In season: April to October; Greek Lettuce - all the year.

The Lettuce is said to have been introduced into England in 1562, but from what country is unknown. Various kinds from Maryland are now possessed by us. It possesses in its juice a species of opium.

If the stem of the lettuce when it is coming into flower be wounded with a knife, a milky fluid appears. In the open air it soon grows brown and dries; its smell resembles opium and is narcotic. It has a pungent bitter taste, and acts like opium.

The principal ingredient in it is said to be a substance called Lactucine, of which the extract contains about one-fourth of its weight. The juice is called Lactucarium. It exists, of course, in all lettuce leaves; therefore a salad has narcotic and soothing properties. Eaten at night, it induces sleep; by day it calms the nervous system. Lettuce is therefore a valuable article of food.