THE PATH OF EVOLUTION 



tion again by contact with other normally swift- 

 moving atoms. 



In the study of the mechanical forces a relation is 

 established between gravitation and other forms of 

 energy, by the assumption that " potential force," or 

 the energy of position, is possessed by a body raised 

 to a position from which it can fall ; that the body 

 holds potentially the energy that has been exerted 

 upon it to raise it against gravitation, and which 

 becomes again active in its fall. This enables the 

 calculations to be made between the motion of a fall- 

 ing mass and the heat produced by its fall, or the 

 energy required to restore the mass to its former 

 elevation. But under the Atomic Ether theory it 

 should be looked upon as the measure of the energy 

 expended to resist the impulsive or gravitic action of 

 the Ether atoms. " Potential force " serves to form 

 a " working theory," as the phlogiston theory served 

 a useful purpose in its time, until the discovery of 

 oxygen and the true theory of combustion displaced 

 it. Ever since then men have wondered that so simple 

 an explanation remained so long unknown. 



The brilliant experiments of Prof. H. Hertz, of 

 Karlsruhe, "Ueber Strahlen elektrischen Kraft 

 (Sitzensberichte der K. Preusseriischen Akademie der 

 Wissenschaften," Dec., 1888), have established the 

 identity of the movements of the electric waves with 



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