the Cheshire Rock- Salt District. 317 



best foundation for inquiries into the origin of the fossil- 

 salt. The best, or rather the only memoir on this subject 

 which I have had the opportunity of seeing, is one by 

 M. Hassenfraiz, contained in the eleventh volume of the 

 Aiinalss de Chimie. From this memoir it would appear 

 that tiie general situation of the rock-salt in Transylvania 

 and Poland is very similar to that which it occupies ia 

 Cheshire; the beds of this mineral being disposed in small 

 plains, bounded by hills of inconsiderable height, forming 

 3 kind of basin or hollow, from which there is usually only 

 a narrow egress for the waters. The situation of the 

 Austrian sa!t-mines near Salzburgh is however very dif- 

 ferent. The mineral here appears to be disposed in beds 

 of great thickness, v^hich occur near the summit of lime- 

 stone hills, at a great elevation above the adjoining country*. 

 This fact is a singular one; and, if we admit the idea that 

 rock-salt is formed from the waters of the sea, makes it 

 necessary to suppose the occurrence on this spot of the 

 most vast and wonderful changes. M. Hassenfratz states 

 it as a general fact, that in countries where salt-mines 

 occur, fragments of primitive rocks appear in great abun- 

 dance over these beds. It does not seem, however, that 

 any deduction of importance can be connected with this 

 fact. 



The disposition of the beds of salt in the continental 

 mines seems to be very generally a horizontal one, and as 

 in the English mines, they are separated by strata of clay of 

 a varying thickness. It would appear, however, with re- 

 spect to ej^tent of dimensions, that they are in general 

 greatly inferior to the bodies of rock-salt met with in our 

 own island. In Hungary and Poland these beds do not 

 present a thickness of more than one or two feet, and are 

 separated by layers of clay a few inches in thickness. 

 Much, however, it is evident, must depend upon the num- 

 ber of the beds thus dib-posed, but this I do not find any 

 where noticed. The earthy saline contents of the foreign 

 rock-salt very exactly resemble those of the Chesliire ; the 

 gypsum existing in much larger proportion than the other 

 earthy salts, and appearing in considerable masses, both 

 distinctly, and in mixture with the beds of clay. It is an 

 imjKjrtant fact, however, that sea-shells and other marine 



* I am informed bv Mr. Greenough that the Inpehgrnhm, which is the 

 highest gallery of the ealt-miiic at HaJBladt, is blated in Von Bueh's Travels 

 through CJermany and Italy to bo two thousand nine hundred and seventy- 

 five leet above the sea, and tiiat the salt mines at Hall in the Tyrol are at a 

 much more considerable elevation. 



Z 2 exuviae 



