ON THE SALT SPRINGS OF WORCESTERSHIRE 



from sea water. Granting this view to be correct, it would 

 greatly favour the supposition that the valley of Droitwich was 

 at one time part of a salt-water lake. Those who maintain this 

 to be the origin of salt say, that whenever the sea water in the 

 valleys became separated from the sea, the salt contained in it 

 would subside by the natural process of evaporation, which would 

 be much assisted by any internal heat of the earth below the 

 water. One strong objection to this view is the fact, that the 

 rock-salt of Cheshire and Droitwich differs much from that con- 

 tained in the sea, inasmuch as the earthy salts of magnesia, 

 which are found mixed in the waters of the ocean, do not exist in 

 the brine of Cheshire or of Worcestershire. 



There is also a very strong proof against the notion that the 

 beds of rock-salt in these two counties are depositions from sea 

 water, in the circumstance that no marine exuvias have ever be^n 

 found in the strata. Other objections also offer themselves to the 

 validity of this theory; such as the enormous depth of sea 

 water necessary to the, production of a body of rock-salt forty 

 yards in thickness, and also the difficulty of accounting by this 

 means for the mountain of rock-salt at Cardona, in Spain, to 

 which I have before alluded. Nevertheless, the high authority 

 of Mr. Lyell seems rather to favour the opinion that there may 

 have occurred immense depositions of salt in the above manner. 

 He says in his Principles of Geology, when speaking of the 

 Mediterranean — "What profundity, then, may we not expect 

 some of the abysses of this sea to reach ! The evaporation 

 being, as we before stated, very rapid, the surface water becomes 

 impregnated with a slight excess of salt; and its specific gravity 

 being thus increased, it instantly falls to the bottom, while 

 lighter water rises to the top, or that introduced by rivers and 

 by the current from the Atlantic flows over it. But the heavier 

 fluid does not merely fall to the bottom, but flows on till it 

 reaches the lowest part of one of those submarine basins, 

 into which we must suppose the bottom of this inland sea to be 

 divided. By the continuance of this process additional supplies 

 of brine are carried to deep repositories, until the lower strata of 

 water are fully saturated, and precipitation takes place ; not in 

 thin films, such as are said to cover the alluvial marshes along 

 the western shores of the Euxine, nor in minute layers, like those 

 of the salt * etangs of the Rhone, but on the grandest scale — ■ 

 continuous masses of pure rock-salt extending, perhaps, for 

 hundreds of miles in length, like those in the mountains of 

 Poland, Hungary, Transylvania, and Spain."* 



There can be no doubt that the whole of the vale of Worces- 

 tershire has been at some distant period part of the bed of an 

 immense ocean, and therefore it is possible that our salt may 

 have been deposited in some such manner as Mr. Lyell thinks ^s 



» Vol. 1st, p. 298, 

 July, 1835. — VOL. II. NO. xii. 3 b 



