0 a salty-tasting white powder used to preserve meat, and also used in producing explosives and fertilizers (= substances that help plants grow) --
Heating turns the saltpetre into potassium oxide or hydroxide, which absorbs carbon dioxide from the air.
This resulted in an improved method of extracting saltpetre and consequently higher quality gunpowder.
The saltpetre was used in the production of gunpowder.
It also has saltpetre, gunpowder, and lead-smelting works.
Soon this became a trading centre for saltpetre.
After testing the saltpetre, they find that instead of sodium nitrate, the can contains sodium nitrite.
The method of making it by heating sulphur with saltpetre has been attributed to him.
Natural saltpetre has the same origin as common salt.
