All simple or compound colors, and all the shades of color which nature or art can produce, and which might be thought proper for the different kinds of painting, would form a very extensive catalogue, were we to take into consideration only certain external characters, or the intensity of their tint. But art, founded on the experience of several centuries, has prescribed bounds to the consumption of coloring substances, and to the application of them to particular purposes. To cause a substance to be admitted into the class of coloring bodies employed by it is not sufficient for it to contain a color; to brightness and splendor it must also unite durability in the tint or color which it communicates.

To make Black Paint.

Usage requires attention in the choice of the matters destined for black. The following are their properties:

Black from peach-stones is dull.

Ivory-black is warm. strong and beautiful when it has been well attenuated under the muller.

Black from the charcoal of beech-wood, ground on porphyry, has a bluish tone.

Lampblack may be rendered mellower by making it with black which has been kept an hour in a state of redness in a close crucible. It then loses the fat matter which accompanies this kind of soot.

Black furnished by the charcoal of vine-twigs, ground on porphyry, is weaker, and of a dirty gray color when coarse and alone, but it becomes blacker the more the charcoal has been divided. It then forms a black very much sought after, and which goes a great way.

To make Paints from Lampblack.

The consumption of lampblack is very extensive in common painting, It serves to modify the brightness of the tones of the other colors, or to facilitate the composition of secondary colors. The oil paint applied to iron grates and railing, and the paint applied to paper snuff-boxes, to those made of tin-plate, and to other articles with dark grounds, consume a very large quantity of this black. Great solidity may be given to works of this kind by covering them with several coatings of the fat turpentine, or golden varnish, which has been mixed with lampblack, washed in water, to separate the foreign bodies introduced into it by the negligence of the workmen who prepare it.

After the varnish is applied the articles are dried in a stove by exposing them to a heat somewhat greater than that employed for articles of paper. Naples yellow, which enters into the composition of black varnish, is the basis of the dark brown observed on tobacco-boxes of plate-iron, because this color changes to brown when dried with the varnish.

To make a Superior Lampblack.

Suspend over a lamp a funnel of tin plate having above it a pipe to convey from the apartment the smoke which escapes from the lamp. Large mushrooms, of a very black, carbonaceous matter, and exceedingly light, will be formed at the summit of the cone. This carbonaceous part is carried to such a state of division as cannot be given to any other matter, by grinding it on a piece of porphyry.

This black goes a great way in every kind of painting. It may be rendered drier by calcination in close vessels.

The funnel ought to be united to the pipe, which conveys off the smoke, by means of wire, because solder would be melted by the flame of the lamp.

To make Black from Ground Pitcoal.

The best for this purpose is that which has a shining fracture. It affords, perhaps, the most useful brown the artist can place on his palet, being remarkably clear, not so warm as Vandyke brown, and serving as a shadow for blues, reds, or yellows, when glazed over them. It seems almost certain that Titian made large use of this material. Coal, when burnt to a white heat, then quenched in water, and ground down, gives an excellent blue black. This belongs to artists' colors.

To make Black from Wine-lees.

This black results from the calcination of wine-lees and tartar, and is manufactured on a large scale in some districts of Germany, in the environs of Mentz, and even in France. This operation is performed in large cylindric vessels, or in pots, having an aperture in the cover to afford a passage to the smoke, and to the acid and alkaline vapors which escape during the process. When no more smoke is observed, the operation is finished. The remaining matter, which is merely a mixture of salts and a carbonaceous part very much attenuated, is then washed several times in boiling water, and it is reduced to the proper degree of fineness by grinding it on porphyry.

If this black be extracted from dry lees, it is coarser than that obtained from tartar, because the lees contain earthy matters which are confounded with the carbonaceous part.

This black goes a great way, and has a velvety appearance. It is used chiefly by copper-plate printers.

Another. - Peach-stones, burnt in a close vessel,, produce a charcoal, which, when ground on porphyry, is employeed in painting to give an old gray.

