What is "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.

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.

   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.

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

n. (context dated English) naphtha

n. a dark oil consisting mainly of hydrocarbons [syn: petroleum, crude oil, crude, fossil oil]

Rock oil can refer to either:

• Naphtha
• Petroleum, which literally means "rock oil"
• Rock oil (Scotland) - a substance gathered off sea rocks and used medicinally

Rock oil , is an ointment made from a thin film obtained on rocks by the sea, and used for a relief for burns and scalds.

It is not to be confused with petroleum which means the same.