OF GEOLOGICAL DYNAMICS. 115 



work, and we distinguish between action, or rate 

 of action, as defined by Newton, and the integral 

 amount of action or integral amount of work done 

 after any operation of force is completed. Again, 

 in modern physical dynamics we have learned that 

 every performance of work consists in merely a 

 transformation or intertransposition of materials, 

 or a stopping of some motion and generating of 

 other instead, and that when work is performed in 

 one locality, another locality must on that account 

 be left with so much less of the wherewithal for the 

 farther performance of work. This " wherewithal " 

 is called energy ; and thus the performance of work 

 is simply the drawing of energy from one store 

 and laying it out elsewhere. Any irreversible 

 transformation of energy is called a dissipation of 

 energy ; of which the most prominent examples 

 are the conduction of heat from warmer to colder 

 parts of a body, or of the matter occupying any 

 portion of space, and the generation of heat by 

 friction or collision. 



32. Plutonic action is, therefore, to be defined as 

 any transformation of energy going on within the 



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