cloudy. It was then allowed to stand for two days at room temperature. 

 The substance separated slowly in the form of globular masses or rosettes 

 of microscopic needles. The crystal form was identical with that pre- 

 viously described for the tribarium inosite hexaphosphate. The substance 

 was filtered and washed in dilute alcohol, alcohol and ether, and dried 

 in the air. It was re-crystallized a second time by dissolving in the 

 minimum quantity of 2 per cent, hydrochloric acid, filtering, and adding 

 alcohol until a slight permanent cloudiness remained. After standing 

 for two days the substance had separated in the same form as before. 

 It was filtered, washed free of chlorides with dilute alcohol, and then in 

 alcohol and ether and dried in the air. It was obtained as a snow-white, 

 crystalline powder. It was free from chlorides and inorganic phosphates. 



For analysis it was dried at 105° in vacuum over phosphorus pen- 

 toxide. 



0.2922 gram substance lost 0.0334 gram H 2 0. 



0.2588 gram substance gave 0.0291 gram H 2 and 0.0648 gram C0 2 . 



0.1421 gram substance gave 0.0944 gram BaSO, and 0.0867 gram 

 Mg 2 P 2 7 . 



* Found : C = 6.82 ; H = 1 .25 ; P = 17.00 ; Ba = 39.09 per cent 

 H 2 0= 11.43 percent. 



For tribarium inosite hexaphosphate, C„H 12 24 P 6 Ba 3 = 1066. 



Calculated: C = 6.75; H=1.12; P=17.44; Ba = 38.65 per cent. 



For s HoO calculated 11.90 per cent. 



PREPARATION OF THE FREE INOSITE 



HEXAPHOSPHORIC ACID 



Inosite hexaphosphoric acid is easily prepared from the purified 

 barium salt by the method of Patten and Hart (1904). The barium salt 

 is suspended in water and decomposed with a slight excess of sulfuric 

 acid. After removing the barium sulfate, the filtrate is precipitated with 

 a hot, concentrated solution of copper acetate. The precipitate is 'filtered 

 on a Buchner funnel and washed thoroughly in water. It is then sus- 

 pended in water and decomposed with hydrogen sulfide. The copper 

 sulfide is filtered off and the nitrate is concentrated in vacuum at a 

 temperature of about 45° until a thick syrup remains. This is trans- 

 ferred to an evaporating dish and dried in a vacuum desiccator over 

 sulfuric acid. 



METHOD OF ANALYSIS OF THE BARIUM 



INOSITE HEXAPHOSPHATE 



Most authors working with organic phosphorus compounds report 

 much difficulty in obtaining proper values for the carbon. This difficulty 

 is particularly great in burning compounds such as those reported above 



29 



