r with
nihility. The only consideration which restrains us is our conception
of its atomic constitution; and here, even, we have to seek aid from
our notion of an atom, as something possessing in infinite minuteness,
solidity, palpability, weight. Destroy the idea of the atomic
constitution and we should no longer be able to regard the ether as an
entity, or at least as matter. For want of a better word we might term
it spirit. Take, now, a step beyond the luminiferous ether--conceive a
matter as much more rare than the ether, as this ether is more rare than
the metal, and we arrive at once (in spite of all the school dogmas) at
a unique mass--an unparticled matter. For although we may admit infinite
littleness in the atoms themselves, the infinitude of littleness in the
spaces between them is an absurdity. There will be a point--there will
be a degree of rarity, at which, if the atoms are sufficiently numerous,
the interspaces must vanish, and the mass absolutely coalesce. But
the consideration of the atomic constitution being now taken away, the
nature of the mass inevitably glides into what we conceive of spirit. It
is clear, however, that it is as fully matter as before. The truth is,
it is impossible to conceive spirit, since it is impossible to
imagine what is not. When we flatter ourselves that we have formed
its conception, we have merely deceived our understanding by the
consideration of infinitely rarified matter.

_P._ There seems to me an insurmountable objection to the idea
of absolute coalescence;--and that is the very slight resistance
experienced by the heavenly bodies in their revolutions through space--a
resistance now ascertained, it is true, to exist in _some_ degree, but
which is, nevertheless, so slight as to have been quite overlooked by
the sagacity even of Newton. We know that the resistance of bodies
is, chiefly, in proportion to their density. Absolute coalescence
is absolute density. Where there are no interspaces, there can be no
yielding. An ether, absolutely dense, would put an infinitely more
effectual stop to the progress of a star than would an ether of adamant
or of iron.

_V._ Your objection is answered with an ease which is nearly in the
ratio of its apparent unanswerability.--As regards the progress of the
star, it can make no difference whether the star passes through the
ether _or the ether through it_. There is no astronomical error more
unaccountable than that which reconciles