

TROPICAL FOOD MATERIALS 41 



increase in the amount of protein undergoing metabolism ; also, 

 when Diets III. and IV., or IV. and V., are contrasted, the fact 

 that there must be an accompanying increased absorption from 

 the " constants " of the diets will be clear. Thus 



Diet III. N. of constants+ 3'74 grms. N. from rice, 10-49 grms. absorbed, 

 IV. +3-12 ,, 9-86 



which would mean, if the increase of nitrogen absorption all came 

 from the extra rice in Diet III., that 0-62 gramme gave an 

 absorption of 0-63 gramme. This is impossible, and the explana- 

 tion simply is that there is a greater amount of protein absorbed 

 from the " constants " and from the rice when the bulk of 

 the diet is decreased. A similar comparison of Diets IV. and 

 V. exemplified this also. 



If the Diets I., II., and III. be examined, it will be found 

 that where the amount of rice is beyond the optimum, in this 

 combination, 12 ounces, the reverse conditions obtain. As the 

 rice increases in quantity, and the bulk of the diet becomes 

 greater, a lower and lower percentage of protein absorption takes 

 place from both " constants," and from the varying quantities of 

 rice. 



These results serve to illustrate the impossibility of obtaining 

 any fixed figures for the coefficients of the protein absorption of 

 rice, or other foodstuffs of a bulky nature, when the quantities 

 of the food materials entering into the composition of the 

 dietaries are large. Under such conditions they also show that 

 when a bulky food, such as rice, is combined with other materials, 

 not in themselves bulky, the degree of protein absorption from 

 both the rice and the other foodstuffs varies inversely with the 

 total volume of the diet. 



It is quite different when food materials of a more concentrated 

 nature are experimented with, and when bulk does not cause any 

 interference with protein absorption. 



In connection with the poor protein absorption obtained from 

 vegetable dietaries, Hutchison, quoting Hofman, states that in a 

 number of prison diets of an exclusively vegetable nature, it was 

 found that on an average from 25 to 47 per cent, of the protein 

 escaped absorption results that are very much the same as 

 those obtained in investigating the nutritive values of the 

 vegetable gaol dietaries of Bengal. 



Hutchison has collected the results of a number of experiments 



