The pervasive formula for early propellants was a simple mechanical mixture of charcoal, sulfur, and potassium nitrate, known as black powder. This technology did not arise in Europe until the thirteenth century A.D., although it is likely that the Chinese had launched projectiles with black powder two hundred to three hundred years earlier.
Priming smoke in rear and discharge smoke in front of firearm
Image courtesy of www.militaryheritage.com
Most old formulas called for charcoal made from the wood of certain tree species. Willow wood was highly prized as a source of charcoal. The quality of the charcoal affected many aspects of propellants, including ease of mixture, power, and cleanliness. Varying the ratio of the three components produced different black powders for different purposes. For example, the formula for blasting powder has traditionally differed from that for propellant use. Modern, propellant-grade black powder is seventy-five parts potassium nitrate (KNO3), fifteen parts charcoal, and ten parts sulfur.