Gunpowder

Gunpowder was an explosive substance that was used mostly in warfare, such as cannons. This was used in cannons to explosively propel objects forward. It is usually used on Earth, and on some primitive planets such as Ribos. (DW: The Ribos Operation)

One of the most notable uses of gunpowder was in 1605, where Guy Fawkes and his anti-parliament regime attempted to blow up the Houses of Parliament, placing several barrels of gunpowder beneath it. (MA: The Plotters)

While searching through a manor that was near the vicinity of the Terileptil escape pod, the Doctor and his companions discovered gunpowder, power packs and the mark of a high energy weapon. The gunpowder was residue from a fight between the owners of the manor and Terileptils. (DW: The Visitation)