Tar is a product obtained by the destructive distillation of the wood of several varieties of pine. It contains pyroligneous acid, methylic alcohol, acetic acid, creosote, and several hydrocarbons, one of which is called toluene, also oil of tar, with other oily bodies, and pyrocatechin.

The rectified oil, oleum picis liquidae rectificatum, is used locally and by inhalation. It contains a large number of compounds, among which are creosote and carbolic acid.

Tar ointment has 50% of tar. The syrup of tar has 5 Gm. in 1000 mils. Average dose, ʒ i.-4 mils.