232 THE PHENOMENA OF MOTION 



abstraction of heat, or by the expenditure in mechanical 

 motions of the available force of living parts. 



By the combination of the oxygen introduced in the 

 arterial blood with such constituents of the body as 

 offer no resistance to its action, the temperature neces- 

 sary for the manifestation of vital activity is produced. 



From the relations between the consumption of oxy- 

 gen on the one hand, and the change of matter and 

 development on the other, the following general rules 

 may be deduced. 



For every proportion of oxygen which enters into 

 combination in the body, a corresponding proportion 

 of heat must be generated. 



The sum of force available for mechanical purposes 

 must be equal to the sum of the vital forces of all tis- 

 sues adapted to the change of matter. 



If, in equal times, unequal quantities of oxygen are 

 consumed, the result is obvious, in an unequal amount 

 of heat liberated, and of mechanical force. 



When unequal amounts of mechanical force are ex- 

 pended, this determines the absorption of corresponding 

 and unequal quantities of oxygen. 



For the conversion of living tissues into lifeless com- 

 pounds, and for the combination of oxygen with such 

 constituents of the body as have an affinity for it, time 

 is required. 



In a given time, only a limited amount of mechani- 

 cal force can be manifested, and only a limited amount 

 of heat can be liberated. 



