y are
seen surrounded by rings, as if the light was intercepted and increased
alternately. This is no doubt due to a small effect of interference,
caused by change of velocity in passing through the rarefied nucleus of
these planetary vortices, near the body of the planet, and through the
denser ether beyond, acting first as a concave, and secondly as a convex
refracting body; always considering that the ray will deviate _towards_
the side of least insistence, and thus interfere.

That heat is simply atomic motion, and altogether mechanical, is a
doctrine which ought never to have been questioned. The interest excited
by the bold experiments of Ericson, has caused the scientific to
_suspect_, that heat can be converted into motion, and motion into
heat--a fact which the author has considered too palpable to deny for
the last twenty years. He has ever regarded matter and motion as the two
great principles of nature, ever inseparable, yet variously combined;
and that without these two elements, we could have no conception of
anything existing.

It may be thought by some, who are afraid to follow truth up the rugged
precipices of the hill of knowledge, that this theory of an
interplanetary plenum leads to materialism; forgetting, that He who made
the world, formed it of matter, and pronounced it "very good." We may
consider ethereal matter, in one sense, _purer_ than planetary matter,
because unaffected by chemical laws. Whether still purer matter exists,
it is not for us to aver or deny. The Scriptures teach us that "there is
a natural body and there is a spiritual body." Beyond this we know
nothing. We, however, believe that the _invisible_ world of matter, can
only be comprehended by the indications of that which is visible; yet
while humbly endeavoring to connect by one common tie, the various
phenomena of matter and motion, we protest against those doctrines which
teach the eternal duration of the present order of things, as being
incompatible with the analogies of the past, as well as with the
revelations of the future.

FOOTNOTES:

[35] Silliman's Journal, vol xxxv., page 283.

[36] The real diameter of the earth in that latitude, whose sine is
one-third, is a little greater than this; but the true mean is more
favorable for the Newtonian law.

[37] This is, perhaps, the nearest ratio of the densities and distances.

[38] This is an important consideration, as bearing on the geology of
the earth.

[39]