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 ?ts to evaporate the water 

 to a certain extent. 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 which.* 

 the water really contains. 



