The following is recommended as a rust remover: Cover the metal with sweet oil, well rubbed in, and allow to stand for forty-eight hours. Then rub with unslaked lime reduced to as fine a powder as possible. A second recipe is as follows: Immerse the article to be cleansed, for a few minutes until all dirt and rust is taken off, in a strong solution of potassium cyanide—say about one-half ounce in a wine-glassful of water. Take out and clean with a tooth-brush with some paste composed of potassium cyanide, Castile soap, whiting, and water, mixed into a paste of about the consistence of thick cream.