Fire and brimstone! You’ve heard the phrase. But what’s brimstone?
Sulfur has some interesting properties. It’s flammable, and when burned, it emits a blue flame (as it produces sulfur dioxide, SO2) and melts into a blood-red liquid. Many of its compounds smell horrible. Sulfur compounds are responsible for the smell of skunk scent and rotten eggs, among other things.
Why does brimstone have historical importance? Many reasons, but probably chief among them is that it’s one of the three ingredients used to make black gunpowder, the other two being charcoal and saltpeter. Brimstone (sulfur) and charcoal are the fuels, and saltpeter is the oxidizer. Thus during the Gunpowder Age, these three raw materials have value. In one of my upcoming books, one of the conflicts centers around a trade agreement over shipments of brimstone, which one country has lots of and another country doesn’t. No brimstone, no gunpowder.
For more information, I recommend this book: Gunpowder: Alchemy, Bombards, and Pyrotechnics : The History of the Explosive That Changed the World, by Jack Kelly.