1815.) of Dunblane and Pitcaithly. 357 
from the combined operation of muriate of lime and muriate of 
iron. 
It deserves to be remarked, that in the most essential ingredients, 
the muriate of lime and the iron, the Dunblane and Pitcaithly 
waters are similar to the Bath water, only with regard tothe former 
ingredient much stronger ; the other differences are unimportant ; 
the larger quantity of sulphate of lime, and the small quantity of 
silica in the latter, cannot be supposed to contribute any thing to 
its medicinal operation; the difference in the proportion of sulphate 
ef soda is trivial, and the larger proportion of muriate of soda in 
the other waters may rather be.an advantage, rendering them more 
agreeable to the taste and to the stomach. The principal difference 
will therefore be that of strength with regard to the most active in- 
gredient, the muriate of lime. The quantity of this isso large that 
the tonic quality of the Dunblane or the Pitcaithly waters can 
scarcely be observed, and perhaps evgn scarcely: obtained, their 
action being more peculiarly on the bowels. It is accordingly as a 
saline purgative that the Pitcaithly water has been celebrated; and 
it is principally in those diseases in which this effect is sought to be 
obtained that it has been used. The Dunblane water, from the 
similarity of its operation, would no doubt be employed in diseases 
of asimilar kind. But whatever advantage might be derived from 
this purgative effect, it cannot fail to be perceived that a different 
eperation, not less useful, may be obtained from them. If suffi- 
ciently diluted, so as to avoid altogether the operation on the bowels, 
the stimulant operation on the stomach and general system might 
be exerted by these waters, similar to that of the Bath waters, and 
under this form they might prove useful in diseases very different 
from those in which they might otherwise be employed. As they 
would require, too, large dilution to reduce them to this state, the 
temperature of the Bath water might easily be given, by adding 
the requisite proportion of hot water, by which a greater similarity 
of operation would be obtained. And the Dunblane water in par- 
ticular, containing so much larger a proportion of iron-than the 
Bath water does, the dilution requisite to give it the same strength, 
with regard to the muriate of lime, would still leave an equal degree 
of chalybeate impregnation. If the preceding observations, there- 
fore, are just, the Dunblane and Pitcaithly waters may be con- 
verted, in all the essential parts of the chemical composition, inte 
a water similar to that of Bath. } 
From the preceding statement of their composition, it is easy to 
discover how this may be done. To give the same proportion of the 
principal ingredient, the muriate of lime, the Dunblane water 
would require to be diluted with from six to seven parts of pure 
water ; the same degree of dilution would bring it to nearly the 
same strength with regard to the iron; if a pint of it were diluted 
with this portion of water, about 35 grains of sulphate of soda 
would require to be added, to render the composition, with regard 
fo this ingredient, perfectly alike, if this were thought essential, 
