Question: In what year did a German scientist succeed in isolating opium’s active ingredient, thereby paving the way for the production of heroin?

Explanation: The lectures explain that morphine was first isolated from opium in 1804–1805 (Sertürner). In 1804 opium was isolated and morphine was created; in 1874 morphine was modified/processed and heroin was created (diacetylmorphine). (Lecture/Reading: Boon, The Road of Excess, Chapter 3; also referenced in Breen, The Age of Intoxication.)