Bitumen
Besides coal there is found in the earth a class of inflammable bodies--liquids, semi-liquids, and solids--which possess properties very similar. The purest and most fluid of these hydrocarbons is naphtha; when of the consistence of oil it is termed petroleum; slightly thicker it is pitch; after which we have elastic bitumen, and in its hardened state it is called asphaltum.
Naphtha dissolves bitumen and caoutchouc. See PETROLEUM; ASPHALTUM.