224 THE PHENOMENA OF MOTION 



those of the food, has lost its condition of life, and has 

 been expelled in combination with oxygen. 



The one individual, which, being exposed to the 

 lower temperature, consumed more food, has also ab- 

 sorbed more oxygen ; a greater quantity of the con- 

 stituents of its body has been separated in combination 

 with oxygen ; and, in consequence of this combination 

 with oxygen, a greater amount of heat has been lib- 

 erated, by which means the heat abstracted has been 

 restored, and the proper temperature of the body kept 

 up. 



Consequently, by the abstraction of heat, provided 

 there be a full supply of food and free access of oxy- 

 gen, the change of matter must be accelerated ; and, 

 along with the augmented transformation, in a given 

 time, of living tissues, a greater amount of vital force 

 must be rendered available for mechanical purposes. 



With the external cooling, the respiratory motions 

 become stronger ; in a lower temperature more oxygen 

 is conveyed to the blood ; the waste of matter increases, 

 and if the supply be not kept in equilibrium with this 

 waste, by means of food, the temperature of the body 

 gradually sinks. 



But, in a given time, an unlimited supply of oxygen 

 cannot be introduced into the body ; only a certain 

 amount of living tissue can lose the state of life, and 

 only a limited amount of vital force can be manifested 

 in mechanical phenomena. It is only, therefore, when 

 the cooling, the generation of force, and the absorption 



