Japanners’ gilding

is done by sprinkling or daubing with wash leather, some gold powder, over an oil sized surface, mixed with oil of turpentine. This gives the appearance of frosted gold. The gold powder may be obtained, either by precipitating gold from its solution in aqua regia by a solution of pure sulphate of iron, or by evaporating away the mercury from some gold amalgam. II. Chemical Gilding , or the application of gold by chemical affinity to metallic surfaces. A compound of copper with one seventh of bra is the best metal for gilding on; copper by itself being too soft and dark coloured. Ordinary bra , however, answers very well. We shall describe the proce of wash gilding, with M. D’Arcet’s late improvements, now generally adopted in Paris. Wash gilding , consists in applying evenly an amalgam of gold to the surface of a copper alloy, and di ipating the mercury with heat, so as to leave the gold film fixed. The surface is afterwards burnished or deadened at pleasure. The gold ought to be quite pure, and laminated to facilitate its combination with the mercury; which should also be pure.