(1) Cover the metal with sweet oil well rubbed in, and allow to stand for 48 hours; smear with oil applied freely with a feather or piece of cotton wool, after rubbing the steel. Then rub with unslaked lime reduced to as fine a powder as possible.

(2) Immerse the article to be cleaned for a few minutes until all dirt and rust is taken off in a strong solution of potassium cyanide, say about 1/2 oz. in a wine-glassful of water; take out and clean it 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.