12 Prof. Faraday on Gravity. [Jan. 19, 



Such, I think, must be the character of the conclusion, if it be 

 supposed that the attraction of the sun upon the earth arises because 

 of the presence of the earth, and the attraction of the earth upon the 

 sun, because of the presence of the sun : there remains the case of 

 the power, or the efficient source of the power, having pre-existed 

 in the sun (or the earth) before the earth (or the sun) was in 

 presence. In the latter view it appears to me that, consistently 

 with the conservation of force, one of three sub-cases must occur : 

 either the gravitating force of the sun, when directed upon the 

 earth, must be removed in an equivalent degree from some other 

 bodies, and when taken off from the earth (by the disappearance 

 of the latter) be disposed of on some other bodies ; — or else it 

 must take up some neiv form of power when it ceases to be gravi- 

 tation, and consume some other form of power when it is 

 developed as gravitation ; — or else it must be always existing 

 around the sun through infinite space. The first sub-case is not 

 imagined by the usual hypothesis of gravitation, and will hardly 

 be supposed probable : for, if it were true, it is scarcely possible 

 that the effects should not have been observed by astronomers, when 

 considering the motions of the planets in different positions with 

 respect to each other and the sun. Moreover, gravitation is not 

 assumed to be a dual power, and in them only as yet have such 

 removals been observed by experiment or conceived by the mind. 

 The second sub-case, or that of a new or another form of power, is 

 also one which has never been imagined by others, in association with 

 the theory of gravity. I made some endeavours, experimentally, to 

 connect gravity with electricity, having this very object in view 

 {Phil. Trans. 1851, p. 1) ; but the results were entirely negative. 

 The view, if held for a moment, would imply that not merely the 

 sun, but all matter, whatever its state, would have extra powers set 

 up in it, if removed in any degree from gravitation ; that the 

 particles of a comet at its perihelion would have changed in 

 character, by the conversion of some portion of their molecular 

 force into the increased amount of gravitating force which they 

 would then exert ; and that at its aphelion, this extra gravitating 

 force would have been converted back into some other kind of 

 molecular force, having either the former or a new character : the 

 conversion either way being to a perfectly equivalent degree. One 

 could not even conceive of the diffusion of a cloud of dust, or its 

 concentration into a stone, without supposing something of the same 

 kind to occur ; and I suppose that nobody will accept the idea as 

 possible. The third sub-case remains, namely, that the power is 

 always existing around the sun and through infinite space, whether 

 secondary bodies be there to be acted upon by giavitation or not : 

 and not only around the sun, but around every particle of matter 

 which has existence. This case of a constant necessary condition 

 to action in space, when as respects the sun the earth is not in 

 place, and of a certain gravitating action as the result of that pre- 



