Lini Semen. The seed of Linum usitatissimum; common Linseed or Flax; Lin. Syst., Pentandria pentagyuia: an indigenous plant.

Lini Farina. Linseed Meal. Lini Oleum. Linseed Oil.

Description. The seed is small, oval, oblong, and flattened, pointed at one end; dark brown and shining on the surface, and white within. The flour or linseed meal, consists of the seeds ground and deprived of their oil by expression. The oil is of a light yellow colour, similar in appearance to most other vegetable oils.

Prop. & Comp. The seeds contain a fixed oil, about 20 per cent., and mucilage, together with the ordinary constituents of seeds; the oil is found in the kernel, the mucilage in the envelope or testa of the seed. After the expression of the oil, the marc which remains is called linseed or oil-cake: and when powdered, linseed meal. The fixed oil, sp. gr. 0.93, rapidly absorbs oxygen from air and forms a varnish, hence called a drying oil; it contains oleine and margarine. The oleic acid from linseed oil differs somewhat from ordinary oleic acid.

Off. Prep. of the Meal. Cataplasma Lini. Linseed Poultice. [Not officinal in U. S. P.] (Boiling water, ten fluid ounces; linseed meal, four ounces; olive oil, half a fluid ounce. Mix the linseed meal with the oil, then add the water gradually, constantly stirring.)

Of the Seed. Infusum Lini. Infusion of Linseed. [Infusum Lini Composituin. U. S.] (Linseed, one hundred and sixty grains; fresh liquorice, sliced, sixty grains; boiling distilled water, ten fluid ounces.)

Therapeutics. Internally, when given in the form of the infusion linseed is demulcent, from the mucilage and the little oil contained in it, and has been employed in catarrhal and urinary affections; also in diarrhoea and dysentery. Externally, linseed powder is used as a poultice to inflamed and suppurating parts. The oil is a useful emollient to burns or scalds, either alone or mixed with lime-water, and the Linimentum Calcis, Edin., is made with it in place of olive oil.

Dose. The infusion may be taken ad libitum.

Linum Catharticum, or Purging Flax, was contained in the Edinburgh Pharmacopoeia, 1848. The dried plant is used made into infusion, and given in doses of about thirty grains; it has no particular value as a purgative.