The Dead Sea. — History. The Dead Sea was called by the Hebrews the Salt Sea. and by the prophets the Eastern Sea also. The Greeks and Romans named it the Sea of Asphalt and the Dead Sea. The Arabs give it the same name, but more commonly call it Bahr Lût, or Lake of Lot, Mohammed having introduced the story of Lot into the Koran. The earlier accounts of the Dead Sea were somewhat exaggerated, and our first accurate information about it is due to the expedition which the United States of America sent to explore it in 1848 (see Report of the Expedition of the United States to the Jordan and Dead Sea, by W. F. Lynch). Further explorations have been made by De Sauloy, the Duc de Luynes, and the Palestine Survey Expedition. (Comp. also. Blankenhorn, Entstehung und Geschichte des Toten Meeres, in ZDVP. xix. If.) — The subsidence that formed the whole Jordan - `Araba depression dates from the transition between the tertiary and quaternary periods. The valley was never covered by the sea; the Dead Sea could never have been connected with the Red Sea as was at one time supposed, because the watershed between them, at the S. end of the `Araba, rises to the height of 820 ft. above the Mediterranean. This inland lake was, on the other hand, the collecting reservoir for the enormously copious rainfall of the first ice age, during which the water-level was about 1400 ft. higher than at present, or about 100 ft. above the level of the Mediterranean. Lacustrine deposits, with traces of freshwater fauna, were discovered at this height by Hull.
The Dead Sea is 47 M. in length (about the same as the Lake of Geneva), and its greatest breadth to the S. of Wâdi Môjib is 9 1/2 M. ; the breadth of the strait opposite the peninsula is 2 3/4 M.; towards the N., near Râs Mersed, the sea narrows to 7 1/2 M., and at Râs el-Feshkha, to 6 M. On the E. and W. sides it is flanked by precipitous mountains, with often little or no space between them, and the water. The shallow S. bay of the sea, which, however, is not visible from the N. end, is bounded by a low peninsula (Arab. El-Lisân, 'tongue'; Josh. xv. 2). At the S.W. end of the lake rises a hill of salt.
The mean depth of the Dead Sea is 1080 ft., that of the S. bay nowhere more than 11 ft. ; the greatest depth between 'Ain Terâbeh (W.) and the mouth of the Zerka Ma'îa (E.) is 1310 ft.
Level of Dead Sea below level of Mediterranean 1292 ft.
Greatest depth of Dead Sea 1310 ft.
Total depth of the depression below the level of the Mediterranean 2603 ft.
Height of Jerusalem above Mediterranean . . 2494 ft.
Height of Jerusalem above Dead Sea .... 3?86 ft.
The level of the Dead Sea varies 12-20 ft. with the seasons, as will be seen by the pieces of wood encrusted with salt which lie on its banks. It has recently been maintained that the N. bank has considerably receded within the historic period.
It has been calculated that 6 1/2 million tons of water fall into the Dead Sea daily, the whole of which prodigious quantity must be carried off by evaporation. In consequence of this extraordinary evaporation the water that remains behind is impregnated to an unusual extent with mineral substances. The water contains 24 to 26 per cent of solid substances, 7 per cent of which is chloride of sodium (common salt). The chloride of magnesium which also is largely held in solution is the ingredient which gives the water its nauseous, bitter taste, while the chloride of calcium makes it feel smooth and oily to the touch. There are also many other ingredients in small quantities. The water boils at 221° Fahr. The specific gravity of the water is not everywhere the same; it varies from 1.021 to 1.256, the average being 1.166. It is lightest at the mouth of the Jordan, and for some distance opposite to it, and heaviest, i.e. most charged with mineral ingredients, in the deepest parts of the sea. The human body floats without exertion on the surface, and can only be submerged with difficulty; but swimming is unpleasant, as the feet have too great a tendency to rise to the surface. Irritation of the skin is often experienced by persons who bathe in the Dead Sea, but this is probably caused chiefly by exposure to the fierce rays of the sun. After the bath, however, the skin retains an oily sensation. The water appears to have been used at one time for sanatory purposes. — The salt of the Dead Sea has from the earliest times been collected and brought to the Jerusalem market, and is considered particularly strong. Asphalt is said to lie in large masses at the bottom of the lake, but it seldom comes to the surface except when loosened by storms or earthquakes. Others, however, think that the asphalt proceeds from a kind, of breccia (a conglomerate of calcareous stones with resinous binding matter) which lies on the W. bank of the lake, and finds its way thence to the bottom; and that, when the small stones are washed out, the bituminous matter rises to the surface. The asphalt of the Dead Sea was highly prized in ancient times.
It is now well ascertained that the Dead Sea contains no living being of any kind, with the exception of a few microbes (bacilli of tetanus, etc.) discovered by Lortet in the mud of the N. bank (comp. ZDPV. xvii. 142). Neither shells nor coral exist in it, and sea-fish put into its waters speedily die. The assertion, however, that no living thing exists on its banks, and that no bird can fly across it, is quite unfounded. The poverty of the fauna must be admitted, but is to be ascribed to the want of fresh water and the consequent absence of vegetation, and not to any supposed poisonous property of the air. Where a supply of fresh water exists, the soil bears a luxuriant vegetation. The banks of the lake were once inhabited (chiefly by hermits), as ruins found on them indicate. The lake was navigated in the time of Josephus, in the middle ages, and even later, but for a long period after that not a boat was to be seen upon it.
In clear weather the scenery presented by the mountains and water is beautiful. The promontory on the right is Râs el-Feshkha. Farther to the S. is Râs Mersed, beyond which lies Engedi. To the left, at some distance, is seen the ravine of the Zerkâ Ma'in. The mountains of the Dead Sea, however, are rarely seen with great distinctness, as a slight haze usually veils the surface of the water; but when seen from a distance, and especially from a height, the atmosphere seems perfectly clear, and the water is of a deep blue colour. When seen from the immediate neighbourhood the colour of the water is greenish, and it has a somewhat oily appearance.