Year: 1867

Copper is one of the primitive
metals, and with the exception of
iron and tin it is the lightest of them,
and except iron it is the hardest. 1t
alloys readily with gold and silver.
1t is often found in native alloy with
the latter metal. Pure copper in
mass is hard and sonorous, but is not
so hard but that it can be cut with a.
knife. Its hardness is increased by
hammering or by rolling into sheets
and by drawing into wires. By re.
peating the process the metal be-
comes quite brittle, but its malleabil-
ity may be restored by annealing.
This is done by heating it and plung-
ing it into cold water the reverse
operation of annealing iron or steel
When the soft mettle is broken the
fracture is red, shining, and granu-
lar, and if the metal is very soft it
presents a crystalline appearance ;
but when the metal is hard the frac-
ture presents lightish red, silky,
and tibrous appearance.


OF heat it is an excellent conduct
or, and if we take gold at 1000, the
heat conducting power of copper is
898. 1t is an excellent conductor of
electricity, and if we take its conduc-
ting power of 100, gold will be about
so and iron about Is.


Copper is used largely i'll the arts
and for industrial purposes all gold
and silver coinage is alloyed with it,
and it is the preponderating agent in
all yellow alloyed metals. 1t is also
employed TO certain extent in the
white alloyed metals, such as specu-
lum metal, bell and Babbitt metal,
Britannia metal and German silver.
1t is also used as a basis of all conn.,
pound metals where a sonorious
quality is sought for. Copper and
tin, both soft metals, become very
hard when alloyed in certain proper
tions, and zinc and copper make the
alloy of soft brass. Copper is large
ly infused through the organic as
well as inorganic nature, and although
we know its salts to be poisonous,
both to animal as well as vegetable
life, it has sometimes been found in
SO great quantities in the common
| oyster as to be detrimental to health.
1t is also found in mussels, crabs,
snails, III the ashes of plants, and
even In the blood of man.


The most brilliant green paints are
compound of copper with other sub
stances, and other combinations pro-
duce valuable blue colors. 1t is also
| largely y used in enamel.work and col
or-making, With sulphur and sui
phurates of definite composition nj
trio acid will rapidly dissolve it, with
the evolution of nitric oxyd. which, by
coming into contact with the atmO-
sphere, will be converted into the
violet colored fumes of nitrous acid.
In concentrated sulphuric acid, by
application OF heat sulphurious acid
gas is evolved, and the production is
sulphate of copper With excess of
air, muratic acid dissoIves it, but
quite slowly. Strong solutions of the
alkalies,as they contain no atmosphe
ric air, have no action On copper but
weak solutions, especially Of ammo
MIA, with access of ain rapidly dis
solve it. The solutions of copper are
either green or purple in color the
solution of ammonia is remarkable
for it's deep purple color. The green
color of the pickles We see upon our
tables is often due 20 solution of
copper contained in the acid in which
the vegetables are prepared.


The Oxyde of copper obtained by
naturalization with alkalies from So
lutions in acid, may be obtained in
pure metallic form by passing i vol
ume Of hydrogen over them in close
tube and exposed to heat. The OK
yds will be decomposed with a heat
below redness, and the production
will be metallic copper and water; it
may also be obtained by putting iron
or zinc into solutions of it in acid
Copper in solution will exist as a salt
of the protoxyd, and if a piece of clean
iron be immersed in it it becomes
coated with it, if the solution be not
too dilute with the metallic copper.
The iron wire Of commerce that we
see coated with a film of copper is
immersed in bath of sulphate of
copper dissolved in water-American
ArtiSGn