i 
ae 
4 
best attained. 'That bul being interposed, I 
& - . ~~ % 
mee 
< 
Second Letter fiom Dp Hare to Prof. Faraday. &, ” . 
If as you ast, the interposition | of ponderable petioles hid ; 
pm 
oe 
any tendency to promote inductive influence, (xiv,) there | 
be some number of | such particles by which this effect, will 
“o 
how the intensity of a - electro-polarity, thus gene in re 
ervening particles, can, by a diminution of their a 
“quire a proportional i increase ; wine rip in no can t 
versely as the ‘squaresiof the. distances, jes correc y a 
the aggregate influence of an electrified ball, B, situa ai a 
centre of a hollow sphere, C, will be a constant quantity, ie oe 
ever may be the diameter of C. This is perfectly analogous to" 
the illuminating influence of a luminous body situated, at the 2 5 
centre of a hollow sphere, which would of course receive the 
whole of the light emitted whatever mi be its diameter, pro- 
vided that there were nothing interpose to intercept any ee 
of the rays. But in order to answer the objection which | 
advanced, that the diminution of the density of a.“ dielectric” 
‘ is ale be compensated .by any consequent increase of inductive 
n 
intensity, it must be shown in the case of several similar hollow 
spheres, in which various numbers of electrified equidistant balls 
should exist, that the influence of such balls upon each other, and 
upon the mite of the spheres, would not be directly as the 
number of the balls and inversely as the size of the containing 
spaces. Were gas lights substituted for the balls, it must be ev- 
ident that the intensity of the light, in any one of the spheres, 
would be as the number of lights which it might contain. Now . 
one of your illustrations (viii,) above noticed makes light and 
' electrical induction, obey the same law as respects the influence * 
of distance upon the respective intensities. - 
From these considerations, and others above stated, I infer, 
that if electrical induction were an action of particles in prox- 
imity operating reciprocally with forces varying in intensity with 
the squares of the distances, their aggregate influence upon any 
_ surfaces, between which | they might be situated, would be pro- 
portionable to their number; and since experience demonstrates 
that, the inductive power is not diminished by the reduction of 
the number of the intervening pane I conclude that it is in- 
Vol. xx1, No, 1,—April-June, 1841, 
