If the solution is evaporated slowly, and with a jrentle heat, and the vessel in which it crvstalizes has a broad flat bottom, the crystals are very
beautiful, long, shining, (tinted, prisms. If the solution is exhausted nearly to the point of crystalization while it remains hot. and this is done with a
higher heat, it either shoots into small fibrous crystals, or concretes into a shapelei-s mass.
Obs. The most important property of this salt is its yielding, when decomposed by heat, thenitrous oxide.
MURIATES.
451. The muriates have a saltish taste, more or less pure. They emit white fumes when mixed with sulphuric acid. With nitric acid they emit oxymtiriatic acid
gas. They are all soluble in water, and difficultly decomposed by heat.
452. Muriate of Soda. Common salt. Sea salt. Of all the saline substances this is the most common and abundant in nature. It is frequently found in extensive
solid masses in the earth, or dissolved in springs and lakes far inland. The ocean, is however, the great depository of this salt, about a thirtieth of its
weight being muriate of soda. Illus. In Cheshire, England, there is a mine of this salt, . whose beds are alternate with those of clay. The first bed of salt
commences about 90 feet below the surface, and varies from 60 to 00 feet-in thickness. Below this there is another bed whose thickness is not known, though
it has already been penetrated to a great depth. The salt fro.-a this mine is carried to Liverpool where it is purified by solution in sea water, and by
subsequent crystallization. Many thousand tons are annually shipped from that place, and hence it has acquired the name of Liverpool salt.
453. In Spain are many salt springs ; and in Catalo- . nia there is a mountain of rock salt, whose height is estimated at 500 feet, and it is about three
miles in circumference.
454. Common salt is also found in great abundance in Poland, Germany, Russia, and most other countries. In France are found many salt springs, but no mines.
455. In the desert of Lybia there is an immense plain covered with a crust of this salt.
456. In America there has already been discovered many localities of common salt, eitlwr in a solid state or dissolved in springs of water.
457- In Peru are numerous salt mines situated at a great elevation above the sea. It has also been found in Chili, Calafornia, St. Domingo, &c.
458. In the United States, salt springs are numerous in several districts. These springs sometimes flow naturally, but are more frequently formed by sinking
wells in those places where this salt is known to exist. Most of these springs are west of the Allegany mountains; but in the state of New-York, there are
several in the vicinity of the Cayuga and Onondaga lakes.