335 



Uiidulatory Theory of Light, as opposed to the Emission 

 Theory of Newton, esteeming the former to be true, and the 

 latter false science. 



33. But if I am riglitin this I nmst necessarily conclude that 

 tlie undulations, pulsations, or vibrations must take place in 

 some medium which is not of the gross and material (that is, 

 ponderable) nature of that which we usually call matter. 



3-1. It is not a little remarkable that the profound contempla- 

 tions of Sir Isaac Newton should have led him to the following 

 inquiries:* — "Is not heat conveyed through a vacuum by the 

 vibrations of a much more subtle medium than air ? Is not this 

 medium the same by which light is refracted, and reflected, and 

 communicates heat to bodies, and is put into fits of easy trans- 

 mission and reflexion ? Do not hot bodies communicate their 

 heat to cold ones by the vibrations of this medium ? And is it 

 not exceedingly more rare and subtle than the air, and exceed- 

 ingly more elastic and active ? and does it not readily pervade 

 all bodies ? and is it not by its elastic force expanded through 

 all the heavens." It is remarkable that the undulatory theory 

 of light, in displacing his own, should have lent the most beautiful 

 and convincing evidence to the truth of these suggestions. How 

 little can we rest upon the authority of great names in science, 

 when the same individual at diflPerent times may so contradict 

 his own opinions. 



35. And that in a point of the utmost importance, for it must 

 be admitted that such a scientific fact, if true, is of the grandest 

 dimensions. This imponderable ether, if it exists, must neces- 

 sarily fill all space, and extend as far as the light is visible of 

 the most distant stars. Now, *^ it has been calculated that 

 some of the stars seen with Lord Rosse^s telescope shine 

 from such an enormous distance that light takes upwards of 

 50,000 years in travelling to us from them. Now, consider for 

 a moment the flight of a light ray from a star at this distance 

 on one side of our system to another as far off on the opposite 

 side. For 100,000 years the light speeds onwards, each second 

 sweeping over nearly 200,000 miles, past stars and systems. It 

 rushes on, but far away ; on every hand are other stars and 

 other systems, to which it comes not near. During 5,000 

 generations of mortal men, if one can conceive that our race 

 could last out that time, the pulsations of the ether are 

 transmitted along the tremendous line which separates the two 

 stars.^'t 



^ Ojjtics, by Sir Isaac ewtou. 

 t The Orbs around n.s^ Proctor, p. 45. 

 9 A 9. 



