the dust may be caught in bags, or washed out by water
sprays or thrown down by electricity. The blast furnaces for iron also
throw off potash-bearing fumes.

Our six-million-ton crop of sugar beets contains some 12,000 tons of
nitrogen, 4000 tons of phosphoric acid and 18,000 tons of potash, all of
which is lost except where the waste liquors from the sugar factory are
used in irrigating the beet land. The beet molasses, after extracting
all the sugar possible by means of lime, leaves a waste liquor from
which the potash can be recovered by evaporation and charring and
leaching the residue. The Germans get 5000 tons of potassium cyanide and
as much ammonium sulfate annually from the waste liquor of their beet
sugar factories and if it pays them to save this it ought to pay us
where potash is dearer. Various other industries can put in a bit when
Uncle Sam passes around the contribution basket marked "Potash for the
Poor." Wool wastes and fish refuse make valuable fertilizers, although
they will not go far toward solving the problem. If we saved all our
potash by-products they would not supply more than fifteen per cent. of
our needs.

Though no potash beds comparable to those of Stassfurt have yet been
discovered in the United States, yet in Nebraska, Utah, California and
other western states there are a number of alkali lakes, wet or dry,
containing a considerable amount of potash mixed with soda salts. Of
these deposits the largest is Searles Lake, California. Here there are
some twelve square miles of salt crust some seventy feet deep and the
brine as pumped out contains about four per cent. of potassium chloride.
The quantity is sufficient to supply the country for over twenty years,
but it is not an easy or cheap job to separate the potassium from the
sodium salts which are five times more abundant. These being less
soluble than the potassium salts crystallize out first when the brine is
evaporated. The final crystallization is done in vacuum pans as in
getting sugar from the cane juice. In this way the American Trona
Corporation is producing some 4500 tons of potash salts a month besides
a thousand tons of borax. The borax which is contained in the brine to
the extent of 1-1/2 per cent. is removed from the fertilizer for a
double reason. It is salable by itself and it is detrimental to plant
life.

Another mineral source of potash is alunite, which is a sort of natural
alum, or double sulfate of potassium and