There is no "opium good". Would you propose we add a new good to the game for that?
If we are going to add new goods, I'd also be most interested in a "Coal" item that appears in the last two time periods.
Then we can have the Steam Frigate engines be coal-powered instead of burning planks.
Btw @Pieter Boelen if we are adding goods I would like to add "Iron" or something like that to so i have more things for the smith fetch quest.