Mississippi Democrat. (Carrollton, Miss.) 1844-18??, 1845-01-22

that space occupied by the rest of the So
lar system. There has been actually OBJ. |
served by Arrago within the orbit of Mer.
curry as many as thirty comets which have
their perihelion therein and thus we have
the conclusion that there are moving in
our system, certainly, 3,750,000 of these
bodies But he does not stop here. We
know that it is very difficult to observe all
the comets within the Mercury's orbit, from
its proximity to the sun, and it is there
fore highly improbable that more than half
the number have been seen. There are,
doubtless, says Arongo, at least sixty; and
thus we conclude that there are no less
than 100000 comets in our solar sys-
tenn. Indeed, the planets of the system
are beyond doubt. fitting througe a swarm
of $500 900 comets.
Now, with such facts as these devel-
oped to our consideration, we are natu.
rally anxious to learn something of the
character of these bodies, and what are
the chances of the interruption of our sys-
tenn by them. Such questions are ration
al and appropriate. We find, first, that
the grecs majority of comets are bodies
destitute of solidity: in fact, they are com.
posed of an exceeding thin, attenuated va
por, so thin, that we are enabled to see
the smallest telescope stars through the
very body of the comet. Sir John Her.
schel, said the lecturer, assured me, some
time since. in England, that he had seen,
through the very centre of comet, a
cluster of stars of the sixteenth magnitude,
the smallest known to the telescope obser-
walton, and so minute that the smallest
mist, the thinest haze in our atmosphere,
would conceal them from our view. Yer
they have been seen through globutar
mass, composing the body of comet,
10000 miles IN thickness or diameter.
Thus this mass of vapor must be far more
attenuated than air itself; more attenua-
ted than any vacuum which we can pro-
duce by the most perfect air-pump we can
construct; and we are able 10 produce a
vacuum in which no respiratory creature
can live, nor the fame of candle burn
for single moment. And this vacuum
would, in such state, be even massive
compared with the yapoF of which The CO.
met is composed. But this is not to be
unhesitatingly assumed of all the comets.
Some astronomers believe that all are
not mere @riform matter, and that it is
probable that there are some which are
composed of solid matter. This opinion
is based chiefly upon the belief that the
great degree. of brightness which ema-
mates from them is superior to what could
possibly emanate from body composed
merely of unsubstantal or eriform matter.
The probability is from this fact that there
are few which possess a 8rtain degree
of solidity.
Another and very remarkable quality Of
the comet, and which indeed constitutes in
many cases its chief character, is the pc
culiar appendage Familiarity known as the
tall This is, indeed, by many supposed
10 be an inseparable adjunct of comets /;
hbut it's so far from being so that we find
a great number of comets have no tail at
allf and indeed it is an appendage which
is observable only when the. comet comes
into the more immediate region of the sun.
The question then presents itself, what are
the tail of comets, and what is the cause
lof them, and this is a question, frankly
admit, much more easily asked than an
Iswered. All we know of them is that
Ithey are composed of luminous matter, so
Exceedingly thin and transparent that we
i distinctly see the smallest stars through
/ the very midst Of them. But their most
4 remarkable character is their enormous
land almost incredible magnitude. The
i most learned and astute astronomers have
Instituted enquiry ii vain. There have
! been made two suggestions, mere sugges-
i lions, protesting 70 explain the causes,
| bothof which are, however, liable to fatal
! obiectons. The. first of these assumes
II that the tail is nothing more than an ate.
i nuated fluid, exuded or driven out of The
lbody of the comet by the heat Of the suns
rays. This conjecture IS based upon the
i Preservation that the tail is generally turn.
i ed from the sun. There are however co.
i NETS with two tails, and comets whose tails
Il are turned in every conceivable direction
-lrelatlyely with the sun; such an explana;
ton of the cause is therefore altogether
inadmissables il Is also liable to anothel
Iobiection, even were the other not utterly
fatal. The influence Of heat or fire Is
I Ito evaporate, but not to drive the evapora.
/ ted particles away mot to repsl them. The
/ other explanatioe or conjecture, like the
4 FIRST, supposes rhe tail to be composed d
lvapor, driven out of the. body Of the co
7 met BY the heal Of the sun, and being
,Elighter than The body Of the comet: did no
travel SO fisE, or rather IS the comet rush
& les through space, the vapor IS LETT behind
! following rnare slowly than the comet e
Itself. But there i an objection 70 Chi
proposition altogether fatal, iglasnneh q
II a5sls faainlv on the supposi lion that llf