i88i.] The Source of Electric Energy. 387 
becomes partly converted into atom motion or intra- 
molecular heat force. 
It becomes advisable here to more fully consider the rela- 
tions between the molecules of heterogeneous surfaces. Their 
influence upon each other is, very probably, a strong effort 
to produce homogeneity. Two molecules vibrating in con- 
tact:, or in close contiguity, seek to force each other into 
accordant vibratory conditions. Each affects the tension of 
the other by changing each other’s attractive relations. Yet 
in each there is a resistance to this effort to produce con- 
formity, and this resistance is strengthened by the aCtion of 
the more distant molecules of its own kind. There is thus a 
marked distinction between the aCtion of homogeneous and 
of heterogeneous surfaces upon each other. In homogeneous 
surfaces the molecules all vibrate in strict accordance, and 
the only effeCt of the passage of motive energy from one to 
the other is an increased width of vibration, constituting 
heat conduction. In heterogeneous surfaces, the molecules 
of the two surfaces vibrate discordantly. Each seeks to 
force the other into harmony with itself, and each resists 
this effort. There results a disturbance of motive conditions 
in each, the degree of disturbance being controlled by the 
degree of resistance. This disturbance, however, does not 
seem to be a forcing of each molecule as a whole to vibrate 
at a new rate, but it appears to be a separation of the normal 
vibration into two components, one at a higher and the other 
at a lower vibratory pitch than the normal, and a localisation 
of these separate vibrations upon the two poles of the mole- 
cule. And, further, the low pitch vibration of one molecule 
occupies the pole contiguous to that occupied by the high 
pitch vibration of the other. Such we conceive to'be the 
essential character of the force disturbance known as 
electric induction. Each disturbed molecule similarly 
affects all contiguous molecules of its own kind, so that the 
inductive effect runs back indefinitely through both sub- 
stances. 
In a non-conduCting substance this is the extent to which 
inductive action proceeds. The disturbance is molecular 
only, and does not extend, to the mass. But in conducting 
bodies the aCtion is exerted upon the mass. Molecular 
energy is first disturbed, and the poles of the molecules 
become respectively positive and negative. But this is 
followed by eleCtric conduction from molecule to molecule, 
which consists in a neutralisation of the eleCtric disturbance 
on the adjacent poles of each two contiguous molecules. 
These possibly vibrate together, and their opposite eleCtric 