Another. - Vine twigs reduced to charcoal give a bluish black, which goes a great way. When mixed with white it produces a silver white which is not produced by other blacks; it has a pretty near resemblance to the black of peach stones, but to bring this color to the utmost degree of perfection, it must be carefully ground on porphyry.

To make Ivory and Boneblack.

Put into a crucible surrounded by burning coals, fragments or turnings of ivory, or of the osseous parts of animals, and cover it closely. The ivory or bones, by exposure to the heat, will be reduced to charcoal. When no more smoke is seen to pass through the joining of the cover, leave the crucible over the fire for half an hour or longer, or until it has completely cooled. There will then be found in it a hard carbonaceous matter, which, when pounded and ground on porphyry with water, is washed on a filter with warm water and then dried. Before it is used it must be again subjected to the matter.

Black furnished by bones is reddish. That produced by ivory is more beautiful. It is brighter than black obtained from peach-stones. When mixed in a proper dose with white oxide of lead, it forms a beautiful pearl gray. Ivory-black is richer. The Cologne and Cassel-black are formed from ivory.

Fine Black Color.

Take some camphor and set it on fire; from the flame will arise a very dense smoke, which may be collected on a common saucer by holding it over the flame. This black, mixed with gum arabic, is far superior to most India-ink.

Miniature painters, who use colors in small quantities, sometimes obtain a most beautiful and perfect black by using the buttons which form on the snuff of a candle when allowed to burn undisturbed. These are made to fall into a small thimble, or any other convenient vessel which can be immediately covered with the thumb, to exclude the air. This is found to be perfectly free from grease, and to possess every desirable quality.

To Paint in White Distemper.

Grind fine in water Bougival white, a kind of marl or chalky clay, and mix it with size. It may be brightened by a small quantity of indigo, or charcoal-black.

The White destined for varnish or oil requires a metallic oxide, which gives more body to the color. Take ceruse, reduced to powder, and grind it with oil of pinks and 1/4 oz. of sulphate of zinc for each pound of oil. Apply the second coating without the sulphate of zinc, and suffer it to dry. Cover the whole with a stratum of sandarach varnish. This color is curable, brilliant and agreeable to the eye.

Boiled linseed oil might be employed instead of oil of pinks, but the color of it would in some degree injure the purity of the white.

Another. - White is prepared also with pure white oxide of lead, ground with a little essence, added to oil of pinks and mixed with gallipot varnish. The color may be mixed also with essence diluted with oil, and without varnish, which is reserved for the two last coatings. If for a lively white, the color is heightened with a little Prussian blue or indigo, or with a little prepared black. The latter gives it a gray cast. But pure white lead, the price of which is much higher than ceruse, is reserved for valuable articles. In this particular case, if a very fine durable white be required, grind it with a little essence, and mix it with sandarach or varnish.

To Paint in Light Gray and Distemper.

Ceruse, mixed with a small quantity of lamp-black, composes a gray, more or less charged, according to the quantity of black. With this matter, therefore, mixed with black in different doses, a great variety of shades may be formed, from the lightest to the darkest gray

If this color be destined for distemper, it is mixed with water; if intended for oil painting, it is ground with nut-oil, or oil of pinks, and with essence added to oil, if designed for varnish. This color is durable and very pure, if mixed with camphorated mastic varnish; the gallipot varnish renders it so solid that it can bear to be struck with a hammer, if, after the first stratum it has been applied with varnish, and without size. For the last coating sandarach varnish, and camphorated varnish are proper; and for the darkest gray, spirituous sandarac varnish.
 

Ceruse, or white lead, still predominates in this color, which is treated as the other grays, but with this difference, that it admits a mixture of lake instead of black. Take the quantity, therefore, of cernse necessary, and grind it separately. Then mix it up, and add the lake and Prussian blue, also ground separately. The quantities of the last two colors ought to be proportioned to the tone of color required.

