55. To prevent Fire-Irons becoming Rusty.—Rub them with sweet oil, and dust over them unslaked lime. If they be rusty, oil them for two or three days, then wipe them dry, and polish with flour emery, powdered pumice-stone, or lime. A mixture of tripoli with half its quantity of sulphur, will also remove rust; as will emery mixed with soft soap, boiled to a jelly. The last mixture is also used for removing the fire-marks from bright bars.
56. To Color the Backs of Chimneys with Lead Ore.—Clean them with a very strong brush, and carefully rub off the dust and rust; pound about a quarter of a pound of lead ore into a fine powder, and put it into a vessel with half a pint of vinegar, then apply it to the back of the chimney with a brush. When it is made black with this liquid, take a dry brush, dip it in the same powder without vinegar; then dry and rub it with this brush, till it becomes as shining as glass.
57. To blacken the fronts of Stone Chimney-pieces.—Mix oil-varnish with lamp-black, and a little spirit of turpentine to thin it to the consistence of paint. Wash the stone with soap and water very clean; then sponge it with clear water; and when perfectly dry, brush it over twice with this color, letting it dry between the times. It looks extremely well. The lamp-black must be sifted first.
58. Composition that will effectually prevent Iron, Steel, &c., from rusting.—This method consists in mixing, with fat oil varnish, four-fifths of well rectified spirit of turpentine. The varnish is to be applied by means of a sponge; and articles varnished in this manner will retain their metallic brilliancy, and never contract any spots of rust. It may be applied to copper, and to the preservation of philosophical instruments; which, by being brought into contact with water, are liable to lose their splendor, and become tarnished.