MINERAL WATERS OF DUNBLANE. 489- 



It might be supposed, that so large a proportion of carbo- 

 nate of soda, could not exist with the muriates of magnesia 

 and lime without decomposing them ; that this view of the- 

 constitution of this water is therefore precluded ; and that 

 Bergman's is ju t. And, in this case, the non-precipitation of 

 the carbonates of magnesia and lime, may be supposed to be* 

 owing to the solvent power of the excess of carbonic acid ; 

 to which cause, accordingly, it has been ascribed. But on ma- 

 king the experiment, I found that the above quantities might 

 be dissolved in a pint of water, independent of the presence of 

 the excess of carbonic acid, without any apparent decomposi- 

 tion ; the solution being transparent, and remaining so on ex- 

 posure to the air. The same fact has even been observed with" 

 regard to the natural water ; for although on exposure to the 

 air it becomes vapid, and its taste is merely sensibly alkaline, 

 the carbonates are not precipitated^ the precipitation takes 

 place only when heat is applied, so ?is to evaporate the water 

 to a certain extents And with regard to this, a fact is men- 

 tioned by. Bergman not less conclusive. The carbonate of 

 lime is first deposited, with scarcely any mixture of carbonate 

 of magnesia ; the latter separates only by continued evapora- 

 tion ; and it is even necessary to evaporate to dryness, and re- 

 dissolve in hot water, to obtain it entirely, — proving that it 



does. 



of real muriate of magnesia. In converting the first of these muriates into car- 

 bonate, 3.2 grains of dry common carbonate, or sub-carbonate of soda, would be 

 expended ; and in the conversion of the second muriate, 5.7 grains, making 8.9 

 grains, to which are to be added 1.4 grain, the quantity contained in the 4 

 grains of the crystallised carbonate obtained as the direct product of the analy- 

 sis, making in all, as stated above, 10.3 grains. Lastly, in these decompositions- 

 of the earthy muriates, 9.7 grains of muriate of soda would be formed, which,., 

 deducted from the 17.5 obtained in the analysis, leaves 7.8 as the quantity whicki 

 the water really contains. 



