Energ'y in Animals 47 



very much as electrical energy is measured. 

 The quantity is a product of the volume and 

 the potential. A high potential comes from 

 extreme activity, and large volume comes 

 from a long time during which concentration 

 occurred. The rate at which energy dissi- 

 pates under a given degree of idleness is 

 proportional to its potential, much as the 

 rate at which heat radiates from one body to 

 another is proportional to the difference in 

 temperature of the bodies. 



If a quantity of energy be concentrated 

 in an animal at a high potential by reason 

 of extreme activity continued over a short 

 period, a considerable degree of idleness will 

 permit the concentrated energy to dissipate 

 rapidly. If the same quantity of energy be 

 concentrated at a less potential by a less 

 degree of activity extending over a longer 

 period of time, then the same degree of idle- 

 ness will not permit such a rapid rate of dis- 

 sipation, and it requires longer for the animal 

 to lose the same amount of energy in the 

 second case than in the first. The perma- 



