Linked from
The 28 pages that link to Gunpowder, each with the reason it gives.
FirearmRelated: Its use as a propellant made early firearms possible.
Cartridge (firearms)Related: Its combustion creates the pressure that drives the projectile forward.
Potassium nitrateRelated: Potassium nitrate is the oxidizer in traditional black powder.
ArquebusRelated: Its rapid combustion propelled the arquebus’s lead ball.
Wujing ZongyaoRelated: The compendium records early Song recipes and military uses of gunpowder.