In '724 Hermann Boernaave referred to the oleum terrae of Burma, and "Barbados tar" was then well known as a medicinal agent.
The Latino-barbaric word Olibanum (quasi Oleum Libani), the common name for frankincense in modern commerce, is used in a bull of Pope Benedict IX.
The volatile oil - oleum cubebae - is also official, and is the form in which this drug is most commonly used, the dose being 5 to 20 minims, which may be suspended in mucilage or given after meals in a cachet.
The dry salt is very hygroscopic; it deliquesces into an oily solution ("oleum tartari") in ordinary air.
Ferric chloride, FeCl31 known in its aqueous solution to Glauber as oleum martis, may be obtained anhydrous by the action of dry chlorine on the metal at a moderate red-heat, or by passing hydrochloric acid gas over heated ferric oxide.