first suggested the existence of the metallic bases of the earths and
alkalies, which fact was demonstrated twenty years thereafter by
Sir Humphry Davy, by eliminating potassium and sodium from their
combinations; and afterward by the discovery of the metallic bases of
baryta, strontium, and lime. The earth alumina resisting the action of
the voltaic pile and the other agents then used to induce decomposition,
twenty years more passed before the chloride was obtained by Oerstadt,
by subjecting alumina to the action of potassium in a crucible heated
over a spirit lamp. The discovery of aluminum was at last made by Wohler
in 1827, who succeeded in 1846 in obtaining minute globules or beads
of this metal by heating a mixture of chloride of alumina and sodium.
Deville afterward conducted some experiments in obtaining this metal at
the expense of Napoleon III., who subscribed L1,500, and was rewarded by
the presentation of two bars of aluminum. The process of manufacture was
afterward so simplified that in 1857 its price at Paris was about two
dollars an ounce. It was at first manufactured from common clay, which
contains about one-fourth its weight of aluminum, but in 1855 Rose
announced to the scientific world that it could be obtained from a
material called "cryolite," found in Greenland in large quantities,
imported into Germany under the name of "mineral soda," and used as a
washing soda and in the manufacture of soap. It consists of a double
fluoride of aluminum, and only requires to be mixed with an excess of
sodium and heated, when the mineral aluminum at once separates. Its cost
of manufacture is given in this estimate for one pound of metal: 16 lb.
of cryolite at 8 cents per pound, $1.28: 21/2 lb. metallic sodium at about
26 cents per pound, 70 cents; flux and cost of reduction, $2.02; total,
$4.

Aluminum is used largely in the manufacture of cheap jewelry by making a
hard, gold-colored alloy with copper, called aluminum bronze, consisting