I FRAGMENTS OF SCIENCE. 



vague or fanciful conception on the part of scientific men. 

 Of its reality most of them are as convinced as they are of 

 the existence of the sun and moon. The luminiferous 

 ether has definite mechanical properties. It is almost 

 infinitely more attenuated than any known gas, but its 

 properties are those of a solid rather than of a gas. It 

 resembles jelly rather than air. This was not the first 

 conception of the ether, but it is that forced upon us by a 

 more complete knowledge of its phenomena. A body thus 

 constituted may have its boundaries; but although the ether 

 may not be co-extensive with space, it must at all events 

 extend as far as the most distant visible stars. In fact it 

 is the vehicle of their light, and without it they could not 

 be seen. This all-prevading substance takes up their mo- 

 lecular tremors, and conveys them with inconceivable 

 rapidity to our organs of vision. It is the transported 

 shiver of bodies countless millions of miles distant, which 

 translates itself in human consciousness into the splendor 

 of the firmament at night. 



If the ether have a boundary, masses of ponderable 

 matter might be conceived to exist beyond it, but they 

 could emit no light. Beyond the ether dark suns might 

 burn; there, under proper conditions, combustion might 

 be carried on; fuel might consume unseen, and metals be 

 fused in invisible fires. A body, moreover, once heated 

 there, would continue forever heated; a sun or planet once 

 molten, would continue forever molten. For, the loss of 

 heat being simply the abstraction of molecular motion by 

 the ether, where this medium is absent no cooling could 

 occur. A sentient being, on approaching a heated body 

 in this region, would be conscious of no augmentation of 

 temperature. The gradations of warmth dependent on 

 the laws of radiation would not exist, and actual contact 

 would first reveal the heat of an extra ethereal sun. 



Imagine a paddle-wheel placed in water and caused to 

 rotate. From it, as a center, waves would issue in all 

 directions, and a wader as he approached the place of dis- 

 turbance would be met by stronger and stronger waves. 

 This gradual augmentation of the impression made upon 

 the wader is exactly analogous to the augmentation of 

 light when we approach a luminous source. In the one 

 case, however, the coarse common nerves of the body 

 suffice; for the other we must have the finer optic nerve. 



