THE SALTS OF THE SEA. " 155 



minerals which yield one kind of salts or soluble matter, another 

 river runs through a limestone or volcanic region of country, and 

 brings down in solution solid matter — it may be common salt, 

 sulphate or carbonate of lime, magnesia, soda, potash, or iron — - 

 either or all may be in its waters. Still, the constituents of sea 

 water from the Mediterranean and of sea water from the Red Sea 

 are quite the same. But the waters of the Dead Sea have no con- 

 nection with those of the ocean ; they are cut off from its channels 

 of circulation, and are therefore quite different, as to their com- 

 ponents, from any arm, frith, or gulf of the broad ocean. Its in- 

 habitants are also different from those of the high seas. 



297. '' The solid constituents of sea water amount to about 3| 

 per cent, of its weight, or nearly half an ounce to the pound. Its 

 saltness may be considered as a necessary result of the present 

 order of things. Rivers which are constantly flowing into the 

 ocean contain salts, varying from ten to fifty, and even one hund- 

 red grains per gallon. They are chiefly common salt, sulphate 

 and carbonate of lime, magnesia,*soda, potash, and iron ; and these 

 are found to constitute the distino^uishins^ characteristics of sea 

 water. The water which evaporates from the sea is nearly pure, 

 containing but very minute traces oT salts. Falling as rain upon 

 the land, it washes the soil, percolates through the rocky layers, 

 and becomes charged with saline substances, which are borne sea- 

 ward by the returning currents. The ocean, therefore, is the 

 great depository of every thing that water can dissolve and carry 

 down from the surface of the continents ; and, as there is no chan- 

 nel for their escape, they of course consequently accumulate."! 



298. " The case of the sea," says Fowner, " is but a magnified 

 representation of what occurs in every lake into which rivers flow, 

 but from which there is no outlet except by evaporation. Such 

 a lake is invariably a salt lake. It is impossible that it can be 

 otherwise ; and it is curious to observe that this condition disap- 

 pears when an artificial outlet is produced for the waters." 



299. How, therefore, shall we account for this sameness of 

 compound, this structure of coral (^ 293), this stability as to ani- 

 mal life in the sea, but upon the supposition of a general system 

 of circulation in the ocean, by which, in process of time, water 

 from one part is conveyed to another part the most remote, and 



* See Appendix E. f Youmans's Chemistry. 



