A. Black, or Melaconise; a black earthy looking substance found at
Chessy and other places. It is deutoxide of copper.
B. Protoxide or red oxide of copper; ziegelerz. Crystallizes in the
regular octahedron; specific gravity 5·69; scratches calc-spar; fusible
at the blowpipe into the black oxide; and reducible in the smoke of the
flame to copper; acted upon by nitric acid with disengagement of nitrous
gas; solution is rendered blue by ammonia. Its constituents are oxygen
11·22; copper 88·78. It occurs near Chessy, and upon the eastern slope
of the Altai mountains.
9. _Phosphate of Copper._ Dark green; crystallizes in octahedrons;
specific gravity 3·6 to 3·8; scratches calc-spar; yields water with
heat; and affords metallic copper with soda flux; acted on by nitric
acid. Its constituents are, phosphoric acid 28·7; oxide of copper 63·9;
water 7·4. It occurs at the mines of Libethen in Hungary.
10. _Pyritous Copper_; Kupferkies; a metallic looking substance, of a
bronze-yellow colour, crystallizing in octahedrons which pass into
tetrahedrons; specific gravity 4·16; fusible at the blowpipe into beads
attractable by the magnet, and which afterwards afford copper with a
soda flux; soluble in nitric acid; solution is rendered blue by ammonia,
and affords an abundant precipitate of iron. Its composition is, sulphur
36; copper 34·5; iron 30·5; being a combined sulphuret of these two
metals. This is the most important metallurgic species of copper ores.
It occurs chiefly in primitive formations, as among gneiss and mica
slate, in veins or more frequently masses in very many parts of the
world--Cornwall, Anglesea, Wicklow, &c. It is found among the early
secondary rocks, in Shetland, Yorkshire, Mansfeldt, &c. The finest
crystallized specimens come from Cornwall, Derbyshire, Freyberg, and
Saint Marie-aux-Mines in France.
11. _Seleniate of Copper_; Berzeline. Is of metallic aspect; silver
white; ductile; fusible at the blowpipe into a gray bead, somewhat
malleable; is acted upon by nitric acid; consists of selenium 40; copper
64.
12. _Sulphate of Copper_; Cyanose. Blue; soluble, &c. like the
artificial sulphates, which see.
_Brochantite_ is a subsulphate of copper observed in small crystals at
Ekaterinenbourg in Siberia.
13. _Sulphuret of Copper_; Kupferglanz. Of a steel gray metallic aspect;
crystallizes in rhomboids; specific gravity 5·69; somewhat sectile, yet
brittle; fusible with intumescence at the blowpipe, and yields a copper
bead with soda; soluble in nitric acid; becomes blue with ammonia, but
lets fall scarcely any oxide of iron. Its constituents are, sulphur 19;
copper 79·5; iron 0·75; silica 1·00. It occurs in small quantities in
Cornwall, &c.
The chemical preparations of copper which constitute distinct
manufactures are, Blue or Roman vitriol; for which see _Sulphate of
Copper_; Scheele’s green and Schweinurth green, Verditer, and Verdigris.
See these articles in their alphabetical places.
COPPER, _Statistics of_.--Copper ores may be imported into Great Britain
for smelting, from any country, and under any flag. On arrival of the
cargo at Swansea or elsewhere, a bond is given at the Custom-house,
which binds the party to return the quantity of copper which the lot of
ores shall be ascertained to contain, into bond within a limited period,
or pay thereon the duty as foreign copper, which is 27_l._ per ton. The
cargo of ore is then weighed out by the custom-house officer, and
samples are taken which are sent to two assay-masters in Cornwall, the
highest produce of the two being entered as that of the cargo. This
fixes the quantity of copper that must be exported under the bond.
The copper produced from foreign ores must then find a market, as cake
or pig copper, in France, Holland, Germany, Italy, the United States of
America, &c. At Calcutta, it is subject to a duty of 6 per cent.; and at
Bombay, to a duty of 10 per cent. _ad valorem_.
The export of British unwrought copper to the continent of Europe, and
to the United States of America, was formerly inconsiderable. These
countries drew the bulk of their supplies either from the north of
Europe, or direct from South America in pig copper. In point of fact,
the copper derived from the import of foreign ores for smelting, has
produced for itself a new market, as the following table, taken from the
official returns will show.
Export of unwrought copper from Great Britain to all parts, except
Asia:--
Years ending Jan. 5th. 1830 881 tons.
-- 1831 857 --
-- 1832 1326 --
-- 1833 2471 --
-- 1834 2523 --
-- 1835 3267 --
-- 1836 4083 --
-- 1837 2546 --
In the last year, that ended with 5th January, 1838, the export of
unwrought copper was about 5000 tons.
Let any candid and practical man consider attentively this table, and
compare it with the import of foreign ores for the same period, and with
the gradual advance in the value of copper; and then let him, if he can,
avoid the conclusion that the admission of foreign ores for smelting was
a great boon conferred upon the British copper mines, for it made this
country what it now is, the regulator and distributor of the copper
produce of the world--the country to which all others consuming and not
producing copper, must look for a regular, certain, and economical
supply. We want the admission merely under proper and safe regulations,
of foreign copper for refining, to draw to this country the whole
supply of copper for the world, by which prices would be regulated and
maintained, and our copper-mining interests put beyond the reach of
successful rivalry.
This country did not furnish any supply of unwrought copper to the
continent of Europe, or to the United States of America, which was
worthy of notice, before the year 1830; in fact, previous to that time,
we imported considerable quantities of foreign copper for re-exportation
to India. It is easy to explain how the produce of foreign ores, being
prohibited from export in any other shape, has, in fact, opened for
itself a new _debouché_, and this is illustrated by the table, showing
the growth of the export of unwrought copper from 1830. To prove that
this is not merely a simultaneous advance in the export of all sorts of
copper, a corrected table is subjoined from the official returns,
comprising the whole export, and divided so as to illustrate the
operation of the copper produce of foreign ores upon our foreign copper
trade.