was in successful operation under Colonel Isaac White, in about the year 1812. Other salt-works were situated on Big Muddy River, not far below Murphysborough, in Jackson county, and on the east fork of Silver Creek, in Madison county, as well as on the upper branches of Little Muddy Creek. All of these works produced considerable quantities of salt, but much less than those at the Ohio Saline, like which, and most others in the State, they have fallen into disuse. Although salt springs abound in the States of Pennsylvania, Virginia, Missouri, and Tennessee, from which considerable quantities of salt were manufactured by the early settlers for domestic purposes, very little at present is made in these States. Mines of rock salt also exist in Missouri, Utah, California, and in other parts of the Far West, which promise at some future day to become of vast account. But perhaps the most reliable source for obtaining salt in the United States is from the evaporation of sea-water by solar heat, all along the coast, from New Jersey to the Rio Grande. South of Cape Florida, salt can be economically manufactured wholly by this process, if the French method of concentrating it on a part of the works as hereinafter described, be adopted, and, if convenient points be selected both for making and shipping the article. North of that point, it can be made cheaply by the aid of "graduation," (technically so called,) and other analogous methods of increasing evaporation, if concentrating it on a part of the works, as above, be not found sufficiently powerful in practice. The southern coast of Texas and the Florida Keys are peculiarly fitted for making solar salt without extensive artificial aids to evaporation, but most of the States and Territories in the Union have supplies of brine, and the climate is sufficiently hot and dry to bring them to saturation without fire, if care be taken to crystallize slowly and in such a manner as the science of chemistry unfolds. Solar made salt can also be produced cheaply on the coast of California from San Francisco to San Diego. In fact, from the seasons being divided into dry and wet, that region is peculiarly fitted for salt-making by solar heat. The Great Salt Lake of Utah seems the strongest and purest brine fountain known. Its water is generally at 22° Beaumé. Captain Stansbury records that he saw millions of bushels of salt crystallized on its western borders, and that he made use of the unstrengthened water of the lake successfully to cure beef. A singular salt lake, or pond, is found some 55 miles northward from Brownsville, in Texas, comprising 30 to 40 acres in extent. The salt is crystallized over the bottom of this pond to an unknown depth, with brine over it to the depth of one or two feet. Salt is cut out for use, but soon crystallizes again to the same level. The following table will exhibit the relative strength of the different brines from which salt is manufactured in the United States : At Nantucket, 350 gallons sea-water* give a bushel of salt. 280.. .do. Lockhart's, Mississippi, do.. .do. .... Shawneetown, (second saline,) 123. St. Catharine's, Upper Canada, 120. Kenhawa, Virginia, Illinois River, Arkansas. Montezuma, N. Y., (new wells) 70.... 50 to 60...do.. 40 to 45 do..... .do.... .do.... ..do 30 to 35...do.......... do................ Let us now briefly examine some of the principal processes for making salt by solar evaporation on a large scale; and as the French methods. are believed to produce the best articles, and those pursued in that country without the aid of graduation being well adapted to the extreme southern part of the United States, we will begin with them. Besides many salt-works at brine springs in the interior, salt is extensively manufactured along the Mediterranean, and on the Atlantic side, principally around the mouth of the Loire, and the low coast in its vicinity. In the last-named region, where the tides rise high, extensive reservoirs are kept at high water by means of swing gates, which open at the flood and close at the ebb, being placed in a dam across some arm of the sea. Each of these reservoirs frequently supplies numerous salt-works. Salt-making is a government monopoly; the works are national property, and are divided into lots of from 30 to 500 acres, to suit the convenience of the persons who rent them. These works are so situated as to be commanded by the level of a principal reservoir, whether they be large or small, the sea-water flowing slowly from it into a series of lesser reservoirs and long winding conduits, till it comes to the crystallizing pans, between which, there are also long, narrow passages, each of the works being arranged with these smaller reservoirs and pans, wherein the salt crystallizes in such a manner that the incoming water flows over the strengthened brine from reservoir to reservoir, through the passages named, till it has evaporated to the point of saturation, when it is permitted to crystallize in a pan prepared for the purpose. It is then *Of the sea-water at New York, about three hundred gallons would give a bushel of salt. The following are the results of an examination of a portion of water taken from the East River, at very high tide: Specific gravity at 60° F., 1.02038. 