THE ETHER 109 



the electronic theory of matter be correct, it not 

 merely penetrates matter, but is matter. 



The properties of ether are, of course, wholly 

 inferential ; and, as we said before, mathematicians 

 have found it very difficult to make these con- 

 sistent inter se. It was at first conceived as a 

 fluid, but it is certainly not a fluid, nor a solid, 

 nor a gas, nor radiant matter ; and different 

 physicists picture it in different ways. Maxwell 

 supposed it to be formed of tiny spheres, rapidly 

 rotating. Mendeleef reached the conclusion that 

 it is an inert gas with an atomic weight a million 

 times less than hydrogen, and with a velocity of 

 2250 kilometres per second. Others, again, have 

 pictured it as a homogeneous elastic jelly ; others 

 have , suggested that it may be " fibrous, like a 

 bundle of hay." Professor Osborne Reynolds, a 

 well-known mathematician, who has worked at the 

 subject for years, claims that "there is one, and 

 only one, purely mechanical system capable of 

 accounting for all the physical evidence, as we 

 know it, of the universe. The system is neither 

 more nor less than an arrangement of indefinite 

 extent, of uniform spherical grains, generally in 

 normal piling so close that the grains cannot 

 change their neighbours although continually in 

 relative motion with each other, the grains being 

 of changeless shape and size." The grains he 



