Dead Sea is the usual name, dating from the time of Jerome, for a most remarkable lake in the south-east of Palestine, called in the Old Testament The Salt Sea, Sea of the Plain, or East Sea; by Josephus, Lacus Asphaltites; and by the Arabs now, Bahr-Lût, 'Sea of Lot.' It is 46 miles long, with a breadth of from 5 to 9 miles. Its surface, which is lower than that of any water known, is 1292 feet below the level of the Mediterranean. The depth of the greater part, the northern section, is about 1300 feet; but at the southern end the water is only from 3 to 12 feet deep. The shape is that of an elongated oval, interrupted by a promontory which projects into it from the south-east. The Dead Sea is fed by the Jordan from the north, and by many other streams, but has no apparent outlet, its superfluous water being supposed to be entirely carried off by evaporation. Along the eastern and western borders of the Dead Sea there are lines of bold, and in some cases perpendicular, cliffs rising in general to an elevation of 1500 feet on the west, and 2500 feet on the east. These cliffs are chiefly composed of limestone, and are destitute of vegetation save in the ravines traversed by fresh-water streamlets. The north shores of the lake form an extensive and desolate muddy flat, marked by the blackened trunks and branches of trees, strewn about and incrustated with salt. The southern shore is low, level, and marshy, desolate, and dreary. On this shore is the remarkable ridge of rock-salt, 7 miles long and 300 feet high, called Khasham Usdom ('Ridge of Sodom'). Lava-beds, pumice-stone, warm springs, sulphur, and volcanic slag prove the presence here of volcanic agencies at some period. The neighbourhood of the Dead Sea is frequently visited by earthquakes, and the lake still occasionally casts up to its surface large masses of asphalt. The basin of the sea and the valley of the Jordan seem both to be due to a great fault or crack in the earth's surface of very ancient date. The long-entertained belief that the exhalations from this lake were fatal is not founded upon fact. Within the thickets of tamarisk and oleander, which here and there may be seen upon its brink, the birds sing sweetly, and they fly over and swim about on its surface. But the salinity of the waters is adverse to life, though some lower organisations are found in them.
The water of the Dead Sea is characterised by the presence of a large quantity of magnesian and soda salts. Its specific gravity ranges from 1172 to 1227 (pure water being 1000). The proportion of saline matter is so great, that whilst sea-water contains only 3.5 per cent. of salts, the water of the Dead Sea contains upwards of 26 per cent., or more than eight times as much as that of the ocean. In all lakes or collections of water without any outflow, the water acquires an infusion of salt, its feeders constantly bringing in this material, while none can go off by evaporation, even when the shores do not as here abound in salt and nitre. The evaporation is great as the heat is intense, and the sea rather contracts than increases. Rain hardly ever falls; the water is nearly as blue and clear as that of the Mediterranean; and though its taste is horribly salt and fetid, a bath in it is refreshing. Owing to the great specific gravity of the water, it is almost impossible for the bather to sink in it, strive as he may. Several of those who have navigated and explored the sea have fallen victims to a fatal fever. The story of the 'Cities of the Plain' is given in Gen. xix. See PALESTINE; and Conder says, 'It is now generally agreed that the Dead Sea and Jordan were formed by a great fault or crack in the earth's surface long before the creation of man, and that the district presents in our own days much the same aspect as in the days of Abraham. It is vain, therefore, to suppose that the "cities of the plain" were beneath the present sea, although this view was held as early as the time of Josephus' (Bible Geography, 1884). See also Ritter's Geography, and the works on Palestine by Robinson, Stanley, and Tristram; De Luynes' Mer Morte (1874); Lieutenant Lynch's Report of the United States Dead Sea Expedition (1852); and Professor Hall's Survey of Western Palestine (Palestine Exploration Fund, 1886).