Lactucarium. The concrete milk-juice of Lactuca virosa Linné (Nat. Ord. Compositae). (U. S. P.) Dose, gr. v— 3 j.

Tinctura Lactucarii

Dose, 3 ss— 3 ij.

Syrupus Lactucarii

Dose, 3 j— 3 iij.

Composition

Lactucarium contains several organic substances and eight to ten per cent of inorganic matter. It yields about fifty-eight per cent of lactucerine or lactucone, an inodorous, tasteless neutral substance, a crystallizable bitter principle, lactucine, and lac-tucic acid.

Physiological Action, and Therapy

The soporific quality of lettuce is known to all who eat this vegetable. Notwithstanding this universal experience, careful experiments have shown that lactucarium possesses a very feeble hypnotic quality, if it be not entirely inert. It is only used as a substitute for opium and its alkaloids when these disagree. The sirup of lactucarium is prescribed to relieve cough, but it is better employed as a vehicle for more powerful agents of the class of expectorants.