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A MANUAL OF VETERINARY PHYSIOLOGY 



the heat given off from the body is compared with the heat 

 obtainable from the food, and both the material and energy ex- 

 penditure ascertained. The amount produced per hour for every 

 kilogramme (2-2 pounds) of body weight is given by Colin as 

 follows :* 



Horse 

 Sheep 

 Dog 



Thermometers 



1*643 large calories. 

 2-6 



Thermometer 



Air inlet «-^ 



') -> Air outlet 



Fig. 109. — Calorimeter. 



The animal is resting in the chamber, which has a double wall containing water. 

 There is an air inlet and outlet to the chamber, and delicate thermometers 

 for ascertaining the temperature of the water, and of the incoming and 

 outgoing air. The whole is placed within another chamber and surrounded 

 by packing of non-conducting material. 



A, Outer insulating chamber ; B, middle water-chamber ; C, inner chamber. 



Assuming that the living body and water have the same density, 

 the horse produces per unit of time enough heat to raise by i° C. 

 a mass of water fifty times greater than that of his body. 



A horse loses, according to Colin, 20,684 large calories per diem, 



* These results are higher than those obtained by calculation and tabu- 

 lated on the previous page. Colin's figures are based on Boussingault's 

 experimental inquiry into the income and expenditure of the body. 



