There is no difficulty in accounting for the saltness of the Dead Sea. There are large quantities of salt, and salty matters generally, in the volcanic rocks of the region, but, even if this were not so, when a river empties into a lake with no outlet to the sea, and which therefore loses its water by evaporation only, the water will gradually become very salt, since the remaining waters of such a lake contain more or less salt, while the water they lose by evaporation contains none.
The waters of the Dead Sea are very salt, but not the saltest in the world. In every 100 pounds of Dead Sea water twenty-four pounds consist of salty matters. The waters of the Great Salt Lake, in Utah, contain eighteen per cent of salty matters. Lake Van, in eastern Turkey, is, perhaps, the saltest lake on earth, it containing no less than thirty-three pounds of salty substances in every 100 pounds of water.
Daubeny, an authority on volcanoes, and quite competent to give an opinion concerning what is possible in this line, describes what he believes took place, as follows:
"Briefly then to recapitulate the train of phenomena by which the destruction of the cities might have been brought about, I would suppose that the River Jordan, prior to that event, continued its course tranquilly through the great longitudinal valley, called El Arabah, into the Gulf of Akaba; that a shower of stones and sand from some neighboring volcano first overwhelmed these places; and that its eruption was followed by a depression of the whole of the region, from some point apparently intermediate between the lake of Tiberius and the mountains of Lebanon, to the watershed in the parallel of 30°, which occurs in the valley of El Arabah above-mentioned. I would thence infer that the waters of the Jordan, pent-up within the valley by a range of mountains to the east and west, and a barrier of elevated table-land to the south, could find no outlet, and consequently by degrees formed a lake in its most depressed portion, which, however, did not occur at once, and therefore is not recorded by Scripture as a part of the catastrophe, though reference is made in another passage of its existence _in what was before the valley of Siddim_."