Lead Dioxide: Red Lead Treated with Nitric Acid (Thorpe 1912)

Lead dioxide, the puce oxide of lead, is a dark brown, almost black powder and a strong oxidiser. Nitric acid takes part of the lead out of red lead as lead nitrate and leaves the dioxide behind. Source: Thorpe, Dictionary of Applied Chemistry vol. 3 (1912), Lead. Not given: amounts, acid strength or heat; warming, washing and drying are ours. Lead compounds are poisonous. It catches fire when ground with sulphur, so keep it away from sulphur and organic matter. Picture drawn by Youblob.