jS'ew York Agkicultural Expekiment Station. 155 



effort to remove inorganic phosphates. From the work of Hart and 

 Andrews^ they believed themselves justified in considering the 

 inorganic soluble phosphates present in wheat bran as a negligible 

 quantity. While we cannot enter into any discussion of the above 

 work here, it is to be noted that in the determination of the soluble 

 inorganic phosphates in plant constituents Hart and Andrews 

 extracted the material with 0.2 per ct. hydrochloric acid for 15 

 minutes and determined the inorganic phosphorus in the filtered 

 extract by precipitating with nearly neutral ammonium molybdate. 

 By this method they found 0.036 per ct. inorganic phosphorus in 

 wheat bran. The total amount of phosphorus compounds soluble 

 in 0.2 per ct. hydrochloric acid was found to be equivalent to 0.951 

 per ct. phosphorus. 



The inorganic phosphorus found by the above authors is there- 

 fore equal to 3.78 per ct. of the total phosphorus soluble in 0.2 per 

 ct. hydrochloric acid. 



Suzuki and Yoshimura^ report phosphorus determinations in 

 wheat bran. They found 0.638 per ct. phosphorus soluble in 0.2 

 per ct, hydrochloric acid; of this, 0.050 per ct. was found to be 

 inorganic, and 0.579 per ct. organic. The inorganic phosphorus 

 found in this case is therefore equal to 8.63 per ct. of the total phos- 

 phorus soluble in 0.2 per ct. hydrochloric acid. 



The work of Forbes and associates^ seems to show that the time 

 allowed by Hart and Andrews, 15 minutes, is not sufficient for com- 

 plete extraction and that neutral molybdate solution is not suitable 

 for precipitation in all cases; that when three hours is allowed for 

 extraction a considerably larger amount of inorganic phosphorus is 

 obtained. 



In the preparation of the '' phytin " products from wheat bran 

 Patten and Hart* do not mention any definite time allowed for 

 extraction but only state that " the bran was extracted for several 

 hours with 0.2 per ct. hydrochloric acid," apparently therefore a 

 longer time than allowed by Hart and Andrews in their determi- 

 nations of inorganic-phosphorus. 



When wheat bran is digested for several hours in 0.2 per ct. 

 hydrochloric acid we have found that the resulting extract always 

 contains a considerable quantity of inorganic phosphates. Quanti- 

 tative determinations have, however, not been carried out and we 

 are at present unable to state whether the inorganic phosphates 

 were present in the bran originally or if they have been formed by 

 hydrolysis of the organic-phosphorus compounds, but we purpose 

 to take up this phase of the subject later. 



1 N. Y. Agr. Exp. Station Bull. 238. 1903. 



2 Bull. Coll. Agr. (Tokyo) 7: 498. 

 ^Loc. cit. 



* hoc. cit. 



