Principal Depressions on the Surface of the Globe. 2G3 



rivers Jordan, in both cases losing themselves in the salt-water lakes. 

 They closely resemble each other both in area of surface and dimensions 

 of basin. The waters of the two are almost equally heavy, and equally 

 salt, though they differ entirely in the nature of their saline contents, as 

 will be seen below ; and they are most unlike each other in matter of 

 depth. 



Dead Sea.* 

 sp. gr. 

 1-22 



In 1000 grains of water. 



Great Salt Lake, 

 sp. gr. 

 1-17 



Common Sea Water, 

 sp. gr. 

 1-027 



Chloride of Magnesium, 145-8 



„ Calcium, 31 



„ Sodium, 78 



„ Potassium 6 



Other Salts 6 



200 

 20 



25 

 5 



266-8 220 30 



It will thus be seen, that though in all likelihood the great American 

 lake owes its saltness to the rivers washing away the salt from the rocks 

 around, and carrying it down to be concentrated as in a great salt pan, a 

 like explanation by no means suffices for the saltness of the Dead Sea, 

 whose ingredients are wholly different from those composing rock or com- 

 mon rock or sea salt. 



Depths of the Sea. — I have confined my observations to the depres- 

 sions on the surface of the dry land, chiefly dealing with those which were 

 either beneath the level of the adjoining countries, and not filled up with 

 water, or those receding far beneath the surface of the ocean both embo- 



* We have retained in the text the analyses given by Dr Buist, though they 

 are very imperfect. We append more complete analyses of sea water, of 

 the waters of the Dead Sea, and of that of the Elton Lake, described by Gustav 

 Rose, in his " lleise nach dem Ural." This lake, and the numerous brine 

 pools which exist in the neighbourhood of the Caspian, complete the analogy of 

 that district, with that of the Dead Sea, and the Great Salt Lake referred to in 

 the preceding paragraph. 





Sea Water. 



Sea Water. 



Elton Lake. 



Chloride of sodium, . . 



65-77 



26-72 



131-24 



magnesium, . 

 calcium, . . 



. 105-43 

 28-94 



3-23 



105-42 



potassium, 

 aluminum, 



13-98 

 0-18 



1-28 



2-22 



Bromide of magnesium, . 



sodium, . . . 



2-51 



0-51 



07 



Sulphate of lime, . . . 



magnesia, 

 Silica, 



0-88 

 0-03 



1-62 

 1-97 



16-65 



Water, ...... 



. 782-27 



964-67 



744-40 



1000-00 



100000 



1000-00 



It is worthy of observation, that the Dead Sea water and that of the Elton 

 Lake closely resemble in composition the mother liquor which is obtained 

 when sea water is evaporated, so as to separate the greater proportion of its 

 common salt. That the Dead Sea is such a mother liquor, seems to be indicated 

 by the abundance of rock-salt which is found in the neighbourhood. If, there- 

 fore, the explanation of the saltness of the Great Salt Lake given by Dr Buist 

 is correct, the whole difference between the two is, that in the case of the Dead 

 Sea, the concentration is further advanced. — Edit. Phil. Journal. 



