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?" 



Albuminoids 

 Fats 



Carbohydrates 

 Cellulose 



1st Food 



•568 



•045 



2-5741 



1-330/ 



474 



100 



43-1 = 



27 

 4-5 



168-2 



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 lb. of hay, the second to the 10 lb. 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 lb. of hay and 



10 lb. of oats w T ill have their potential 

 follows : — 



ind actual energy expressed as 



' Deducting four-fifths from the 

 total potential energy leaves 

 2093 foot-tons for external 

 work. 



Deducting four-fifths from the 

 total potential energy leaves 

 3138 foot-tons for external 

 work. 



