examination in this direction except the last one ; viz., the water- 

 soluble product precipitated by alcohol and which analyzed for inosite 

 diphosphate. The remainder (0.94 grams dry substance) was hydro- 

 lyzed with dilute sulfuric acid in a sealed tube at ISO to 160° for about 

 2y 2 hours and the inosite isolated in the usual way. The amount of 

 inosite obtained was 0.28 gram or about 88 per cent, of the theory. 

 The substance gave the reaction of Scherer and melted at 222° (uncor- 

 rected) which leaves no doubt that it was pure inosite. 



It is evident that all of the barium precipitates described above 

 are mixtures. It could hardly be expected that a complete separation 

 into pure chemical compounds of the salts of these inosite esters could 

 be effected by the method used. The analytical results, however, show 

 that it is possible to isolate from partially decomposed inosite hexa- 

 phosphoric acid certain substances approximating in composition vari- 

 ous phosphoric acid esters of inosite which on complete cleavage 

 yielded inosite, just as does inosite hexaphosphoric acid itself. This 

 fact, we believe, supports the view previously expressed that inosite 

 hexaphosphoric acid suffers a gradual and partial decomposition ; i. e., 

 molecules of phosphoric acid are eliminated one by one. We believe 

 also that these facts taken in connection with the formation of inosite 

 from the acid on mere drying at 105° must be considered as a strong 

 support of the theory that it is inosite hexaphosphoric acid and not 

 some complex compound, as previously held. 



ATTEMPT TO PREPARE A METHYL ESTER OF INOSITE 

 HEXAPHOSPHORIC ACID 



The silver salt previously described as hepta-silver phytate (An- 

 derson 1912 (2) ) was used. Of this salt, 5.4 grams were suspended in 

 100 cc. of absolute methyl alcohol and 4 grams of methyl iodide (a 

 little over the required amount) were added and the mixture shaken 

 for several hours, the flask being protected from the light. At the 

 end of this time the white silver phytate had changed into the yellow 

 silver iodide. The precipitate was filtered off and washed several 

 times in absolute methyl alcohol and the filtrate several times evap- 

 orated in vacuum to dryness under addition of methyl alcohol for the 

 removal of the excess of methyl iodide. The residue was dissolved in 

 methyl alcohol and evaporated to dryness in vacuum over sulfuric 

 acid. The substance was then obtained as a light-yellow-colored, thick 

 syrup of faint, aromatic odor. It was strongly acid in reaction and 

 of sharp acid taste. For analysis it was dried in vacuum at 105° over 

 phosphorus pentoxide. It then turned very dark in color. 



0.1985 gram substance gave 0.0608 gm. H 2 and 0.1016 gm. C0 2 . 



Found : C = 13.95 ; H = 3.42 per cent. 



61 



