352 Report of the Department of Chemistry of the 



drying as above for about 20 hours. After decomposing by the 

 Neumann method it was found to contain 27.68 per ct. of phosphorus. 

 The dry preparation gave the following: 



0.2348 gram dry subst. gave 0.0733 gram Mg 2 P 2 7 equivalent to 

 8.70 per ct. of phosphorus, or 31.43 per ct. of the total phosphorus 

 was present as inorganic phosphoric acid. 



Before drying: 



0.2651 gram (dry subst. calculated) gave 0.0295 gram Mg 2 P 2 7 

 equivalent to 3.10 per ct. of phosphorus or 11.19 per ct. of the total 

 phosphorus had been hydrolyzed in about 18 months under ordinary 

 room conditions. 



In the above case about 20.2 per ct. of the total phosphorus had 

 been hydrolyzed on drying at 105° for about 20 hours. 



A sample of the pure recrystallized barium phytate was examined 

 for inorganic phosphoric acid in the same way. The fresh preparation 

 gave no reaction with ammonium molybdate. After standing in 

 the laboratory for five or six weeks the following results were obtained : 



After drying at 105° in vacuum over phosphorus pentoxide 0.2108 

 gram subst. gave 0.0104 gram Mg 2 P 2 7 equivalent to 1.37 per ct. 

 of phosphorus. 



Before drying: 



0.2060 gram (dry subst. calculated) gave 0.0030 gram Mg 2 P 2 7 

 equivalent to 0.40 per ct. of phosphorus. 



By drying at 105° the inorganic phosphorus increased about 

 2\ times. 



A portion of the inorganic phosphoric acid found in the above 

 determinations was probably due to cleavage of the phytic acid by 

 the dilute nitric acid. Such cleavage appears to take place slowly 

 and uniformly as shown by the following experiment: Another 

 portion (0.1876 gram subst.) of the same barium phytate without 

 previous drying gave 0.0022 gram Mg 2 P 2 7 after heating one hour 

 with the ammonium molybdate, or 0.32 per ct. inorganic phos- 

 phorus; after heating the solution § hour more 0.0010 gram Mg 2 P 2 7 

 was obtained; further heating for 1 hour gave 0.0022 gram Mg 2 P 2 7 

 and a fourth hour heating gave 0.0040 gram Mg 2 P 2 7 . The total 

 inorganic phosphorus obtained after heating 3| hours as above 

 was 1.39 per ct. The results indicate that the cleavage under these 

 conditions is slow and that it proceeds at a very uniform rate. 



EXPERIMENT TO DETERMINE WHETHER INOSITE IS FORMED IN THE 

 SPONTANEOUS DECOMPOSITION OF PHYTIC ACID. 



The sample of old phytic acid previously referred to was used. As 

 shown by the analysis on page 34, the preparation contained 3.10 

 per ct. inorganic phosphorus. Of this acid, 12.8 grams (corre- 



