486 ANALYSIS OF THE 



more so, that, previous to the evaporation by which they are 

 obtained, it contains muriate of lime, which being acted on by 

 the sulphate of soda, forms muriate of soda, and sulphate of 

 lime. It is even not improbable, that the carbonate naturally 

 existing in the water, is not carbonate of magnesia, but carbo- 

 nate of soda, which, re-acting, from the concentration by the 

 evaporation, on sulphate or muriate of magnesia, causes the 

 production of the carbonate of magnesia with a corresponding 

 portion of sulphate or muriate of soda ; or, what is equally pro- 

 bable, and presents the same ultimate results, the sulphate of 

 magnesia may, in the progress of the evaporation, be first act- 

 ed on, by the carbonate of soda, forming carbonate of magne- 

 sia and sulphate of soda ; and the sulphate of soda, during the 

 farther concentration, may act on the muriate of lime, and 

 form muriate of soda, and sulphate of lime. It is much more 

 probable, indeed, from the known insolubility of carbonate of 

 magnesia, that it is produced in this way, than that it should 

 exist in a state of solution in so large a quantity, as that in 

 which it is afforded by the evaporation. And thus this water 

 will present a striking example, that the real ingredients of a 

 mineral water, and their proportions, may be very diflFerent 

 from those obtained by the dii'fect analysis ; for it is too obvi- 

 ous, after the preceding observations, to require illustration, 

 that the actual production of certain ingredients by evapora- 

 tion, or any other analytic process, is no certain proof that 

 they pre-existed in the water. It is obvious, too, that if it 

 wei'e proposed to imitate the Cheltenham water by artificial 

 preparation, it could be done much more easily according to 

 this view, than by attempting to dissolve the ingredients obtained 

 by the analysis, an attempt, indeed, which would not succeed. 

 The Dunblane or Pitcaithly water might be converted, so far 

 38 regards the saline ingredients, into a water similar to that of 



Cheltenham, 



