| easy fusion. 
COPPERAS. 
862 
that of gold containing one-twelfth, that of silver 
one-sixteenth of the mass. With platina, it 
forms an alloy, ductile, and susceptible of a fine 
polish. With tin, it forms several valuable al- 
loys, which are characterized by their sonorous- 
ness. 
The sulphurets are the ores from which copper 
is usually extracted. The ore is roasted by a low 
heat, in a furnace with which flues are connected, 
in which the sulphur that is volatilized is collec- 
ted. The remaining ore is then smelted in con- 
tact with the fuel. The iron present in the ore, 
not being so easily reduced or fused as the cop- 
per, remains in the scoria, while the copper is 
run out. It often requires repeated fusions, and, 
even after these, it may be still alloyed with por- 
tions of metals which are not volatile, and are of 
Hence the copper of commerce is 
never altogether pure, but generally contains a 
little lead, and a smaller portion of antimony. 
The carbonates of copper reduced by fusion, in 
contact with the fuel, afford a purer copper, as 
does also the solution of sulphate of copper which 
is met with in some mines, the copper being pre- 
cipitated in its metallic state, by immersing iron 
in the solution. The precipitate which is thus 
formed is afterwards fused. 
Copper, being ductile and easily wrought, is 
applied to many useful purposes. It is formed 
into thin sheets by being heated in a furnace, 
and subjected to pressure between iron rollers. 
These sheets being both ductile and durable, are 
applied to a variety of uses, such as the sheath- 
ing of the bottoms of ships, the covering of roofs 
and domes, the constructing of boilers and stills 
of a large size, &c. Copper is also fabricated 
into a variety of household utensils, the use of 
which, however, for preparing or preserving ar- 
ticles of food, is by no means free from danger, 
on account of the oxidizement to which copper is 
liable. It has been attempted to obviate this 
danger by tinning the copper, as above described. 
This method answers the purpose as long as the 
coating of tin remains entire. Copper may be 
forged into any shape, but will not bear more 
than a red heat, and, of course, requires to be 
heated often. The bottoms of large boilers are 
frequently forged with a large hammer worked 
by machinery. The bolts of copper used for 
ships, and other purposes, are either made by 
the hammer, or cast into shapes, and rolled. The 
copper cylinders used in calico printing are either 
cast solid upon an iron axis, or are cast hollow, 
and fitted upon the axis. The whole is after- 
wards turned, to render the surface true. 
COPPERAS, or Green Virrion. A mineral 
substance, formed by the decomposition of py- 
rites by the moisture of the atmosphere. Its col- 
our is bright green, and its taste very astringent. 
A solution of it in water, dropped on oak bark, 
instantly produces a black spot. Copperas is 
occasionally found in grottoes, caverns, the gal- 
leries of mines, and other places. It is in much | 
COPPICE. 
request with dyers, tanners, and the manufac- 
turers of ink, and, for their use, is artificially 
prepared from pyrites. This mineral being 
moistened and exposed to the air, a crust is 
formed upon it, which is afterwards dissolved in 
water: from this the crystals of vitriol are obtain- 
ed by evaporation. The principal use of green 
vitriol is in dyeing woollen articles, hats, &c., 
black. It is the basis of ink, and is used in the 
manufacture of Prussian blue. If it be reduced 
to powder by the action of fire in a crucible, and 
mixed with powder of galls, it forms a dry, port- 
able ink. 
COPPICH, or Corsz. A natural wood of shoots 
and shrubby trees, periodically cut, and prevent- 
ed from rising to the proper height of timber- 
trees. It has the same origin, consists of the 
same plants, and possesses essentially the same 
character as a grove,—only that, while the latter 
matures its trees, the coppice is always retained 
in the condition of shrubbiness and underwood ; 
it originates in either natural or artificial sow- 
ing, and is, in no instance, a plantation ; it may 
be of any extent, from half an acre to many 
square miles; and if at any time it be thinned 
and cease to be cut, it rises out of its proper 
character as a coppice, and assumes the charac- 
ter of a grove. 
Many coppices are sown and maintained in parks 
and pleasure-grounds as objects of ornament and | 
covers for game; and in such situations, when 
judiciously laid out, and when planned with 
tasteful reference to the toning of a whole land- 
scape, they appear to great advantage, and form 
a powerful and agreeable foil to neighbouring 
groves. Coppices on swelling isles and intricate 
promontories of fresh-water lakes and marine 
lakes, have, in many instances, a better effect, 
because more in symmetry with the other fea- | 
tures of the scene, than masses of taller wood ; 
and mimic or miniature coppices are admirably 
adapted, on principles of both economy and beauty, 
to occupy small corners and broken spots in ara- 
ble fields, occasioned by the operations of mining 
or quarrying, or to cover broken, rugged, and 
impracticable banks of lakes and rivers. 
the principal coppices of Britain are maintained, 
and in many instances were originated, for the 
express purpose of furnishing by their produce a 
profitable return to landlord or tenant ; and such 
of these as are on dry soils, usually consist of oak, 
hazel, and chestnut,—such as are on medium 
soils, of maple, ash, and birch,—such as are on 
wet soils, of willow and alder,—and such as have 
been ill managed or are on varied soils, of a con- 
siderable diversity of trees in both timber and 
habit. Coppices for profit, in some districts of 
England, are maintained in strictly coppice con- 
dition, or kept entirely free from full-growing 
trees; and, by being thoroughly swept at every 
periodical cutting, are supposed to yield a larger 
remuneration, in the aggregate of. years, than if 
they contained a mixture of tall trees. One con- 
But | 
