Explosive Dust, Part of a 1605 Plot in England
Puzzle 10 of Hot Things Piece of Cake Pack
Question is: Explosive Dust, Part of a 1605 Plot in England
and the answer is: GUNPOWDER
Word Meaning:
GUNPOWDER — An explosive mixture of saltpetre (potassium nitrate), charcoal and sulfur; formerly used in gunnery but now mostly used in fireworks.
Definitions from Wiktionary.