1,000 grains contained 26.8 grs. of dry saline matter, namely: Carbonate of lime, 1.22; carbonate of magnesia, 0.5; sulphate of lime, 0.8; sulphate of magnesia, 1.72; chloride of magnesium, 2.26; chloride of sodium, 20.3. raked out and placed in piles to drain, whence it is removed to storehouses for use. As above stated, the crystallizing pans are to be arranged so that the brine can be made to flow from one to another through the passages, that a part of the series can be used for strengthening the brine when the weather is unfavorable; besides, the rapidity of the crystallization is greatly increased when the saturated brine is in motion. The distance that the brine flows from the main reservoir to the last pan is frequently more than 10 miles in the largest works, and seldom less than 3 in the smallest. This plan not only purifies the brine, and produces a salt free from the defects of other kinds of solar-made salt, but hastens the process of making to such an extent as to render it of the first importance in so variable a climate as ours. This plan enables the salt-maker to concentrate the evaporation of his whole works on as many of the lowest pans in the series as he may find the most advantageous, or the state of the weather requires, in order that at least a part of the accumulation may be made, even in the most unfavorable seasons. At many of the French salt-works, other plans are adopted to hasten the evaporation, such as pumping the weak brine into tanks 20 to 30 feet high, and then letting it down in showers through fagots placed in frames of that height, and which are frequently 50 by 100 feet, or upwards, on the ground. Weak brine is also thrown into the air with machines similar to fire engines, and falls in showers on high piles of brush. Many of these plans for increasing evaporation are in use on the Mediterranean, where, the range of tides being limited, the water necessarily has to be pumped up into main reservoirs, sufficiently high to command the level of the general works. In many parts of France, salt is made by collecting the mud during the dry, hot season, from places where the sea occasionally flows over it, and placing it on thick layers of straw in an elevated position, after which the water is pumped on it, and leaches through the mud and straw, finally descending through a system of fagots, to increase the evaporation. This brine is much stronger than sea-water when it first leaves the mud and straw, according to the degree in which the mud has been impregnated. Salt is also extensively manufactured in the interior of France from brine springs, the strongest of which are in the vicinity of La Meurthe. These contain, on an average, 35 per cent. of salt. The system of graduation is pursued at many of these works. In the southern part of Germany, and, in fact, throughout the greater part of that country, much good salt is made from sea-water, from brine springs, and from the solution of impure rock salt, these brines being brought to the point of saturation with common salt in some works after the French plan, aided by a system of fagots called "graduation," and by throwing weak brine into the air and letting it fall in showers on high piles of brush, and other analogous methods to increase evaporation. The greater number of these springs, however, are far too dilute, with the existing prices of salt, to repay the cost of evaporation by means of fuel. At Salzhausen, for instance, the production of 100 pounds of salt presupposes the evaporation of about 339 cubic feet of brine. At Schönebeck, the annual produce of upwards of 57,500,000 pounds of salt is obtained by the evaporation of 19,000,000 cubic feet of water. In all the brine springs, therefore, which are far removed from a state of saturation, the greater portion of the water is reduced in bulk by evaporation in the air, (graduation,) the smaller portion by boiling. The graduation house is intended to distribute the brine in the form of rain, and expose it to the air in this state, whilst the action of the latter is increased by stopping and retarding the single drops as they fall. The brine is caused to fall from the trough or cistern 4, as indicated by the following cut, into the tank K; the retardation is effected by means of a wall of twigs, or fagots, L, and its distribution in the form of rain by means of a series of perforated tubes and plugs, as shown in the following diagram. The motive power raises the brine into a large reservoir, generally placed in a tower, whence it must be enabled to flow freely into the trough A as it is wanted. By means of the horizontal pipes C C, the brine is conducted in a thin stream to the dropping channel B B, which extends throughout the whole length of the graduation, and from thence it falls, drop by drop upon the wall The of twigs L. This structure is composed of fagots of black-thorn, placed between the lath-work 7 l, in a horizontal even manner. protecting board I I, prevents the wind, which must pass through the thorns, from giving a wrong direction to the drops which are constantly falling on the outer side. That the air may exert its full influence, the whole structure for graduation is erected in an airy place, and in a direction at right angles to that of the prevailing wind. It is obvious that this arrangement must expose the extended surface of the brine for a longer time to a constant current of air. If the wind changes, and threatens to carry the brine away from the wall and over the structure, the graduation must be reversed to the opposite surface of the wall of fagots; and this is done by a simple movement of the lever E, for which purpose it is attached to the wooden rod FF, supporting the boxes G G. The lever brings the wooden rod forward, and with it the boxes G G are moved into a position just under the horizontal pipes, so that their narrow lips at the back project over the cross channels H H. Thus the brine is intercepted above the channels B and carried to the other side and opposite surface of the fagots, by a channel precisely similar to B. That the whole arrangement of spigots, channels, &c., may be easily managed, planks for walking are laid on both sides of A, and these are furnished with a railing. The erection for graduation here described, as it is practised in Salzhausen, is known as the "one-walled" graduation house, and is used in small works where building materials are scarce. The walls of thorns, however, are frequently made in pairs, as indicated in the annexed cut, and sometimes the outer surfaces m m, only |