ELECTRICITY IN EQUILIBRIUM. 



tracted when in dissimilar states. This is a consequence immedi- 

 ately deducible from the mutual attraction of redundant matter, 

 and redundant fluid, aud from the repulsion supposed to exist 

 between any two portions, either of matter or of fluid ; and it 

 may also easily be confirmed by experimental proof. A neutral 

 body, if it were a perfect nonconductor, would not be affected 

 either way by the neighbourhood of an electrified body : for while 

 the whole matter contained in it remains barely saturated with the 

 electric fluid, the attractions and repulsions balance each other. 

 But, in general, a neutral body appears to be attracted by an 

 electrified body, on account of a change of the disposition of the 

 fluid which it contains, upon the approach of a body either posi- 

 tively or negatively electrified. The electrical affection produced 

 in this manner, without any actual transfer of the fluid, is called 

 induced electricity. 



When a body positively electrified approaches to a neutral body, 

 the redundancy of the fluid expels a portion ef the natural quan- 

 tity from the nearest parts of the neutral body, so that it is accu- 

 mulated at the opposite extremity ; while the matter, which is left 

 deficient, attracts the redundant fluid of the first body, in such a 

 manner as to cause it to be more condensed in the neighbourhood 

 of the second than elsewhere ; and hence the fluid of this body is 

 driven still further off, and all the effects are redoubled. The 

 attraction of the redundant fluid of the electrified body, for the 

 redundant matter of the neutral body, is stronger than its repul- 

 sion for the fluid which has been expelled from it, in proportion as 

 the square of the mean distance of the matter is smaller than that 

 of the mean distance of the fluid : so that in all such cases of 

 induced electricity, an attraction is produced between the bodies 

 concerned. And a similar attraction will happen, under contrary 

 circumstances, when a neutral body and a body negatively electri. 

 lied, approach each other. 



The state of induced electricity may be illustrated by placing a 

 long conductor at a little distance from an electrified substance, 

 and directed towards it ; and by suspending pith balls, or other 

 light bodies from it, in pairs, at different parts of its length : these 

 will repel each other, from being similarly electrified, at the two 

 ends, which are in contrary states of electricity, while at a certain 

 point towards the middle they will remain at rest, the conductor 

 leing here perfectly neutral. It was from the situation of this 



c4 



