454: NUTRITION ANIMAL HEAT AND FORCE. 



HEAT-VALUE OF TEX GRAIXS OF THE MATERIAL OXIDIZED IXTO CARBOX 



DIOXIDE, WATER AXD UREA IX THE ANIMAL BODY (FRAXKLAXD). 

 Articles of food. Heat-units. ' Articles of food. Heat-units. 



Butter 18-68 Potatoes -j-.-ii; 



Beef-fat (dry) 23-33 Cabbage 1-08 



Lump-sugar 8-61 Milk 1-64 



Grape-sugar 8-42 Egg (boiled) 5-86 



Wheat-flour 9-87 Cheese 11-20 



Bread-crumb 5-52 Lean beef 3-66 



Arrowroot 1O06 Ham (boiled) 4-30 



Ground rice 9-52 , Mackerel 4-14 



In the following, selected from the table quoted by Chapman, the heat- 

 units are calculated as kilo.-degrees C. 



HEAT-VALUE OF ONE GRAMME OF THE MATERIAL OXIDIZED IXTO CARBOX 

 DIOXIDE, WATER AXD UREA IN THE ANIMAL BODY (FRAXKLANO). 



Articles of food. Heat-units. 



Butter 7-264 



Beef-fat (dry) 9-069 



Lump-sugar 3-348 



Grape-sugar 3-227 



Wheat-flour 3-840 



Bread-crumb 1-450 



Arrowroot 3-912 



Ground rice . . 3-760 



Articles of food. Heat-unite. 



Potatoes 0-990 



Cabbage 0-450 



Milk 0-620 



Egg (boiled) 2-280 



Cheese 4-360 



Lean beef 1-420 



Ham (boiled) 1-680 



Mackerel . . . 1-610 



The heat-value of one gramme of alcohol taken from a table compiled 

 by Landois is equal to 8-958 heat-units (kilo.-degrees C.), or the heat- value 

 of 10 grains of alcohol is equal to 23 heat-units (pound-degrees Fahr.). 



As regards the processes of combustion which take place in the living 

 organism, the oxidation of the constituents of food produces carbon dioxide 

 and water, but it is probable that the quantity of heat produced bears a defi- 

 nite relation to the total consumption of oxygen, the heat, as far as this is 

 concerned, being the same whether the oxygen unite with carbon or with 

 hydrogen (Pniiger). This relation between the quantity of oxygen consumed 

 and the production of heat seems to be disturbed by muscular exercise ; but 

 it has thus far been found impossible to estimate accurately the quantity of 

 heat represented by the force expended in muscular work, circulation, respi- 

 ration etc. 



The heat-producing processes undoubtedly are represented mainly by the 

 exhalation of carbon dioxide and water, and to a less degree by the discharge 

 of urea, the quantity of heat produced by other chemical processes being 

 comparatively small. It is also true that the carbohydrates and fats are 

 more important factors in calorification than the albuminoids ; but it seems 

 beyond question that there must be heat evolved in the body by oxidation of 

 nitrogenized matters. When the daily quantity of food is largely increased 

 for the purpose of generating the immense quantity of heat required in ex- 

 cessively cold climates, the nitrogenized matters are taken in greater quan- 



