acid and, consequently, an increase in weight. The actual composition 

 can therefore never be determined by analysis of the free acid itself. 



The inosite phosphoric acid preparations which have been isolated 

 and analyzed recently by Rather (1918) were obtained by the following 

 method : 



"Digest the ground material in 0.2 per cent, hydrochloric acid for 

 3 hours with frequent stirring. Pass the digestion mixture through a 

 double cloth and filter the resulting extract. Add copper acetate in excess 

 immediately, filter and wash the precipitate with water on a Buchner 

 funnel. Suspend the washed copper precipitate in water and decompose 

 it with hydrogen sulfide. Filter off the copper sulfide and wash with 

 water. Evaporate the filtrate to small volume at a temperature of 55° to 

 60° under a strong current of air. Take up the residue in six volumes 

 of 95 per cent, alcohol. Filter off any insoluble matter. Dissolve the 

 insoluble matter, consisting of acid salts, in dilute acid and precipitate 

 this solution with copper acetate. Decompose the copper precipitate with 

 hydrogen sulfide and evaporate the filtrate to small volume as before and 

 take up in alcohol. If any alcohol-insoluble matter results repeat the 

 copper acetate precipitation as before. Evaporate the combined alcoholic 

 solutions to a syrup at 50° under a strong current of air, take up the 

 residue again in alcohol, filter if necessary, and evaporate as before. 

 This process removes all inorganic bases. The inosite phosphoric acid 

 is then separated as follows : Weigh the crude acid and dissolve it in 

 about 3 liters of water, filter off the insoluble matter, if any, and add to 

 the warm solution an amount of reprecipitated strychnine equal in weight 

 to the acid syrup. It is necessary to use this ratio of strychnine to acid 

 in order to get a salt of the inosite phosphoric acid which will not give 

 equivocal results on analysis. All of the strychnine should go into solu- 

 tion. Filter if necessary and concentrate at a temperature of 55° to 60° 

 under a strong current of air until crystals begin to form. Then allow 

 to cool. Filter off the crystals and concentrate the mother-liquor as 

 above until crystals begin to appear, cool and filter off the crystals. Con- 

 centrate the mother-liquor again for another crop of crystals. Purify 

 the fractions by re-crystallization in the usual manner. This process 

 separates the inosite phosphoric acid from orthophosphoric acid, oxalic 

 acid and other acids. . . . 



"The silver salts are prepared from the strychnine salts as follows : 

 Three grams of the purified strychnine salt are dissolved in warm water 

 and the strychnine precipitated by excess of ammonia. The mixture is 

 cooled rapidly and the strychnine is filtered off. The filtrate is washed 

 with ether to remove any strychnine which may remain in solution. The 

 filtrate is then boiled to expell the excess of ammonia. A solution of 3 

 grams of silver nitrate is then added to the hot solution of the ammonium 

 salt and the resulting silver salt is filtered off and washed with water and 



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