334 Mr. Faraday [Feb. 27, 



out of sight its origin, its static and dynamic induction, its magnetic 

 influence, its chemical and heating efi^ects? or our idea of any one 

 of these results, if we left any of the others unregarded ? That 

 there should be a power of gravitation existing by itself, having 7to 

 relation to the other natural powers, and no respect to the law of 

 the conservation of force, is as little likely as that there should be 

 a principle of levity as well as of gravity. Gravity may be only 

 the residual part of the other forces of nature, as Mossotti has tried 

 to show ; but that it should fall out from the law of all other force, 

 and should be outside the reach either of further experiment or 

 philosophical conclusions, is not probable. So we must strive to 

 learn more of this outstanding power, and endeavour to avoid any 

 definition of it which is incompatible with the principles of force 

 generally, for all the phenomena of nature lead us to believe that 

 the great and governing law is one. I would much rather incline 

 to believe that bodies affecting each other by gravitation act by 

 lines of force of definite amount (somewhat in the manner of mag- 

 netic or electric induction, though without polarity), or by an ether 

 pervading all parts of space, than admit that the conservation of 

 force could be dispensed with. 



It may be supposed, that one who has little or no mathematical 

 knowledge should hardly assume a right to judge of the generality 

 and force of a principle such as that which forms the subject of 

 these remarks. My apology is this, I do not perceive that a 

 mathematical mind, simply as such, has any advantage over an 

 equally acute mind not mathematical, in perceiving the nature and 

 power of a natural principle of action. It cannot of itself intro- 

 duce the knowledge of any new principle. Dealing with any and 

 every amount of static electricity, the mathematical mind can, and 

 has balanced and adjusted them with wonderful advantage, and has 

 foretold results which the experimentalist can do no more than 

 verify. But it could not discover dynamic-electricity, nor electro- 

 magnetism, nor magneto-electricity, or even suggest them ; though 

 when once discovered by the experimentalist, it can take them up 

 with extreme facility. So in respect of the force of gravitation, it 

 has calculated the results of the power in such a wonderful manner 

 as to trace the known planets through their courses and perturbations, 

 and in so doing has discovered a planet before unknown ; but there 

 may be results of the gravitating force of other kinds than attraction 

 inversely as the square of the distance, of which it knows nothing, 

 can discover nothing, and can neither assert nor deny their possi- 

 bility or occurrence. Under these circumstances, a principle, which 

 may be accepted as equally strict with mathematical knowledge, 

 comprehensible without it, applicable by all in their philosophical 

 logic whatever form that may take, and above all, suggestive, 

 encouraging, and instructive to the mind of the experimentalist, 

 should be the more earnestly employed and the more frequently 

 resorted to when we are labouring either to discover new regions of 



