The situation of salt in beds or springs at the foot of mountain chains, as already mentioned, may in some measure tend to illustrate its formation, as it is probable that they (the mountain chains) were once the boundaries of inland seas or lakes, when our con tinents and oceans bore a different relative position from what they now exhibit."* 4. On the Uses of Salt.
The uses of salt are numerous and important. It is used in the following articles of manufacture.
" Sal ammoniac, says Dr. Van Rensselaer, or mu riate of ammonia, is made in abundance from common salt, which contains 51 per cent. of muriatic acid.
The manufacture of this article was abandoned in England, in consequence of the heavy duty of .L30 per ton laid on salt. In consequence, however, of bittern from the salt works being allowed in Scotland for the manufacture, the price has been reduced nearly one half, and before the duty was taken off, was sold at X 120 per ton.
In the manufacture of glass, salt is largely employ ed; soda, which is procured from common salt, is used for plate glass; potash for flint glass, and com mon salt, mixed with kelp, for crown-glass.
Oxy-muriate of lime, and other oxy-muriatic salts employed in bleaching, are made from salt, and con sume a large quantity of it in the manufacture.
Spirit of salt, or muriatic acid, requires large quan tities of salt. Mr. Parkes consumed twenty tons year ly in the production of it; and at least 1000 tons are used for this purpose in England every year. It is used in a variety of processes in dyeing and calico printing.
Glauber's salt is made from what remains in the stills after the distillation of muriatic acid. This re siduum was formerly thrown away, until a person employed it in making Glauber's salt.
Epsom salt is produced from salt, or the evapora tion of sea water. The brine, which yields 100 tons of salt, gives from four to five tons of this valuable article. Dr. Henry, has discovered a process of pre paring it from magnesian limestone, and has reduced the price one half. It can be made however still cheaper from sea water. Magnesia is made from salt brine, or sea water.
Crystallized soda is also made from common salt; and as the duty is taken off salt, the importation of American or Russian pot and pearl ashes may be su perseded, and 10,000 tons may be used annually in Great Britain. Several hundred tons are used in
washing alone.
Barilla of an excellent quality is made from salt. In the manufacture of hard soap, salt is a necessary ingredient.
Corrosive sublimate is always made from common salt. It is not only a medicine, but is used extensive ly in calico printing, and in other arts.. Salt is always used in making corrosive sublimate: every 6lbs. of quicksilver require 121bs. of salt; and in making ca lomel, every 9lbs. of quicksilver require 161bs. of corrosive sublimate.
Patent yellow is also prepared from common salt.
In the fisheries, in salting provisions for the sea service, and for exportation, salt is largely employed. For these purposes, however, it should contain no muriate of magnesia, which deliquesces and dissolves the salt. It is always present when salt is made by a rapid evaporation.
Butchers, morocco dressers, and skinners, employ it in large quantities.
Housekeepers employ salt in quantities, of which no accurate estimate can be made. By inquiring of the best bakers in this city (New York), I find that upon an average throughout the year, 31 lbs. of salt are required for two barrels of flour, or half a pound of salt to every bushel of flour. Hence it may be pre sumed, that every adult consumes an ounce of salt per week, or three and a quarter pounds per annum in bread only. Thus, then, ten millions of people (our population) consume yearly in bread 32,500,000 lbs. or 14,500 tons, or 580,360 bushels of salt. In Eng land double this quantity would be consumed, since there a pound of salt is used to every bushel of flour.
Farmers use great quantities in making butter and cheese, and for steeping wheat to prevent smut; for which purpose it proved the best in a trial of fourteen substances, simple and compound. Bishop Watson says, that in Northwich alone 3,000 tons of salt were annually sold to the farmers of that district.
In glazing earthenware much salt is consumed, and it is far to the preparations of lead, which are liable to be dissolved by vinegar, and eaten. In England the manufacturers of earthenware sometimes used to pay one-twelfth of the real amount of their sales for salt.