This color is proper for distemper, varnish, and oil painting. For varnish, grind it with mastic gallipot varnish, to which a little oil of pinks has been added, and then mix it up with common gallipot varnish. For oil painting, grind with unprepared oil of pinks, and mix up with resinous drying nut-oil. The painting is brilliant and solid.

When the artist piques himself upon carefully preparing those colors which have splendor, it will be proper, before he commences his labor, to stop up the holes formed by the heads of the nails in wainscoting with putty.

Every kind of sizing which, according to usual custom, precedes the application of varnish, ought to be prescribed as highly prejudicial, when the wainscoting consists of firwood. Sizing maybe admitted for plaster, but without any mixture. A plain stratum of strong glue and water spread over it, is sufficient to fill up the pores to prevent any unnecessary consumption of the varnish.

The first stratum of color is ceruse without any mixture, ground with essence added to a little oil of pinks, and mixed up with essence. If any of the traces are uneven, rub it lightly, when dry, with pumice-stone. This operation contributes greatly to the beauty and elegance of the polish when the varnish is applied.

The second stratum is composed of ceruse changed to flaxen gray by the mixture of a little Cologne earth, as much English red or lake, and a particle of Prussian blue. First, so make the mixture with a small quantity of ceruse, that the result shall be a smoky gray, by the addition of the Cologne earth. The red, which is added, makes it incline to fleshcolor, and the Prussian blue destroys the latter to form a dark flaxen gray. The addition of ceruse brightens the tone. This stratum and the next are ground, and mixed up with varnish as before.

This mixture of colors, which produces flaxen gray, has the advantage over pearl gray, as it defends the ceruse from the impression of the air and light, which makes it assume a yellowish tint. Flaxen gray, composed in this manner, is unalterable. Besides, the essence which forms the vehicle of the first stratum contributes to bring forth a color, the tone of which decreases a little by the effect of drying. This observation ought to serve as a guide to the artist, in regard to the tint, which is always stronger in a liquid mixture than when the matter composing it is extended in a thin stratum, or when it is dry.
 

The basis of this color is still formed of ceruse. Three-fourths of this oxide, and a fourth of ochre de rue, umber earth, and yellow de Berri; the last three ingredients being employed in proportions which lead to the required tint, give a spatter equally proper for distemper, varnish, and oil.
 

A given quantity of ceruse, half that quantity of ochre de rue, a little umber earth, red ochre, and yellow ochre de Berri; compose this color proper for distemper, varnish, and oil.

For varnish, grind with a little drying nut-oil, and mix up with the gallipot varnish.

For oil painting, grind with fat oil of pinks added to drying oil or essence, and mix up with plain drying oil, or with resinous drying oil.
 

The composition of these is simple, yellow ochre mixed with ceruse, ground with water, if destined for distemper; or drying nut-oil and essence, in equal parts, if intended for varnish; and mixed up with camphorated mastic varnish; if for delicate objects, or with gallipot varnish, give a very fine color the splendor of which depends on the doses of the ceruse, which must be varied according to the particular nature of the coloring matter employed. If the ground of the color is furnished by ochre, and if oil painting be intended, the grinding with oil added to essence may be omitted, as essence alone will be sufficient. Oil, however, gives more pliability and more body.
 

This is employed only in distemper. It may, however, be used with varnish. A vegetable color serves as its base. It is made with Dutch pink and ceruse, and ground with mastic gallipot varnish, and mixed up with gallipot varnish.
 

Cases often occur when it is necessary to produce a gold color without employing a metallic substance. A color capable of forming an illusion is then given to the composition, the greater part of which consists of yellow. This is accomplished by Naples or Montpellier yellow, brightened by Spanish white, or by white of Morat, mixed with ochre de Berri and realgar. The last substance, even in small quantity, gives to the mixture a color imitating gold, and which may be employed in distemper, varnish, or oil. When destined for oil, it is ground with drying or pure nut-oil, added to essence or mixed with drying oil
 

Yellow is the foundation of chamois color, which is modified by a particle of minium, or what is better, cinnabar and ceruse in small quantity. This color may be employed in distemper, varnish, and oil. For varnish, it is ground with 1/2 common oil of pinks, and 1/2 of mastic gallipot varnish. It is mixed with common gallipot varnish. For oil painting, it is ground and mixed up with drying oil.
 

