THE CAUSE OF GRAVITATION 



Theory of the Ether, formulated by George Louis 

 Le-Sage ; born in Geneva, 1724 ; died there in 1803. 

 He adopted and perfected the ideas of Leucippus and 

 Democritus concerning the atoms. These theories he 

 published under the title of the " Lucrece New- 

 tonian " in the " Memoires de P Academic Royal," 

 Berlin, 1782. The latter treatise served as a basis 

 npon which S. Tolver Preston * has expanded the 

 supposition of Le-Sage into the present theory as 

 already described, and also as being the cause of grav- 

 itation. The Ether is supposed to be composed of 

 ultimate atoms. They are excessively minute and 

 move with extreme swiftness, constituting a medium 

 somewhat of the nature of a gas (the properties of 

 gases will be described later), but in which the par- 

 ticles are almost infinitely small, and move in all 

 directions with a swiftness greater perhaps than the 

 transmissions of light itself. These particles move 

 through free paths of possibly greater length than 

 even planetary distances. It is known that the speed 

 of motion and the length of the free path of a cor- 

 puscle i. e.j the distance it can move without col- 

 lision with another corpuscle is inversely to the 

 square of the size or diameter of the corpuscles. 



* London, Edinburgh and Dublin Philosophical Magazine and 

 Journal of Science, 1877, et seq. See also the Encyclopedia Brittanica, 

 9th Edit. 



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