taken up in hot water. It was decolorized with animal charcoal. The 

 solution was neutral in reaction. It strongly reduced Fehling's solu- 

 tion on boiling, possibly due to sugars introduced with the bran ex- 

 tract. The solution was found to contain barium and also phosphorus 

 in organic combination, evidently inosite monophosphate. The aque- 

 ous solution was precipitated by adding about an equal volume of 

 alcohol and the white, amorphous precipitate filtered off, the filtrate 

 being reserved for further examination. 



ISOLATION OF INOSITE MONOPHOSPHORIC ACID 



The above precipitate, which formed on the addition of alcohol, 

 was dissolved in water, slightly acidified with acetic acid, and then 

 precipitated with lead acetate in excess. After settling, this was 

 filtered, washed in water and suspended in hot water and decomposed 

 with hydrogen sulfide. It was then filtered and the filtrate boiled to 

 expel excess of hydrogen sulfide. It was re-precipitated several times 

 with lead acetate in the same manner until a white lead precipitate 

 was obtained. This was finally decomposed with hydrogen sulfide, 

 filtered, and evaporated to small bulk in vacuum and then dried in 

 vacuum over sulfuric acid until a thick syrup remained. On scratch- 

 ing with a glass rod, this crystallized to a white, solid mass. It was 

 digested in alcohol and filtered, washed in alcohol and ether, and dried 

 in the air. It weighed 1.6 grams. It had all the properties of inosite 

 monophosphoric acid. For further purification it was dissolved in a 

 few cubic centimeters of water and filtered. Alcohol was then added 

 until the solution turned cloudy ; it was heated until it cleared up and 

 more alcohol was added until a faint permanent cloudiness remained. 

 It was allowed to stand for about 48 hours at room temperature, when 

 the substance had separated 'in massive, practically colorless crystals. 

 After filtering, washing in alcohol and ether, and drying in the air, 

 one gram, substance was obtained. When heated in a capillary tube 

 it began to soften at 188 to 189° and melted under decomposition and 

 effervescence at 190° (uncorrected). The appearance and properties of 

 the substance corresponded exactly with those described for inosite 

 monophosphoric acid and the analysis was therefore omitted. 

 Isolation of Inosite. 



The filtrate, after precipitating the above barium salt of inosite 

 monophosphate with alcohol, was evaporated on the water-bath until 

 the alcohol was removed. It still contained barium, chlorides, etc. 

 The barium was quantitatively precipitated with dilute sulfuric acid 

 and the solution again concentrated on the water-bath. 



The addition of lead acetate caused no precipitate. Basic lead 

 acetate was then added so long as any precipitate formed. This pre- 



47 



