_To the, Editor of the Scientific American_:
The following subject, substantially, was written more than a year ago
with a view to its publication. It was not, however, until January of
the present year that I sent a brief communication to the _Brooklyn
Eagle_, which was published Feb. 3, giving my views in relation to
cometary phenomena. With this I might remain satisfied, were it not
that the interesting paper by G. D. Hiscox, published in the SCIENTIFIC
AMERICAN SUPPLEMENT, Feb. 16, impressed me with the idea that the theory
I advanced might assist in explaining others, if brought to the notice
of those interested through the columns of your valuable journal.
The theory that I advance to account for the several phenomena relating
to comets' tails is, that comets are non-luminous, transparent bodies;
that they transmit the light of the sun; that the transmitted light
reflected by the particles of matter in space constitutes the tails of
comets. "Like causes produce like effects." By contraries, then, like
effects must be produced by similar causes; for, if an effect produced
by a cause which is known is similar to an effect produced by a cause
which is not known, the cause which is known must be similar to the
cause which is not known. This is true or not.