Lead Nitrate: Litharge Dissolved in Dilute Nitric Acid and Crystallised (Faraday 1830)

Faraday purified all his lead this way before making optical glass. Iron and carbon in litharge stained his glass and ate his platinum trays. Dissolving the litharge in nitric acid and crystallising the nitrate leaves those impurities behind. Source: Faraday, On the Manufacture of Glass for Optical Purposes, Phil. Trans. 1830, paragraphs 14-17. He gives no amounts of acid or water. 166 parts of the nitrate stand for 112 parts of lead oxide. Ours: porcelain vessels for his earthenware. Lead compounds are poisonous: gloves, no dust, wash hands. Picture drawn by Youblob.