Closing Years of the Nineteenth Century.
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encloses a large number of molecules, but which is small compared with measurable quantities; and this equation may be written
.
Now, if Ṗ refers to differentiation at a fixed point of space (as opposed to a differentiation which accompanies the moving body), we have
,
and ;
so that
and therefore
.
This equation determines the part of which arises from the dielectric molecules.
The general equations of the aether thus become, when the averaging process is performed,
.
In order to assimilate those to the ordinary electromagnetic equations, we must evidently write
The equations then become (writing ρ for ρ1, as there is no longer any need to use the subscript),
where
S = conduction-current + convection-current + Ḋ + curl [P.w].