This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Caraway consists of the half-fruits or mericarps, commonly called seeds, of Carum Carui, a small biennial umbelliferous plant, growing wild in many parts of Europe, and cultivated both there and in this country.
They are usually separate, about two lines long, rather flat, slightly curved inwards, with five yellowish longitudinal ridges, and intervening spaces of a dark-brown colour. They have an aromatic odour and taste, which depend on a volatile oil. This, when separated by distillation, is at first colourless, but becomes yellow with age, and ultimately brownish. It is lighter than water. The medical properties and uses are the same as those of fennel-seed. An Infusion is prepared in the same way, and used in the same dose. The Volatile Oil (Oleum Cari, U.S.; Oleum Carui, Br.) is likewise used for the same purposes, and in the same manner as that of fennel-seed, in a dose varying from one to ten drops. It is occasionally applied to the relief of toothache, by being introduced upon cotton into the carious cavity. It probably acts by deadening sensibility through its powerful stimulation. There is an officinal Water (Aqua Carui,Br,), which is prepared from the seeds by distillation, and used like fennel-water. The old London Spirit of Caraway was abandoned in the preparation of the British Pharmacopoeia. Caraway was known to the ancients.