealed 

 tube. Without determining the actual relation between carbon and 

 phosphorus, he named the acid inosite phosphoric acid, but suggested 

 no constitutional formula. Posternak, as a result of his extensive in- 

 vestigations, concluded that the empirical formula of the acid was 

 C 2 H s 9 P 2 ; i. e., the relation of C : P was as 2 : 2 and he believed it to 

 have the following constitution : 



H 



OH 



C.H.O-P = 







OH 

 OH 



C.H.O-P = 



. I OH 



H 



This relation found expression in the name "anhydro-oxy-methyleu 

 -diphosphoric acid." On hydrolysis the "anhydrooxymethylen," accord- 

 ing to this author, combined, producing inosite by synthesis. 



The same author gave the name "phytin" to the calcium salt of 

 this acid, which was placed on the market as a pharmaceutical prepar- 

 -ation. Since that time the organic phosphorus compounds isolated 

 from various plant material have been described under the name of 

 phytin, phytates or phytic acid, as well as inosite phosphoric acid. Phytin 

 is a trade name for a commercial product and the use of this name for 

 various organic phosphorus compounds isolated from plants which fre- 

 quently differ in composition is likely to lead to confusion. The use of 

 the terms inosite, hexa-, penta-, etc., phosphoric acid in the scientific 

 literature to designate such substances would probably be more 

 ■desirable. 



