100 



HEALTH AND DISEASE 



the actual amount of food digested by certain numbers which represent the 

 comparative heat-forming value of fat, albumen, and starch. 



The co-efficients are: fat 100, albumen 47'4, starch 43'1; and he gives 

 the following example in answer to the question: "What is the com- 

 parative heat-forming value of the following foods?" 



IST FOOD 



2ND FOOD 



Albuminoids 



Fats 



Carbohydrates 



r^ 11 i 



Cellulose ... 



1-04 



-468 

 4'30 \ 



i~> l" 



-22 J 



47 -4 

 100 



49'3 

 46'8 



]q , 



lot 



290-9 



This second food is obviously about one and a half times as heat- 

 producing and work-producing as the first food; the two foods together 

 represent the typical average food of a horse, the first being equivalent to 

 the 12 Ib. of hay, the second to the 10 Ib. of oats. To find out the 

 number of foot-tons produced by this diet, it is necessary to go back to 

 Frankland's table, and, having found the number of heat units for the 

 article of diet in question in albumen, fat, starch, or sugar, deduct four- 

 fifths, as not more than one-fifth of the whole potential energy of the food 

 will be converted into work. Thus the typical diet of 12 Ib. of hay and 

 10 Ib. of oats w r ill have their potential and actual energy expressed as 

 follows : 



Ft. -tons of 



12 Ib. of Hay. Lb. Potential 



Energy. 



Albuminoids ... '568 = 1,572 

 Fats ... ... -045 = 272 



Carbohydrates ... 2'574\ s 6^0 

 Cellulose ... ... 1-330/ = 



Deducting four- fifths from the 

 total potential energy leaves 

 2093 foot-tons for external 

 work. 



10,464 



10 Ib. of Oats. 



Albuminoids 

 Fats 



Carbohydrates 

 Cellulose 



Lb. 



1-04 

 468 



4-30 

 22 



Ft. -tons of 

 Potential 

 Energy. 



2,879 

 2,830 



Deducting four-fifths from the 

 total potential energy leaves 

 3138 foot-tons for external 

 work. 



