864 ARON AND HOCSON. 



diet more or less deficient in nitrogen and phosphorris. As these ques- 

 tions seemed to ns to be of fundamental importance, and as they were 

 emphasized by Schaumann ^ in his last extensive publication, we con- 

 tinued the experiments which were described previously,* using prisoners 

 in Bilibid Prison. Our thanks are again due to the authorities of that 

 institution for their kindness. Two medical students ^ also served with 

 great enthusiasm as subjects for further experiments. 



The basis of all rations was rice. In addition, we gave varying amounts of 

 vegetable and animal foodstuffs, such as bread, fruits, vegetables, sugar, fish, 

 bacon, and lard. The bread used in a great number of experiments was made 

 of fine wheat-flour, very similar to white rice in its content of nitrogen, phosphorus, 

 and carbohydrates. The arrangement of the experiments was practically the 

 same as described in our previous paper. The subjects were all healthy men. 

 Most of the prisoners had previously undergone small surgical operations, but 

 had fully recovered at the time they volunteered for the experiments. We paid 

 especial attention to securing men free from intestinal disturbances and who had 

 good digestion. Their faeces, in two microscopical examinations, were free from 

 intestinal parasites and eggs. The prisoners were isolated in a shady room of 

 the hospital and did no work during the experiments. An exact control was 

 possible only in this way. At the same time the secretion of sweat could be 

 reduced to a minimum. Both medical students who took part in the experiments 

 lived near the laboratory and performed but little laboratory work during the 

 period of special diet. Therefore, the daily amount of work which our subjects 

 did was extremely limited and the food was comparatively low in caloric value. 

 Experiments conducted during severe muscular work with a corresponding greater 

 intake of food of composition similar to that given in our experiments, are 

 desirable. However, siieh experiments in the Tropics would be very complicated 

 owing to the necessity of collecting the sweat and determining the nitrogen 

 secreted in it. 



Four experiments " not open to criticism, have been found by us in the litera- 

 ture. In these, nitrogen metabolism has been determined on a diet consisting 

 mainly of rice. They are compiled in Table III. 



So far as we know, phosphorus metabolism on a diet such as that given 

 in Table III hitherto has not been investigated. A summary of our own 

 15 experiments on 9 normal men is given in Table IV. It shows the 

 quantities of nitrogen and phosphorus taken with the food, the amounts 

 of nitrogen and phosphorus excreted in the uiine and faeces, the per- 

 centage distribution of nitrogen and phosphorus, and, finally, the nitrogen 

 and phosphorus balance. 



' Arch. f. Schiffs- u. Trop.-Hyg., Beiheft (1910), 14, 13-372. 



* Loc. cit. 



^ Messrs. Velarde and Feliciano. 



«Max Riibner, Ztschr. f. Biol. (1879), 15, 115-202; Karl Thomas, Arch. f. 

 Anat. u. Phys. (1909), 219-302; Muneo Kumagawa, Virchow's Arch. (1889), 

 116,370-431. 



