The Placer herald., 1872-04-27
Written for the HERALD.
METALS THEIR ANTIQUITY AND USES
No. 10.--ZINC

fracture. Its specific gravity Is 0.S. TO Ia IL
is more maeable than iron, though less so than
lead, and more ductile than tin or lead, but not
very elastic. A wire one tenth of an inch in di-
ameter will support weight of twenty-six
pounds. If heated to temperature between
2000 and 25O0 its maeability is greatly increased
and it may be rolled out into thin sheets, but if
the heat greatly exceeds this or amounts to 400o,
it becomes quite brittle and may be pounded to
powder. 1t fuses at 773o, and at bright red
heat boils. If the air be admitted it takes fire
and burns with beautiful green light. Zinc
furnishes by exposure to air, but does not oxi-
die much under such circumstances. 1t decom-
poses water slowly at common temperatures but
if steam be passed over red hot zinc it is rapidly
decomposed, and oxide of the metal is formed.
The flowers of zinc, and the philosophers wool
of early writer's, is the pure white oxide of this
metal. Zinc alloys with iron, copper, antimony,
gold, silver, lead, tin mercury, potassium, and
sodium. The most important alloy namely
brass, is that produced by copper and zinc in
variable proportions of GS to 65 of copper with
80 to 35 of zinc. The proportions of the more
valuable kind called Dutch brass, is 70 to 3O,
common sort. 1t is reported by some that the
Tutenag of the Chinese is pure zinc, while others
believe it to be an alloy of two or three metals,
zinc being one. Little, however, is known about
it. This metal was not obtained in the metallic
form till the sixteenth century, though its ores
We're probably known to the ancents, and used
by them in the formation of their brass or bronze.
1Dac ,nt oftua cfo m
abundant ores are the sulphuret, called blende,
common in most veins which contain sulphurets
of iron, lead, and copper, in every country; and
silicate and carbonate of zinc, or calamine. The
ore is roasted, pounded, and mixed with char
coal, and reduced in earthen melting pots and
the metal either passes through iron tubes, or is
volatzed, according to the heat applied, and is
collected in vessels of water. Zinc is very much
employed in making rain-water pipes, cutters,
chimney pots, ETC., which are formed of thin
plates. Another important purpose to which it
is applied is the construction of volatile batteries
as they are called, used for envolving electricity
by chemical action. Sulphate of zinc, also called
white vitrol, is used in medicine an astringent
in lotions for the eyes. For some years past n
great quantity of zinc has been employed for
coating iron plates much in the same way as tin
is used for a similar purpose. 1t is called gal
vanized iron and is extensively used for the
sides and roofs of buildings, for stack pipes,
wire fencing pals, hand bowls, and many other
articles which have to bear rough usage For
the sides and roofs of buildings, the successful
application of this material will very much de-
pend upon the locality. Near the sea, and in a
humid atmosphere generally, the zinc is soon
acted upon, and then, by its galvanic action
helps to destroy the iron it was intended to pro-
tect. Galvanized iron is in great repute in many
of the English colonies, and especially in Aus
tralia, where it is believed, that in consequence
of the dryness of the atmosphere, it will be
exceedingly durable.
MANGANESE.
Of this metal, in its pure state very little is
known. So strong is its affinity for oxygen, that
it is with difficulty reduced from its ores. Its
color is grayish white, of a somewhat crystal
line texture, like cast iron. 1t is very hard and
brittle, and can only be preserved from oxidation
by keeping it immersed in naphtha. The spe-
ticic gravity of manganese is g 80 to 80. The
most abundant ore of this metal is the binoxide,
commonly called the proxide. 1t is a soft and
brittle black earthly substance, found in Devon
shire and some other parts of England, and was
long considered to be an ore of iron. 1t is
valuable substance to chemists as it yields pure
oxygen gas in great quantities by heating it to
redness in an iron retort. 1t is also employed
to color earthenware; and by glass makers to
remove the greenish tint which the iron contain
ed in the sand is liable to give to the glass.
Another use to which the oxide of manganese is
applied is in the manufacture of chloride of lime,
of which immence quantities are required for
bleaching
This metal was obtained in 1882, from an ore
of gold with which metal it is found combined
in the Pennsylvania mines. In color 1t most
nearly resembles silver. 1t is scarce metal,
very light and brittle with specific gravity OF
$780, easily fused, and volatile that it burns II
heated in the air 1t has not been used in any
form, and is only interesting to scientific chem
lists and metallurgists.
Was discovered in 1803 in mineral resembling
tungsten, brought from Sweden. 1t was named
after the planet Gers, and the ore from which 1t
is obtained is called creite.
The New York Tribune charges that