On the Muriate of Soda^ or Common Salt. 3 



probably harder than the other parts. There is an extensive 

 formation of rock salt on each side of the Carpathian nif)un- 

 taiiis for six hundred miles, from Weleiska in Poland to Rim- 

 mie in Moldavia. Rock salt and salt springs most generally 

 occur near the feet of extensive mountain ranges, which 

 adds probability to the opinion that these ranges v^^ere once 

 boundaries of extensive lakes of salt water. In some parts 

 of Africa there are salt lakes which rest on beds of solid rock 

 salt : these beds were probably formed by fresh depositions 

 of salt as the water evaporates. Near Algiers the salt lakes 

 are dried up in summer, and leave immense masses of rock 

 salt at the bottom. 



The lake Yelta, beyond the river Volga, supplies all Rus- 

 sia with salt.* 



Muriate of soda is most generally associated with beds of 

 clay, which frequently alternate with those of the salt; sand, 

 sandstone, and compact, fetid and bituminous limestone 

 usually accompany the deposits of salt. But the most in- 

 timate connexion exists between this salt and the sulphate 

 of lime or gypsum, over which the beds are usually placed, 

 or sometimes they even alternate with it. The constant 

 occurrence of the muriatic and sulphuric acids in the same 

 situations is an interesting fact, which, in a more advanced 

 state of chemical and geological science may serve to eluci- 

 date the formation of gypsum and rock salt. 



In the United States, salt springs are very numerous. 

 They sometimes flow naturally, but are generally formed by 

 sinking wells in those places where salt is known to exist, as 

 in certain marshes, salt hcks, &c. 



The country on the Arkansas river furnishes some salt ; it 

 differs, however, from most other places in the United States, 

 by existing in pools, and forming incrustations on the soil of 

 plains and prairies. There is no salt obtained in Arkansas 

 by boring, the usual mode of procuring it in other localities. 



There are many salt springs in Missouri ; the working of 

 many of them, however, has been suspended or entirely re- 

 linquished, in consequence of the reduced price of the salt. 

 The principal one now in operation is at Boon's Lick. 



There are no salt works in operation on the Wabash. 

 There is one manufactory in operation at Tohota, on a trib- 



* Philosophical Transactions, Vol. 77, and Foster's Introduction to Mineralo- 

 gy, page 32. 



