159. MANHEIM GOLD

Melt together 3 parts copper, 1 of zinc, and a little tin.

160. TOMBACK, OR RED BRASS

Melt together 8 parts of copper, and 1 part of zinc.

161. IMITATION GOLD

Take of platina 8 parts, of silver 4 parts, copper 12 parts, melt all together.

162. IMITATION SILVER

Take of block tin 100 parts, metallic antimony 8 parts, bismuth 1 part, and 4 parts of copper; melt all together.

163. TRUE IMITATION OF GOLD

Dr. Harmsteadt's imitation of gold, which is stated not only to resemble gold in colour, but also in specific gravity and ductility, consists of 16 parts of platinum, 7 parts of copper, and 1 of zinc, put in a crucible, covered with charcoal powder, and melted into a mass.

164. TRUE IMITATION OF SILVER

Imitation of pure silver, so perfect in its resemblance that no chemist living can tell it from pure virgin silver. It was obtained from a German chemist now dead; he used it for unlawful purposes to the amount of thousands, and yet the metal is so perfect that he was never discovered. It is all melted together in a crucible, here it is: 1/4 oz. of copper, 2 oz. of brass, 3 oz. of pure silver, 1 oz. of bismuth, 2 ozs. of saltpetre, 2 ozs. of common salt, 1 oz. of arsenic, and 1 oz. of potash.

165. MOULDS AND DIES

Take copper, zinc, and silver, in equal proportions, and melt them together, and mould into the forms you desire, and bring the same to a nearly white heat; now lay on the thing that you would take the impression of, and press it with sufficient force, and you will find that you have a perfect and beautiful impression. All of the above metals should be melted under a coat of powdered charcoal.

166. TO SOFTEN HORN

To 1 lb. of wood ashes, add 2 lbs. of quicklime; put them into a quart of water, let the whole boil till reduced to one third, then dip a feather in, and if, on drawing it out, the plume should come off, it is a proof that it is boiled enough, if not, let it boil a little longer; when it is settled filter it off, and in the liquor thus strained put in shavings of horn; let them soak for three days, and, first anointing your hands with oil, work the horn into a mass, and print or mould it into any shape you please.

167. TO MAKE MOULDS OF HORN

If you wish to take the impression of any coin, medal, &c., previously anoint it with oil, then lay the horn shavings over it in its softened state; when dry the impression will be sunk into the horn, and this will serve as a mould to reproduce, either by plaster of Paris, putty and glue, or isinglass and ground egg shells, the exact resemblance of the coin or medal.

168. TO CASE FIGURES IN IMITATION OF IVORY

Make isinglass and strong brandy into a paste, with powder of egg shells, very finely ground; you may give it what colour you please, but cast it warm into your mould, which you previously oil over; leave the figure in the mould till dry, and you will find, on taking it out, that it bears a very strong resemblance to ivory.

169. TRUE GOLD POWDER

Put some gold leaf, with a little honey or thick gum water, (whenever I speak of gum I mean gum arabic,) into an earthen mortar, and pound the mixture till the gold is reduced to very small particles; then wash out the honey or gum repeatedly with warm water, and the gold will be left behind in a state of powder, which, when dried, is fit for use.

170. TRUE GOLD POWDER

Another, and perhaps better method of preparing gold powder is to heat a prepared amalgam of gold in a clean open crucible, (an amalgam of any metal is formed by a mixture of quicksilver with that metal) continuing a very strong heat till all the mercury has evaporated, stirring the amalgam all the while with a glass rod; when the mercury has entirely left the gold, grind the remainder in a Wedgewood's mortar, with a little water, and when dried it will be fit for use. The subliming the mercury is, however, a process injurious to the health.

171. COLOUR HEIGHTENING COMPOSITIONS

For yellow gold, dissolve in water 6 ozs. of saltpetre, 2 ozs. of copperas, 1 oz. of white vitriol, and 1 oz. of alum. If wanted redder, add a small portion of blue vitriol.

172. FOR GREEN GOLD

Dissolve in water a mixture consisting of 1-1/2 oz. of saltpetre; vitriol and sal-ammoniac, 1-1/4 oz. of each, and 1 oz. verdigris.

173. FOR RED GOLD

Take 1-1/2 oz. of red ochre in fine powder, the same quantity of calcined verdigris, 1/2 oz. of calcined borax, and 4 oz. of melted yellow wax; the verdigris must be calcined, or else, by the heat applied in melting the wax, the vinegar becomes so concentrated as to corrode the surface, and make it appear speckled. These last three are colours for heightening compositions.

174. MOSAIC GOLD

Mosaic gold, or aurum mosaicum, is used for inferior articles. It is prepared in the following manner: 1 lb. of tin is melted in a crucible, and 1/2 lb. of purified quicksilver added to it; when this mixture is cold, it is reduced to powder, and ground with 1/2 lb. of sal-ammoniac, and 7 ozs. of flower of sulphur, till the whole is thoroughly mixed; they are then calcined in a mattrass, and the sublimation of the other ingredients leaves the tin converted into the aurum mosaicum, which is found at the bottom of the glass, like a mass of bright flakey gold powder. Should any black or discoloured particles appear, they must be removed. The sal-ammoniac used here must be very white and clear, and the mercury quite pure and unadulterated. When a shade of deeper red is required, it can easily be obtained by grinding a very small quantity of red lead along with the above materials.

175. DUTCH OR GERMAN GOLD

A gilding powder is sometimes made from Dutch gold, which is sold in books at a very low price. This is treated in the same way as the real gold leaf in making the true gold powder. It is necessary, when this inferior powder is used, to cover the gilding with a coat of clear varnish, otherwise it soon loses its metallic appearance. The same remark applies, though to a less degree, to Mosaic gilding.

176. COPPER POWDER

This is prepared by dissolving filings or slips of copper with nitrous acid in a receiver. When the acid is saturated, the slips are to be removed; or, if filings be employed, the solution is to be poured off from what remains undissolved; small bars are then put in, which will precipitate the copper from the saturated acid, in a powder of the peculiar appearance and colour of copper, and the liquid being poured from the powder, this is to be washed clean of the crystals by repeated levigations.

177. COMMON SIZE

The size used by painters for most sorts of common work is prepared by boiling in water pieces of parchment, and of the skins of animals and fins of fish, and evaporating the solution to a proper consistency. It only differs, however, from a solution of glue containing fewer foreign ingredients, and in not being so strong.

178. DR. JOHN'S VARNISH FOR PLASTER OF PARIS CASTS

Take of white soap and white wax, each half an ounce, of water two pints; boil them together for a short time in a clean vessel. This varnish is to be applied when cold, by means of a soft brush. It does not sink in, it readily dries, and its effect may be heightened by lightly using a silk pocket handkerchief.

179. GENERAL DIRECTIONS FOR BRONZING

This art is nothing but a species of painting, but far from being of the most delicate kind. The principal ingredients made use of in it are the true gold powder, the German gold, the aurum mosaicum, and copper powder, (all above described.) The choice of these powders is, of course, to be determined by the degree of brilliancy you wish to obtain. The powder is mixed with strong gum water or isinglass, and laid on with a brush or pencil; and when not so dry as to have still a certain clamminess, a piece of soft leather wrapped round the finger, is dipped in the powder and rubbed over the work; when