Oleum Picis Liquidae. Oil of Tar. Oleum Picis Rectificatum, Rectified Oil of Tar.

Botanical name: 


Related entries: Resin - Canada turpentine - Oil of Pine - Oil of Turpentine - Frankincense - Tar - Hemlock spruce bark - Burgundy Pitch - Larch bark

Oil of tar is obtained by the distillation of wood tar, and consists of hydrocarbons and phenols. It is official in the U.S.P., and occurs when freshly distilled as a colourless liquid, but becomes yellowish to reddish-brown in colour on exposure to air. It has a strong tarry odour and taste. Specific gravity, 0.950 to 0.970 (0.945 to 0.965 at 25°). Creosote is known in some districts as oil of tar.

Soluble in alcohol, the solution having an acid reaction on litmus.

Action and Uses.—Oil of tar has the properties of wood tar in a less objectionable form. It is employed as an inhalation with hot water in chronic catarrhal affections, and is administered with syrup and glycerin as a pulmonary antiseptic in phthisis. It is also occasionally used as an anthelmintic and intestinal antiseptic. Externally, it is used as an antiseptic and stimulant in eczema and other skin diseases.

Dose.—½ to 3 decimils (0.05 to 0.3 milliliters) (1 to 5 minims).


Synonyms.—Light Oil of Tar; Spirit of Tar.

Rectified oil of tar is obtained by redistillation of oil of tar from the brown resinous bodies which are formed in it by oxidation. The distillate is treated with soda-lye to remove creosote, and redistilled, this treatment being repeated several times. The product is a mobile, colourless, highly refracting oil, which tends to become sherry-coloured on keeping. Specific gravity, 0.840 to 0.870.

Action and Uses.Rectified oil of tar is a powerful deodoriser, antiseptic, and parasiticide.


Pigmentum Picis cum Iodo, B.P.C.—TAR AND IODINE PAINT. Syn.—Pigmentum Iodi et Olei Picis; Pasta Iodi et Picis; Coster's Paste.
Iodine, 20; rectified oil of tar, 80. Used as an application for ringworm.

The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.