THE 
PHILOSOPHICAL MAGAZINE 
AND JOURNAL. 
I, Experiments made upon the hard Water at Black Rock 
near Cork, with a view to render the Waters of Limestone 
Districts more applicable to domestic Uses. By EDMUND 
Davy, Professor of Chemistry and Secretary to the Cork In- 
stitution. 
To Mr. Tilloch. 
Tuerr is a striking similarity in the appearance and in the 
composition of the great arrangements of Nature in different 
countries, and it extends to the waters, as well as to the atmo- 
sphere and the solid strata of the earth. The chemical consti- 
tution of water is uniformly the same in every part of the globe, 
and all the variable properties it exhibits in different situations, 
whether evanescent or permanent, are principally owing to a di- 
versity of soil. All natural waters contain a variable quantity of 
foreign ingredients, which they derive from the strata through 
which they flow, or the atmosphere by which they are sur- 
rounded. ‘The purest springs usually rise in beds of gravel, or 
in silicecus or argillaceous rocks, and they contain, for the most 
part, only a minute portion of saline matter, which is principally 
common salt. The waters of limestone or calcareous districts 
generally contain a much larger quantity of solid ingredients. 
The substances they frequently hold in solution are carbonate 
and sulphate of lime, and these earthy salts occasion that pecu- 
liar quality in waters, commonly known by the name of harduess. 
Hard waters, as is well known, do not readily dissolve soap, or 
form a good lather with it; on the contrary, they partially de- 
compose it, and a light flocculent substance is produced, which 
is insoluble in water. Hence such waters, in their common 
state, are unfit for washing, and for other domestic purposes ; 
and they are conceived to be very inferior to soft waters, for 
making vegetable infusions, such as tea, coffee, &c. 
The waters in the limestone strata, in the county of Cork, so 
far as 1 can learn, and especially those situated in such strata on 
the south side of the river Lee near Cork, belong to the class of 
Vol. 52, No.243, July 1818. A2 hard 
