New York Agricultural Experiment Station. 327 



PREPARATION OF THE FREE ACID. 



The acid was prepared in the usual way from 10 grams of the first 

 crystalline barium salt. The aqueous solution finally obtained was 

 concentrated in vacuum at 40° too 45° to small bulk. It was then 

 divided into three portions — one was dried in vacuum over sul- 

 phuric acid and then analyzed — the others were used for the 

 preparation of the silver salts to be described later. 



The dry acid was obtained as a practically colorless syrup. Its 

 dilute aqueous solution gave no reaction with ammonium molyb- 

 date showing absence of inorganic phosphoric acid. Its reactions 

 in other respects were identical with those previously described. 

 For analysis it was dried first in vacuum over sulphuric acid at 

 room temperature and finally in vacuum over phosphorus pentoxide 

 at 105°, when it turned quite dark in color. 



0.3931 gram subst. gave 0.1088 gram H 2 and 0.1540 gram C0 2 . 

 0.1840 gram subst. gave 0.1826 gram Mg 2 P 2 7 . 



Found: C = 10.68; H = 3.09; P = 27.66 per ct. 

 For inosite hexaphosphate, C 6 Hi 8 2 4P6 = 660. 



Calculated: C = 10.90; 11 = 2.72; P = 28.18 per ct. 



PREPARATION OF THE SILVER SALT FROM THE ABOVE ACID. 



One portion of the free acid previously mentioned was dissolved 

 in 100 c.c. of water and the solution neutralized to litmus with 

 ammonia. Silver nitrate solution was then added which caused 

 a heavy, perfectly white, amorphous precipitate. This was filtered 

 and carefully washed in water and dried in vacuum over sulphuric 

 acid, desiccator being kept in a dark place. After drying, the 

 substance was a faintly cream-colored powder which was very 

 slightly sensitive to light. On moist litmus paper it showed a 

 strong acid reaction. It was free from ammonia. For analysis 

 it was dried at 105° in vacuum over phosphorus pentoxide. On 

 drying as above, not protected from light, the substance darkened 

 somewhat in color. 



0.3064 gram subst. gave 0.0150 gram H 2 and 0.0446 gram C0 2 . 

 0.1640 gram subst. gave 0.1387 gram AgCl and 0.0596 gram 

 Mg 2 P 2 7 . 



Found: C = 3.96; H = 0.54; P = 10.13; Ag = 63.65 per ct. 



Deducting the above percentage of silver and allowing for an 

 equivalent amount of hydrogen and water we obtain the following 

 results : 



Calculated: C = 10.74; H = 3.08; P = 27.45 per ct. 



