34 Proceedings of the Boyal Physical Society. 



the waters of the Dead Sea accounts for the relatively small 

 percentage of chloride of sodium in solution. As fast as this 

 arrives from the Jordan it is precipitated in the solid form, 

 and hence, instead of remaining in solution, it occurs as 

 crystals in the mud at the bottom of the lake. 



Amongst the numerous other examples of the same nature 

 as the lakes just mentioned, reference may also be made to 

 the Salt Lake of Utah. This area of inland drainage, like 

 the Caspian, the Dead Sea, and others referred to, is the 

 shrunken remnant of a former lake of greater extent, whose 

 waters are still gradually diminishing as a consequence of 

 the excess of evaporation over the supply brought in by the 

 rivers that feed it. As in the case of the Dead Sea terraces 

 of Jebel Usdem and the parts adjacent, the marks of the 

 former levels at which the waters of the Salt Lake stood are 

 plainly to be seen on the mountain sides around. [These 

 features were beautifully illustrated when this paper was 

 read the second time, by lantern slides of the Salt Lake, 

 taken by Dr Tempest Anderson.] 



The waters of the Salt Lake contain salts in solution to 

 the amount of 224*22 per thousand, of which 90'64 per cent, 

 is chloride of sodium, 1*3 per cent, of chloride of magnesium, 

 and 8*23 per cent, of sulphate of soda. 



There is not space here for more than a brief reference to 

 other salt lakes. But besides the numerous salt lakes in the 

 steppe regions of Asiatic Russia, they abound in Persia, and 

 constitute an important source of the salt used there. Lake 

 Urimiyeh is well known in this respect on account of the 

 enormous quantities of salt it contains. There are many 

 others in Northern Africa, from the Mle to Morocco. The 

 salt in the Bitter Lakes of Suez is estimated to amount to 

 2,134,000,000,000 lbs. Salt lakes abound also in the arid 

 parts of South Africa. In India, salt is obtained in consider- 

 able quantities from the Sambhur Lake. 



In addition to these inland areas where chloride of sodium 

 is in process of formation, it is well known that there are 

 thousands of miles of coast-line where salt is obtained by 

 the evaporation of sea-water. One well-known instance is 

 that of the Rann of Cutch (Lyell, "Principles," 10th ed.. 



