Evening star., 1912-03-10
SUNDAY, MAGAZINE FOR MARCH TO- 1912
OF METALS

search began for new sources from which
thoria could be obtained, and this search is
not yet finished.
Originally the metal was found only in
rare minerals in Norway. About ten years
ago, however, it was discovered that the
mineral monazite contains a liberal amount
of thoria and monazte is found in North
Carolina, Canada, and Brazil. The price Of
thoria is now much lower than it was at
first, although it still commands fifteen or
twenty dollars, and even more, a pound, the
price fuctuating with the supply.
Saving Platinum
THE increasing demand for platinum, par
ticularly for use in the manufacture of
gas mantles, has led to the invention of a
process of saving the fine powdery grains of
this metal found in the gold placer deposits
of Southern Oregon and elsewhere.
The platinum, being in a state OF very fine
division, almost in the form of dust, will not
settle in placer sluice so long as the water
is briskly stirred After the metal-bearing
water has passed over rifle table, on which
nearly all the gold settles, it is drawn more
slowly over a cocoa mat rifle, on which the
platinum settles, and is then collected by
rlnsing the mats over tanks. Formerly the
platinum was all wasted. at first because its
identity was not recognized, and afterward
because no process was then known for
saving it.
Aluminium Brass
EXPERIMENTS aimed at developing the
- resistance of brass to the action of sea
water, with view to its employment for
constructing submarines in France, have
q IL, 4 1.%.1
of aluminium. The internal structure of the
alloy is strikingly changed by small per-
centage of aluminium, and the color changes
are surprising. From half of one per cent.
up to five per cent. of aluminium gives the
brass deep golden color. If the quantity
of aluminium is increased beyond five per
cent, a superb rose color results, which
reaches its maximum when the aluminium
amounts to seven per cent. With ten per
cent of aluminium the color turns to silvery
white.
Platinum Known to Egyptians
TT is within the bounds of probability that
some bespectacled German Psychologist
will soon discover that radium was known to
the ancients, inasmuch as many of the dis
coveries in this line during recent years are
claimed to have been but Implications of
earlier Investigations and results.
For many years it was supposed that
platinum had first been found in the early
half of the sixteenth century, when gold ore
from the Spanish mines in Darien was
found to include particles of white metal
possessing properties of what the alchemists
termed the noble" metals, which could
not be identified. The expectation of this
new metal was prohibited by law, and not
until 1850 did it become generally known
and made the subject of investigation.
1t was not long ago that German savant,
when in Egypt, was examining the contents
of tomb ascribed to an Egyptian Queen of
the seventh century before Christ. Among
articles of use and adornment he came
across plate which at first he took to be
silver; but on closer investigation this
turned out to be platinum, probably from
alluvial deposits washed down from the
Upper Nile in times of flood. Since then
other discoveries have led to the conclusion
that the metal was known to the Egyptians
and esteemed for its useful properties