an unctuous inflammable substance, drawn from several natural bodies, as animal and vegetable substances. See Chemistry and Materia Medica Index. For the construction of an oil mill, see Gray's Experienced Millwright; and for an account of a very simple apparatus for expressing oils from different seeds at Bangalore in the East Indies, see Phil. Mag. vol. xxx. p. 329.

Rock Oil. See Petroleum, Mineralogy Index.

Ointment, in Pharmacy. See Unguent, Materia Medica Index.