388 The Source of Electric Energy. [July, 
energies combine, and produce the intermediate heat vibra- 
tion. Thus the only unsatisfied electric disturbance is that 
of the outward poles of the surface molecules. And this 
electric vibration probably flows back over these molecules, 
which thus become the eledtrified poles of the mass. A 
condudtor thus differs from a non-condudtor in the fadt that 
in the latter case the molecules are independently eledtrified, 
in the former the whole mass adts as a single eledtrified 
molecule, the eledtricity being confined to its surface, and it 
being neutral internally. 
Physical science is, in a much larger sense than is usually 
supposed, a science of molecules, and scientists have made 
many serious errors through confining their attention to 
masses and being oblivious to the fadt that every adtion dis- 
played by masses simply results from a partial restridtion of 
the diredtions of molecular movements. Molecules are, 
very largely, independent of any common control. So far 
as eledtrisation goes, the molecules of non-condudtors are 
thus independent, each adting as a separate mass. But in 
condudtors they mutually restrain each other, and the 
eledtrisation becomes confined to the exterior molecules, 
which cannot discharge their force inwardly on account of 
this mutual restraint, nor outwardly on account of the 
resistance to conduction in the surrounding medium. 
If, now, it be asked what is the underlying cause of the 
peculiar charadteri sties of induction, we cannot hope to give 
more than a conjectural answer. Why, for instance, does 
positive electric force repel positive induced force and 
attract negative, so that there is a distinct separation and 
special arrangement of these energies in the induced body ? 
In fact, however, but three results could possibly arise from 
the approach of an electrified to a neutral body. In the 
first conceivable case, the body must remain unaffected, its 
molecular forces being undisturbed. In the second, the 
electrified body might attract similar electricity, or produce 
a like electric polarisation to its own on the adjacent sur- 
face of the second body. This result would affect all the 
molecules, two adjacent negative and two adjacent positive 
poles succeeding each other alternately, for the molecules 
must act upon each other on the same principle as masses 
affect each other. Such a state of affairs would absolutely 
hinder any conduction of electricity. There could be no 
electric neutralisation from molecule to molecule, while 
there would be a tendency to neutralisation of the opposite 
energies in the same molecule ; and thus conduction, and 
perhaps production, would be forcibly prevented. 
