bitumen
noun[L.]
This name is used to denote various inflammable substances, of a strong smell, and of different consistencies, which are found in the earth. There are several varieties, most of which evidently pass into each other, proceeding from Naphtha, the most fluid, to Petroleum, a viscid fluid, Maltha, more or less cohesive, elastic bitumen or mineral caoutchouc, and Asphalt, which is sometimes too hard to be scratched by the nail.