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.