THE PATH OF EVOLUTION 



strength of the current being proportionate to that 

 of the ring. . . . He who dares to plant his feet in 

 the path opened up by Helmboltz and Thompson has 

 no other properties to work with than inertia, invari- 

 able density and perfect mobility. . . . The difficul- 

 ties of this method are enormous, but the glory of 

 surmounting them would be unique." * 



The theory of the ether satisfactorily accounts for 

 the transmission of light and heat. The movement 

 of the Electric and Magnetic radiant waves has been 

 proved to be of a like nature, or rather radiant heat, 

 light, electricity and electro-magnetism are forces 

 essentially identical each with the others: they are 

 governed by the same laws and have the same 

 method of transmission. The existence of the Ether 

 is now asserted absolutely, so that the text-books of 

 our Colleges place the study of the phenomena of 

 Radiant Energy, or Light, Heat, Electricity, Mag- 

 netism, etc., under the heading of the Physics of 

 the Ether. 



Notwithstanding the statement of Clerk Maxwell 

 that the theory that attributes a homogeneous and 

 continuous structure to the substance of the Ether is 

 impossible of demonstration and incapable of any 

 explanation, yet it is generally assumed by mathe- 

 maticians that the Ether consists of a jelly-like sub- 



J. C. Maxwell, Enc. Brit. "Atom." 

 130 



