462 
The Source of Electric Energy . 
[August, 
charge, so that this surface remains electrically neutral, and 
only the negative charge on the adjacent surface is apparent. 
On increasing the distance between the bodies the induCtive 
effeCt diminishes, and negative electricity appears on the 
whole surface. On diminishing the distance the induCtive 
effect increases, and positive electricity reappears on the 
remote surface. 
This view of the case dispenses with the usual idea that 
positive repels positive, and attracts negative, and vice versa. 
Each conductor simply a<5ts towards the other as it would 
upon an uncharged conductor. If the first be positive and 
the second negative, the first exerts an induCtive influence 
upon the second, causing negative force to appear on the 
neighbouring, and positive on the remote, pole. This new 
force is added to or subtracted from the previously existing 
negative of the second, so that this energy is augmented on 
one surface and decreased on the other. The second body 
exerts a like influence, in the opposite direction, upon the 
first. In the case of both being positive, or both negative, 
the rule is the same. Each aCts on the other as on an un- 
charged body. The charge on each has added to it an 
induced charge, which weakens it in one direction and 
strengthens it in the other. There is no real attraction of 
unlike and repulsion of like electricities, though the result 
gives that impression. In the interior of a charged con- 
ductor a similar rule holds good. If one surface be plane 
and the other concave internally, the lines of induction from 
the concave to the plane surface are divergent, those from 
the plane to the concave are convergent. Thus the induc- 
tive effeCt upon any portion of the concave surface exceeds 
that upon an equal area of the plane surface. The charge 
on any area of the concave surface is augmented, that on an 
equal area of the plane surface decreased, by this difference 
in induCtive aCtion. Thus the surface charge of a conductor 
varies in amount in strict conformity to the shape of the 
surface of the conductor. 
The conclusions thus arrived at lead to another probable 
conclusion, at which we have already glanced. In a charged 
conductor the primary effeCt of neutralisation of the internal 
molecular charge would be to confine the effective elec- 
tricity to the outwardly directed poles of the surface mole- 
cules. But the neutralisation of the opposite charge on the 
inwardly directed poles of these molecules must render this 
restriction impossible. The eleCtric disturbance necessarily 
flows back and affeCts the molecule as a whole. Instead of 
its having a normal heat and two opposite abnormal atomic 
