COAL TAR n.
A thick, black, tarry liquid, obtained by the distillation of bituminous coal in the manufacture of illuminating gas; used for making printer's ink, black varnish, etc. It is a complex mixture from which many substances have been obtained, especially hydrocarbons of the benzene or aromatic series.
COKE n.
of its bitumen, sulphur, or other volatile matter by roasting in a kiln or oven, or by distillation, as in gas works. It is lagerly used where [Written also coak.] Gas coke, the coke formed in gas retorts, as distinguished from that made in ovens.