the hard Water at Black Rock near Cork. | 7 
of improving the Black Rock water, by which it may be rendered 
soft, and more generally applicable to the purposes of life. One 
is, by the use of an alkaline substance ;—the other, by continued 
boiling for at least a quarter of an hour. And it may be pro- 
per to make a few remarks upon each of those methods. 
1. It is well known to chemists, that waters naturally hard, 
from whatever cause their hardness may arise, are rendered soft 
by an alkali; and the fixed alkalies, in their caustic or car- 
bonated state, afford a general remedy, applicable to every par- 
ticular case of the kind, that can occur. Boiling, on the con- 
trary, is only a particular remedy for hardness in waters, in cases 
when it arises, as in the water at Black Rock, from carbonate 
of lime held in solution by carbonic acid gas. The acid being 
volatile, and its combination with the earthy salt retained by a 
feeble affinity, their union is destroyed by continued boiling; the 
earthy salt (the cause of the hardness in the water) being pre- 
cipitated, and the acid expelled. In other cases, where the 
quality of hardness in waters is occasioned by the presence of 
sulphate or muriate of lime, &c. no changes can be produced in 
such waters by boiling, and the agency of an alkali is indispensa- 
bly necessary to render them soft. The addition of any alkaline 
substance to the Black Rock water, such as potash or soda and 
their carbonates; the substances known in commerce by the 
names of kelp, barilla, pearlash, &c, will all neutralize the fixed 
air in the water, precipitate its earthy matter, and render it soft. 
I found about ten grains of pure dry soda sufficient to render a 
gallon of the water perfectly soft; but the use of this substance 
is precluded, from its expense, and the difficulty of procuring it, 
in this part of the country. I conceive about twenty grains of 
the common potash or soda of commerce would answer the same 
purpose, As any of the alkaline substances before enumerated 
may be used with success, a few practical trials would be suffi 
cient to enable any one to decide upon the alkali that is the 
‘most efficient and ceconomical. In cases when the water is to 
be rendered soft by an alkali, for the purpose of washing, no 
danger can be apprehended from a slight excess of alkali; on 
the contrary,it would be an advantage ; for the alkali, as is well 
known, is the efficient cleansing principle in soap. It would, I 
think, be advisable to add the alkali to the water previous to 
its being heated; and to stir it until it is dissolved. A friend of 
mine was informed that limewater might be used for improving 
the water by separating the fixed air it contains. Lime is al- 
most the only common substance possessing alkaliue properties, 
that cannot be employed for such a purpose ; the existence of 
the smallest quantity of it im a water is sufficient to give it a cer- 
tain degree of hardness, It is to the salts of lime, ecamungeed 
A4 the 
