244 THE PHENOMENA OF MOTION 



necessary for the manifestation of vital activity is 

 produced. 



From the relations between the consumption of 

 oxygen on the one hand, and the change of matter 

 and developement of heat on the other, the follow- 

 ing 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 pur- 

 poses must be equal to the sum of the vital forces 

 of all tissues 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 

 expended, this determines the absorption of corre- 

 sponding and unequal quantities of oxygen. 



For the conversion of living tissues into lifeless 

 compounds, and for the combination of oxygen with 

 such constituents of the body as have an affinity for 

 it, time is Teqidred. 



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

 chanical force can be manifested, and only a limited 

 amount of heat can be liberated. 



That which is expended, in mechanical effects, in 

 the shape of velocity, is lost in time ; that is to say, 

 the more rapid the motions are, the sooner or the 

 more quickly is the force exhausted. 



The sum of the mechanical force produced in a 



