168 Notices of Memotrs—Prof. Edward Hull— 
alkaline mineral water, the saline contents of which consist chiefly 
of sodic, magnesic, potassic, and calcic chlorides and sulphates, 
together with a number of other substances in much smaller pro- 
portion. The total amount of dissolved contents in the water of 
the open ocean varies from about 28 to 39 grammes per litre. 
Forchhammer fixes the mean amount of such contents at 34-404 
grammes per litre, and the mean proportions of the constituent 
substances to each other and 100 parts of chlorine are as follows” :— 
: by , 2 Total saline 
Sodium. Magnesium. Calcium. Chlorine. COnetinenies 
14:26 6642 2114 100 181:10 
9. What is most striking in this analysis is the large proportion 
of chlorine, and the greatest difficulty we are met with in order to 
account for the salts of sea water is the abundance of this gas. 
Recollecting that chloride of sodium is the most abundant salt both 
in most salt lakes and in sea water, we are justified in seeking for a 
solution to our problem by an examination into the mode of origin 
of salt lakes. 
10. Now there is one peculiarity which characterizes all salt lakes 
over the surface of the globe, namely—that they have no outlet; 
they are closed lakes. Whether we take the case of the salt lakes 
of Western America, those of Central Asia and the Dead Sea, we 
shall find that they are not drained by rivers. 
11. In such cases the lakes are constantly receiving supplies of 
water from streams and springs, but do not give it off in the same 
manner, inasmuch as it is evaporated into the air as fast as it falls. 
In the case of freshwater lakes it is otherwise. Here the water of 
the streams which enter the lake is at least partially discharged by 
means of rivers flowing out, in consequence of which the water 
remains fresh, as the saline ingredients are carried away as fast as 
they are delivered. Of these two varieties of inland lakes we have 
remarkable examples in the case of the Dead Sea and the Sea of 
Galilee. In the former case the river Jordan entering at the 
northern end keeps up a constant supply, but this lake, which is 
about 1292 feet below the level of the Mediterranean, has no outlet, 
in consequence of which the water supplied by the Jordan passes 
away into the atmosphere in the state of vapour. In the case of 
the Sea of Galilee it is otherwise. The river which enters at the 
north passes out again at the south; hence the water of the lake is 
fresh and supports an abundant fauna of fishes and molluscs, while 
the waters of the Dead Sea are (as the name indicates) absolutely 
destitute of living beings, and fish entering it from the Jordan imme- 
diately perish. If there had been an outlet to the southwards from 
the Dead Sea into the Gulf of Akabah, and a continuous stream had 
been flowing from the time the depression was formed, the waters 
of the Dead Sea would have only difiered from those of the Sea of 
Galilee by a somewhat greater proportion of salts and carbonates. 
Several other examples might be cited, but those of the Sea of 
Galilee and the Dead Sea are the most familiar and striking. 
1 Phil. Trans. civ. 308, e¢ seg. 2 Watt’s Dict. Chem., vol. v. 1019. 
