the hard Water at Black Rock near Cork. 5 
though there are some who do not think its flavour agreeable. 
After it has been exposed to the air a little time, it acquires a 
degree of flatness, and produces in the mouth an unpleasant 
taste, as though it contained putrid matter. The insipid and 
disagreeable flavour of the water after exposure to the atmo- 
sphere, seems to be owing to a loss of air from a diminution of 
atmospheric pressure ; for no sooner is the water raised from the 
well, than small glebules of air are disengaged from it, and this 
effect continues for some time. 
2. The water gradually changes litmus paper, and gives to its 
blue colour partial tints of red: but this change does not take 
place after the water has been boiled. The mineral acids, as 
the muriatic and sulphuric, disengage from the water minute 
globules of gas; indeed the water by simple exposure to the air 
evolves gas; and this effect is promoted by the addition of an 
acid, and destroyed by that of an alkali. Liimewater in small 
quantity occasions an immediate cloudiness in the water, which 
soon disappears, and the water resumes its former transparency 5 
but when added in large proportion, there is a permanent de- 
position of carbonate of lime. Even after the water has boiled, 
limewater occasions a milkiness in it; but this effect is not pro- 
duced after the boiling has been kept up for a quarter of an 
hour. These results prove that the water contains an uncombined 
acid; that this acid is the carbonic, and that continued boiling 
is necessary to expel it. 
3. After the water had been exposed in a large shallow glass 
vessel to a warm atmosphere, upon the top of the Observatory 
of the Institution, (during the greater part of two fine summer 
days in June,) an extremely thin and scarcely perceptible earthy 
crust began to form on its surface. This crust dissolved with 
effervescence in diluted muriatic acid, and its earthy matter was 
precipitated by the fixed alkalies in their caustic and carbonated 
state, but not by ammonia. Hence it was carbonate of lime 
originally held in solution, as would seem from the foregoing 
statements, by carbonic acid gas. The separation of carbonate 
of lime in this case is to be referred to the diminished solvent 
power of the water, arising from the loss of a portion of carbonic 
acid, and of water,by evaporation. The water, after the ex- 
posure mentioned, still rendered limewater milky, and afforded 
with alkaline substances, a precipitate having similar properties 
to the earthy crust already noticed. And these circumstances 
seem to prove that the water still contained carbonic acid. gas 
and carbonate of lime. 
4, The water immediately decomposes an aqueous solution of 
soap, and a white flocculent substance swims upon the surface. 
Hence the water in its common state is unfit for washing. If 
F AG, “- a-sohrtion 
