PHOSPHORUS STARVATION: I. 91 



These analyses strikingly demonstrate not only that the total amount 

 of phosprorus in unpolished rice is considerably higher than in polished, 

 but also that a greater percentage of the total phosphorus in the red 

 variety than in the white is in a readily soluble condition. Therefore, 

 if the same quantity of red as of white rice is eaten, twice the total 

 quantity of phosphorus and nearly three times as much of the soluble 

 phosphorus compounds will be ingested. (See diagram.) 



I next endeavored to ascertain if lack of phosphorus, and especially if 

 that in the soluble form, is the cause of the deleterious action of white 

 rice. If this is correct, then the addition of organic phosphorus (phy- 

 tin) to white rice should render the latter harmless. 



I began with experiments on fowls, following the method of Eykman, 

 and convinced myself that chickens fed on white rice contract poly- 

 neuritis whereas control birds fed on unhusked and even white rice, 

 if the latter is carefully mixed with rice bran (darac), remain healthy 

 for two and a half months. 



It is not my intention to prove to what extent the polyneuritis of 

 Eykman and the disease which we term beriberi in man are related, 

 or even to decide whether or not they are one and the same; but I 

 believe these experiments give us a basis of investigation in order to 

 ascertain the importance of the lack of certain food constituents (such 

 as phosphorus) in producing pathologic changes in the nerves and other 

 tissues. 



In pursuance of this field of observation, I fed two groups of chick- 

 ens; the one on white rice and phytic acid prepared from rice husk; the 

 other on white rice alone. The phytic acid was isolated in the following 

 way from the bran of white rice which is separated by the process of 

 polishing between the rotating stones of the mill : 



Four kilos of this material (native name darac) were placed in a small 

 barrel and extracted with 6 liters of 0.3 per cent hydrochloric acid for from 

 four to six hours, the mixture being stirred from time to time. The extract 

 was filtered, sodium acetate added to the filtrate, and the phytic acid precipitated 

 as its copper salt by means of copper acetate. The phytate of copper was 

 separated, washed with small amounts of water, suspended in this liquid and 

 the copper precipitated by hydrogen sulphide, the precipitate separated by 

 filtration and the filtrate evaporated on a steam bath. A brownish, highly 

 acid sirup was obtained in this way. Its reactions, as well as the manner 

 of its preparation, identified it as phytic acid, according to Patten and Hart. M 



The free acid was used in the first series of experiments. The rice 

 to be fed was either cooked or only mixed with about 10 cubic centimeters 

 of a solution of phytic acid which corresponded to 0.2 gram of P 2 5 . 

 At first the birds ate this rice very well, but great difficulty in inducing 

 them to take enough of the prepared rice arose subsequently. In a 

 second series of experiments, I therefore endeavored to improve the at- 

 tractiveness of the preparation of phytin, at first by adding sugar; but 



