Page:The American Cyclopædia (1879) Volume XIV.djvu/598

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574
SALT

14th century. At each royal election the nobles always stipulated that the salt of Wieliczka should be supplied to them at the mere cost of extraction. From Wieliczka a saliferous region extends on both sides of the Carpathians, through Galicia, Hungary, and Transylvania, into Wallachia and Moldavia. The richest mines of Hungary are in the county of Mármaros. In Transylvania the mines have been worked since the times of the ancient Romans, and there is also a large number of salt springs.—In Switzerland the brine springs of Bex have been worked since the middle of the 16th century. They formerly belonged to a family of Augsburg named Zobel, but are now the property of the government of the canton (Vaud). In 1823, in consequence of the gradual failure of the springs, the mountain was pierced by a gallery, which led into a vein or dike of salt, varying from 2 to 50 ft. in thickness. Springs are found in other parts of Switzerland. In Italy the lagoons and springs, still highly productive, were worked in ancient times. Venice formerly owed her prosperity in great part to her salt lagoons and her control of the trade in salt in southern Europe. During the decline of her power her salines remained unproductive, until they were reëstablished on a vast scale during the French rule. They are again largely worked in the artificial enclosures aronnd the city connected with the sea. Salt is a strict government monopoly, and the springs and salines furnish one of the chief articles of export.—Spain has one of the most remarkable salt mines in Europe, at Cardona in Catalonia. Here is a hill 500 ft. high, covering an area of three quarters of a square mile, composed of nearly vertical beds of salt, gypsum, and clay belonging to the cretaceous series, the salt constituting about four fifths of the entire mass. The workings are in the form of long steps of one metre (39 in.) in height and width, cut in the salt, in the open air, by means of blasting and the pick. The salt is simply ground and washed to prepare it for sale. Salt springs are found in other parts of Catalonia and along the Pyrenees, in beds of the same age, as at Pamplona in Navarre. But most of the salt of Spain is obtained from sea water, especially in Valencia and Catalonia. Salt is a strict monopoly in Spain, and can be sold by individuals only for exportation.—In Portugal salt is manufactured principally from sea water, and the business is largely carried on, sustaining a considerable export and coasting trade. The St. Ubes salt, well known in commerce, and much esteemed for packing provisions, is a product of Portugal. The export, and that of the Cape Verd islands also, is principally to Brazil and the United States.—In France, which by the treaty of 1871 has lost its principal rock salt deposits of Vic and Dieuze, formerly comprised in the department of Meurthe, there are both important deposits and springs in the adjoining regions, along the Jura, and in the central departments. Along the Pyrenees rock salt and springs are found in the cretaceous formation. But the greatest portion of the product of France is from the lagoons on the Atlantic and Mediterranean coasts.—England, which now produces more salt than any other country, obtains her supply almost exclusively from mines and springs in beds of the same geological age as those of Vic and Dieuze, principally in Cheshire and Worcestershire; there are also brine springs in Staffordshire, from which Hull is supplied. Northwich and Winsford in Cheshire, on the river Weaver, furnish six sevenths of the whole; and the beds of rock salt are chiefly limited to the region drained by this river. They occur in detached masses of limited area beneath the plains of this district, sometimes spreading out, as at Northwich, to a breadth of three fourths of a mile. The strata penetrated at this locality are gypsiferous clays and marls to the depth of 120 ft., below which are found beds of salt 60 to 90 ft. thick, resting on 80 to 40 ft. of indurated clays containing seams of rock salt, and below these rock salt about 100 ft. thick. The purest salt is in a portion of 4 ft. thickness about 10 or 12 ft. above the bottom of the upper bed, and in another of 20 ft. thickness 60 or 70 ft. below the top of the lower bed. Other portions of the beds are earthy. The salt is not stratified, but divided into vertical prisms sometimes 3 ft. in diameter. But the Cheshire salt, known in commerce as Liverpool salt, is mostly obtained from wells of 200 to 250 ft. depth, terminating in the lower bed of rock salt. In these the brine is pumped up and conveyed to the evaporating pans, which are 20 ft. wide, 30 to 80 ft. long, and 16 to 20 in. deep. In Scotland, before the abolition of the duty, much salt was made, from sea water, but most of the salt works are now abandoned. In Ireland two beds of rock salt, making together a thickness of 120 ft., covered by 630 ft. of red marls, were discovered about 1853 at Carrickfergus near Belfast; since which time the annual product has gradually increased to many thousands of tons.—The total product of the mines and springs of Europe was estimated in 1821 at 1,250,000 to 1,500,000 tons. It is now certainly twice as great as the larger of these estimates; and with the addition of that from sea water and salt lakes, the total product is probably 5,000,000 tons.—In Asia salt is no less abundant than in Europe. In Siberia and Tartary plains are covered with saline incrustations. Extensive mines of rock salt have been worked from ancient times at Nakhitchevan in Armenia. This variety abounds in Persia, where are also many salt lakes with no outlets. Lake Urumiah, 90 m. long and 20 to 30 m. broad, and about 4,300 ft. above the sea, contains brine of extraordinary strength, the percentage of pure salt being 18.116 and of other salts 2.434. Its specific gravity is 1.155. In summer, over a breadth of 3 or 4 m. around parts of this lake, the incrustation of salt is