300 MODERN SCIENCE READER. 



all dynamos, of electric motors, of light, of telegraphy, and 

 of most other things. Indeed, it is a question whether it 

 does not underlie everything that we know in the whole of 

 the physical sciences ; and whether it is not the basis of our 

 conception of the three dimensions of space. 



Lastly, we have the fundamental property of matter 

 called inertia, which, if I had time, I would show could be 

 explained electromagnetically, provided the ethereal dens- 

 ity is granted as of the order of 10 12 grams per cubic 

 centimeter. The elasticity of the ether would then have 

 to be of the order of 10 33 c.g.s. ; and if this is due to in- 

 trinsic turbulence, the speed of the whirling or rotational 

 elasticity must be of the same order as the velocity of light. 

 This follows hydrodynamically ; in the same sort of way 

 as the speed at which a pulse traveling on a flexible run- 

 ning endless cord, whose tension is entirely due to the 

 centrifugal force of the motion, is precisely equal to the 

 velocity of the cord itself. And so, on our present view, 

 the intrinsic energy of constitution of the ether is incred- 

 ibly and portentously great ; every cubic millimeter of space 

 possessing what, if it were matter, would be a mass of a 

 thousand tons, and an energy equivalent to the output of a 

 million horse-power station for forty million years. 



The universe we are living in is an extraordinary one; 

 and our investigation of it has only just begun. We know 

 that matter has a psychical significance, since it can consti- 

 tute brain, which links together the physical and the 

 psychical worlds. If any one thinks that the ether, with 

 all its massiveness and energy, has probably no psychical 

 significance, I find myself unable to agree with him. 



SUPPLEMENTARY REMARKS CONCERNING DENSITY OF ETHER 



I observe that it is surmised by at least one thoughtful 

 and friendly critic that in speaking of the immense density 

 or massiveness of ether, and the absurdly small density or 

 specific gravity of gross matter by comparison, I intended 

 to signify that matter is a rarefaction of the ether. That, 



