The figures are more or less beautiful and diversified, according to the degree of heat, and relative dilution of the acid. Place the tin-plate, slightly heated, over a tub of water, and rub its surface with a sponge dipped in a liquor composed of four parts of aquafortis, and two of distilled water, holding one part of common salt or sal ammoniac in solution. Whenever the crystalline spangles seem to be thoroughly brought out, the plate must be Immersed in water, washed either with a feather or a little cotton (taking car • not to rub off the film of tin that forms the feathering), forthwith dried with a low heat, and coated with a lacker varnish, otherwise it loses its lustre in the air. If the whole surface is not plunged at once in cold water, but if it be partially cooled by sprinkling water on it. the crystallization will be finely variegated with large and small figures. Similar results will be obtained by blowing cold air through a pipe on the tinned surface, while it is just passing from the fused to the solid state.

How To Crystallize Tin

Sulphuric acid, 4 oz.; soft water, 2 to 3 oz., according to strength of! the acid- salt, 1¼ oz; mix; heat the tin hot over a stove, then with a sponge apply the mixture, then wash off directly with clean water. Dry the tin, and varnish with demar varnish.

Improved Tinning Flux

Muriatic acid, 1 lb.; put into it all the zinc it will dissolve and 1 oz. sal ammoniac, and it is ready for use.