TENDENCIES OF MODERN PHYSICS 53 



ometers choose to advance other and contradictory 

 postulates as axioms? 



Let us now turn to some of the specific difficulties 

 of this new theory. In addition to many absurd prop- 

 erties ascribed to the old elastic solid ether, its chief 

 defects were, that it must, at the same time, have 

 friction and not have friction, and that it could not 

 account for electricity. If it had friction, then the 

 ether would absorb light and heat energy, and the mo- 

 tion of bodies through it would affect the properties of 

 light in a manner which could be detected; both of 

 these have been found to be contrary to experience. 

 On the other hand, the ether must have friction to 

 permit the communication of atomic vibrations to it. 

 To escape these dilemmas, Professor Larmor supposes 

 the electro-magnetic ether to be without mechanical 

 friction and so to remain quiescent when any body 

 moves through it, but he apparently forgot that he had 

 assumed that the essence of substance is electricity. 

 If bodies are forms of electricity how can they move 

 through an electrical medium without disturbing it? 

 Since we have abandoned the theory that light and 

 heat are mechanical waves for the supposition that they 

 are electro-magnetic disturbances caused by periodic 

 variations of electric charges, the new ether must, in 

 some way, be modified by electric variations in order 

 to receive and to transmit light and heat. But anyone 

 can see we are just where we started. The electro- 



