OF SEA-WATER. 241 



and that, acting on a portion of the muriate of lime, it forms 

 sulphate of lime. 



In other analyses, in those, for example, of the salt brines 

 of Lorraine, by Nicholas *, muriate of soda, sulphate of soda, 

 sulphate of lime, muriate of magnesia, and muriate of lime, are 

 enumerated as ingredients.' Here it is still more evident, that 

 there is no proof of the previous existence of sulphate of lime; 

 on the contrary, as both muriate of lime and sulphate of soda 

 are present, they must, in the concentration of the liquor by 

 evaporation, form by their mutual action muriate of soda and 

 sulphate of lime ; and the quantity therefore of this sulphate 

 which may be obtained, must have this origin. 



In general, when muriate of lime and muriate of magnesia 

 are stated as ingredients with sulphate of lime, no sulphate of 

 soda or sulphate of magnesia is found. The reason is obvious, 

 that if either of these salts existed, it would re-act on the mu- 

 riate of lime, and form sulphate of lime. But when muriate 

 of lime is not found, sulphate of magnesia, or sulphate of soda, 

 is often stated as an ingredient, obviously owing to the circum- 

 stance, that although a portion of muriate of lime has been 

 present, so as to form sulphate of lime, there has not been a 

 quantity sufficient to decompose the whole sulphate of soda, or 

 sulphate of magnesia. 



A striking example of these facts is to be found in Dr Hen- 

 ry's analysis of the different varieties of sea and rock salt f . 

 In four varieties of rock-salt, there were found small quanti- 

 ties of muriates of lime and magnesia, with a portion of sul- 

 phate of lime, but no sulphate of magnesia ; while in the dif- 

 ferent varieties of sea-salt, British and foreign, there was no 

 appreciable quantity, and in some of them no trace whatever 



Vol. VIII. P. L ' H h of 



* Annales de Chimie, t. 20. 



^f* Philosophical Transactions, 1810. 



