Gunpowder

Gunpowder is a propellant used in firearms, fireworks, and rockets. It is a mixture of charcoal, sulfur, and saltpeter (potassium nitrate).

Gunpowder is a low explosive - it burns rapidly without outside air, and in a confined space, will build up enough pressure to cause an explosion. However, it does not detonate in the manner of a high explosive.

History

Gunpowder was first developed in China, no later than the eleventh century A.D., and possibly earlier. (Early texts are not clear if the mixture described is true gunpowder or not.) It was introduced into Europe in the thirteenth century, through unknown routes. The earliest known description of a true gunpowder formula is in a letter from Francis Bacon to Pope Clement IV in 1267 A.D. By 1275, Albertus Magnus described a formula of four parts saltpeter to one part charcoal and one part sulfur; the chemically ideal proportions are closer to 75% saltpeter, 11.5% sulfur, and 13.5% charcoal.

Gunpowder was used as a propellant for rockets, and to propel shot in cannons and guns. It has gradually been superceded in common use by other propellants which provide higher energy density, lack of smoke, or other desirable properties.