\Naph"tha\, n. [L. naphtha, Gr. ?????, 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}.