A volatile oil distilled from tar.
PROPERTIES.--An almost colorless liquid when freshly distilled, but soon
acquiring a dull, reddish brown color, and having a strong tarry odor
and taste. Soluble in alcohol.
DOSE.--Horses and cattle, 1 to 2 oz.; sheep and pigs, 2 to 4 dr.; dogs,
¹⁄₂ to 2 dr.
ACTIONS.--Internally, is an antiseptic stimulant expectorant.
Externally, it is rubefacient and if continually rubbed in may cause
papules and pustules.
USES.--Tar or the oil is commonly used in cough mixtures and in
subacute and chronic bronchitis. By inhalation (which is done by pouring
tar on a heated shovel or a shovel containing live coals or by adding a
pint of tar to a gallon of water, heating the mixture by placing hot
bricks or stones in the solution) either method is excellent for its
local antiseptic and stimulating effects in the various catarrhal
diseases; bronchitis, distemper, strangles, etc. Care should be used so
that the vapor be not inhaled too hot.
Externally, it is a very useful agent in various skin diseases, both
parasitic and non-parasitic; for this the official ointment may be used,
or if used on a large surface on dogs it should be diluted with an equal
amount of zinc ointment.