Page:The chemical history of a candle.djvu/157

of the water, I find that it tastes a little acid to the mouth: it is impregnated with carbonic acid; and if I now apply a little lime-water to it, that will give us a test of its presence. This water will make the lime-water turbid and white, which is proof of the presence of carbonic acid.

Then it is a very weighty gas—it is heavier than the atmosphere. I have put their respective weights at the lower part of this table, along with, for comparison, the weights of the other gases we have been examining:—

	Pint.	Cubic Foot.
Hydrogen,	3/4 grains.	1/12 ounce.
Oxygen,	11 9/10 "	1 1/3 "
Nitrogen,	10 4/10 "	1/16 "
Air,	10 7/10 "	1 1/5 "
Carbonic acid,	16 1/3 "	1 19/16 "

A pint of it weighs 16 1/3 grains, and a cubic foot weighs 1 9/10 ounce, almost two ounces. You can see by many experiments that this is a heavy gas. Suppose I take a glass containing nothing else but air, and from this vessel containing the carbonic acid I attempt to pour a little of this gas into that glass;