10 R. W. Fox on Electrical Action. 



to understand that if these curves are interrupted and broken, 

 and the magnetic elements coerced from their natural posi- 

 tion by the approach of an electrical conductor, such a reci- 

 procal action must occur between the magnet and conductor 

 as will cause them, if freely suspended, to assume some other 

 relative positions, the uniformity of which may be governed 

 by the arrangement of the magnetic elements with respect to 

 each other. The opposite poles of the latter may overlap 

 each other, for instance, in one uniform manner so as to de- 

 termine them towards a tangential position with respect to the 

 axis of a magnet when acted upon by an electrical conductor: 

 the spiral form, and perhaps some other forms, might im- 

 part to them this tendency. The same reasons may explain 

 why a magnet does not produce electricity in a metallic wire 

 when moved in the direction of their common axes, as the 

 opposite poles of a magnet, in this case, have a tendency to 

 counteract each other's influence. 



Many phsenomena in electro-magnetism seem to counten- 

 ance the probability of a rotation of the electric elements, such 

 as the rotation of mercury, water, &c, when under the joint 

 influence of electricity and magnetism. There is also a me- 

 chanical fact, which I published some time ago in the Journal 

 of the Royal Institution, and which, perhaps, may be consi- 

 dered as favouring the opinion of the rotatory motion, or rather 

 tendency, even of common electricity, viz. that when a needle or 

 any sharp-pointed instrument rapidly revolving round its own 

 axis is made to pierce a card, a bur is raised on each side of 

 the card precisely similar to the effects produced by an electric 

 discharge*. Moreover, the analogies afforded by the apparent 

 undulatory motion of light and sound, seem to favour the 

 opinion that a corresponding action exists in the case of elec- 

 tricity. 



Note. — Since I have completed the experiments above re- 

 ferred to, and, indeed, written the greater part of this paper, a 

 friend of mine has sent me W. S. Harris's paper on the laws 



* I do not mean to use this mechanical illustration as an argument in 

 favour of a complete elementary rotation in the case of an electric discharge 

 from a Leyden jar, for a semircvolution of the electric elements might, per- 

 haps, suffice to produce the burs; and if we assume that the opposite elec- 

 tric poles attract each other on either side of the glass, such a partial ro- 

 tation, or. mere undulation of the elements in the series or circuit, when a 

 conductor is applied, seems to he all that is required to restore the natural 

 arrangement and equilibrium of forces. The burs might possibly, however, 

 be produced by the meeting of the opposite undulations at the card. The 

 same explanation may be given of the common electric spark, under or- 

 dinary circumstances, as of the electrical discharge from a Leyden jar : 

 thus presenting a marked difference of action from what I have supposed 

 to exist in the cases of voltaic, and thermo-electricity. 



