The Sun.
London, England, 1861-11-01 00:00:00

SPEC7'RAL ANALYSIS.

e some time ago gave an account of Mr. Crookes's dis-
covery of a new element, closely resembling sulphur, by
means of the spectrum obtained by the transmission of the
light emitted by the flame of certain substances through a
prism, just as is done with the sun-light, which, as is gene-
rally known, is thus decomposed, giving rise to the colours
of the rainbow. The 111oniteur now publishes a highly
interesting article, from the pen of M. Dumas, on spectral
analysis, of which we give the substance :—The solar spec-
trum transmitted through the prism is wanting in certain
shades of the seven colours, and their places are occupied
in the spectrum by black bands or streaks, If we sub-
ject the light of the moon or planets to the same
analysis, we shall find these bands in exactly the same
places ; but if we analyse the light of the fixed stars by the
same method, we shall find that the black streaks are not
arranged in the same way ; nay, every fixed star varies in
regard to their arrangement. Artificial light derived from
different sources also furnishes spectra,
which, however,
we remark coloured and brilliant lines which are ndamentalot to be
yhis
found in the solar spectrum. It is upon t
circumstance that the whole theory of spectral analysis
rests. All the salts of a given metal, when brought into
contact with a flame, produce in its spectrum brilliant
colours of the same tint and position ; the salts of different
metals yield other colours, differing from the former in
shade and position ; and infinitely small particles of a metal
will suffice to produce its specific colours. Here, then, we
have a method of analysis of extreme delicacy ' • by
merely observing the spectrum yielded by a given sub-
stance, we can at once ascertain its nature or its ingre-
dients with astonishing accuracy. Let but a thousand-
millionth of a gramme of kitchen-salt, for instance, be in-
troduced into a flame, and it will at once cause it to reveal
through the prism the characteristic lines and tints pertain-
ing to sodium. It is thus M.M. Bunsen and Kirchhoff, pro-
fessors at the University of Heidelberg, who have just been
decorated by the Emperor of the French, as our readers
know, have been enabled to ascertain that certain elements,
supposed to be very rare, such as lithium for instance, aro
extremely common, while at the same time they have dis-
covered in certain sediments and rocks of very frequent oc-
currence new elements the existence of which had not even
been suspected. These are rubidium and caesium, which
belong to the family of metals. But one of the most. singu-
lar consequences deduced from spectral analysis
of the solar atmosphere. For, since the. solar
peculiarlys') apper..
devoid of certain shades of colours,
that we are enabled to ascertain the chemical coeralusosmitioina
whole e converse, the
viwige.ayconalude that
tthaienseinnitoestiaislvera,
recopwpaenrt,in
existence in the solar spectrum
alto
ws that these metals are
to iron, chromium, and nickel, oh
and, what is still
parts of the solar sp er
component gandthelreeafd;
ce'rtain
streaks
peculiar
more singular, soleiare
;wind
_alumine isuunm,. so abundant
our glob®, are not to be

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