salts contain carbon and phosphorus in the ratio of 6 : 6, whereas in 

 less carefully purified products the percentage of carbon is generally 

 higher. 



The contradictory results in ultimate composition obtained by vari- 

 ous investigators of the inosite phosphoric acids from seeds or other 

 plant material can be explained, it seems to us, only as being due to 

 any one of the following three causes ; viz : 



1. Insufficient purification. The preparations which have been 

 analyzed have either contained unknown quantities of inorganic im- 

 purities or else organic complexes, such as pentoses or other carbohy- 

 drates, have been carried down by absorption with the salts of inosite 

 phosphoric acid. 



2. Partial hydrolysis during isolation due to enzyme action or 

 partial hydrolysis during the process of purification due to repeated 

 boiling of the solutions of salts of the inosite phosphoric acid or the 

 repeated evaporation of aqueous or alcoholic solutions of the acid 

 itself. 



3. The existence in plaut material of different inosite phosphoric 

 acids. 



This last cause might be quite important in connection with cer- 

 tain seed cakes, such as cottoonseed meal. Varying degrees of heat are 

 applied to the crushed seed during the expression of the oil. This 

 process might affect the composition of the resulting residue or the 

 meal might be stored under conditions of heat and moisture which 

 may favor enzymatic processes. In one report Rather (1917 (1) ) states 

 that he obtained an inosite phosphoric acid from cottonseed meal 

 which correspond in composition to inosite triphosphoric acid, but 

 he was never able to isolate this acid from any other sample of the 

 material. 



PROPERTIES OF INOSITE PHOSPHORIC ACID 



The inosite hexaphosphoric acid, when prepared from pure salts, 

 is obtained as a colorless syrup, the consistency, of course, depending 

 upon the amount of water which is present. When the acid has been 

 dried in a desiccator over sulfuric acid until it is practically water 

 free it forms a solid, glassy, brittle mass which is very hygroscopic. 

 The acid, which is colorless when freshly prepared, assumes gradually 

 at room temperature a light yellow, yellowish, straw and finally, after 

 many months, a very dark color. The color change, which is very 

 gradual at room temperature, is very much hastened by heat. After 

 drying at 100° for a few hours to Constant weight the acid is practi- 

 cally black in color. Drying at the temperature of boiling chloroform 

 or alcohol gives a product which is light brown or brown in color. 

 This change in color is associated with some decomposition and sep- 



14 



