Chemicals · Vol. IV|Gunpowder|c. 9th century

Gunpowder

c. 9th century

Alchemists in Tang China mixed saltpeter, charcoal, and sulfur and found a powder that burned too fast to be a medicine. Song armies used it in fire-arrows, bombs, and early guns. The recipe moved west. Gunpowder is a chemical store of energy that does not need a furnace at the moment of use — a portable, delayed fire.

China (Tang–Song)

Gunpowder — Original plate drawn for this atlas. Not a photograph of a museum object or a copyrighted portrait.

How the mechanism is arranged

Saltpeter, charcoal, and sulfur. Mixed, they store chemical energy that can be released as gas and heat.

How it works

Mix potassium nitrate (oxidizer) with charcoal and sulfur (fuels).
Confine the mix; when ignited, gases expand far faster than a wood fire.
Direct that expansion: a rocket, a bomb, or a ball in a tube.

Why it mattered

Changed fortification and the social cost of armored elites.
Gave mining a blasting tool as well as armies a weapon.
Showed that chemistry could store work for later.

What it unlocked

1876 (Otto four-stroke)Internal combustion engine

For further study

Needham, Science and Civilisation in China, Vol. 5. Gunpowder epic.
Chase, Firearms: A Global History to 1700. Spread and use.

Check

Which ingredient supplies oxygen so the mix can burn in a closed tube?