MINERAL WATERS OF DUNBLANE. 479 



ant medicinal effect. And with regard to the other substan- 

 ces, the reasoning whence their possible operation has been 

 inferred, instead of removing the difficulty, rather places it in 

 a clearer light. 



The view of the constitution of mineral waters stated above, 

 enables us to assign to the Bath water a much more active che- 

 mical composition. There is every probability that muriate 

 of lime is its powerful ingredient. The principal products of 

 its analysis are sulphate of lime, muriate of soda, and sulphate 

 of soda. The proportion of sulphate of lime is such, that part 

 of it must pre-exist in the water, but part of it, there is reason 

 to conclude, is a product of the analysis ; the muriate of soda is 

 entirely so, and the quantity of sulphate of soda is larger than 

 what the analysis indicates. In other words, there exist in it 

 muriate of lime, sulphate of soda, and sulphate of lime, and 

 during the evaporation, the muriate of lime being acted on by 

 a portion of the sulphate of soda, muriate of soda and a cor- 

 responding portion of sulphate of lime are formed. 



On the probability of this view, I need not, after the prece- 

 ding illustrations, offer any observations. The obtaining cer- 

 tain saline compounds from a mineral water by evaporation, 

 leads, no doubt, at first to the conclusion, that they are its in- 

 gredients ; it is the conclusion, accordingly, which has hither- 

 to been always drawn, and we are disposed to regard this as 

 evidence establishing this conclusion, in some measure, in op- 

 position to any different view of the composition. But this is 

 merely oversight or prejudice. If it can be shewn, that the ele- 

 ments of these compounds may equally exist in the water in a 

 different state of combination, which the evaporation must 

 change, the conclusion that they do exist in such a state is a priori 

 as probable, as the conclusion that they exist in the state in which 

 they are actually obtained. It is demonstrable, that if muriate 

 of lime and sulphate of soda exist in a mineral water, or, what 



8 P 2 is 



