152 THE FKESH-WATER LOCHS OF SCOTLAND 
as a general tendency. The resemblance is due partly to the disappear- 
ance of calcium sulphate from solution, and would not have existed at 
a period when the lakes were no more concentrated than the ocean ; 
partly also it results, at least in the case of Great Salt Lake, from an 
inflow of exceptionally chloridic river waters. On the other hand, the 
Caspian, which actually began life as an arm of the ocean, has become 
much more sulphatic, being fed largely by alkaline waters. So 
pronounced is the accumulation of sulphate, that when, in the 
Karaboghaz Giilf, local concentration of Caspian water takes place, 
sodium sulphate (Glauber's salt) is thrown down. 
We have seen how the early stages in the concentration of lake 
waters produce, by elimination of calcium, waters in which sodium is 
the chief metal. When, to go a step further, a lake is so near the 
end of its ca,reer that it has for a long time deposited sodium salts, 
magnesium becomes predominant. The waters now contain much 
magnesium chloride and sulphate, and resemble in every way the 
artificial bitterns " or mother-liquors which remain when common 
salt is manufactured by crystallisation out of sea-water. The waters 
tabulated below are familiar examples of this. The Karaboghaz is 
merely a gulf of the Caspian Sea, in which large deposits of sodium 
sulphate and chloride have crystallised out. Lake Elton, an oceanic 
derelict, has deposited salt and gypsum, and is said to yield a crop of 
magnesium sulphate in the winter. The Dead Sea is a concentrate of 
Jordan water, an abnormal river water of which an analysis is adduced 
for comparison. 
Karaboghaz 
Gulf 
(Schmidt).i 
Lake 
Elton 
(Erdmann).- 
Dead 
Sea 
( Terrell 
River 
Jordan 
(Anderson).^ 
Dissolved matter : 
Parts per thousand. 
285-0 
265-0 
259-9 
1-61 
,Ca 
xAIg 
Percentage composi- 
tion of dissolved \ qq 
matter. ^j^^^^ 
VSi02 
15-8 
11-5 
1-8 
53*4 
17-4 
0-10 
17-5 
11-3 
6-b 
64-2 
6-8 
6-6 
15-9 
5-5 
1-7 
trace 
70-0 
0-24 
trace 
7-9 
9-5 
15-5 
1-1 
12-7 
49-4 
3-6 
0-15 
The final state towards which these waters, which are more or less 
of the oceanic type, tend is that of a solution of little else than 
1 Bull. Acad. St. Petersburg, xxiv. p. 177, 1878. 
2 Pogg. Ann., xxxv. p. 172, 1835. 
Gomptes rendus, Ixii. p. 1329, 1866, 
^ Eep. U.S. Dead Sea Expeditioti, p. 202, 1852. 
