New York Agricultural Experiment Station. 333 



acid was then added until the precipitate was just dissolved and 

 the solution precipitated by adding an equal volume of alcohol. 

 The precipitate was filtered, washed in dilute alcohol and then dis- 

 solved in 0.5 per ct. hydrochloric acid and reprecipitated with 

 alcohol. The precipitate was then filtered, washed in dilute alcohol, 

 alcohol and ether, and dried in vacuum over sulphuric acid. It was 

 analyzed after drying at 105° in vacuum over phosphorus pentoxide. 



Found: C = 8.23; H = 1.56; P = 16.19; Ba = 37.48 per ct. 



In another case 6 grams of the second preparation were heated in 

 a sealed tube with 45 c.c. of 1,5 /n sulphuric acid in the steam-bath 

 for twenty-four hours and then allowed to stand for four days at 

 room temperature. After isolating in the same manner as above 

 3.7 grams were recovered. It was analyzed after drying as above. 



Found: C = 8.42; H = 1.66; P = 16.17; Ba = 37.08 per ct. 



These treatments apparently caused no change in composition. 



The free acid was then prepared and analyzed. From the first 

 preparation, the acid was prepared in the usual way — i. e. the 

 barium was precipitated with slight excess of sulphuric acid, filtered, 

 and the filtrate precipitated with copper acetate. The copper salt 

 was filtered, washed and decomposed with hydrogen sulphide, 

 filtered and evaporated in vacuum at a temperature of 40°-45° 

 and finally dried in vacuum over sulphuric acid. It was thus obtained 

 as a thick, practically colorless syrup. For analysis it was dried 

 to constant weight over boiling chloroform in vacuum over phos- 

 phorus pentoxide. The color turned very slightly dark on drying 

 in this way. 



Found: C = 13.24; H = 3.26; P = 25.50 per ct. 



The acid prepared from the repurified barium salt gave the 

 following result on analysis after drying as above. 



Found: C = 13.17; H = 3.39; P = 25.48 per ct. 



The composition of the acid agrees with that required for the 

 above barium salts and one might suppose from the close agreement 

 of analytical results that the substance was homogeneous. 



It was found, however, that after the barium salt had been 

 precipitated a great number of times from dilute hydrochloric acid 

 by barium hydroxide and alcohol alternately that the composition 

 did change slightly. The same result was also observed on digesting 

 the barium salt in dilute acetic acid. After treating in the above 

 manner, barium salts of the following composition were obtained: 



I: C = 7.49; H = 1.63; P = 16.77; Ba = 37.89 per ct. 



II: C = 7.69; H = 1.47; P = 16.75; Ba = 37.72 per ct. 



Ill: C = 7.26; H = 1.75; P = 16.45; Ba = 36.40 per ct. 



