\Car*bon"ic\, a. [Cf. F. carbonique. See {Carbon}.]
(Chem.)
Of, pertaining to, or obtained from, carbon; as, carbonic
oxide.
{Carbonic acid} (Chem.), an acid {H2CO3}, not existing
   separately, which, combined with positive or basic atoms
   or radicals, forms carbonates. In common language the term
   is very generally applied to a compound of carbon and
   oxygen, {CO2}, more correctly called {carbon dioxide}. It
   is a colorless, heavy, irrespirable gas, extinguishing
   flame, and when breathed destroys life. It can be reduced
   to a liquid and solid form by intense pressure. It is
   produced in the fermentation of liquors, and by the
   combustion and decomposition of organic substances, or
   other substances containing carbon. It is formed in the
   explosion of fire damp in mines, and is hence called
   {after damp}; it is also know as {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.
{Carbonic oxide} (Chem.), a colorless gas, {CO}, of a light
   odor, called more correctly {carbon monoxide}. It is
   almost the only definitely known compound in which carbon
   seems to be divalent. It is a product of the incomplete
   combustion of carbon, and is an abundant constituent of
   water gas. It is fatal to animal life, extinguishes
   combustion, and burns with a pale blue flame, forming
   carbon dioxide.