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ANALYSIS OF ORES OF GOLD.

or by precipitating this solution by immersing plates of copperin it. It is laid on with super-saturated borate of soda andgum-water, or oil, burned in and polished.

The gilding of glass

Is commonly effected by covering the part with a solution ofsuper-saturated borate of soda, and applying gold-leaf upon it,which is afterwards fixed by burning.

The edges of tea cups, &c.

Are frequently gilt in a less durable manner by applying avery thin coat of amber varnish, upon which gold-leaf is to befixed, and when the varnish is dry, the gold is burnished.

The gilders of wood, and other compositions designed to sup-ply the place of carved work, make use of gold leaf, which iseither laid on with size, or boiled oil, and afterwards burnished.

ANALYSIS OF ORES OF GOLD.

Native gold when imbedded in earths, or stones, may be ana-lyzed by reducing the ore to a very fine powder, weighing adeterminate portion, and effecting their solution in nitric or ra-ther in nitro-muriatic acid, care being taken to digest the orewith the acid repeatedly, or as long as it extracts any thing.The solution must be evaporated to dryness, in order to force itas much as possible from its excess of acid, and then dissolvedin water. If the ore contains silver this metal will fall to thebottom in the form of a white heavy precipitate, it may beseparated by filtration and reduced by fusing it with soda. Inorder to separate the gold, let the solution be made hot and pourinto it a solution of sulphate of iron, which will precipitate the

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