The central Presbyterian. [volume] (Richmond, Va.) 1856-1908, 1881-07-20
Scientific and Useful.

0ne elemenls VI winch the sun and the
fixed stars are composed, is one of the
greatest marvels of modern science.
The spectroscope, with which the obser-
vatlons are made, is an instrument which
is used in different shapes. The one
which is found most convenient for ex-
aiming the light from the heavenly
bodies resembles in appearance tele-
scope; but in the interior, instead of lem
ses, there are several prisms or triangu-
lar pieces of glass. The instrument is
pointed at the sun or star, and single
ray Of light is admitted into it through
narrow slit. The observer, looking into
the other end of the spectroscope, sees the
ray expanded by the prisms into beau
tiful band or ribbon of light, colored
with the precise hues Of the rainbow,
varying from red through all the other
shades to violet. This colored band is
the famous spectrum" long since made
known to the world by the illustrious
Newton. But through some defect in
his means of observation, that great phil
osopher failed to remark that this band
of varl-colored sunlight is crossed by
many narrow, dark lines, which always
maintain precisely the same position in
1T; that is to say, some of them are in the
red light, some in the yellow. others in
the violet, and so on In recent times
these lines have been observed, and
have excited attention. They have been
compared with the lines which appear
IN the spectrum when the light from
flames colored by some of the elements,
such as iron, sodium, copper, zinc, and
hydrogen, in a heated state, is examined;
and 1t has been found that the lines in
the suns ray are precisely the same in
position AID number as those from the
flames thus colored. By experiments of
this sort it has been determined that ten
at least of the elements which are found
in our earth exist in the sun.
But 1t is when the spectroscope is
turned towards the stars that it's powers
appear to US most astonishing. The
bright star Aldebaran is more than
hundred millions Of millfons of miles
from our earth. A ray of light from it
is at Least twelve years in reaching us;
yet when the ray arrives, and is received
through the narrow slit OF the spectre
scope, 1t dlscloses the fact that hydrogen,
sodium, calcium, iron, anthony, mer-
curry, and other well-known elements,
exist IN this star We arrive at the con-
that the whole visible universe
is formed of the same substances. The
infinite intelligence which created it
worked on the same plan, and with the
same materials, so far as we can discern,
IN the uttermost regions to which the
flaming bounds of time and space" ex-
tend.
OF the uses of this discovery in science
1T is too soon to speak. New metals have
been added by its delicate test
to the list of elements. 1t must be re-
membered, however, that many of the
powers of electricity were known for
nearly century before Professor Morse
made 1t convey his first message along
the wire and one cannot but think that
the disclosures of the spectroscope will
IN time be turned to account in some
way not now anticipated, which will
confer equal if not greater benefits upon
the world.
The FooD FISHES OF THE SEA.-Pro-
lessor Huxley, in a lecture in England
on the food fishes of the sea, gives some
estimates of their fecundity that are
almost startling. He says that $780,
100000 or thereabouts of herring are
every year taken out of the North Sea
and the Atlantic. He assumes that their
number is even greater-3, 100000, 900.
Now, he says, "prodigious as is APP
parently this number, it is not more than
one shoal, covering dozen square
miles," and that shoals of much larger
size are on record. 1t is safe to say, that
scattered through the North. Sea and the
Atlantic, at one time there must be
scores Of shoals, any one of which would
go long way toward supplying the
whole Of mans consumption of herring.
And that statement is made with the fact
before him that nine-tenths of all the
herring eggs deposited in the sea are lost
Professor Huxley counts that in 1879,
100000 of cooling and hake were taken
by the Scotch fishermen, and estimates
that these fish alone had consumed g.
0Oo, 5OO,OOO,OO0 herring during the year.
This enormous destruction Of smaller
fish by the cod finds its parallel in the
absorbing qualities Of our own native
fish; the Ponoatomats SoZtot2ir-ou we'll
known blue-fsh. Nothing is more des-
tructive than the blue-fsh; and the ..
>. Fish Commission reports state, that
making an allowance of ten fish per diem
for the blue-fsh on our coast, and that
they keep eating fish at this rate for one
hundred and twenty days, before the