Opium is a narcotic drug, which that is obtained from the unripe seed pods of the opium poppy (Papaver somniferum). To harvest opium, the skin of the ripening pods is scored by a sharp blade. The slashes exude a white, milky latex which dries to a sticky brown material that is scraped off the pods as raw opium.
Opium has been a major item of trade for centuries, and widely used as a painkiller and sedative. Most patent medicine of the 19th century were based around laudanum (a solution of opium in alcohol). In the 19th century, the attempt by China to stop the British trade in opium from India was the cause of the Opium War which led to Britain acquiring Hong Kong.