The Superior times. [volume] (Superior, Wis.) 1870-1912, 1903-10-03
NATIVE PLATINUM.
The "voble" "details Extracted From
This Peculiar Substance.

the "NObie" heta1s Extracted FROM
This Peculiar Substance.
On the slopes of the Ural mountains
and in Brazil, California, Australia,
Canada and many other countries pc
cuiar substance known as native plati-
mum is found. This is an alloy of the
metals platinum, palladium, iridium,
osnium, rhodium and ruthenium, to-
gether with little gold and iron. All
of these except the last mentioned are
the noble" metals. They do not tar
any single acid. The most plentiful
metal occurring in native platinum Is
that from which ii takes its name.
This metal is Of grayish color and
with one exception is the heaviest sub
stance known It's fusing point Is ex-
tremely high, and this property. to
gether with its freedom from tarnish-
ing. causes il TO be largely used for the
l.anufacture of cruciblcs and other
vessels required by scientists TO stand
very high temperature. 1t is also
sometimes used as substitute for gold
In photography, and when deposited In
Il thin film on the interior of the tubes
of telescopes it forms a dead black
surface, which prevents the light from
being reflected by the polished sides.
Palladium is Of lustrous white
color 1t Is the most easily fused OF
the metals found in platinum ore, and
can even be yolatilized. \ curious
quality which this metal possesses Is
thai when heated to redness 1t Is
porous TO hydrogen gas, ellowlng 1t to
pass through somewhat In the same
mar er taat hiotting paper permits the
passage OF water. The slvery white
color Of palladium and It's freedom
from furnishing render ii useful for
making scales and division marks on
scientific instruments. A mixture or
this metal with mercury Is sometimes
used for filling teeth. Osmium is a
metal which possesses two remarkable
properties-it is the most refractory
Of the metals resisting FUSION at the
most intense heat, and 1t Is also the
heaviest substance known, being TWEEN
ty-two and half times heavier than
water. Together with iridium IL oc-
ours principally In n peculiar variety OF
native platinum called osmlrluiuil.
This mineral differs from ordinary
platiuum ore in that 1t contains a
larper proportion of osmium and irld-
ium than platinum. Osmiridlum i
found in small particles. varying IN
weight from one-siXth to one-thlru OF
a grain. These particles are extremely
hard and are used for pointing non.
wearing pens.
Metallic iridium possesses Whlte
steel-like appearance. The knIfe edges
of delicate balances and other bearings
which require extreme hardness are
often made OF it. An alloy OF ~ per
cent iridium and 30 per cent platinum
has bepn found TO be very little affected
In volume by changes OF temperature
and is the substance OF which the
standard meter kept in the information.
sl metric bureau at Paris Is mhue'
Rhodium and rutbenium are metals ot
little prgctical use. The former occurs
in platinum ORE TO the extent OF 10
per cent. The latter is found only III
osmiridium and averages about . per
cont of that mineral The metal which
ranks next to platinum in price Is zir'
coninm. which occurs in hyaclnth and
some other rare minerals Uranium l.
remarkable for its high atomic weight
the heaviest known. Chambers Jour
nal