The concrete milk-juice of Lactu'ca viro'sa Linné.
BOTANICAL CHARACTERISTICS.—A biennial, rank-smelling herb, abounding in a milky, acrid juice. Root napiform; stem 2 to 4 feet high, erect, slender, glaucous, slightly prickly below, covered here and there with blood-red spots. Leaves with midrib prickly, otherwise smooth, finely toothed; radical leaves obovate, undivided, those of the stem lobed, auricled, and partly clasping. Flower-heads panicled, with small heart-shaped bracts; flowers all ligulate, perfect, light yellow.
SOURCE.—Europe; chiefly produced in Scotland, France, and Prussia.
DESCRIPTION OF DRUG.—In sections of plano-convex circular cakes, or angular pieces, of a grayish or reddish-brown color, breaking with a waxy, yellowish-white fracture; odor opium-like and disagreeable, characteristic; taste bitter and acrid. It is partly soluble in alcohol and ether. When triturated with water it yields a turbid solution; boiling water dissolves about 50 per cent., forming a brown infusion.
Powder.—Grayish-brown to dark brown, consisting almost entirely of irregular, angular masses, without any cellulose structure; when mounted in hydrated chloral T.S. the fragments become clear, showing a granular ground mass; from this separated rod-shaped crystals, monoclinic prisms and rosette-shaped crystal-like masses.
To powder lactucarium, the crude drug should be dried at a temperature not exceeding 70°C,
CONSTITUENTS.—Lactucin, lactucopicrin (very bitter and acrid), lactucic acid, O44H32O21 (very bitter, probably an oxidation product of lactucopicrin), lactucerin (lactucone), and wax. Ash, not more than 10 per cent.
Preparation of Lactucerin, Lactucone.—Boiling alcohol extracts it in almost pure state from lactucarium, which has been deprived of resin and caoutchouc.
ACTION AND USES.—Anodyne, hypnotic, and sedative, resembling opium in its action, but much feebler and without the depressing aftereffects. Dose: 5 to 60 gr. (0.3 to 4 Gm.).
- OFFICIAL PREPARATIONS.
- Tinctura Lactucarii (50 per cent.), Dose: 10 to 60 drops (0.6 to 4 mils)
- Syrupus Lactucarii (10 per cent. of Tincture) 1/2 to 2 fl. dr. (2 to 8 Mils).
595. LACTUCA SATIVA.—GARDEN LETTUCE. Popularly used as a mild antispasmodic to allay nervous irritability and mental worry. It yields a lactucarium during flowering, but before that period the juice is pellucid and insipid.
596. LACTUCA CANADENSIS.—WILD LETTUCE. Used as a mild soporific for children. Dose: 20 gr. (1.3 Gm.).
A Manual of Organic Materia Medica and Pharmacognosy, 1917, was written by Lucius E. Sayre, B.S. Ph. M.