Concepts explained
Searching for the Elixir of Life, They Made Gunpowder
Some people searched for a medicine of long life. They mixed all manner of things and heated them. Then they burned off their beards and blew up their houses. The record of that accident is the first record of gunpowder. Six hundred years later a man in Goryeo worked out how to make it.
Why it burns so fiercely
Piece one said burning needs oxygen from the air — the reason a glass over a candle puts it out. So an ordinary fire burns only as fast as air can reach it. That is why a log takes hours.
But one of the three, a white powder called saltpetre, carries oxygen inside itself. No need to wait for air. It hands oxygen straight to the charcoal and sulphur beside it.
The old makers had no word for oxygen. But they learned by experience that saltpetre gives out 'what fire needs' on its own. So they varied the proportions to make fireworks, fired signals instead of lighting beacons, and in the end built weapons.
Nobody would teach the recipe
Once gunpowder became a weapon, the recipe became a secret. In late Goryeo, pirates raided from the sea, and Goryeo had no gunpowder. China would neither sell it nor teach it.
Charcoal and sulphur are easy to get. The trouble was saltpetre. It is not a mineral you dig. It gathers slowly in the soil under old floors, around hearths, on the ground of animal pens. You collect that soil, steep it in water, boil it down and filter it to get white crystals. Which soil, how many steepings — all of it is know-how, impossible to find unless someone tells you.
Choe Museon gathered that know-how piece by piece from Chinese merchants passing through the capital. In 1377 the state opened an office for making gunpowder. Three years later, facing five hundred pirate ships off Jinpo, he sailed out with cannon aboard and burned them — one of the earliest organised uses of gunpowder weapons at sea anywhere.
A little further in
Why it pushes so hard
There is one more reason gunpowder pushes so hard. Remember piece five: gas grains want a big room. Gunpowder is a solid, but in the instant it burns almost all of it becomes gas. The same grains suddenly demand a room hundreds of times larger. That shove hurled stones and broke ships.
Piece one's candle became gas too — slowly, only as fast as air arrived. Candle and gunpowder are the same event. Only the speed differs.
They never found the elixir. But this series' last piece is about chemistry that truly kept people alive: the man who made bread from air.
The question that remainsThey found something entirely different from what they sought. Should that be called failure?