Olive color is a composition the shades of which may be diversified. Black and a little blue, mixed with yellow, will produce an olive color. Yellow de Berri, or d'Auvergne, with a little verdigris and charcoal, will also form this color.

It is ground and mixed up with mastic gallipot, and common gallipot varnishes. For oil painting, it is ground with oil added to essence, and mixed up with drying oil.
 

To make Olive Color for Distemper.

When intended for distemper, it will be necessary to make a change in the composition. The yellow above-mentioned, indigo, and ceruse, or Spanish white, are the new ingredients which must be employed.
 

Blue belongs to the order of vegetable substances, like indigo, or to that of metallic substances, like Prussian blue; or to that of stony mineral substances, as ultramarine; or to that of vitreous substances colored by a metallic oxide, as Saxon blue. Ultramarine is more particularly reserved for pictures. The same may, in some degree, be said of Saxon blue.

When prussiate of iron or indigo is employed without mixture, the color produced is too dark. It has no splendor, and very often the light makes it appear black; it is. therefore, usual to soften it with white.

To make Blue Distemper.

Grind with water as much ceruse as may be thought necessary for the whole of the intended work; and afterwards mix it with indigo, or Prussian blue.

This color produces very little effect in distemper, it is not very favorable to the play of the light; but it soon acquires brilliancy and splendor beneath the vitreous lamina of the varnish. Painting in distemper, when carefully varnished, produces a fine effect.

To make Prussian Blue Paint.

The ceruse is ground with oil if for varnish, made with essence, or merely with essence, which is equally proper for oil painting; and a quantity of either of these blues sufficient to produce the required tone is added.

For varnish, the ceruse is generally ground with oil of pinks added to a little essence, and is mixed up with camphorated mastic varnish, if the color is destined for delicate objects; or with gallipot varnish if for wainscoting. This color, when ground and mixed up with drying oil, produces a fine effect, if covered by a solid varnish made with alcohol or essence.

If this oil color be destined for expensive articles, such as valuable furniture subject to friction, it may be glazed with the turpentine copal varnish.

Ultramarine.

A vitreous matter colored by oxide of cobalt gives a tone of color different from that of the prussiate of iron and indigo. It is employed for sky-blues. The case is the same with blue verditer, a preparation made from oxide of copper and lime. Both these blues stand well in distemper, in varnish, and in oil.

Saxon blue requires to be ground with drying oil, and to be mixed with gallipot varnish. If intended for oil painting, it is to be mixed up with resinous drying oil, which gives body to this vitreous matter.

Blue Verditer

May be ground with pure alcoholic varnish added to a little essence; and may be mixed up with compound mastic varnish if the color is to be applied to delicate articles. Or mastic gallipot varnish, added to a little drying oil, may be used for grinding, and common gallipot varnish for mixing up, if the painting is intended for ceilings, wainscoting, etc. This color is soft and dull, and requires a varnish to heighten the tone of it, and give it play. Turpentine copal varnish is proper for this purpose, if the article has need of a durable varnish.
 

Every green color, simple or compound, when mixed up with a white ground, becomes soft, and gives a sea-green of greater or less strength, and more or less delicate, in the ratio of the respective quantities of the principal colors. Thus, green oxides of copper, such as chrome green, verdigris, dry crystallized acetate of copper, green composed with blue verditer, and the Dutch pink of Troyes, or any other yellow, will form, with a base of a white color, a seagreen, the intensity of which may be easily changed or modified. The white ground for painting in distemper is generally composed of Bougival white (white marl), or white of Troyes (chalk), or Spanish white (pure clay); but for varnish or oil painting, it is sought for in a metallic oxide. In this case, ceruse or pure white oxide of lead is employed.

