0.2588 gm. substance gave 0.0538 gm. H 2 and O.1046 gm. C0 2 . 



0.1691 gm. substance gave 0.1027 gm. BaS0 4 and 0.0890 gm. 

 Mg 2 P 2 7 . 



Found : C=l 1.02 ; H=2.32 ; P=14.67 ; Ba=35.74 per cent. 



In the combustion of this substance a practically white ash was 

 ■cbtained. 



This compound is evidently a complex acid salt of inosite tri-phos- 

 phate and agrees with the following formula : 



C 18 H 35 45 P 9 Ba 5 =i937. 



(Calculated: C=11.15; H=1.80; P=14.40; Ba=35.46 per cent.) 

 which may be graphically represented as follows : 



C a H„0 IS P a -P, 



\. 



sa 

 / 

 QH n 1= P 3 =Ba 



\, 



Ja 

 / 

 QH, 2 ls P a =Ba 



That is, three molecules of mono-barium inosite triphosphate 

 joined by two atoms of barium. Whether it is a compound as repre- 

 sented above or a mixture of various acid salts of inosite triphosphate 

 can hardly be determined. 



PREPARATION OF THE FREE ACID 



The barium salt from above was suspended in water and the 

 barium precipitated with a slight excess of dilute sulfuric acid. 



The barium sulfate was filtered off and the nitrate precipitated 

 with excess of copper acetate. The copper precipitate was filtered 

 and washed with water until it gave no reaction with barium chloride. 

 It was then suspended in water and decomposed with hydrogen sulfide. 

 The copper sulfide was filtered off and the filtrate evaporated in 

 vacuum at a temperature of 40 to 45° to small bulk and then dried in 

 vacuum over sulfuric acid. The substance was then obtained as a prac- 

 tically colorless syrup. After continued drying it forms a hard, sticky 

 hygroscopic mass. It is extremely soluble in water and also readily 

 soluble in alcohol and in absolute alcohol. Much time was consumed 

 in endeavoring to obtain it in crystalline form but without success. 

 The syrupy substance was therefore analyzed after drying first for 

 several days in vacuum over sulfuric acid at room temperature and 

 finally at 100° C. in vacuum over phosphorus pentoxide. On drying at 

 this temperature it turned quite dark in color. 



41 



