This table shows how inadequate was the reaction of the United States to
the war demand for potassium salts. The minimum yearly requirements of
the United States are estimated to be 250,000 tons of potash.

This completes our survey of the visible sources of potash in America.
In 1917 under the pressure of the embargo and unprecedented prices the
output of potash (K_{2}O) in various forms was raised to 32,573 tons,
but this is only about a tenth as much as we needed. In 1918 potash
production was further raised to 52,135 tons, chiefly through the
increase of the output from natural brines to 39,255 tons, nearly twice
what it was the year before. The rust in cotton and the resulting
decrease in yield during the war are laid to lack of potash. Truck crops
grown in soils deficient in potash do not stand transportation well. The
Bureau of Animal Industry has shown in experiments in Aroostook County,
Maine, that the addition of moderate amounts of potash doubled the yield
of potatoes.

Professor Ostwald, the great Leipzig chemist, boasted in the war:

America went into the war like a man with a rope round his neck
which is in his enemy's hands and is pretty tightly drawn. With
its tremendous deposits Germany has a world monopoly in potash,
a point of immense value which cannot be reckoned too highly
when once this war is going to be settled. It is in Germany's
power to dictate which of the nations shall have plenty of food
and which shall starve.

If, indeed, some mineralogist or metallurgist will cut that rope by