378 NOTES ON THE GEOLOGY 



and fertile, so as to be called the garden of the Lord, has, since 

 the destruction of Sodom and Gomorrah, been one of the most 

 desolate spots on earth. It is well known that common salt, when 

 mixed in proper quantity with the soil, very much increases the 

 fertility ; but, if applied in too large proportion, it is eminently 

 fatal to vegetation. If the Dead Sea existed before the catastrophe 

 of Sodom, it would impart sufficient saltness to the surrounding 

 region to render it very fertile. But if its limits, after that event, 

 were much enlarged, and especially if Usdum was protruded to 

 the surface, so as to impart saltness to most of the fountains, the 

 excess of salt would produce the sterility which now reigns there. 

 It so happens that we have at least three good illustrations of 

 these views, on the western shore of the Dead Sea. At Ain Jidy 

 is a copious fountain of fresh water, and along the banks of the 

 stream issuing from it, is the most luxuriant growth of vegetables 

 which Dr. Robinson ever saw. The same is true around Jericho, 

 although the surrounding country is very sterile. A similar fer- 

 tility exists along the mouths of the streams that empty into the 

 sea on its southeast side, near the site of the ancient cities. I 

 shall hereafter quote another example from the vicinity of a sim- 

 ilar salt lake in Persia. In short, I do not doubt, that if a sufficient 

 quantity of fresh-water sti-eams were now to flow into the Dead 

 Sea, unless they passed across Usdum itself, its shores would 

 again become as luxuriant as Egypt. 



9. Finally, we see, in the facts detailed, the principal origin of 

 the salts contained in the Dead Sea. It is not Usdum, as some 

 have supposed ; for then common salt should be the chief ingre- 

 dient. Yet doubtless Usdum increases the quantity of that sub- 

 stance, and so do the brackish springs along the shore have some 

 effect. But the principal source of its peculiar quaUties, I doubt 

 not, arc the hot springs on the west shore of the Sea of Tiberias, 

 as I have ah-eady endeavored to show. These waters flow into 

 the sea, and are evaporated by the gi*eat heat which prevails there, 

 and thus the solution becomes condensed almost to saturation. 

 It is seldom, it seems to me, that we can ti*ace effects more satis- 

 factorily to their source, than in this instance. And yet I do not 

 recollect to have seen these springs mentioned as the source of the 



