It was saltpeter. I didn't read far enough. The shaggy-haired man put saltpeter in his pipe to cause it to flame and smoke. Then, from the "East, West, North and South" four shaggy-haired men came with saltpeter in their torches and burned the chateau of the murdered Marquis. "Fire Rises" is a the most breathtaking, extraordinary chapter in Dickens oeuvre. I could not have read this book completely through before.