rock oil

Naphtha Naph"tha (n[a^]f"th[.a] or n[a^]p"th[.a]), n. [L. naphtha, Gr. na`fqa, fr.Ar. nafth, nifth.] 1. (Chem.) The complex mixture of volatile, liquid, inflammable hydrocarbons, occurring naturally, and usually called {crude petroleum}, {mineral oil}, or {rock oil}. Specifically: That portion of the distillate obtained in the refinement of petroleum which is intermediate between the lighter gasoline and the heavier benzine, and has a specific gravity of about 0.7, -- used as a solvent for varnishes, as a carburetant, illuminant, etc. [1913 Webster]

2. (Chem.) One of several volatile inflammable liquids obtained by the distillation of certain carbonaceous materials and resembling the naphtha from petroleum; as, Boghead naphtha, from Boghead coal (obtained at Boghead, Scotland); crude naphtha, or light oil, from coal tar; wood naphtha, from wood, etc. [1913 Webster]

Note: This term was applied by the earlier chemical writers to a number of volatile, strong smelling, inflammable liquids, chiefly belonging to the ethers, as the sulphate, nitrate, or acetate of ethyl. --Watts. [1913 Webster]

{Naphtha vitrioli} [NL., naphtha of vitriol] (Old Chem.), common ethyl ether; -- formerly called {sulphuric ether}. See {Ether}. [1913 Webster]