Resisting Medium and a Repulsive Force, 465 



without suffering any diminution, the other is intercepted even 

 by a simple screen. Both these forces are universal ; for they 

 occur everywhere throughout the system of Nature. 



Having at length finished the sketch of M. Faye's memoir, it 

 is now proposed to make a few remarks thereon : and these 

 remarks will principally apply to two points — an argument in 

 favour of the existence of a resisting medium, the aether of space, 

 and some objections to the proposed repulsive force. 



But before proceeding, it may not be out of place to notice that 

 the appearance of speculations from such an illustrious man, and 

 in such a distinguished publication, is another notable sign of 

 the times, and proves that there is a growing desire in the 

 scientific world to emancipate itself from that thraldom to the 

 accumulation of facts which in the first instance is wise, if only 

 the means to an end, but which, if dogmatically adhered to as 

 intrinsically valuable in itself, can never enlarge the field of 

 science. It is like the folly of the miser who accumulates money, 

 but never applies it to its legitimate use. Facts we must have, 

 they are the raw material of science ; but a good hypothesis is 

 of more value than a multitude of similar facts. To the same 

 effect M. Faye observes that his hypothesis has already proved 

 to be fruitful, and that it will in the hands of practical men 

 render much greater services ; for to observe well, a good theory 

 is almost as necessary as a good telescope. Acting on this prin- 

 ciple, how much Laplace has accomplished in France ; and in 

 this country Newton has done more for science than any other 

 man by his theory of gravitation, which was not attained by 

 personal industry in accumulating facts, but by pondering on 

 known facts till utilized by generalization; for, as he says in 

 writing to the astronomer Flamsteed, " all the world knows that 

 I make no observations myself." 



It would seem that the great difficulty in accepting the exist- 

 ence of a resisting medium depends on the discrepancy between 

 the calculated and the observed amount of the variation in the 

 eccentricity of Encke and Faye's comets : but are the data of 

 these calculations so perfectly reliable, that the failure in the 

 analysis can subvert the established opinion concerning the 

 nature of the aether of space ? If it be ignored, what becomes of 

 the beautiful undulatory theory which explains the progression 

 of light and radiant heat ? It is difficult to conceive that any 

 physical force, including gravitating force, can be transferred 

 from one part of the solar system to another without a successive 

 action and reaction on intermediate parts. In times past the 

 actio in distans was accepted because the phenomenon viewed 

 only superficially presented this appearance; and to revert to 

 such a doctrine, unless supported by indisputable facts, can be 



