368 ARON AND. HOCSON. 



The detailed records of five of these experiments have already been 

 published in a previous paper'' (Nos. 5, 6, 7, 10, and 11), virhile a 

 complete record of the remaining ten will be found at the end of this 

 paper. 



NITROGEN METABOLISM. 



In their experiments with a rice diet, neither Riibner nor Thomas was 

 able to establish nitrogen equilibrium in spite of a comparatively great 

 intake of calories. However, they experimented only with Europeans. 

 The nitrogen excretion likewise exceeded the nitrogen taken with the 

 food in our experiments numbered 1 to 4, made on Malays. Kumagawa 

 succeeded in establishing nitrogen equilibrium in only 1 experiment, in 

 which 8 grams of nitrogen, or 0.19 gram per kilogram and 2,590 calories' 

 per kilogram were consumed. However, it must not be forgotten that in 

 addition he ate considerable quantities of turnips and other foodstuffs. 

 (See Table III.) Therefore, in metabolism experiments carried on by 

 our method, it appears to be difficult to give the amount of nitrogen 

 needed by the body by means of a diet of pure rice, with such additions 

 as sugar, bacon, and bananas as are shown in Table IV. It might be 

 easier to give the quantities of protein necessary to establish nitrogen 

 equilibrium if the subjects were performing muscular labor with a 

 resulting greater demand on energy than was the case with our volunteers 

 Avho practically did no work. A number of experiments on metabolism 

 in which mixed diets of rice and fish, or rice and meat and vegetables, 

 were given, have been perfonned, but it would take too much space to 

 review all of these.® Therefore,- we will limit our discussion to experi- 

 ments numbered 5 to 15 in our series. We employed in these instances 

 Tarying quantities of nitrogen as well as varying numbers. of calories. 



To facilate comparison we have reduced the figures for calories, the 

 nitrogen intake, and the nitrogen balance,' to a uniform standard of 50 

 kilograms of body-weight and these values are given in Table V.' 



^ Loc. cit. 



"W. O. Atwater and C. F. Longworthy, Bull. V. 8. Dept. Agr. Off. Exp. Sta. 

 (1898), No. 45. C. Cijkmann,. Firc/iow's Arch. .(1893) , 131, 147, 180. Taniguti, 

 Arbeit a. d. kais. jap. militdr Med. Lebraust, 1, 85, 90. Review Malys Jahres- 

 bericht (1892), 22, 467-8. 



