The Superior times. [volume] (Superior, Wis.) 1870-1912, 1904-02-27
NATIVE PLATINUM.
The ~Nobls" Metals Extracted From
Thi. Peculiar Substance.

On the slopes OF the Ural mountains
and in Brazil, California, Australia,
Canada and many other countries n pc
cullar substance known rs native plati-
aum Ia found This Is nm alloy Of the
metals platinum, palladium, Iridium,
osnium, rhodium and ruth"nium, to-
gether with n little gold and iron. All
Of these except the last mentioned are
the noble" metals. They do not tar.
nish In the air and are not soluble in
any single acid The most plentiful
metal occurring In native platinum Is
that from which II takes It's name.
This metal IL OF graylsh color and
with one exception is the heaviest sub.
stance known lts fusng point IL ex-
tremely high, and this property, TO
Kether with It's freedom from tarnlsh-
fng. causes II TO be largely used for the
manufacture OF crucibles aud other
vessels required by scientists to stand
very high temperature II Is also
sometimes used M n substitute for gold
In photography, and when deposited In
a thin film on the interior Of the tubes
Of telescopes It forms n dead black
surface, which prevents the Hight from
being reflected by the polished sides.
Palladium liz OF lustrous white
color II II the most easily fused OF
the metals found In platinum ore, and
can even be yolatiized A curious
quality which this metal possesses IL
that when heated TO redncss 1t IL
porous TO hydrogen gas, allowing 1t to
pnss through somewhat In the same
manner that blottlng paper permits the
passage OF water. The silvery white
color of palladium and Its freedom
from furnishing render II useful for
making scales aud division marks on
scientific Instruments A mixture Of
thls metal with mercury IL sometimes
used for nllng teeth Damium Is Il
metal which pusscasea two remarkable
properties II IL the most refractory
of the metals resisting fusion ut the
most intense heat and II IL also the
heaviest substance known. being TWEEN
tytwo and half times heavier than
water Together with iridium, II oc
ours principally in n peculiar variety OF
native platinum called osmirdium
This M differs from ordinary
platinu q In that 1t contains
larger proportion OF osmium aud irid
ium than platinum usmiridlum Is
found In small particles, varying In
weight from one sixth To ouc.thlrd Of
u grain These particles are extremely
hard and are used for pointing non
wearing pens
Metallic iridium possesses white
steel like appearance. The knife edges
OF delicate balances and other bearings
which require extreme hardness ARE
often made " H. An alloy Of 10 per
| cent iridium and ~ per cent platinum
has been found to be very little affected
In volume by changes OF temperature
and is the substance Of which the
standard meter kept In IN. Information
al metric bureau al Paris Is made
Rhodum ana rutheulum are metals al
little practical use The former occurs
In platinum ore to the extent Of > to
per cent The latter il found only H.
osWiridlum and averages about ! pei
cent Of that mineral The metal Nhiri
ranks next to platinum in price Is cir
coulum. which occurs in hyRCinth nnd
some other rare minerals Uranium /.
remarkable fOr It's high atomic weight
the heaviest known.-Chambcrs Jour