MINERAL WATERS OF DUNBLANE. 471 



more than sufficient to convert the whole muriate of lime in 

 the water into sulphate ; and, according to the known solubili- 

 ty of this sulphate, the quantity of water was not sufficient to 

 retain it all dissolved. This quantity was even reduced to a 

 certain extent by evaporation, without any precipitation. The 

 result seems therefore to prove, that sulphate of lime had not 

 been formed, and that sulphate of soda may exist with muriate 

 of lime in solution without decomposition, in the state of dilu- 

 tion which this mineral water affords. 



Another result which I obtained, and which so far favours 

 the opinion that the sulphate of lime is formed in the pro- 

 gress of the evaporation by the reciprocal action of sulphate 

 of soda and muriate of lime, is, that when a small portion of 

 sulphate of soda has been added, the quantity of sulphate of 

 lime obtained is increased : when 10 gi-ains, for example, of 

 crystallised sulphate of soda were added to a pint of the water, 

 after evaporation to dryness, 4 grains of sulphate of lime, 

 which is double the proportion that the water would otherwise 

 have yielded, were obtained, — affording a proof that when sul- 

 phate of soda is dissolved in the water, it produces, in the pro- 

 gress of the evaporation, a corresponding portion of sulphate 

 of lime, and of course also of muriate of soda. 



These results do not absolutely establish the conclusion, that 

 the sulphuric acid exists in this water in the state of sulphate 

 of soda ; yet, on the whole, this is the more probable opinion. 

 If it be admitted, the preceding statement of the ingredients, 

 and their proportions, must be altered. The sulphate of lime 

 is of course to be omitted. The sulphate of soda, which is to 

 be substituted for it, cannot be obtained by any method ; but 

 the quantity of it may be inferred, from the quantity of sul- 

 phate of lime which is formed by its action on the muriate of 

 lime. Real sulphate of lime, and real sulphate of soda, are 



3 2 very 



