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Blues

- Blue bice, Prussian blue.

Reds. Rose-pink, vermilion, red-lead, Indianred, lake cinnabar. Yellows. English pink, masticot, English ochre, Saunders blue, smalt.

Greens. Verdigris, terra vert, verditer.

The ultramarine for blue, and the carmine for red, are rather to be bought in powders, as in that state they are less apt to dry; and as the least tint of these will give the picture a cast, mix up what is wanted for present use with a drop or two of nut-oil upon the pallet with the pallet-knife.

Then lay a sheet of white paper on the table, and taking the picture in the left hand, with the turpentine side next you, hold it sloping (the bottom resting on the white paper), and all outlines and tints of the prints will be seen on the glass; and nothing remains but to lay on the colors proper for the different parts, as follows: To Use the Colors.

As the lights and shades of the picture open, lay the lighter colors first on the lighter parts of the print, and the darker over the shaded parts; and having laid on the brighter colors, it is not material if the darker sorts are laid a little over them; for the first color will hide those laid on afterwards. For example: Reds. Lay on the first red-lead, and shade with lake or carmine.

Yellows. The lightest yellow may be laid on first, and shaded with Dutch pink.

Blues. Blue bice, or ultramarine, used for the lights, may be shaded with indigo. one upon another, the shade will naturally be stronger; and when this is finished, lay the colors for garments and complexions.

To Prepare Lake for Glass.

Grind the lake with water impregnated with gum and salt; then make use of it with the brush.

The shading is operated by laying a double, treble, or more coats of the color, where it is wanted darker.

Blue Purple for the same.

Make a compound of lake and indigo, ground together with gum and salt water, and use it as directed in the preceding article.

Green.

Mix with a proportionable quantity of gamboge ground together as above.

Yellow.

Grind gamboge with salt water only.

White.

Heighten much the white parts with a pen.

To Transfer Engravings on Glass.

Metallic colors prepared and mixed with fat oil, are applied to the stamp on the engraved plate.

Wipe with the hand in the manner of the printers of colored plates; take a proof on a sheet of silverpaper, which is immediately transferred on the tablet of glass destined to be painted, being careful to turn the colored side against the glass; it adheres to it, and as soon as the copy is quite dry, take off the superfluous paper by washing it with a sponge; there will remain only the color transferred to the glass; it is fixed by passing the glass Greens. Lay on verdigris first, then a mixture | through the ovens. The bases of all the colors employed in painting on glass, are oxidized metallic substances.

In painting on glass, it is necessary that the matter should be very transparent.

To Prepare Metallic Oxides and Precipitates of Gold.

A solution of gold in aqua-regia, which is evaporated to dryness, leaves gold, which is used for glass, enamel, and porcelain gilding; or by prethe solution with green vitriol dissolved in water, a similar powder is produced. This powder is mixed with some essential oil, as oil of spike, and calcined borax, and the whole made to adhere to the surface of the glass by a solution of gum Arabic. It is then applied with a fine pencil, and burnt in under a muffle.

To Prepare Oxide of Cobalt.

When regulus of cobalt is exposed to a moderate fire in the open air, it calcines; and is reduced to a blackish powder.

This oxide vitrifies with vitrifiable matters and forms beautiful blue glasses. Cobalt is, at present, the only substance known which has the property of furnishing a very fine blue that is not changed by the most intense heat.

To Prepare Zaffre.

Zaffre is the oxide of cobalt, for painting pottery ware and porcelain of a blue color. Break the cobalt with hammers into pieces about the size of a hen's egg; and the stony gangue, with such other foreign matters, separate as much as possible.

Pound the chosen mineral in stamping-mills, and sift it through brass-wire sieves. Wash off the lighter parts by water, and afterwards put it into a large flat-bottomed arched furnace resembing a baking-oven, where the flame of the wood reverberates upon the ore, which stir occasionally, and turn with long-handled iron hooks or rakes; and the process is to be continued till its fumes cease. The oven or furnace terminates by a long horizontal gallery, which serves for a chimney, in which the arsenic, naturally mixed with the ore, sublimes. If the ore contains a little bismuth, as this semi-metal is very fusible, collect it at the bottom of the furnace. The cobalt remains in the state of a dark gray oxide, and is called zaffre. This operation is continued four, or even nine hours, according to the quality of the ore. The roasted ore being taken out from the furnace, such parts as are concreted into lumps, pound and sift afresh. Zaffre, in commerce, is never pure, being mixed with two, or rather three parts of powdered flints. A proper quantity of the best sort of these, after being ignited in a furnace, are to be thrown into water, to render them friable and more easily reduced to powder; which, being sifted, is mixed with the zaffre, according to the before-mentioned dose; and the mixture is put into casks, after being moistened with water. This oxide, fused with 3 parts of sand and 1 of potassa, forms a blue glass which, when pounded, sifted, and ground in mills (included in large casks), forms smalt.

The blue of zaffre is the most solid and fixed | of all the colors employed in vitrification. It suffers no change from the most violent fire. It is successfully employed to give shades of blue to enamels, and to crystal-glass made in imitation of opaque and transparent precious stones; as the lapis lazuli, the turquoise, the sapphire, and others.

Purple of Cassius.

Dissolve some pure gold in nitro-muriatic acid; add either acid or metal, until saturation takes place. Now dissolve some pure tin in the same kind of acid; observe the same point of saturation as with the gold, and pour it into the solution of must be collected and washed in distilled water. gold. A purple powder will be precipitated , which This beautiful purple color, as before mentioned, is extremely useful to enamellers and to glassstainers. When brought into fusion with a clear, transparent glass, it tinges it of a purple, red, or violet color. Hence the method of making false rubies and garnets.

To Paint Colored Drawings on Glass.

This art is exercised two ways. 1. Plates of stained glass are cut into the shape of figures and joined by leaden outlines. On these plates a shading is afterwards traced by the painter, which gives features to the face and folds to the drapery. 2. Vitrifiable colors are attached to plates of white glass, which are afterwards placed in the oven, and thus converted into a transparent enamelling. The first sort is cheaper, but the shading wears off by the insensible corrosion of the atmosphere. The second sort defies every accident except fracture; but the color of the figures suffers in the oven.

For small objects, the first sort, and for large objects, the second, as far as art is concerned, seems best adapted. Flux for Staining Glass. 1. When the colors used are not affected by lead, 100 parts powdered quartz, 125 red-lead, 50 of bismuth. 2. When the flux is required free from lead, 100 parts quartz, 75 glass of borax, 12½ saltpetre, 124 powdered statuary marble.

Colors for Staining Glass.

To 6 cwt. of flux or flint-glass are to be added as follows:

White (soft), 24 lbs. white arsenic, 6 lbs. antimony. White (hard), 200 lbs. putty-powder.

Blue (transparent), 2 lbs oxide of cobalt.

Azure, 6 lbs. protoxide of copper.

Ruby, 4 oz. oxide of gold.

Amethyst, 20 lbs. oxide of manganese.

Common Orange, 12 lbs. iron ore, 4 lbs. oxide of manganese.

Emerald Green, 12 lbs. copper scales and 12 lbs. iron ore.

Gold Topaz (canary glass), 3 lbs. oxide of uranium.

The colors will vary with the degree of heat to which the glass is subjected. The whole glass may be colored, or the mixture of flux and oxide may be laid on the surface, and then vitrified.