143 



probability the water which conveyed it away would deposit 

 another substance in its place. 



This water contains a very large amount of Chloride of Calcium, 

 but the deficiency of the Sulphate of Soda and of Magnesia will 

 prevent its being used successfully as medicinal water. Chloride 

 of Sodium, or common Salt, is the most prominent of the substances 

 which it holds in solution, amounting to more than one half of the 

 solid contents. The Skiddaw Slate, through which the water 

 percolates, contains a small quantity each — of Lime, Magnesia, 

 and Soda, but it is scarcely possible that the whole of these 

 substances contained in the water can be derived from that 

 source ; therefore, it is natural to suppose that a large bed of Rock 

 Salt must exist in the heart of the mountain, or beneath its base. 

 I say large, because the water has been bearing it away for ages, 

 and it is still unexhausted. The quantity of salt contained in the 

 water is 110-23 grains in the imperial pint ; and calculating the 

 flow of water at 1,200 pints per minute, it will give a total of 

 i8f lbs. per minute, 12 tons 3 cwt. every twenty-four hours, 

 4,434 tons every year, or 443,400 tons in one hundred years. We 

 may suppose that the position of this bed of rock salt is at the 

 base of the mountain, and it may probably extend from Manisty 

 to the northern side of the highest peak of Catbells ; or, there may 

 be two beds, one beneath Maiden Moor, and the other beneath 

 the peak of Catbells : but the exact position of the bed, or beds, 

 and their extent, are questions that will in all probability remain 

 forever unsolved. Their origin is also equally obscure. 



Rock salt is rarely met with in primary rocks, being chiefly 

 found in formations of a much more recent date. In the valley 

 of the Weaver, near Northwich, an immense bed of this mineral 

 occurs in the Trias formation, which in some parts attains a thick- 

 ness of one hundred and seventy feet. It is generally supposed 

 that this and similar deposits have been formed by the evaporation 

 of sea water. If we suppose that a lagoon existed on the sea 

 shore, separated from the ocean by a sand bar, so high that only 

 high tides could overflow it, and thus replace the water that was 

 constantly being carried off by evaporation, we can readily under- 



