RICE AS FOOD. 



371 



animal constituents. For this reason, the quantity of nitrogen in the 

 faeces, expressed in percentages of the vegetable nitrogen in the food, is 

 practically a constant value of 35 per cent. Therefore, it is necessary 

 to know the relative value between the protein of animal and of vegetable 

 origin in order to determine the physiologic value of the protein content 

 of a given food. jSTeaiiy one-third of the protein from rice and wheat 

 passes unabsorbed through the intestines into the faeces; this must be 

 subtracted as physiologically valueless. 



According to the recent investigations by Micliaud ^ and by Thomas," the 

 biologic value of various classes of proteins differs widely. Therefore, protein in 

 rice certainly would have a lower biologic value than protein from animal sources. 

 It is to be regretted that our knowledge of the chemical composition of the 

 protein of rice is so meager, whereas many detailed investigations on other 

 vegetable proteins of considerably minor importance exist. 



Finally, we wish to emphasize the fact that the absorption of nitrogen 

 can be determined only by an exact knowledge of the nitrogen content 

 of the faces. The quantity of the nitrogen absorbed is equal to the quan- 

 tity ingested, minus the amount in the faeces. The quantity of nitrogen 

 excreted in the urine is equal to the amount absorbed only in case the 

 subject is in exact nitrogenous equilibrium, so that miscalculations would 

 result in many instances if the former figures were to be taken. 



PHOSPHORUS METABOLISM. 



A summaiy of our experiments is given in Table VII ; the quantity 

 of phosphorus ingested and the phosphorus balance being reduced to 50 

 kilograms of body weight. 



Table VII. — Phosphorus metaboUsin reduced to 50 Icilograms body weight. 



Experi- 

 ment 

 number. 



P.O5 

 intake. 



balance. 





Per cent. 



Per cent. 



5 



1.15 



—0.8 



4 



1.45 



—0.45 



7 



1.45 



—0.3 



10 



1.60 



+ 0.01 



14 



1.60 



—0.10 



9 



1.65 



—0.01 



12 



1.65 



-0.2 



13 



1.65 



—0.1 



3 



3.30 



4-0.16 



6 



3.85 



-1-1.2 



31 



5.20 



-^0.6 



'■-Ztschr. f. phys. Chcm. (1907), 59, 405-91. 

 " hoc. cit. 



