

THE CONSERVATION OF ENERGY 



advance thinkers who had grasped the import of the 

 doctrine of conservation could at once appreciate the 

 force of Thomson's doctrine of dissipation, and real- 

 ize the complementary character of the two concep- 

 tions. 



Here and there a thinker like Rankine did, indeed, 

 attempt to fancy conditions under which the energy lost 

 through dissipation might be restored to availability, 

 but no such effort has met with success, and in time 

 Professor Thomson's generalization and his conclusions 

 as to the consequences of the law involved came to be 

 universally accepted. 



The introduction of the new views regarding the nat- 

 ure of energy followed, as I have said, the course of 

 every other growth of new ideas. Young and imagina- 

 tive men could accept the new point of view ; older phi- 

 losophers, their minds channelled by preconceptions, 

 could not get into the new groove. So strikingly true 

 is this in the particular case now before us that it is 

 worth while to note the ages at the time of the revolu- 

 tionary experiments of the men whose work has been 

 mentioned as entering into the scheme of evolution of 

 the idea that energy is merely a manifestation of mat- 

 ter in motion. Such a list will tell the story better 

 than a v< >lume of commentary. 



Observe, then, that Davy made his epochal experi- 

 ment of melting ice by friction when he was a youth of 

 twenty. Ymmij was no older when he made his first 

 communication to the Royal Society, and was in his 

 twenty-seventh year when he first actively espoused 

 the undulatory theory. Fresnel was twenty-six when 

 he made his first important discoveries in the same 



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