2l8 



FOOD REQUIRED 



[chap. 



for peas without any serious loss in the supply of energy ; 

 to be exact, 5 lb. 2\ oz. of maize would be equivalent to 

 5 lb. of peas. But the albuminoid ratio of maize is 

 much lower than that of peas, so it is necessary to know 

 if the albuminoid ratio of the new ration is below what 

 might be considered safe. This may be calculated as 

 follows, still using Table XVII. : — 



Digestible Constituents. 



By multiplying the percentages of digestible protein by 

 the weight of each food we obtain in the third column a 

 total of 296 digestible protein food units in the ration. 

 To obtain the number of digestible non-protein units we 

 must similarly multiply their percentages by the weight 

 of food, but the oil percentages must be further multi- 

 plied by 2-3 to make them equivalent to the carbo- 

 hydrates. Thus we get a total of 203 food units from 

 the oil in the ration and 1656 from the carbohydrates, 

 making 1859 non-protein food units in all. This total 

 must be divided by 296, the number of protein units, in 

 order to obtain the albuminoid ratio of the whole. As 

 in the case in question, this is still as narrow as i : 6, we 



