725 | 28,285 | 36,485 | 49,718 |
| Chile | 22,428 | 26,016 | 29,632 | 27,112 |
| Germany | 16,799 | 20,635 | 22,492 | 20,818 |
| Australasia | 10,160 | 23,368 | 34,483 | 41,910 |
| Mexico | 12,806 | 22,473 | 70,010 | 61,127 |
| Russia | 5,364 | 8,128 | 8,839 | 15,240 |
| +----------+----------+----------+---------+
| World's production | 339,994 | 496,819 | 699,514 | 723,807 |
+---------------------+----------+----------+----------+---------+

As the stock on hand rarely exceeds three months' demand, and is often
little more than a month's supply, it is evident that consumption has
kept close pace with production.

The large demand for copper to be used in sheathing ships ceased on the
introduction of iron in shipbuilding because of the difficulty of
coating iron with an impervious layer of copper; but the consumption in
the manufacture of electric apparatus and for electric conductors has
far more than compensated.

_Alloys of Copper._--Copper unites with almost all other metals, and a
large number of its alloys are of importance in the arts. The
principal alloys in which it forms a leading ingredient are brass,
bronze, and German or nickel silver; under these several heads their
respective applications and qualities will be found.

Oxides and hydroxides.

_Compounds of Copper._--Copper probably forms six oxides, viz. Cu4O,
Cu3O, Cu2O, CuO, Cu2O3 and CuO2. The most important are cuprous oxide,
Cu2O, and cupric oxide, CuO, both of which give rise to well-defined
series of salts. The other oxides do not possess this property, as is
also the case of the hydrated oxides Cu3O22H2O and Cu4O35H2O,
described by M. Siewert.

Cuprous oxide, Cu2O, occurs in nature as the mineral cuprite (q.v.).
It may be prepared artificially by heating copper wire to a white
heat, and afterwards at a red heat, by the atmospheric oxidation of
copper reduced in hydrogen, or by the slow oxidation of the metal
under water. It is obtained as a fine red crystalline precipitate by
reducing an alkaline copper solution with sugar. When finely divided
it is of a fine red colour. It fuses at red heat, and colours glass a
ruby-red. The property was known to the ancients and during the middle
ages; it was then lost for several centuries, to be rediscovered in
abo