The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-11-08


coming, so that extinction would not
necessarily overtake the comet as it
certainly would the moon and the plan
cts
The spectroscope not only tells us
on the existence of light intrinsic to
the comet, but its evidence goes much
further; 1T informs us actually as to
what the very elements must be 20
whose presence in the comet the light
owes its origin We here note the Pc
cular advantage of the spectroscopic
methods OF research. They detect spec
lal dlHerences in the rays of light, thus
OFTEN enabling us to trace each differ
ent type of lighs to its sources.
DISCOVERY IN COMET RADIATION
The first notable achievement in the
determination of the peculiar character
of the radiation from a comet was
made by DR.. Higgins in 1863 He
showed that some of the rays of a
comet which appeared that year were
indicative OF the presence of the ele-
ment carbon in the body of the object
In the case of this particular element,
the available information carried US
somewhat further than is often the
case. Not only was the existence of
the element demonstrated, but the par
tIcular chemical combination in which
that element appeared was disclosed
gives rise to an important series of
compounds. The substances thus pro-
duced are very familiar 1t need not
be mentioned that the common pc
troleum, which we use in our lamns.
is combination of carbon and hydro
gen. The spectrum of a hydro-carbon,
as one of these compounds is termed,
is of such characteristic nature that
1t can be used as a test to show
whether the hydro-carbon itself is
present. DR.. Higgins compared the
spectrum OF the comet now referred to
with the spectrum OF tlsSe hyGeO-s ar
bons. The identity between the two
spedIa was noted, ana thus .ois.l-
did addition was at once made to our
confirmed the important discovery that
nyddo-c3- ioor5 are c.-Ara-aar-stIc com
ponents of many comets
FOR many years no further import /
ant addition was made to our K aowl- I
edge of the elementary subs tances
present in these wandering bodies The /
light they dispensed appeared to be /
partly the reflected light from the sun,
and partly the light due to incandes- /
cent hydrocarbons. But in 1882 a great /
advance was made. A comet was dis
covered that year in Albany by Mr.. (
Wells. AT first this body showed the
bright continuous spectrum due to re-
Elected sunlight. while the indications
of the presence of hydro-carbon were
mainly confined to the neighborhood of
the nucleus After this interesting OBJ
Ject had adorned the heavens for q
couple OF months. DR.. COPELAND row
the distinguished astronomer royal of
Scotland, discovered a bright yellow
line in the spectrum, indicating the
presence of sodium. This observation
was of particular Importance, mas
1, nc p al
dence of the presence in these celectial
wanderers of another element specially
in its terrestrial relations
An emphatic confirmation OF COpeland's
discovery was presently forthcoming.
1t is well known that the bright yellow
line indicative of the presence of So
dunn is seen TO be double when exam
lned under suitable circumstances As
the comet approached the sun the
sodium light became
quite strong. The nucleus gIared with
the distinct yellow hue belonging to
this element; and, indeed by filtering
away all other light in a process with
which the SpectroScopist is familiar,
an outline of the head of the comet was
which was produced by sodi-
lm light alone.
SCOTTISH SCIENTISTS WORK.
To DR.. Copeland and Dr. Lohse at
ne Earl or CraWfOrd'S observatory at
Dunecht, we are also indebted for yet
one more important addition TO our
of the composition of these
bodies. In the autumn of 1882 we were
Visited by another comet, which must
'ank as one of the most famous of
hese objects which have appeared |
Turing this century. On the 18th of
September, 1882 the two astronomers
have named observed in the spec
rum of this comet not only the sodium
inc, but also six other lines. The j
'laces of these were carefully meas
red, and it was found afterwards that )
hey were undoubtedly the chief lines
f the iron spectrum Here was, in !
eed, another notable discovery. The I
lement iron, of such transcendent i'm
to us on the earth is now
nown to be a constituent of the COM
tary wanderers through space. Thus :
Ie have learned that the principal ele- !
1ents in comets are among the COM !
ION substances on the earth. Here. =
gain. we find additional testimony to =
hat fundamental unity in the compd- -
ition of heavenly bodies, the percep-
ion of which is one of the most nota-
lie results in modern science.
-