Linum usitatissimum, Linne'. The dried ripe seed with not more than 2 p.c. other seeds or foreign organic matter, yielding not less than 30 p.c. non-volatile, ether-soluble extractive -- 98 p.c. being saponifiable.

Habitat. C. Asia, Egypt, S. Europe, spontaneous in most temperate countries; cultivated in Russia, Egypt, India, United States, S. Europe, England, Holland.

Syn. Flaxseed Flax, Lint-bells, Winter lien; Br. Lini Semina, Lini Semina Contusa (Crushed); Fr. Lin, Semence (Graine) de Lin; Ger. Semen Lini, Leinsamen, Flachssamen.

Li'num. L. See etymology, page 330, of Linaceae.

U-si-ta-tis'si-mum. AS. fleaz, flechten, to braid, plait, twist -- i.e., its fibers, + seed.

Plant

An annual; stem .6 M. (2 degrees) high, stiff, erect, solitary, round, smooth, green; leaves small, lanceolate, acute, entire, sessile, pale green, 2-4 Cm. (4/5-1 3/5') long; flowers June-July; terminal, bluish; fruit August, globular capsule, size of pea, with persistent calyx at base, crowned with sharp spine, 10-seeded in distinct cells. SEED, ovate, oblong-lanceolate, flattened, obliquely pointed at one end, 4-6 Mm. (1/6-1/4') long, brown, smooth, shiny, raphe a distince yellow ridge along one edge, hilum and micropyle in depression below pointed end; internally light yellow, brownish; odor slight; taste mucilaginous, oily.

Powder

yellowish-brown -- large oil globules, irregular fragments of endosperm and seed-coat, the latter with pigment cells filled with brownish insoluble contents, stone cells with porous walls, aleurone grains. MEAL (ground, lini farina, crushed linseed), yellow with numerous brown coarse fragments -- seed-coat and kernel. Test: 1. Boil 1 Gm. fat-free powder or meal with water 50 cc., cool -- filtrate + iodine T.S. not more than faint blue (abs. of starch or starch-bearing seeds). Solvent: boiling water. Dose, 3j-2 (4-8 Gm.).

Adulterations

Seed

Foreign seeds and earthy matter 1-25 p.c. -- mustard, rape and other cruciferous seeds, sand, small stones;

Powder

Damaged flour, cornmeal, other starchy substances, recotnized by microscope or iodine test; expressed cake and tht to which mineral oil has been added.

Commercial

The flax is of ancient origin, being prized for its fabric and medicinal properties; most of our seed now come from Russia and Germany, but the United States furnishes considerable. When exposed to heat, light, damp atmosphere, or otherwise carelessly preserved, especially the ground, it is subject to insect attack, and should not be used after 1 year old.

Constituents

Fixed oil 35-40 p.c. (in nucleus), Mucilage, CHO, 15 p.c. (In integuments--viscid, odorless, nearly tasteless, precipitated by alcohol, lead subacetate, but not by tannin), proteins 25 p.c., tannin, amygdalin (resin, wax, sugar, no starch (except in young seed), ash 4-6 p.c.--phosphates sulphates, chlorides of potassium, calcium, magnesium.

Oleum Lini. Linseed Oil, U.S.P. -- (Syn., Ol. Lini, Oil of Flaxseed, Raw Linseed Oil; Fr. Huile de Lin; Ger. Leinol, Leinsamenol.)  This fixed oil, usually obtained by drying the seed with heat, crushing, and expressing, is a yellowish, oily liquid, peculiar odor, bland taste; gradually thickens and darkens on exposure, acquiring a pronounced odor and taste; slightly soluble in alcohol, miscible with ether, chloroform, petroleum benzin, carbon disulphide, oil of turpentine; slightly acid; sp. gr. 0.930, congeals at -20 degrees C. (-4 degrees F.); consists of liquid glycerides of oleic acid, CHO(5), linolenic acid, CHO(15), and isolinoleic acid, CHO(65) 85-90 p.c., also a mixture of palmitin, myristin, and stearin 10-15 p.c.; also claimed to consist chiefly of linoleic acid, 22-25 p.c. of linolenic acid, and 5 p.c. of solid fatty acids; 1 p.c. of non-saponifiable matter.  Linolein, the glyceride of linoleic acid, is considered the drying constituent, which on exposure is converted into oxylinoleic acid hydrate, and finally into linoxyn, CHO (insoluble in ether, and soon forms in the boiled oil).  Yield by cold process 16-20 p.c., by heat 25-28 p.c., the latter being darker, with stronger odor and more acid taste.  Tests: 1. Linseed oil spread in thin layer on glass plate forms a hard, transparent film (abs. of non-drying oils).  2. Add 3 Gm. Potassium hydroxide to oil 10 cc. + alcohol 10 cc. + distilled water 10 cc., heat on water-bath until clear; the addition of distilled water 100 cc. -- clear solution, free from oily drops (abs. of mineral or rosin oils).  3. Oil 2 cc. + glacial acetic acid 2, agitate, cool, add sulphuric acid 1 drop -- greenish color (abs. of rosin or rosin oils, which produce a violet color).  Impurities: Free acid, non-drying oils, mineral or rosin oils, rosin.  Should be kept in well-stoppered containers, and that which has been "boiled" must not be used or dispensed.  Dose, 3ss-2 (15-60 cc.).

