DEAD SEA (anc. Locus Asphaltites), called by the Arabs Bahr Loot, or Sea of Lot, is situated in the s.c. of Palestine, in lat. 31° 10' to 31° 47' n., and occupies a central posi tion between long 35° and 36° east. It is about 40 m. long, with an average breadth of 9 miles. The depth of the D. S. varies considerably: soundings in the n, bave given about 220 fathoms; this depth, however, gradually lessens towards the southern extrem ity, where the water is shallow. Its surface, which is lower than that of any water known, is 1312 ft. below the level of the Mediterranean. The shape is that of an elon gated oval, interrupted by a promontory which projects into it from the s.e. The D. S. is fed by the Jordan from the n., 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 D. S., there are lines of bold, and in some cases perpendicular cliffs, rising in general to an elevation of upwards of 1000 ft. on the w., and 2.000 ft. on the east. These cliffs are chiefly composed of limestone, and are desti tute of vegetation save on the e. side, where there are ravines, traversed by fresh-water springs. The n. shores of the lake form an extensive and desolate muddy flat, marked by the blackened trunks and branches of trees, strewn about, and incrusted with salt, as everything is that is exposed to the spray of the Dead sea. The southern shore is low, level. and marshy, and desolate and dreary in the highest degree; the air is choking, and no living thing to be seen. On this shore is the remarkable mass of rock called Usdum (Sodom). It is a narrow rugged ridge of hill, extending 5 m. n.yv., and consisting of rock-salt. Large blocks have broken off from this hill, and lie strewn in all directions along the shore, adding to its dreary and death-like aspect. To the n. of Usdum, and at no great distance, is the supposed site of the ancient Sodom. Although the hills sur rounding the D. S. are principally composed of stratified rock, yet igneous rocks are also seen; there are also quantities of post-tertiary lava, pumice-stone, warm springs, sulphur, and volcanic slag, clearly proving the presence here of volcanic agencies at some period. The neighborhood of the D. S. is frequently visited by earthquakes, on
which occasions it has been observed that this lake casts up to its surface large masses of asphaltum, of which substance the cups, crosses. and other ornaments that are made and sold to pilgrims at Jerusalem chiefly consist. The long-entertained belief, that the exhalations from this lake were fatal, is not founded unon fact; birds have been seen flying over and even sitting upon its surface. Within the thickets of tamarisk and ole ander, which here and there may be seen upon its brink, the birds sing as sweetly as in more highly favored quarters. A curious plant grows on the borders of the D. S., the aselepias proeera, which yields fruit called the apples of Sodom, beautiful on the outside, but hitter to the taste, and when mature, filled with fiber and dust.
The water of the D. S. is characterized by the presence of a large quantity of mag nesian 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 only contains 30 parts of salts in the 1000 parts, the water of the D. S. contains about 250, or eight times more than that of the ocean. The saltness of the D. S. has been explained in several ways; but there is no need to advert to more than one. It is a circumstance attending all lakes or collections of water without any outflow, that the water acquires an infusion of salt, its feeders constantly bringing in this material, while none can go off by evaporation. It may, moreover, be remarked that, if the D. S. was formerly at a higher level, and brought down to its present pitch by evaporation, a deposit of salt, such as we see on its banks, would be the natural consequence. Considerable deposits of common salt, sulphate of lime, and carbonate of lime have been formed along the bottom of the lake; and there is reason to believe that the deposits of rock-salt which occur in Cheshire, Poland. and other places, have been formed at remote periods by depositions in lakes similar to those of the Dead sea.