C c H 9 15 P 3 Ba 3 =826. C=8.71 ; H=1.08; P=11.2S; Ba=49.88 per cent. 

 The carbon, however, is high and the phosphorus as well as barium 

 are low, which points to the presence of barium inosite di-phosphate. 



In the hope of approximately separating these barium inosite tri- 

 and diphosphates, the substance, 23.6 grams, was digested in dilute 

 acetic acid for several hours with occasional shaking. It was then 

 filtered and washed in water and the insoluble portion dried in vacuum 

 over sulfuric acid. It weighed 10 grams. 



The filtrate and washings containing the soluble portion of the 

 substance was precipitated by adding lead acetate in excess. After 

 standing over night the white, amorphous precipitate was filtered and 

 washed in water. It was suspended in water and decomposed by 

 hydrogen sulfide, filtered, and the excess of hydrogen sulfide boiled 

 off. It was again precipitated in the same manner with, lead acetate 

 and decomposed with hydrogen sulfide. The solution still contained 

 a considerable quantity of barium. The barium was therefore re- 

 moved with a slight excess of dilute sulfuric acid. After filtering off 

 the barium sulfate the solution was precipitated by adding copper 

 acetate in excess. The copper precipitate was filtered, washed and sus- 

 pended in water and decomposed with hydrogen sulfide. After remov- 

 ing the copper sulfide, the filtrate was evaporated in vacuum to small 

 bulk and finally dried in vacuum over sulfuric acid. There remained 

 a thick, nearly colorless syrup. It was readily soluble in alcohol. The 

 addition of chloroform to this solution caused the substance to separ- 

 ate in small oily drops ; the addition of ether produced a cloudiness 

 and, on standing, a flocculent, amorphous precipitate separated. These 

 solutions could not be brought to crystallize. The acid preparation 

 itself was kept for several weeks in the desiccator over sulfuric acid. 

 It became a hard but sticky mass but showed absolutely no tendency to 

 crystallize. Kept in this manner the color of the preparation gradu- 

 ally darkened. 



Since the acid would not crystallize, the syrupy substance was 

 analyzed after drying at 105° in vacuum over phosphorus pentoxide. 



Found: C=18.58; H=3.82; P=20.38 per cent. 



For inosite triphosphoric acid, C e H 15 O 15 P 3 =420. 



Calculated: C=l7.14; H=3.57; P=22.14 per cent. 



For inosite diphosphoric acid, C 6 H 14 O 12 P 2 =340. 



Calculated: C— 21. 17; H=4.11; P=18.23 per cent. 



This acid preparation is evidently also a mixture of the inosite 

 tri- and diphosphoric acids. 



EXAMINATION OF THE FILTRATE AFTER THE WATER- 

 INSOLUBLE BARIUM SALTS HAD BEEN PRECIPITATED 

 The filtrate was evaporated, as mentioned above, and the residue 



46 



