PHOSPHORUS STARVATION : I. 89 



From the standpoint of physiological chemistry, the process of milling 

 the rice corresponds to that practised with other cereals and, therefore, 

 the pericarp, removed by the process of milling, corresponds to what 

 we term the bran of wheat or rye. In other words, white rice in com- 

 position corresponds somewhat to bread made from fine wheat flour, 

 the red rice to that from whole wheat. 



The importance of the bran from wheat and other cereals was formerly not 

 very seriously considered, but more recently Jordan, Hart and Patten/ 6 Hart and 

 Andrews, 17 and others, have shown that an organic substance containing phospho- 

 rus and termed "phytin," the calcium-magnesium salt of phytic acid, is found 

 therein. Phytic acid, or anhydrooxymethylenediphosphoric acid, was discovered 

 by Posternak ls as a constituent of green plants, and several investigators have 

 since then demonstrated its wide distribution in the vegetable kingdom. Hart 

 and Andrews 1T found that practically all the phosphorus contained in vegetable 

 foodstuffs is present as salts of phytic acid. This also holds true for rice. 

 Suzuki, Yoshimura and Takaishi 10 proved that S5 per cent of the phosphorus in 

 the bran of the rice is present as phytin. Phosphorus, combined in phytin in 

 contradistinction to that in inorganic compounds, is readily soluble in water or 

 dilute acids and can easily be removed from the bran by processes of washing or 

 extraction. This solubility, as the investigations of Hart and his collaborators "" 

 have shown, is of great importance in relation to the behavior of phytic acid 

 in metabolism. The phosphorus of phytic acid is readily absorbed, and is there- 

 fore a valuable compound in which to supply phosphorus in a form which can 

 readily be assimilated. The effect of so-called organic phosphorus on metabolism 

 in general has already been carefully investigated in the case of lecithin, and the 

 superiority in many respects of organic phosphorus over certain inorganic phos- 

 phates seems to be proved. 



The investigations, especially of Patten and Hart, 16 Mendel and Underbill, 21 

 Le Clerk and Cook, 22 proved that the same also holds true for the organic phos- 

 phorus compounds which are found in vegetables, namely, phytic acid and its 

 salts. In addition to the readiness with which it is absorbed, phytic acid, ac- 

 cording to the experiments of Patten and Hart, 16 is both a diuretic and a laxative, 

 and the well-known laxative action of bran is partly produced by its content of 

 this substance. On the other hand, these authors demonstrated in their work 

 that constipation results if the bran is restricted or if a washed bran, poor in 

 phosphorus, is ingested. 



The hypothesis that lack of phosphorus may be an important factor 

 in the etiology of beriberi gains in probability if we consider these facts 

 as they have been found to exist in experiments on cattle, dogs and 

 rabbits, and compare them with what we know concerning the action of 

 different kinds of rice on human beings. For instance, our knowledge 

 that the removal of phytin causes constipation fits well with the general 



16 Amer. Journ. Physiol. (1906), 16, 268; Amer. Chem. Journ. (1904), 37, 564. 

 11 Bull. New York Agric. Exp. Sta, (1903), No. 238. 

 ^Compt. rend. Hoc. biol. (1906), 55, 1190. 

 "Bull. Coll. Agric. Tokyo (1907), 7, 495-572. 



20 Amer. Journ. Physiol. (1909), 24, 86-103. 



21 Amer. Journ. Physiol. (1906), 17, 75-88. 

 -Journ. Biol. Chem. (1907), 2, 203. 



