Taught us to mix sulphur and saltpeter .

你教我们去调配硝石与硫磺。

Where did you get the saltpeter ?

你从哪里拿到硝酸钾?

Back then , potash was derived from the ashes of hardwood trees and other plants , and mainly used to make soap , glass and saltpeter for gunpowder .

那时碳酸钾是从硬木树和其他植物的灰中提取出来的，主要用于生产肥皂、玻璃和火药硝石。

Humberstone processed the largest deposit of saltpeter ( nitrate 's nickname ) in the world and provided the valuable mineral to countries in north america and europe for fertilizers , food preservatives and explosives .

亨伯斯通曾经加工了全世界最大储量的硝酸钾（硝酸盐的小名），并且为北美和欧洲国家提供过用于化肥、食品防腐剂和炸药的有价值矿物。