When a silvered or gilded object is perfectly dry it should be rubbed rapidly with a brush and some fine silver-polishing powder until the opaque white or yellow gives place to a silver or gold lustre. It will then be ready for burnishing with a steel burnisher, or the article may be left with a frosted silver or gold surface. Steel burnishers can be had at any tool-supply house, and when used they should be frequently dipped in castile soapy water to lubricate them. They will then glide smoothly over the surface of the deposited metal, driving the grain down and making it bright at the same time. If the soapy water were not used the action of the hard burnisher over the plate would have a tendency to tear away the film of deposited metal. The burnisher must always be clean and bright, otherwise it would scratch the plated articles; and, when not in use, keep the bright polishing surfaces wrapped in a piece of oiled flannel. Small articles, such as sleeve-buttons, rings, studs, and other things not larger than a twenty-five-cent piece, may be polished by being tumbled in a sawdust bag. A cotton bag is made, three feet long and six inches in diameter, closed at one end and half-filled with fine sawdust. The articles are then put in the bag and the end closed. Grasp the ends of the bag with both hands, as if to jump rope with it; then swing it to and fro, until the articles have had a good tumbling. Look at them to see if they are bright enough; if not, keep up the tumbling. When old work is to be re-plated, or gone over, it will be necessary to remove all of the old plate before a really good job can be done. In some cases it may be removed with a scratch-brush or pumice-stone; but, as a rule, it can be removed much quicker and more satisfactorily with acids. Silver may be removed from copper, brass, or German-silver with a solution of sulphuric acid, with one ounce of nitrate of potash to each two quarts of acid. Stir the potash into the acid, then immerse the article. If the action becomes weak before the silver is all off, then heat the solution and add more of the potash (saltpetre). Gold may be removed from silver by heating the article to a cherry-red, and dropping it into diluted sulphuric acid--one part acid to two parts water. This will cause the gold to peel and fall off easily. Electrotyping The term electrotyping is interpreted in several ways, but, in general, it means the process of electro-plating an article, or mold, with a metal coating, generally copper, of sufficient thickness, so that when it is removed, or separated from its original, it forms an independent object which, to all appearances, will be a fac-simile of the original.