dried in vacuo over phosphorus pentoxide. When the silver salt is 

 protected from light it shows only a slight change in color.'' 



Using this method of isolation and purification, Rather has analyzed 

 the strychnine and silver salts of the inosite phosphoric acid obtained 

 from a large number of feeding materials. He believes, as previously 

 mentioned, that all of his preparations represent salts of inosite pen- 

 taphosphoric ac ; d and that this is the only inosite phosphoric acid which 

 exists in natural plant material. 



Clarke, (1914, 1915), in his examination of the inosite phosphoric 

 acid existing in wild Indian mustard and in wheat bran, isolated the 

 acid from 0.2 per cent, hydrochloric acid extracts of the material by a 

 method similar to that first used by Palladin. The crude phytin thus 

 obtained was purified by means of the crystalline strychnine salts. 

 Judging by the analytical results reported, these salts were evidently 

 mixtures of various inosite phosphoric acids. 



Boutwell (1917), who has recently reported an investigation of 

 the inosite phosphoric acid of wheat bran, also followed in principal 

 the method used by Clarke. The different steps in his process were 

 as follows : The bran was macerated in 2.0 per cent, hydrochloric 

 acid at a temperature of about 20° for five hours. The mixture was 

 then pressed through cheesecloth and allowed to stand over night. 

 The clear extract was then heated to boiling to precipitate the protein 

 and allowed to cool. After filtering off the insoluble matter the clear 

 filtrate was heated to boiling and neutralized with ammonia. The 

 sticky, brown precipitate which formed was filtered from the hot solu- 

 tion and washed with boiling water. The precipitate was then ex- 

 tracted with 8.0 per cent, acetic acid, filtered and the filtrate heated 

 to boiling and, after cooling, the insoluble matter was filtered off. The 

 clear filtrate was diluted with an equal volume of water, heated to 

 boiling and made alkaline with ammonia. The white precipitate 

 wh'ch formed was filtered off from the hot mother liquor and washed 

 in boiling water. This precipitate was extracted with 0.8 per cent, 

 acetic acid and the insoluble matter filtered off. The clear solution 

 was heated to 'boiling, when the phytin separated out as a heavy, pow- 

 dery precipitate which was filtered off, washed with boiling water and 

 dried. 



The product thus obtained consisted of spheroidal crystals which 

 had the following composition : 



C=7.99; H=2.49; P=20.42; Ca=3.65 ; Mg=10.81 per cent. From 

 this material crystalline barium salts were prepared which, however, 

 did not correspond closely in compostion to salts of inosite hexaphos- 

 phoric acid. This author expresses the opinion that the inosite phos- 

 phoric acid existing in bran is probably inosite hexaphosphoric acid 

 and that his preparation may have undergone some change during the 

 repeated heating of the solutions in the purification process. 



33 



