salines in the valley of the Great Kanawha, beginning at Charleston and extending about 20 m. above. They are situated in the lower coal measures. The first wells bored were only 30 ft. deep, but some have since been bored 1,500 ft.; 700 or 800 ft. is as great a depth as is generally profitable, as below this the water does not increase, while the discharge of carburetted hydrogen gas becomes much more copious. This gas was formerly employed for heating the kettles, but its use is now almost discontinued. The bittern or residual liquor contains a good deal of bromine. In 1829 these works produced 1,000,000 bushels. The product for 1870 was 4,633,750 bushels, but for 1875 it was expected to amount to hardly one fourth of that quantity. In S. W. Virginia there is a salt region, in Washington and Smyth counties, along the banks of the N. fork of the Holston river. The Holston springs and rock salt are on the line of an extensive dislocation of the strata, bringing the lower Silurian magnesian limestones into immediate contact with the lower carboniferous strata, the vertical displacement being calculated by Prof. Rogers at not less than 8,000 ft. The dislocation is at least 100 m. long, but no rock salt or workable brine is found except in the Preston valley, on the line of Smyth and Washington counties. Several productive wells have been bored to the depth of 200 to 300 ft. In one well over 300 ft. of rock salt divided by a little clay was passed through without tapping any brine. There appears to be no solid rock, but a deposit of clay and earth, imbedding in places large bodies of rock salt and gypsum, and saturated in its lower portions with highly concentrated brine.—The first attempts in Ohio were made in 1798 at the “old Scioto salt works” in Jackson co. The wells were only 30 ft. deep, and 600 to 800 gallons were required to make a bushel of dark and inferior salt, which however sold for $3 or $4, being carried, even as late as 1808, on pack horses to considerable distances. Until about 1845 the wells were sunk only 400 or 500 ft. in depth, but at Pomeroy they are now 1,200 ft. deep, yielding a copious supply of strong brine, and more than two thirds of the salt of Ohio is at present manufactured in that vicinity. From some of the springs issue large quantities of carburetted hydrogen gas, which has been used as fuel in evaporating. Rock oil is also a product of them. (See Petroleum.) In 1850 Ohio produced 550,350 bushels, and in 1873 4,154,187 bushels. Indiana has numerous salt springs, especially along the Wabash river in the coal measures. The Wabash saline in 1809 made 130,000 bushels, and the United States saline, about 1820, at least 150,000 bushels; but in 1870 the whole product of Illinois was only estimated at 54,000 bushels. In Kentucky salt springs or licks are very numerous, and even before 1795 much salt was made. The principal licks are: one on Salt Lick creek, near the Ohio; the upper and lower Blue springs on Licking river; Drennon's lick, on the Kentucky river; Big Bone, Long, Bullett's, and Mann's licks. The principal works recently in operation are on Goose creek; they made in 1860 about 290,000 bushels, but the product in 1870 was only 64,000 bushels, and is now still less. In Michigan is a valuable salt region in Saginaw co. Many licks and springs have long been known, and in 1838 unsuccessful attempts were made by the state authorities to work some of them. In 1859 the legislature offered a bounty of 10 cts. a bushel for salt made in the state, and a company in E. Saginaw bored a well, and obtained at 669 ft. nearly saturated brine. Since 1860 the production of salt in Michigan has developed with great rapidity, until it has become next to New York the largest salt-producing state in the Union. The product in 1874 was 5,134,875 bushels. In 1862 a deposit of rock salt was discovered on the island of Petite Anse in Vermilion bay, off the coast of Louisiana. It is considered to be geologically more recent than the tertiary, or of quaternary age. It was worked extensively during the blockade of that coast in the civil war, and has since produced more than 100,000 bushels annually. In Kansas, the Indian territory, and western Arkansas, along the Arkansas and Washita rivers, in N. W. Texas, New Mexico, and Utah, is a vast expanse of sterile plains, principally occupied by cretaceous rocks, in nearly every part of which salt lakes and incrustations and vast masses of gypsum occur. But the most famous of these lakes is the Great Salt lake of Utah, about 75 m. long and 30 m. wide, whose waters are nearly saturated, containing 20.2 per cent. of common salt, and 2 per cent. of other salts. For several years the waters in this lake have gradually risen above their former level, and a proportionate diminution of salt has been observed. In California are numerous salt lakes, particularly in Tulare co., at the Cañada de las Uvas, and in the Taheechaypah pass of the Sierra Nevada, near which is a dry lake from which a considerable quantity fit for table use has been taken.—At the present time (1875) the production of salt in the United States may be considered in reference to three different sections, viz.: the region east of the Mississippi river, the Rocky mountain region, and the Pacific coast region. Although during the past 100 years salt has been manufactured in nearly every state east of the Mississippi river, the business is now mainly restricted to three separate areas: the neighborhood of Syracuse, N. Y.; Saginaw valley, Mich.; and the Kanawha valley, including the wells at Pomeroy, near the junction of that river with the Ohio. These three localities produced in 1870, in about 200 establishments, nearly 16,000,000 bushels of salt, the total number of establishments in the country at that time being 282, and the total production 17,606,000 bushels. From 1850 to 1875 the salt industry has grown in Florida and Michigan, while in New York
