Cār'bon, n.

n. [Fr. carbone, from Lat. carbo, coal, Pr. carbo, O. Fr. & Sp. carbon, N. Fr. charbon, It. carbone.] (Chem.) An elementary substance, not metallic in nature, which predominates in all organic compounds. It is combustible, and forms the base of charcoal, and enters largely into mineral coals. In its pure crystallized state it constitutes the diamond, and is the hardest of known substances, occurring in monometric crystals like the octohedron, &c. It enters largely into graphite, or black-lead, and in this it is soft, and occurs in hexagonal prisms or tables. When united with oxygen it forms carbonic acid, and carbonic oxide, according to the proportions of the oxygen: when united with hydrogen, it forms various carbureted hydrogens, one of which is the common illuminating gas.