Car-bōn'ic, a.

a. [Fr. carbonique.] Of, or pertaining to carbon; as, carbonic ether. Gregory.

Carbonic acid (Chem.), an acid composed of one part of carbon and two parts of oxygen. In its ordinary condition it is a gas, but it may be reduced to a liquid or solid state by cold and pressure. It is a heavy gas, totally unfit for respiration. It is given out by animals in breathing, by liquors while fermenting, by the decomposition of all substances, and by the combustion of wood, coal, &c., and will extinguish flame, and even life: hence it is called choke-damp and mephitic air. Water will absorb its own volume of it, and more than this under pressure, and in this state becomes the common soda-water of the shops, and the carbonated water of natural springs. Combined with lime it constitutes limestone, or common marble and chalk. Plants imbibe it for their nutrition and growth, the carbon being retained and the oxygen given out. Gregory.—Carbonic oxide, a gaseous compound of one equivalent of carbon and one equivalent of oxygen. It is fatal to animal life, extinguishes combustion, and burns with a pale blue flame, forming carbonic acid.