rbonate, white lead, in paints; for
lead pipe, cable coverings, and containers of acid active material; and
in lead compounds for various chemical and medical uses. Of the lead
consumed in the United States before the war about 38 per cent was
utilized in pigments, 30 per cent in alloys other than shot, 15 per cent
in pipe, 10 per cent in shot, and 7 per cent in all other uses. During
the war much larger quantities were used in munitions, such as shot and
shrapnel.

The lead content of commercial ores varies widely. It ranges from as low
as .25 per cent in the Joplin district of Missouri, to about 15 per cent
in the Broken Hill deposits of Australia, and over 20 per cent in the
Bawdwin mines of Burma. In the Coeur d'Alene district of Idaho and the
southeastern district of Missouri, the two greatest lead producers in
the United States, the average grades are about 10 per cent and about
3-1/2 per cent respectively. The grade of ore which may be profitably
worked depends not only upon the economic factors,--such as nearness to
consuming centers, and the price of lead,--but also upon the amenability
of the ore to concentration, the content of other valuable metals, and
the fact that lead is very useful in smelting as a collector of gold and
silver.

Most lead ores contain more or less zinc, and lead is obtained as a
by-product of most zinc ores. Argentiferous lead ores form one of the
principal sources of silver, and also yield some gold. Lead and copper
are produced together from certain ores. Thus the separation of many
ores into hard and fast classes, as lead, or zinc, or copper, or silver,
or gold ores, cannot be made; in some of the mineral resource reports of
the United States Geological Survey the statistics of these five metals
are published together.

The main sources of lead ore, named in order of their importance, are
the United States, Australia, Spain, Germany, and Mexico, which account
for over 80 per cent of the world's production. Most of the countries of
Europe outside of Spain and Germany produce small amounts of lead, but
are largely dependent on imports. Spain exports argentiferous lead and
pig lead mainly to England and France, with minor quantities to other
countries of Europe and to Argentina. Before the war Germany, which was
the largest European consumer, utilized all its own production of lead
ores and imported an additional 10 per cent of the world's ores for
smelting, as well as considerable a