10 Professor Faraday [Jan. 19, 



the magnetic condition assigned by some to bismuth {i.e. with 

 reversed pohirities), it then differed from bismuth, producing the 

 contrary deflection. [For a further account of these considerations 

 and investigations, a paper may be referred to, which will appear in 

 the February number of the Philosophical Magazine.] 



It is, pro))ably, of great importance that our thoughts should be 

 stirred up at this time to a reconsideration of the general nature of 

 physical force, and especially to those forms of it which are con- 

 cerned in actions at a distance. These are, by the dual powers, 

 connected very intimately with those which occur at insensible 

 distances ; and it is to be expected that the progress which physi- 

 cal science has made in latter limes will enable us to ap- 

 proach this deep and difficult subject with flxr m.ore advantage than 

 any possessed by philosophers at former periods. At present we 

 are accustomed to admit action at sensible distances, as of one 

 magnet upon another, or of the sun upon the earth, as if such 

 admission were itself a perfect answer to any enquiry into the 

 nature of the physical means which cause distant bodies to affect 

 each other ; and the man who hesitates to admit the sufficiency of 

 the answer, or of the assumption on which it rests, and asks for 

 a more satisfactory account, runs some risk of appearing ridiculous 

 or ignorant before the world of science. Yet Newton, who did 

 more than any other man in demonstrating the law of action of 

 distant bodies, including amongst such the sun and Saturn, which 

 are 900 millions of miles apart, did not leave the subject without 

 recording his well-considered judgment, that the mere attraction of 

 distant portions of matter was not a sufficient or satisfactory thought 

 for a philosopher. 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, he says, to him a great absurdity. Gravity must 

 be caused by an agent, acting constantly according to certain laws ; 

 but whether this agent be material or immaterial he leaves to 

 the consideration of his readers. This is the onward looking 

 thought of one, who by his knowledge and like quality of mind, 

 saw in the diamond an unctuous substance coagulated, when as yet 

 it was known but as a transparent stone, and foretold the presence 

 of a combustible substance in water a century before water was 

 decomposed or hydrogen discovered : and I cannot help believing 

 that the time is near at hand, when his thought regarding gravity 

 will produce fruit : — and, with that impression, I shall venture a 

 few considerations upon what appears to me the insufficiency of the 

 usually accepted notions of gravity, and of those forces generally, 

 which are supposed to act at a distance, having respect to the 

 modern and philosophic view of the conservation and indestructi- 

 bility of force. 



The notion of the gravitating force is, with those who admit 



