Xew York Agricultural Experiment Station. 149 



air-dried, water-free substance melted at 221° C. (uncor.) and it 

 gave the reaction of Scherer. Drying at 110° for one hour caused 

 no loss of weight. On analysis the following results were obtained: 

 0.1634 gm. subst. gave 0.0981 H2O and 0.2374 gm. CO2. 



For CsHiaOe = 180 



Calculated C 40.00: H 6.66 per ct. 



Found C 39.62: H 6.71 per ct. 



DI-INOSITE TRIPYROPHOSPHORIC ACID ESTER 



This ester is formed when dry inosite is heated with excess of 

 pyrophosphoric acid. The molecule of the new ester evidently con- 

 sists of two molecules dipyrophosphoric acid esters of inosite joined 

 by one molecule of pyrophosphoric acid. 



Dry inosite 1.8 gm. (1 mol.) were heated with 10.7 gm. (6 mol.) 

 pyrophosphoric acid under the same conditions as described for the 

 dipyrophosphoric ester and it was isolated as the barium salt in 

 exactly the same way. After precipitating five times from 0.5 per 

 ct. hydrochloric acid with alcohol the product was finally obtained 

 as a perfectly white amorphous powder. Its solubilities corresponded 

 practically with those mentioned for the dipyrophosphoric acid ester 

 and likewise it showed a strong acid reaction on moist litmus paper. 



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

 oxide. 



2086 gm. subst. gave 0.0296 gm. H2O and 0.0614 gm. COg- 

 0.1412 gm. subst. gave 0.0879 gm. BaS04 and 0.0844 gm. Mg2P207. 

 Found C 8.02: H 1.58: P 16.66: Ba 36.63 per ct. 



This substance was then again precipitated twice from 0.5 per ct. 

 hydrochloric acid with alcohol and after drying at 105° gave the 

 following result on analysis : 



0.2420 gm. subst. gave 0.0342 gm. H2O and 0.0725 gm. CO2. 

 0.2331 gm. subst. gave. 0.1422 gm. BaSO and 0.1384 gm. Mg^PjOy. 



For Ci2H2204iPioBa5 = 1818 



Calculated C 7.92: H 1.21: P 17 05: Ba 37 73 per ct. 

 Found I C 8.02: H 1.58: P 16.66: Ba 36.66 per ct. 

 Found II C 8.17: H 1.58: P 16.55: Ba 35.90 per ct. 



As repeated precipitations did not alter the composition it was 

 undoubtedly a homogeneous compound. The barium was found to 

 be too low, but as previously remarked, it is difficult to obtain these" 

 amorphous salts in absolutely pure form. The percentage of the 

 base combined with the acid is apt to vary more or less, depending 

 upon conditions. The analysis of the free ester leaves no doubt 

 but that the substance was the compound in question. 



