New York Agricultural Experiment Station. 371 



added, and the whole kept at a temperature of 65° for one-half hour. 

 The precipitate was then filtered and the phosphorus determined as 

 magnesium pyrophosphate as usual. 



The composition of the above precipitate is quite different from 

 that reported by Rather. It will be noticed, however, that the 

 inorganic phosphorus is equivalent to 75.64 per ct. of inorganic 

 silver phosphate. The second precipitate gave the following: 

 C = 0.98; H = 0.37; Ag = 74.37; total phosphorus = 7. 15; inorganic 

 phosphorus = 6 . 73 per ct. This substance accordingly contained 

 90.74 per ct. of inorganic silver phosphate. 



preparation of the barium salt from the crude acid. 



The 75 c.c. of the crude acid solution was diluted to 500 c.c. with 

 water and precipitated with barium hydroxide in excess. The 

 resulting barium precipitate was reprecipitated as before alternately 

 with barium hydroxide four times and alcohol five times from 0.5 

 per ct. hydrochloric acid. After finally filtering, washing in dilute 

 alcohol, alcohol and ether, and drying in vacuum over sulphuric 

 acid, 7 grams of a snow-white amorphous powder was obtained. 

 It was free from chlorides and inorganic phosphate. 



It was analyzed after drying at 105° in vacuum over phosphorus 

 pentoxide. 



Found: C = 12.31; H = 2.21; P = 13.99; Ba = 33.45 per ct. 



It will be noticed that after removing inorganic phosphate the 

 composition of the barium salt does not agree with a compound of 

 the formula C12H41O42P9 as proposed by Rather, but that the com- 

 position agrees closely with the compound C2oH 45 049P9Ba5 which 

 was described in the earlier paper (loc. tit.); calculated for the above: 



C = 11.79; H = 2.21; P = 13.71; Ba = 33. 76 per ct. 



SECOND PREPARATION OF THE CRUDE ACID FROM WHEAT BRAN BY 



THE METHOD OF RATHER. 



A second lot of the acid was prepared from wheat bran by the same 

 method as before except that the various concentrations were done 

 in vacuum at a temperature of 40°-45° and not on the water-bath 

 as the first time. 



The silver and barium salts were prepared from the crude acid 

 exactly as before. 



The silver precipitate gave the following results on analysis after 

 drying at 105° in vacuum over phosphorus pentoxide: C = 4.56; 

 H = 0.77; Ag = 65.88; total phosphorus = 8.03; inorganic phosphorus - 

 3.15 per ct. 



This approaches in composition the precipitates analyzed by 

 Rather. However, as shown by the above content of inorganic 

 phosphorus it contained 42.54 per ct. of inorganic silver phosphate. 



