that the substance of one a hundred million miles long could, like
the genie in the Arabian story, be inclosed in one of Solomon's brass
bottles.

But the results of recent researches contradict these views:

Padre Secchi, of Rome, observed, in Donati's comet, of 1858, from the
15th to the 22d of October, that the nucleus threw out intermittingly
from itself appendages having the form of brilliant, coma-shaped
masses of incandescent substance twisted violently backward. He
accounts for these very remarkable changes of configuration by the
influence first of the sun's heat upon the comet's substance as it
approached toward perihelion, and afterward by the production in the
luminous emanations thus generated of enormous tides and perturbation
derangements. Some of the most conspicuous of these luminous
developments occurred on October 11th, when the comet was at its
nearest approach to the earth, and on

{p. 66}

October 17th, when it was nearest to the planet Venus. He has no
doubt that the close neighborhood of the earth and Venus at those
times was the effective cause of the sudden changes of aspect, and
that those changes of aspect may be accepted _as proof that the
comet's substance consists of "really ponderable material."_

Mr. Lockyer used the spectroscope to analyze the light of Coggia's
comet, and he established beyond question that--

"Some of the rays of the comet were sent either from _solid