The Robesonian, Lumberton, North Carolina, March 1, 1904

Wikipedia says:

Lactucarium is the milky fluid secreted by several species of lettuce, especially Lactuca virosa, usually from the base of the stems. It is known as lettuce opium because of its putative sedative and analgesic properties. It has also been reported to promote a mild sensation of euphoria, and at least one fatality has occurred during an attempt to use it for intoxication. Because it is a latex, lactucarium physically resembles opium, in that it is excreted as a white fluid and can be reduced to a thick smokable solid.