$48 Analysis of the Mineral Waters [Nov. 
a mineral water exist—-whether the acids’ and bases are in these 
binary combinations which constitute the different neutral salts, or 
wherher they exist in simultaneous combination, the whole acids 
being neutralized by the whole bases. Jf the former, which is the 
more common, and perhaps the more probable opinion, be adopted, 
it is at least certain that the state of combination may be modified 
by the analytic operations, and that the binary combinations ob- 
tained by these may not be precisely those which existed in the 
water. In the case of the Dunblane water, for example, the in- 
gredients ebtained are muriate of soda, muriate of lime, and sul- 
phate of lime. Now it is possible that the sulphate of lime may be 
a product of the operation, not an original ingredient. The sul- 
phuric acid may exist rather in the state of sulphate: of soda, and 
when, in the progress of the evaporation, the liquor beeomes con- 
centrated, this salt may act on a portion of the muriate of lime, 
and by mutual decomposition form corresponding portions of mu- 
riate of soda und sulphate of lime. 
A question of this kind is not merely one of speculation, but the 
solution of it may sometimes throw light on the properties of mine- 
ral waters, particularly on their powers of affecting the living 
system. ‘The present affords a very good example of this. Sulphate 
of lime is a substance apparently inert. If it exist, therefore, as 
such in the water, it can contribute nothing to its efficacy. But in 
the other state of combination which is supposed, both the quantity 
of the muriate of lime, the more active ingredient, will be greater, 
and the presence of sulphate of soda will in part account for the 
‘purgative operation which the water exerts. 
There is no very direct, and perhaps no decisive, experiment by 
which this question may be determined; for any method which 
would cause the separation of eXher substance as a binary com- 
pound, may also be conceived to operate by causing its formation. 
Thus, though sulphate of lime is obtained by evaporation, this is 
no proof of its prior existence, since the concentration of the solu- 
tion might equally cause its formation, by favouring the action of 
the sulphate of soda, if it exist, on the muriate of lime. - Its sepa- 
ration by a precipitant, by alcohol for example, even if it were ob- 
tained, is liable to the same ambiguity ; a certain degree of concen- 
tration of the watery solution would be necessary for the effect, and 
the further operation of the alcoho} might be precisely on the same 
principle—dimi nishing the solvent power of the water, and thus 
aiding the force of cohesion, i in determining the combination of the 
ingredients which form the least soluble compound. If a different 
mode of analysis were had recourse to, if the whole lime, for ex- 
ample, were precipitated by any re-agent, there would still remain 
the uncertainty with what it had been combined, whether entirely 
with muriatic, or partly with sulphuric acid ; and there is no mode 
of determining this, by obtaining the other product of the action of 
the re-agent, which would not be liable to equal ambiguity ; or, if 
the sulphuric acid were abstracted by a re-agent, there would 
