nic mining in that country. For the most part,
European production has been used in Europe and American production in
the United States.

Arsenic is recovered almost wholly as a by-product of smelting ores for
the metals. The potential supply is ample in most countries where
smelting is conducted, but owing to the elaborate plant required to
recover the arsenic, apparatus is not usually installed much in advance
of the demand for production. Rapid expansion is not possible.

Before the war the arsenic needs of the United States (chiefly
agricultural) were supplied by a few recovery plants in the United
States, Mexico, and Canada. Several large smelters had not found it
profitable to install recovery plants, as the market might have been
oversupplied and prices were low. During the war, with the extensive
demand for insecticides for gardening, there was a considerable
deficiency of arsenic supplies. With rising prices production was
stimulated, but was still unable to meet the increased demand. This
situation resulted in regulation of the prices of white arsenic by the
Food Administration.

Production of arsenic in the United States comes chiefly from smelters
in Colorado, Washington, Utah, Montana, and New Jersey. Small amounts
are produced by arsenic mines in Virginia and New York. A Mexican plant
at Mapimi has been shipping important quantities to the United States.
The plant at Anaconda, Montana, is expected to produce an ample supply
in the future.

The United States is entirely independent in arsenic supplies and will
probably soon have an exportable surplus. Export trade, after the
reconstruction period, will probably meet competition from France and
Germany where production was formerly large.

GEOLOGIC FEATURES

Arsenic-bearing minerals are numerous and rather widely distributed, but
only a few of them are mined primarily for their content of arsenic.
Arsenopyrite or "mispickle" (iron-arsenic sulphide) has been used
intermittently as a source of white arsenic in various places,--notably
at Brinton, Virginia, and near Carmel, New York. The former deposits
contain arsenopyrite and copper-bearing pyrite impregnating a
mica-quartz-schist, adjacent to and in apparent genetic relation with
aplite or pegmatite intrusives. In the latter locality arsenopyrite is
found associated with pyrite in a gangue of quartz, forming a series of
parallel stringers in gneiss close to a basic dike.

The orange-red sulphides