238 PROOFS OF THE PROPERTIES OF CARBONIC ACID GAS.

SECT. II.

EXPERIMENTAL PROOFS

OF

THE PROPERTIES OF CARBONIC ACID GAS.

Experiment I.

Carbonic acid gas is unfit for combustion.

To prove this, set a vessel filled with this gas, with its mouthupwards, and let down a lighted candle; the candle will be im-mediately extinguished, and the smoke remaining in the gas willrender its surface visible, which by agitation may be throwninto undulating waves.

The following experiment will show this property in a pleas-ing manner.

Experiment II.

Take three glass tubes, of equal heights, and till the first withatmospheric air, the second with carbonic acid gas, and the thirdwith oxigen gas; plunge successively and with swiftness, alighted taper into these three tubes, first into that containing at-mospheric air, then into the tube filled with carbonic acid gas,and lastly into that filled with oxigen gas. In the tube filledwith atmospheric air, the taper will burn with its usual bright-ness ; in that filled with carbonic acid gas, the flame will be sud-