WS M. CoRDiER on lite Mountain of 



prejudices of the country on the subject. He estimates, 

 from some experiments, that the rain water flowing down 

 the sides of the mountain, ought rarely to acquire a saltness 

 greater than 4°. He finds that the specific gravity of the 

 rock salt of Cardona, in cubic and clear pieces, determined 

 with the essential oil of turpentine, is 22.1967 (that of dis- 

 tilled water being 10). Lastly, supposing that there an- 

 nually falls at Cardona, eight decimetres of rain, and ad- 

 mitting that each decimetre acquires a saltness of 4°, he 

 determines, by a simple calculation, that the eight centi- 

 metres ought annually to carry away from the upper parts 

 of the saline mass a thickness of 15 millimetres, 26 hun- 

 dredths of rock salt ; whence it follows thit the mountain 

 only diminishes 152 centimetres 6 tenths (5 feet, inches, 

 3 lines English) in a century. M. Cordier only offers this 

 as a fair sketch, from which it may easily be understood why 

 the decrease of the mountain of Cardona has always appeared 

 imperceptible. 



We shall finish with the following summary of the prin- 

 cipal geological results of M. Cordier's memoir. 



1. The saline and gypsum rocks of Cardona occur in ver- 

 tical beds. 



2. This system is covered by the most ancient secondary 

 beds, whose superposition is non-conformable (transgres- 

 sive.) 



3. From the nature of this superposition, the gypsum 

 and salt beds are, without doubt, of an era, not only an- 

 terior to, but altogether distinct from, that of the secondary 

 beds. 



4. Pure and occasionally saliferous gypsum occurs in the 

 High Alps, and incontestably forms part of the transition 

 series.* 



* The saliferous gypsum of Bex, so long considered as a decided ex- 

 ample of the occurrence of such rocks in the transition series, has been 

 shewn by Professor Buckland to belong to the saliferous, or new red 

 sandstone formation; it would be much more in accordance with what 

 we know of the general geological position of rock salt, to consider that 