Preparations

Seed

1. Species Emollientes, Emollient Cataplasm, N.F., 20 p.c.  OIL: 1. Sapo Mollis.  Soft Soap.  (Syn., Sapo Moll., Sapo Viridis, Green Soap; Fr. Savon (mou) vert; Ger. Sapo kalinus, Kaliseife, Grune seife.)

Manufacture

Boil, stirring frequently, dekanormal solution of potassium hydroxide 29 cc. and sodium hydroxide 110 with linseed oil 400 and water q.s. 925, add glycerin 50 cc., boil until clear, add hot water q.s. 1000 Gm., let stand, stir until water absorbed.  It is a soft, unctuous, yellowish-white mass, slight characteristic odor, alkaline taste; aqueous solution alkaline; solution in hot distilled water (1 in 20) nearly clear.

Preps.: 1. Linimentum Saponis Mollis.  Liniment of Soft Soap.  (Syn., Lin. Sapon. Moll., Tincture of Green Soap, Spiritus Saponis Kalinus Hebra; Fr. Teinture de Savon vert; Ger. Hebra's Seifenspiritus.)

Manufacture

65 p.c.  Mix oil of lavender 2 cc. with alcohol 30, add soft soap 65 Gm., stir or agitate until dissolved, set aside 24 hours, filter, add alcohol q.s. 100 cc.; used externally.

2.  Linimentum Calcis, 50 p.c.  3. Liquor Cresolis Compositus, 35 p.c.  4. Ceratum Resinae Compositum, Deshler's Salve, N.F., 13.5 p.c.  5. Pasta Zinci Mollis, N.F., 25 p.c.  6. Petroxolinum Sulphuratum, N.F., 37 p.c.

Unoff. Preps.: SEED.  Infusion, 5 p.c.  Compound Infusion, 5 p.c., + glycyrrhiza root 2 p.c.  These were once official and are effective from the dissolved mucilage of the epithelium (testa), which is altered starch.  Dose, ad libitum.  Decoction, 5 p.c.  Poultice.

Properties

Demulcent, emollient, diluent, diuretic.

Uses

Infusion or tea for inflammation of mucous membranes of respiratory, digestive, and urinary organs, renal and vesical irritation, catarrh, dysentery, calculi, strangury.  Decoction, owing to the oil it contains, is less acceptable to the mouth, but all the better for enema.  Poultice of ground meal to enlarged glands, swellings, boils, pneumonia, etc., made by adding boiling water to meal for proper consistency and bringing to a boil.  Should coat skin with glycerin, olive or other oil before applying, and place as near to affected spot as possible; may cover with oiled silk to retain heat and moisture, and may add olive oil, lard, laudanum or any anodyne, stimulating, or astringent solution to poultice.  The oil is laxative (3j; 30 cc.), excellent in piles (3j-2; 20-60 cc. night and morning); sometimes it is added to purgative enemata, also to cover erysipelatous and irritated skin surfaces, but with the disadvantages of soon drying (thus rendering skin stiff) and becoming sour and irritating.  The linimentum calcis is applied to recent burns to allay irritation.

Allied Products

1. Flaxseed Cake, Oil-cake. -- Flaxseed when ground yields cake-meal, and this, after being deprived of oil, becomes oil-cake; it still contains all of the nitrogen, 4-5 p.c., and, moreover, a little oil, thus serving well as a cattle food; yields ash 5-8 p.c.

2. Boiled Linseed Oil. -- Obtained by heating oleum lini to 130 degrees C. (266 degrees F.), while passing a current of air through it, when it boils, losing 6-8 p.c. by weight; or may heat and add litharge, red lead, manganese dioxide, lead acetate or manganous borate, thereby increasing the oil's weight and drying properties.  It is darker in color, thicker, sp. gr. 0.939-0.950, and dries faster, hence useful in painting, varnishing, etc., but must never be used in liniments as a substitute for the official ("raw") oil, since irreparable injury (from forming crusts) might be occasioned to burns, etc., in removing dressings.

3. Flax Liber-fibers. -- These furnish linen, which, when scraped, gives lint, while the primitive short fiber is useful as tow.