94 Report of Department of Animal Industry of the 



previously described and named by the Swiss chemist, Posternak.* 

 Phytin, as this compound is called, is in itself a very interesting 

 substance; but its physical and chemical properties will not be dis- 

 cussed in this report. For descriptions of phytin, the reader is 

 referred to the bulletins mentioned above and the paper by Poster- 

 nak. The author wishes, however, to make a correction \Adth respect 

 to the constitution of phytin as given in these bulletins. The more 

 recent work^ has 'demonstrated that its acid is not anhydrooxy- 

 methylenediphosphoric acid as stated by Posternak and accepted by 

 Hart at the time of publication of his work, but is an inositcphos- 

 phoric acid. Recent work by Anderson^ carried on in the laboratory 

 of this Station confirms this later view of the chemical constitution 

 of phytin. 



PREVIOUS EXPERIMENTS. 



The role of phosphorus in metabolism has been a live question 

 for a long time and a large mass of data has been accumulated 

 regarding it. A number of important facts are definitely established 

 and others have been suggested. ■ Since these have been summarized 

 by Jordan, Hart, and Patten'* and more recently reviewed in detail 

 b}^ Albau and Neuberg,^ the reader is referred to these and only 

 those references will be made which bear on special points as the 

 discussion progresses. Technical Bulletin No. 1 of this Station 

 reports the first three feeding experiments in this series and is a 

 valuable contribution to our knowledge of mineral metabolism. 

 The chief component of the rations used was wheat bran, chosen 

 because of its relatively high content of phytin, which can be easily 

 removed by leaching, the other constituents contributing but a very 

 small amount of phosphorus. By alternating periods of rations 

 containing washed and unwashed bran, a marked contrast in the 

 amount of administered phosphorus was produced. This ranged 

 from thirteen to sixteen grams in the low phosphorus period and 

 from seventy-seven to eighty-one grams in the high phosphorus 

 period. Excepting the variations in calcium, magnesium, and potas- 

 sium, the other conditions were kept as constant as Is practicable 

 in experiments of this kind. A large number of observations were 

 made and from the mass of analj^tlcal data the authors drew con- 

 clusions which may be briefly summed up as follows: 



Increase of phosphorus in the ration increases the phosphorus 

 elimination; 



1 Posternak; Rev. Gen. Bot. 12: 5, 65 (1900); Compt. Rend. Soc. Biol. 55: 1190(1902); 

 Compt. Rend. 137: 202, 337, 439 (1903); 140: 322 (1905). 



2 Suzuki, Yoshimura, Takaishi. Bui. Coll. Agr. Tokio, 7: 495, 503, 1907. 

 Neuberg; Biochem. Ztschr. 9: 557 (1908); Starkenstein ; Biochem. Ztschr. 30: 56 



(1910). 



3 Anderson, R. J. N. Y. Agrl. Expt. Sta. Tech. Bui. No. 19. 



4 Jordan, Hart and Patten. N. Y. Agr. Expt. Sta. Tech. Bull. No. 1. 



^ Albau and Neuberg. Physiologie und Pathologic des Mineralstoff wechsela. 



