ROCK-SALT OF CARDONA. 



173 



surface, it would have been inferred, that brine springs so far below 

 the level of the sea, had their source from the waters of the ocean, 

 percolating through fissures in the earth. 



There are many salt springs in France, but no mines of rock-salt. 

 The salt springs at Salins, in the department of the Jura, rise in the 

 red marl formation ; and the gypsum with which they are associated 

 is exactly similar to the massive gypsum in the English red marl. 

 The strongest of these springs contains 15 per cent, of salt. 



In Switzerland, the rock-salt and gypsum do not occur in the red 

 marl, but between calcareous beds, which are, I believe, analogous 

 to the English lias, and will be again mentioned. 



In Spain, there are several salt springs and beds of rock-salt : the 

 principal formation of rock-salt, at Cardona, in Catalonia, has been 

 described by Count Alexander Laborde, in his magnificent work, 

 entitled. Voyages PiUoresques dans VEspagne. 



"The salt district of Cardona comprehends the hill on which the 

 town is situated, and the environs of more than a league in circum- 

 ference. The surface is, almost every where, covered with vegeta- 

 ble soil to the depth of six inches or more, which renders it produc- 

 tive. The place where the rock-salt is procured, is a valley forming 

 an oval, about one mile and a half in length, and half a mile in 

 breadth from east to west, extending from the Castle of Cardona to 

 the promontory of red salt at the other end. The last is the most 

 considerable of the salt rocks, and has not yet been worked : it is 

 six hundred and sixty three feet in height, and twelve hundred and 

 twenty feet in breadth at its base. This valley .is also traversed by 

 a chain of hills of rock-salt : besides these, there are other rocks of 

 salt at the feet of the fortress, and upon the declivity of the mountain 

 which stretches to the fountain called Cancunillo. The mountain of 

 red salt is so called because that colour predominates; but the colours 

 vary with the altitude of the sun, and the greater or less quantity of 

 rain. At the foot of this mountain a spring of water issues, which 

 comes through a fissure on the summit. The rivulet runs all along 

 the valley from the east, but passes under ground in part of its course, 

 particularly under the hill where the rock-salt is mined : at a little 

 distance, it rises again to the surface, and, after running along the 

 plain, discharges itself into the river Cardona. This brook, in rainy- 

 seasons, swells the waters of the river, which then become salt, and 

 destroy the fish ; but at three leagues lower, the water has no per- 

 ceptible taste of salt. All these salt mountains are intersected by 

 crevices and chasms ; and have also spacious grottoes, where are 

 found stalactites of salt, shaped like bunches of grapes, and of vari- 

 ous colours." — " Nothing can compare with the magnificence of the 

 spectacle which the mountain of Cardona exhibits at sunrise. Be- 

 sides the beautiful forms which it presents, it appears to rise above 

 the river like a mountain of precious gems, displaying the various 

 colours produced by the refracdon of the solar rays through a prism." 

 Count Laborde. 



