A mixture of kerosene oil and emery powder rubbed on with a piece of cloth makes steel as bright as a button. But as prevention is better than cure, to prevent the formation of rust the bright steel should be painted with wax varnish, made by dissolving 1 part of solid paraffin in 15 parts of benzole. This is a much more cleanly application than such fatty compounds as white lead and oil, and is well suited for steel grates and similar goods.
Iron rust can be removed by salt mixed with lemon juice being rubbed on, or either place the article in a bowl containing kerosene oil or wrap it in a soft cloth well saturated with the oil, allow it to remain so for two days, and then scour the rusty spots with brick-dust. If very badly rusted, use salt melted with hot sulphuric acid, after scouring well, rinse in boiling water, and polish clean with soft flannel and a little sweet oil.
To remove rust from marble, an operation which depends upon the solubility of iron sulphide in a solution of potassium cyanide, is thus effected: Clay is made into a thin paste with ammonium sulphide, and the rust spot smeared with the mixture, care being taken that the spot is only just covered. After a lapse of ten minutes, this paste is washed off and replaced by one consisting of white bole mixed with a solution of potassium cyanide,
1 to 4, which is in its turn washed of after a lapse of about two and a half hours. Should a reddish spot remain after washing off the first paste, a second layer may be applied for about five minutes.