A mixture of...
- 75% potassium nitrate (saltpetre ... which was distilled from urine! Blokes during the reign of the Stuarts used to come round by law, force their way into your house and take your piss for making gunpowder! Not a nice job!)
- 15% charcoal
- 10% sulphur
...which when ignited goes BANG!
Discovered by Chinese alchemists who used it for fireworks. It took the west to get down to serious uses for the black powder other than sticking bangers up a cats arrse and celebrating the Year of a specified animal.
Can be used to accelerate pieces of metal (lead) down a tube to high speeds with the aim of perforating a squaddie.