Definition. - The concrete milk-juice of Lactuca virosa L., a biennial rank-smelling herb growing in Europe.

Description and Properties. - It occurs in sections of plano-convex, circular cakes, or in irregular, angular pieces, externally grayish-brown or dull reddish-brown, internally whitish or yellowish, of a waxy luster, heavy narcotic odor, and somewhat bitter taste. It contains lactucin, lactucopicrin, lactucic acid, lactucerin, and wax.

Dose. - 5-60 grains (0.3-4.0 Gm.).

Official Preparations

Tinctra Lactucrii - Tinctrae Lctucrii - Tincture of Lactucarium. - Dose, 1/4-2 fluidrachms (1.0-8.0 Cc).

Syrupus Lactucarii - Syrupi Lactucarii - Syrup of Lactucarium. - Dose, 1-4 fluidrachms (4.0-15.0 Cc.).

Physiological Action and Therapeutics. - It has been thought that lettuce contains a body somewhat resembling hyoscyamine. If this is so the reputed soporific effects are explainable. Its action is in nowise like opium. It is extremely slightly soporific and also diuretic, which properties, especially in the syrup form, render it of some value in cases of irritating cough, as well as in sleeplessness and nervousness of children.