Another recipe formerly much favoured by housewives in the days when copper vessels were much in evidence, is to rub them over with half a lemon dipped in salt; then after washing polish with a soft cloth. This is a useful recipe in that it does not injure an antique appearance or patina, but it will remove stains. A somewhat more powerful preparation for metal-work is a cleaning paste made as follows: oxalic acid, 1 oz.; rotten stone, 6 oz; gum arabic, 1/2 oz.; sweet oil, 1 oz.; and then add as much water as necessary. The following recipe is given for the benefit of advanced collectors who wish to avail themselves of modern methods. Such will no doubt delight in experimenting on the cleansing of newly acquired curios with a cleaning preparation operated by an electric current. Caustic soda, 1/2 lb.; sal soda, 1/2 lb.; resin, 1/4 oz.; and water, 1 gallon; 4 to 8 volts and a current density of 12 amps. The greater the density of the current the quicker the cleaning is performed. A temperature of 120 Fahr. is recommended. Lacquering Metal. When it is desired to lacquer or coat over metal to prevent any future oxidation (not commonly desired by collectors of antiques) the copper or brass article should be pickled for several hours in aqua fortis diluted with water. The acid will rot away a certain portion of the tarnished surface and leave the metal bright. The article should then be put into bran and well shaken until quite dry. It is then ready to be cleaned, and, if desired, polished bright. Old brasswork may be relacquered by the amateur with a little experience, practice, and care. First of all it must be cleaned. The liquid which is best suited to the purpose may be made of a strong lye of wood ashes boiled and strengthened with soap lees. This will fetch the old lacquer off. The article should then be dipped in aqua fortis and water to take off the dirt, and immediately removed and cleansed with clean water, and then when dried it is ready to be lacquered. There are two processes in simple lacquering, which may be defined as cold and hot. The cold lacquer is the application of a preparation of brass lacquer, which can be purchased from any oil-shop, chemist, or metal dealer, put on with a camelhair-brush like varnish, and immediately placed in an oven or a hot stove, and exposed to the heat for a few minutes until the lacquer is quite firm and set. A gas-oven such as those in common use in so many kitchens nowadays answers the purpose very well.