278 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XIV.) 



rather in fact have proved the contrary, namely, that magnetic forces are quite inde- 

 pendent of the matter intervening between the inductric and the inducteous bodies ; 

 but I cannot get over the difficulty presented by such substances as copper, silver, 

 lead, gold, carbon, and even aqueous solutions (201. 213.), which though they are 

 known to assume a peculiar state whilst intervening between the bodies acting and 

 acted upon (1727.)j no more interfere with the final result than those which have as 

 yet had no peculiarity of condition discovered in them. 



1730. A remark important to the whole of this investigation ought to be made 

 here. Although I think the galvanometer used as I have described it (1711. 1720.) 

 is quite sufficient to prove that the final amount of action on each of the two coils or 

 the two cores A and B (1713. 1719.) is equal, yet there is an effisct which w^y be con- 

 sequent on the difference of action of two interposed bodies which it would not 

 show. As time enters as an element into these actions'* (125.), it is very possible 

 that the induced actions on the helices or cores A, B, though they rise to the same 

 degree when air and copper, or air and lac are contrasted as intervening substances, 

 do not do so in the same time ; and yet, because of the length of time occupied by a 

 vibration of the needle, this difference may not be visible, both effects rising to their 

 maximum in periods so short as to make no sensible portion of that required for a 

 vibration of the needle, and so exert no visible influence upon it. 



1731. If the lateral or transverse force of electrical currents, or what appears to 

 be the same thing, magnetic power, could be proved to be influential at a distance 

 independently of the intervening contiguous particles, then, as it appears to me, a real 

 distinction, of a high and important kind, would be established between the natures of 

 these two forces (1654. 1664.). I do not mean that the powers are independent of 

 each other and might be rendered separately active, on the contrary they are pro- 

 bably essentially associated (1654.), but it by no means follows that they are of the 

 same nature. In common statical induction, in conduction, and in electrolyzation, 

 the forces at the opposite extremities of the particles which coincide with the lines of 

 action, and have commonly been distinguished by the term electric, are polar, and in 

 the cases of contiguous particles act only to insensible distances ; whilst those which 

 are transverse to the direction of these lines, and are called magnetic, are circumfe- 

 rential, act at a distance, and if not through the intermediation of the intervening 

 particles, have their relations to ordinary matter entirely unlike those of the electrical 

 forces with which they are associated. 



1732. To decide this question of the identity or distinction of the two kinds of 

 power, and establish their true relation, would be exceedingly important. The ques- 

 tion seems fully within the reach of experiment, and offers a high reward to him who 

 will attempt its settlement. 



* See Annales de Chimie, 1833, torn. li. pp. 422, 428, 



