hing and mechanical concentration.

Certain investigators of the deposits of the Mississippi valley are
extremely reluctant to accept the idea that the ores are formed by
surface waters of ordinary temperatures, and are inclined to appeal to
heated waters from a hypothetical underlying magmatic source. The fact
that barite is a characteristic mineral of many igneous veins, and the
fact that in this same general region it is found in the
Kentucky-Illinois fluorspar deposits,--where a magmatic source is
generally accepted,--together with doubts as to the theoretical efficacy
of meteoric waters to transport the minerals found in the barite
deposits, have led certain writers to ascribe to these barite deposits a
magmatic origin. The magmatic theory has not been disproved; but on the
whole the balance of evidence seems strongly to indicate that the barite
deposits as well as the lead and zinc ores, which are essentially the
same in nature though differing in mineral proportions, have been
concentrated from the adjacent sediments by ordinary surface waters.

BORAX

ECONOMIC FEATURES

Borax-bearing minerals are used almost entirely in the manufacture of
borax and boric acid. Fully a third of the borax consumed in the United
States is used in the manufacture of enamels or porcelain-like coatings
for such objects as bathtubs, kitchen sinks, and cooking utensils. Other
uses of borax or of boric acid are as a flux in the melting and
purification of the precious metals, in decomposing chromite, in making
glass, as a preservative, as an antiseptic, and as a cleansing agent.
Recent developments indicate that the metal, boron, may play an
important part in the metallurgy of various metals. It has been used in
making very pure copper castings for electrical purposes, in aluminum
bronzes, and in hardening aluminum castings; and an alloy, ferroboron,
has been shown experimentally to act on steel somewhat like
ferrovanadium.

The bulk of the world's borax comes from the Western Hemisphere, the
United States and Chile being the two principal producers. There are
additional large deposits in northern Argentina, southern Peru, and
southern Bolivia, which have thus far been little drawn on because of
their inaccessibility. English financial interests control most of these
South American deposits.

The only large European producer of borax is Turkey. Italy and Germany
produce small amounts. There has also been small production of bo