THE PATH OF EVOLUTION 



tent through the same course ridiculed at first, then 

 decried, but ultimately accepted. 



From the above description of the physics of a 

 gas known as the Kynetic theory of gases and so 

 fully demonstrated as to be universally accepted, the 

 analogy between its fundamental principles and those 

 required for the properties of the Atomic theory of 

 the Ether are evident. The atmosphere, though 

 composed of molecules moving in all directions with 

 great speed and with much force, as shown by their 

 dynamic action on the walls that confine them, yet 

 responds as a whole, as an isotropic or a consistent 

 medium or fluid to the vibrations of a cord, bell, or 

 other body, and transmits the varied and complicated 

 molar vibrations, waves, or alternate contractions and 

 expansions that, affecting our auditory nerves, con- 

 stitute musical and articulate sound. 



In somewhat the same manner we may consider 

 the transverse molar vibrations of the Ether that 

 constitute light, heat, etc., to be the phenomena of the 

 Ether, considered as a consistent isotropic substance or 

 medium ; whilst the particles that compose it, con- 

 sidered separately, are very close together, almost in- 

 finitely small, are infinitely numerous, and are mov- 

 ing with a swiftness greater than the waves of light, 

 probably in the ratio that the ultimate molecules of 

 air move swifter than the waves of sound. 



152 



