New York Agricultural Experiment Station. 365 



phate. This part of our paper seems to have escaped the attention 

 of Rather. This author, like Patten and Hart, has made no provision 

 for eliminating inorganic phosphate in his method of isolating the 

 organic phosphoric acid. 



Since inorganic and organic phosphoric acids are both present in 

 the crude acid prepared in accordance with the methods of the above 

 authors naturally the silver precipitates obtained from such an acid 

 neutralized with ammonia must contain both inorganic and organic 

 silver phosphates because both are only slightly soluble in neutral 

 aqueous solution. 



Although the silver precipitates obtained from cottonseed meal and 

 wheat bran may have approximately the same composition it is 

 surprising that anyone could consider them identical; for so far as 

 the most obvious physical property, viz., appearance, is concerned, 

 they are entirely dissimilar. The silver precipitates from the inosite 

 hexaphosphate from cottonseed meal are, as already mentioned, of 

 pure white color and they are very slightly affected by light. The 

 silver precipitates obtained from the acid from wheat bran, on the 

 other hand, are only white at the moment of precipitation. These 

 substances are either extremely sensitive to light or else the silver 

 becomes reduced for the color rapidly darkens and finally turns 

 quite black. Even when working under careful exclusion of direct 

 light we have been unable to obtain a white silver preparation from 

 the wheat bran compound. 



While the amorphous barium salts prepared, as will be described 

 later, from the organic phosphorus compound of wheat bran, show 

 a close agreement in composition with those reported previously 11 

 we do not believe that they are homogeneous compounds. We 

 have been able to separate these amorphous precipitates into several 

 fractions some of which were semi-crystalline, but the composition 

 was not constant. In no case, however, have we been able to obtain 

 a trace of a salt having the composition of inosite hexaphosphate. 



From the results which we have obtained it appears probable 

 that these amorphous barium precipitates are mixtures, probably 

 of various organic phosphoric acids. Some of these are undoubtedly 

 lower phosphoric acid esters of inosite but it is possible that phos- 

 phoric acid esters of other carbohydrates are also present. 



Neither Patten and Hart nor Rather mention the presence of 

 oxalic acid in the preparations from wheat bran which they examined. 

 It would seem from our results, however, that the crude substance 

 obtained by precipitating a dilute hydrochloric acid extract of wheat 

 bran with alcohol contains rather large quantities of oxalates. 



The removal of this oxalate presented greater difficulties than the 

 elimination of inorganic phosphate. As a barium salt oxalic acid is 

 precipitated at every stage along with the salts of the organic phos- 



u Loc. cit. 



