Explanatory notes
… or iron metal in hydrochloric acid or in aqua regia , or by passing gaseous chlorine over red‑hot iron. Anhydrous, in … as a mordant, in photography and photo‑engraving, to give a patina to iron, in medicine (haemostatic or vasoconstrictive … crystals or tablets). Used in dyeing, in ceramics, as a parasiticide or rat‑poison, for purifying industrial water, …