I know laudanum is opium -- this collector in the article was specifically interested in opium as smoked in long pipes heated over a small oil lamp, which you see a lot in sensational fiction of the late 19th/early 20th century but which it turns out most Westerners didn't really know anything about -- it was just hearsay used for exotic effect. My comment was that most of the 19th-century English and American addicts I could name were in fact addicted to the painkiller, not the recreational substance -- i.e., they tended to not actually be frequenting opium dens.