296 



ORGANIC AGRICULTURAL CHEMISTRY 



I gram Carbohydrates, as eaten, yields 98 per cent of 4.1 = 



4.0 Cal. 

 I gram Fats, as eaten, yields 95 per cent of 9.45 = 9.0 Cal. 

 I gram Proteins, as eaten, yields 92 per cent of 4.35 = 4.0 Cal. 



These figures represent the energy in Calories which the 

 human body actually uses, i.e. which is available for metaboliza- 

 tion from each gram of the constituent as eaten. These results 

 have been designated by different names, viz. physiological fuel 

 value, metaholizable energy or available energy. The figures given 

 are for man and are in Calories per gram. Similar data have 

 been obtained for domestic animals, and it is also often desirable 

 to express them in English standards, viz. Calories per pound. 

 In all calculations for the conversion of grams into pounds, 

 453.6 grams = i pound.^ 



The following table gives all of these data together : 



TABLE XIII 



Fuel Values of Food Constituents 



Fuel Values for Cattle. — In working with cattle and other 

 ruminants, Kellner^ found that the values obtained with dogs 



1 U. S. Bureau of Standards, Tables of Equivalents (1906). 



2 "Die Emiihrung der landw. Nutztiere," 191 2. 



