Spring and Mineral Waiters. 57 
.48 lime 
.77 carb. acid 
1.25 
being about 1 grain of salt in 2000 of water. 
This kind of water is hard and curdles soap ; 
but it is much softened by boiling, and de- 
posits the incrustation so often found in ket- 
tles, &c. If water contains sulphate of lime 
along with supercarbonate, the same treat- 
ment may still be adopted as far as respects 
the supercarbonate. I have recently found, 
with some surprise, that the supercarbonate of 
lime as I call it, existing in waters, or made 
artificially, is rather an alkaline than acid 
compound. 
3. Acetate and nitrate of lead tests. These 
salts are-easily obtained in great purity, and 
are excellent tests for carbonic and sulphuric 
acid, which they precipitate immediately in 
combination with the lead. If the precipi- 
tate be treated with nitric acid, the carbo- 
nate of lead is instantly dissolved, and the 
sulphate of lead (if present) remains undis- 
solved and may be collected and dried, from 
which the quantity of sulphuric acid may be 
determined. 
4. Nitrate and muriate of barytes tests. 
When the object is to ascertain the presence of 
VOL. III. H 
