302 MINERALOGY. 



and sulphate of lime. Rock salt is also found at 

 great elevations above the sea, and no marine exuvia 

 have ever been discovered in salt strata. Another 

 objection to this hypothesis is, the enormous depth 

 of sea water necessary to the production of a body of 

 rock salt above forty yards in thickness, such as the 

 insulated mountain of rock salt at Cardona in Spain. 



Salt Springs. 



The salt made at Droitwich supplies nearly one 

 half of England. A salt river twenty- two inches 

 deep, runs about 250 feet under the surface, over a 

 bed of rock salt, whose thickness has not been ascer- 

 tained. Immediately above this subterranean stream 

 is a bed of gypsurn 130 feet thick, which, when 

 penetrated by the borer, permits the water to rise to 

 the surface. The Droitwich springs hold about one- 

 fourth of their weight of salt in solution, no other in 

 England holds more than a ninth. 



Inorganic Matter. 



The different parts of an inorganic body enjoy an 

 independent existence, while the parts of a body be- 

 longing to the organized kingdom depend on their 

 relative situations for the continuance of their struc- 

 ture and properties. 



Inorganic bodies can neither boast of youth nor 

 age, parent or child, while organized bodies have the 

 power of reproduction. The first remain for ever 

 quiescent ; the last are never stationary. A plant 

 or tree may appear externally fixed, internally there 

 is no rest. 



Organized bodies are also distinguished by their 

 integuments, such as the skin, bark, &c. &c. 



Heat of Mines. 

 It is evident that the elevation of a mine above 



