The flowering herb of Lac-tuca virosa. a native of Britain.

Composition.-Extract of lettuce contains, besides many other ingredients, a crystalline bitter principle, lactucin, and lactucic acid, of uncertain composition.

Preparation.

Extractum Lactucae.-A green extract. 1 1/2 in 1. Dose, 5 to 10 gr.

Action And Uses

Lactucin is slightly hypnotic. The extract may cause some confusion of mind, headache, and diaphoresis ; and acting as a mild sedative and carminative, it makes an excellent pill-basis for some purgatives, such as calomel.