heaven. "All rivers run to the sea" and so the sea gets salt, all sorts
of salts, principally sodium chloride (our table salt) and next
magnesium, calcium and potassium chlorides or sulfates in this order of
abundance. But if we evaporate sea-water down to dryness all these are
left in a mix together and it is hard to sort them out. Only patient
Nature has time for it and she only did on a large scale in one place,
that is at Stassfurt, Germany. It seems that in the days when
northwestern Prussia was undetermined whether it should be sea or land
it was flooded annually by sea-water. As this slowly evaporated the
dissolved salts crystallized out at the critical points, leaving beds of
various combinations. Each year there would be deposited three to five
inches of salts with a thin layer of calcium sulfate or gypsum on top.
Counting these annual layers, like the rings on a stump, we find that
the Stassfurt beds were ten thousand years in the making. They were
first worked for their salt, common salt, alone, but in 1837 the
Prussian Government began prospecting for new and deeper deposits and
found, not the clean rock salt that they wanted, but bittern, largely
magnesium sulfate or Epsom salt, which is not at all nice for table use.
This stuff was first thrown away until it was realized that it was much
more valuable for the potash it contains than was the rock salt they
were after. Then the Germans began to purify the Stassfurt salts and
market them throughout the world. They contain from fifteen to
twenty-five per cent. of magnesium chloride mixed with magnesium
chloride in "carnallite," with magnesium sulfate in "kainite" and sodium
chloride in "sylvinite." More than thirty thousand miners and workmen
are employed in the Stassfurt works. There are some seventy distinct
establishments engaged in the business, but they are in combination. In
fact they are compelled to be, for the German Government is as anxious
to promote trusts as the American Government is to prevent them. Once
the Stassfurt firms had a falling out and began a cutthroat competition.