10 FRAGMENTS OF SCIENCE. 



nomena of light as displayed in the ether j which is the 

 name given to the interstellar medium. 



The notion of this medium must not be considered as 

 a 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 knoAvn gas, but its properties are 

 those of a solid rather than of a gas. It resembles jelly 

 rather than air. A body thus constituted may have its 

 boundaries ; but, although the ether may not be coexten- 

 sive with space, Ave at all events know that it extends as 

 far as the most distant visible stars. In fact, it is the ve- 

 hicle of their light, and without it they could not be seen. 

 This all-pervading substance takes up their molecular tre- 

 mors, and conveys them with inconceivable rapidity to our or- 

 gans of vision. It is the transported shiver of bodies count- 

 less 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 lisdit. Bevond the ether dark suns might 

 burn ; there, under proper conditions, combustion might be - 

 carried on ; fuel might consume unseen, and metals be 

 heated to fusion 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 cool- 

 ing 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 



