to be of great extent; and though the production
has hitherto been limited by restrictions imposed by the German
Government, it has nevertheless become considerable.[15] The grade (18
per cent K_{2}O) is superior to the general run of material taken from
the main German deposits, and the deposits have a regularity of
structure and uniformity of material favorable to cheaper mining and
refining than obtains in the Stassfurt deposits.

Other countries have also developed supplies of potash, some of which
will probably continue to produce even in competition with the deposits
of recognized importance referred to above. Noteworthy among the newer
developments are those in Spain.[16] These have not yet produced on any
large scale, but their future production may be considerable. Less
important deposits are known in Galicia, Tunis, Russia, and eastern
Abyssinia, and the nitrate deposits of Chile contain a small percentage
of potash which is being recovered in some of the operations.

Prior to the war the United States obtained its potash from Germany. The
German potash industry was well organized and protected by the German
Government, which made every effort to maintain a world monopoly. During
the war the potash exports from Germany were cut off, excepting exports
to the neutrals immediately adjoining German territory. The result in
the United States was that the price of potash rose so far as to greatly
diminish its use as fertilizer.

The consequent efforts to increase potash production in the United
States met with considerable success, but the maximum production
attained was only about one-fourth of the ordinary pre-war requirements.
The principal American sources are alkaline beds and brines in Nebraska,
Utah, and California, and especially at Searles Lake, California. These
furnished 75 per cent of the total output. Minor amounts have been
extracted in Utah from the mineral alunite (a sulphate of potassium and
aluminum), in Wyoming from leucite (a potassium-aluminum silicate), in
California from kelp or seaweed, and in various localities from
cement-mill and blast-furnace dusts, from wood ashes, from wool
washings, from the waste residues of distilleries and beet-sugar
refineries, and from miscellaneous industrial wastes. At the close of
the war, sufficient progress had been made in the potash industry to
indicate that the United States might become self-supporting in the
future, though at high cost. The renewal of