tralizing with barium hydroxide and adding barium chloride, no precipi- 

 tate or turbidity occurrred. The solution was precipitated with barium 

 hydroxide, filtered and washed in water. The substance was again twice 

 precipitated with barium hydroxide from 3 per cent, hydrochloric acid 

 and finally twice precipitated with alcohol from the same strength hydro- 

 chloric acid. After finally filtering, the substance was washed free of 

 chlorides with dilute alcohol, alcohol and ether, and dried in vacuum 

 over sulfuric acid. It was a snow-white, semi-crystalline powder which 

 weighed n grams. It was free from chlorides and inorganic phosphate 

 and did not contain any bases except barium. 



For analysis it was re-crystallized as follows : 2 grams of the sub- 

 s.tance were dissolved in the minimum quantity of 2 per cent, hydro- 

 chloric acid and the free acid nearly neutralized with barium hydroxide 

 and the solution filtered. The clear filtrate was heated to boiling when 

 the substance separated as a heavy crystalline powder. This was fil- 

 tered and washed in boiling hot water and finally in alcohol and ether 

 and dried in the air. Yield, 1.5 grams. It was re-crystallized a second 

 time in the same manner except that 20 cc. of N/1 barium chloride were 

 added to the solution before boiling. After filtering, washing and drying, 

 as before, about 1.3 grams substance were obtained. It consisted of 

 fine, microscopic, needle-shaped crystals. It was free from chlorides 

 and the nitric acid solution gave no precipitate with ammonium molybdate, 

 showing that inorganic phosphate was absent. 



It was analyzed after drying at 105° in vacuum over phosphorus 

 pentoxide. 



0.3771 gram substance lost 0.0385 gram H 2 0. 



0.1917 gram substance lost 0.0196 gram H 2 0. 



0.3386 gram substance gave 0.0361 gram H 2 and 0.0794 gram C0 2 . 



0.2571 gram substance gave 0.0269 gram H 2 and 0.0617 gram CO a . 



0.1715 gram substance gave 0.1218 gram BaS0 4 and 0.1026 gram 

 Mg 2 P 2 7 . 



Found : C = 6.39 ; H = 1 . 19 ; P = 16.67 ; Ba = 41 .79 per cent. 

 C = 6.54; H = 1.17. 

 H 2 0, 10.20 and 10.22 per cent. 



For heptabarium inosite hexaphosphate (C 6 H 11 24 P 6 ),Ba T = 2267. 



Calculated : C = 6.35 ; H = 0.97 ; P = 16.40 ; Ba = 42.39~per cent. 



For 14 H 2 calculated, 10.00 per cent. 



PREPARATION OF THE CRYSTALLINE TRIBARIUM 

 INOSITE HEXAPHOSPHATE 



This was prepared by dissolving 5 grams of the original substance 

 in 2 per cent, hydrochloric acid, nearly neutralizing with dilute barium 

 hydroxide, filtering and adding alcohol gradually until the solution turned 



28 ] *--,-,._ 



