Hence with diffusive salt old Ocean steeps,
His emerald shallows, and his sapphire deeps.
Oft in wide lakes, around their warmer brim,
In hollow pyramids the crystals swim;
Or, fused by earth-born fires, in cubic blocks
Shoot their wide forms, and harden into rocks.—DARWIN.
Culinary salt, or, as it is termed in chemistry, muriate of soda, exists
abundantly in a native state, both in a solid form, and dissolved in
water. It occurs, in solution, not only throughout the wide range of the
ocean, but in various springs, rivers and lakes; and is known, in its
solid form, as a peculiar mineral, under the names of _rock-salt_,
_fossil salt_, and _salt-gem_. Its beds are mostly beneath the surface
of the ground, but sometimes rise into hills of considerable elevation.
At Cordova, in Spain, a hill, between four and five hundred feet in
hight, is nearly composed of this mineral. But the most celebrated salt
mines are those of Wielicza, in Gallicia, commonly called the salt mines
of Cracow, those of Tyrol, of Castile, (in Spain,) and of Cheshire, in
England. In the province of Lahore, in Hindoostan, is a hill of
rock-salt, of equal magnitude with that near Cordova. The mines of
Iletski, in Russia, yield vast quantities of this substance. It is so
plentiful in the desert of Caramania, and the air so dry, that it is
there used as a material for building. It forms the surface of a large
part of the northern desert of Lybia; and is found in great abundance in
the mountains of Peru. It has a pure saline taste, without any mixture
of bitterness; and crystallizes in cubes when obtained by slow
evaporation from its solution. In Germany the mines of this kind are
numerous: one of the largest is that of Hallein, near Saltzburg, in
which the salt is hewn out from subterraneous caverns of a considerable
range, and exhibits almost every diversity of color, as yellow, red,
blue and white; in consequence of which it is dissolved in water, to be
liberated from its impurities, and afterward recrystallized. The salt
mines of Cracow, and those of Cheshire, merit a particular description.