A Botanical and Economic Study. 179 



The nutrient ratio is a comparison of the albuminoids, or 

 flesh-formers, ami the carbo-hydrates, or fat-formers. It is 

 obtained by adding the quantity of starch, sugar, and the 

 starch equivalent of fat together, and comparing the sum with 

 the protein substances present. For a man at moderate work 

 this ratio should stand as 1:5. The foregoing table gives the 

 nutrient ratio and nutritive value of a large series of foods for 

 comparison with maize. 



The sum of the albuminoids, starch, dextrin and sugar, and 

 the starch equivalent of fats, is called the nutritive value; 

 this value is that of 100 parts (grains, ounces or pounds). It 

 is seen from this table that the various food materials depart 

 more or less from the standard ratio that we have adopted, 

 1 : 5, as most nearly expressing the proportion which the nitro- 

 genous should bear to the starchy food. Maize departs con- 

 siderably from the standard, and is poor in protein substances 

 at the best. This fact rather unfits it for a standard article 

 of food, unless combined with some other products which are 

 richer in albuminoids. Thus peas, with the nutrient ratio of 

 1 12.5, can be combined with maize, and the deficiencies of 

 both be equalized. 



Animal Food. — The food requirements of an animal are very 

 similar to those of man. A proper proportion of flesh producers 

 must be combined with fat producers, in order to nourish the 

 animal satisfactorily. The digestive systems of the different 

 domesticated animals, however, differ from that of man, so 

 the material fed must be of a different kind ; for although 

 broad principles can be deduced from experimental work on 

 man, these principles must be modified and corrected by 

 experiments carried on with farm-yard animals. Again, the 

 kind of feeding must be conditioned by the purposes for 

 which the animal is grown. Mutton for table use must be 

 lean, and the shepherd must have a knowledge of the principles 

 of nutrition, in order to prevent fat accumulation. On the 

 other hand, if the sheep are to be grown for tallow, then 

 fattening foods must be used. When these principles become 

 more thoroughly recognized and observed, it will be possible 



