rths are in general rather widely distributed. The principal
producers are the United States, England, and the other large consuming
countries of Europe. The only important international trade in this
commodity consists of exports from the United States to various
countries for treating mineral oils, and exports from England for
treating vegetable oils.

There is a large surplus production in the United States of fuller's
earth of a grade suitable for refining mineral oils, but an inadequate
production of material for use in refining edible oils, at least by
methods and equipment now in most general use. However, the imports
needed from England are more than offset by our exports to Europe of
domestic earth particularly adapted to the petroleum industry.
Production in the United States comes almost entirely from the southern
states; Florida produces over three-fourths of the total and other
considerable producers are Texas, Georgia, California, and Arkansas.
Imports from England are normally equivalent to about a third of the
domestic production.

GEOLOGIC FEATURES

Fuller's earth is essentially a variety of clay having a high absorptive
power which makes it useful for decolorizing and purifying purposes.
Fuller's earths are in general higher in water content and have less
plasticity than most clays, but they vary widely in physical and
chemical properties. Chemical analyses are of little value in
determining whether a given clay will serve as fuller's earth, and an
actual test is the only trustworthy criterion.

Deposits of fuller's earth may occur under the same variety of
conditions as deposits of other clays. The deposits of Florida and
Georgia consist of beds in slightly consolidated flat-lying Tertiary
sediments, which are worked by open cuts. The Arkansas deposits are
residual clays derived from the weathering of basic igneous rocks, and
are worked through shafts.

GRAPHITE (PLUMBAGO)

ECONOMIC FEATURES

_Crystalline graphite_ is used principally in the manufacture of
crucibles for the melting of brass, bronze, crucible steel, and
aluminum. About 45 per cent of the quantity and 70 per cent of the value
of all the graphite consumed in the United States is employed in this
manner. Both _crystalline_ and _amorphous graphite_ are used in
lubricants, pencils, foundry facings, boiler mixtures, stove-polishes
and paint, electrodes, and fillers or adulterants for fertilizers. The
most important use of amo