The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1869-08-25
Spectrum Analysis.

Spectrum Analysis.
Beyond all comparison, the most brilliant
and startling conquest which the human
mind has yet made over the domain of Ma
ture, consists in that group of discoveries
which is described by the term Spectrum
analysts. Ii provokes amaZement in every
aspect, In the first place, the developments
have been made with a rapidity that is almost
astounding; the whole thing has been done
in ten years. Dr. Wollaston discovered, in
1902, that, by looking carefully at the solar
spectrum with a spy-glass, dark lines could
be seen crossing it. In 1915, Fraunhofer, a
German optieian, rediscovered and made u
map of several hundreds of them, and from
that time they were called, after him, Frdun-
hoter'S lines. But few supposed that there
was the slightest possible significance in
them; they were regarded as mere optical
curiosities, having no higher use than to serve
as landmarks for measuring the spaces of the
colored spectrum. But, in 1856, the two Ger
man chemists Kirchoff and Punsen made the
capital discovery that each chemical element,
when burning in fame, gave out light
that had its peculiar marks or lines, so that
these lines could become a means of detect
ing the element. totally new mode of
chemical analysis was thus hit upon far more
delicate than any thing hitherto known, and
a method, moreover, which was capable of
becoming a reUeldtOr Of the constitution Of the
uniyerSe. Chemistry, at single stroke, was
fused with astronomy, and the universal agent
of light became the powerful servant of the
laboratory.
At the very first step, several new elements
were discovered, the existence of which had
never before been suspected Examining
with the spectrum the ash of some mineral
waters, Prof Bunsen thought he saw some
lines which did not belong to substances al
ready known. He then boiled down forty
four tons of Durkheim spring-water, and got
q couple of hundred grains of residue, from
which he extracted two new metals, C@sium
and Rubidium, which resemble potassium.
This rubidium has been since found in the ash
of oak, of beet-root, of tobacco, COTE, tea,
and cocoa.
The spectrum analysis, however is not
mere instrument of original chemical re-
search; it has practical" applicability.
The Bessemer process" as it is called, is a
method of converting cast iron directly into
steel. Cast iron contains more carbon than
steel, and it is converted into steel by burn
ing this carbon out of the molten white-hot
mass by blast of atmospheric air In this
operation five tons of cast iron are converted
in twenty minutes into five tons of cast steel.
But the success of the process depends upon
being able to stop it at just the right time If
continued ten seconds too long, or stopped
ten seconds too quickly, the batch is spoiled.
The fame of course, is an index of the ad-
vance of the combustion, and, by watching it
with the spectroscope, the appearance and
disappearance of the lines indicate the exact
moment at which the operation is to be ar
rested.
The spectroscope promises also to become
a very valuable instrument in medico-legal
investigations into the evidences of criminali-
ty. Blood stains may be detected by it with
LII I. -, a
the one-thousandth part of a grain of the red
coloring matter of blood-stain may be de-
tected with the greatest certainty.
But it is in its celestial applications that
the spectroscope has performed its most
wonderful achievements. The constitution
of the sun, for example, which, ten years
ago, was a matter of the purest conjecture,
is now matter of definite and positive know
ledge We know what il is composed of =
its chemical cOnstituents-not as completely,
but with the same certainty, as we know the
chemical constitution of the earth. Sixteen
of the elements, with which we are familiar
upon EARTH are proved also to exist in the
atmosphere of the sun They are the follow
ing: sodium, calcium, barium, magnesium,
iron, chromium, nickel, copper, zinc, strOn-
tium. cadmium, cobalt, hydrogen, man.
ganese, aluminium, titanium.
The stars have been also subjected to spec.
troscopic study with equal success. They
are shown to resemble our sun, their light
coming from white-hot matter in their at
mospheres. About eight lines in the spec
trum of the light Aldebaran have been map
ped and it has been ascertained that the at
mosphere of this star contains sodium, mag
nesium, hydrogen, bismuth, tellurium, anti
mony, and mercury Sirius cantains sodium,
magnesium, iron, and hydrogen. About six
ty other stars have been examined, and all
seem to have some chemical element known
on earth.
variable stars show more lines at one
time than at another, but many years must
pass away before the variations in their spec
ira at different times can be mapped and COM
pared. Our own sun, for instance, is to
slight extent a variable star, owing to diff
ference in the sizes of the spots at different
times. Its period of variation from one max
imum to another is about eleven years. Tenn
porary stars sometimes blaze out suddenly
in the heavens, and then disappear or fall of
in brilliancy. On the 18th of May, 1866, a
star of the second magnitude burst out in the
constellation of the Northern Crown, and
was examined with the apparatus just des
cribed on the 10th of the same mouth, when
it had not fallen much below the third mag
nitude. 1t gave two distinct spectra, one
consisting of two very bright lines, and the
other being continuous. The latter spectrum
was crowded with dark lines, proving the
pTcreuCc VI 0lgnly- atmosphere
But the four bright lines must have been
caused BY luminous gases, one of which gases
was hydrogen. 1t appears as If the star were
by some means suddenly supplied with vast
volume of hydrogen, and became enyeloped
for many days in a vast atmosphere Of the
burning gas. Perhaps If our earth fell into
the sun, ii would cause similar confagra-
ton, because steam can be decomposed into
its constituent elements by the action Of q
very intense white heat, like that required to
melt platinum"
We have not here attempted to explain the
principle of the spectroscope. The way to
understand Thoroughly is TO work with the
instrument itself; but, where this is impossi-
BILE, the only way to get an idea of its nature
and operation, is by the extensive use Of IL
lustration and colored plates. All interested
in this beautiful subject will be glad to know
that Prof Roscoe, the eminent chemist Of
Manchester, has undertaken the task of pre-
paringa work which shall present the subject
with all that clearness and copiousness Of IL
lustration which the peculiarly Of its phe-
nomenR requires This work IL now publish