100 Prof. Faraday on some Points of Magnetic Philosophy. 



of all magnetic phenomena, short of the idea of the nature of 

 the magnetic force itself, is supplied. 



3336. For if the dual forces of the poles of a magnet in free 

 space are related to, and dependent upon, each other, and yet 

 not through the magnet (3331.), then it must be through 

 the space around. Then space must have a real magnetic re- 

 lation to the force passing across it, just as it has to the ray of 

 light passing from an illuminating to an illuminated body. 

 Then the directions in which the two forces are exerted upon 

 each other cannot be in right lines, which must, if they existed, 

 pass of necessity through the magnet ; but in curved lines, 

 seeing that it is impossible that any but curved lines can hold 

 the poles in relation to each other through the surrounding space 

 (3297.) : — and if they be curved lines, then I cannot imagine 

 them to be anything else than physical lines of force ; lines fitted 

 to transfer the power onwards in consistency with its inevitable 

 dual relation, and in conformity with that direction which ought, 

 as I think, to be properly called polarity. And it further ap- 

 pears to me, that if we once admit the magnetic relation of a 

 vacuum, then all the phsenomena of paramagnetic and diamag- 

 netic bodies; of differential polarity and individual polarity; of 

 solutions, needles, crystals and moving conductors, are presented 

 in a simple mutual relation, without any contradiction of fact or 

 hypothesis, and in perfect harmony with each other. 



3337. I wish to avoid prolonging this paper by a repetition 

 of the considerations and reasons already advanced on former 

 occasions, and therefore will very briefly call to mind the idea 

 I have put forth, that there are such lines of force in the space 

 around a magnet ; that the mutual dependence of the dualities, 

 which is essential in the isolated magnet, is thus sustained ; and 

 that bodies in this space produce paramagnetic or diamagnetic 

 phaenomena, according as they favour or oppose the degree of 

 sustaining power which mere space possesses. That these bodies, 

 or media as they may be called, have a magnetic relation like 

 that of space, is easily shown by numerous experimental results ; 

 but as they have a further relation amongst themselves, depend- 

 ent upon their relative electro-conducting power, -p- q 



I think a little time may be usefully employed 

 in considering how far the consequent results 

 illustrate the probable condition of space where 

 they are not present. Consider a magnet pole a 

 N, fig. 6, placed in relation to an equal mag- 

 netic pole S, so that their powers are mutually 

 related and sustained, and the space between 

 them, a, a, a, occupied by a vacuum, nitrogen, or some other gas 

 at magnetic zero (2770. &c.) : — the force exerted by N on S, or 



