GALILEO AND HIS JUDGES. 155 



in Scotland throwing additional light upon it, and 

 indicating that not merely the Earth as a whole, but 

 any great mass, such as a mountain, exercises an 

 appreciable attractive force. 



Newton seems to have expected that some further 

 discovery would take place, at no distant period, as to 

 the nature of this occult agency which operates so 

 powerfully in the heavens and on the Earth. In one 

 of his letters he strongly disclaims the opinion that 

 gravity is essential to matter and inherent in it ; he 

 thinks it is " inconceivable that inanimate brute 

 matter should, without the mediation of something 

 else which is not material, operate on and affect other 

 matter without mutual contact .... that gravity 

 should be innate, inherent, and essential to matter, so 

 that one body may act upon another at a distance 

 through a vacuum, without the mediation of anything 

 else by and through which their action and force may 

 be conveyed from one to another, is to me so great an 

 absurdity that I believe no man who has in philo- 

 sophical matters a competent faculty of thinking can 

 ever fall into it." 



And yet we see that what he thought absurd is still 

 apparently true, and that, great as was Newton's 

 sagacity in discovering and proving the effects of this 

 great cosmical law, he failed when he came to specu- 

 late on the more remote causes of it. Since his time, 

 other ingenious theorists have imagined hypotheses in 

 the hopes of accounting for it ; but their efforts have 



