es, and
have been ascribed by French writers to the work of ascending hot waters
carrying aluminum sulphate. They present some unusual features, and
evidence as to their origin is not conclusive.

At the present time bauxite is doubtless forming in tropical climates,
where conditions are favorable for deep and extreme weathering of the
lateritic type. The breaking up of kaolin accompanied by the removal of
silica is not characteristic of temperate climates, though many clays in
these climates show some bauxite. It is possible that, at the time when
the bauxite deposits of Arkansas and other temperate regions were
formed, the climate of these places was warmer than it is today.

In studying the origin of bauxites, it should not be overlooked that
they have much in common with clays, certain iron ores, and many other
deposits formed by weathering.

ANTIMONY ORES

ECONOMIC FEATURES

Antimony is used mainly for alloying with other metals. Over one-third
of the antimony consumed in the United States is alloyed with tin and
copper in the manufacture of babbitt or bearing-metal. Other important
alloys include type-metal (lead, antimony, and tin), which has the
property of expanding on solidification; "hard lead," a lead-antimony
alloy used in making acid-resisting valves; Britannia or white metal
(antimony, tin, copper, zinc), utilized for cheap domestic tableware;
and some brasses and bronzes, solders, aluminum alloys, pattern metals,
and materials for battery plates and cable coverings. Antimony finds a
very large use in war times in the making of shrapnel bullets from
antimonial lead. Antimony oxides are used in white enameling of metal
surfaces, as coloring agents in the manufacture of glass, and as paint
pigments; the red sulphides are used in vulcanizing and coloring rubber,
as paint pigments, in percussion caps, and in safety matches; and other
salts find a wide variety of minor uses in chemical industries and in
medicine.

Antimony ores vary greatly in grade, the Chinese ores carrying from 20
to 64 per cent of the metal. The presence of arsenic and copper in the
ores is undesirable. Several of the more important antimony districts
owe their economical production of that metal to the presence of
recoverable values in gold. Some lead-silver ores contain small
quantities of antimony, and "antimonial lead," containing 12 to 18 per
cent antimony, is recovered in their smelting.

China is by far the most importa