To make Sea-Green for Distemper.

Grind separately with water, mountain-green and ceruse; and mix up with parchment size and water, adding ceruse in sufficient quantity to produce the degree of intensity required in the color. Watin recommends the use of Dutch pink of Troyes and white oxide of lead, in proportions pointed out by experience; because the color thence resulting is more durable.

In the case of a triple composition, begin to make the green by mixing Dutch pink with blue verditer, and then lower the color to sea-green, by the addition of ceruse ground with water.

To make Sea-Green for Varnish and Oils

Varnish requires that this color should possess more body than it has in distemper, and this it acquires from the oil which is mixed with it. This addition gives it even more splendor. Besides, a green of a metallic nature is substituted for the green of the Dutch pink, which is of a vegetable nature.

A certain quantity of verdigris, pounded and sifted through a silk sieve, is ground separately with nut-oil, half drying and half fat; and if the color is intended for metallic surfaces, it must be diluted with camphorated mastic, or gallipot varnish.

On the other hand, the ceruse is ground with essence, or with oils to which 1/2 of essence has been added, and the two colors are mixed in proportions relative to the degree of intensity intended to be given to the mixture. It may readily be conceived that the principal part of this composition consists of ceruse.

If this color be destined for articles of a certain value, crystallized verdigris, dried and pulverized, ought to be substituted for common verdigris, and the painting must be covered with a stratum of the transparent or turpentine copal varnish.

The sea-greens, which admit into their composition metallic coloring parts, are durable and do not change.

The last compositions may be employed for sea-green in oil painting, but it will be proper to brighten the tone a little more than when varnish is used, because this color becomes darker by the addition of yellow, which the oil developes in the course of time.
 

A mixture of lake with vermilion gives that beautiful bright red which painters employ for sanguine parts. This red is sometimes imitated for varnishing small appendages of the toilette. It ought to be ground with varnish and mixed up with the same, after which it is glazed and polished. The mastic gallipot varnish is used for grinding; gallipot varnish for mixing up, and camphorated mastic varnish for glazing.
 

Carminated lake - that which is composed of alum charged with the coloring part of cochineal, ceruse, and carmine - forms a beautiful crimson. It requires a particle of vermilion and of white lead.

The use of this varnish is confined to valuable articles.
 

Violet is made indifferently with red and black, or red and blue; and to render it more splendid, with red, white, and blue. To compose violet therefore, applicable to varnish, take minium, or what is still better, vermilion, and grind it with the camphorated mastic varnish to which a fourth part of boiled oil and a little ceruse have been added, then add a little Prussian blue ground in oil. The proportions requisite for the degree of intensity to be given to the color will soon be found by experience. The white brightens the tint. The vermilion and Prussian blue, separated or mixed, give hard tones, which must be softened by an intermediate substance that modifies, to their advantage, the reflections of the light.
 

This color is composed of red, yellow and black. The English red, or red ochre of Auvergne, ochre de rue and a little black, form a dark chestnut color. It is proper for painting of every kind. If English red, which is dryer than that of Auvergne, be employed, it will be proper, when the color is intended for varnish, to grind it with drying nutoil. The ochre of Auvergne only be ground with the mastic gallipot, and mixed up with gallipot varnish.

The most experienced artists grind dark colors with linseed oil, when the situation will admit of its being used, because it is more drying. For articles without doors nut-oil is preferable. The colors of oak-wood, walnut-tree, chestnut, olive, and yellow, require the addition of a little litharge ground on porphyry: it hastens the desiccation of the color, and gives it body.

But if it is intended to cover these colors with varnish, as is generally done in wainscoting, they must be mixed up with essence, to which a little oil has been added. The color is then much better dispersed to receive the varnish, under which it exhibits all the splendor it can derive from the reflection of the light.
 

Vitreous oxide of lead (litharge), is of no other use in painting than to free oils from their greasy particles, for the purpose of communicating to them a drying quality. Red litharge, however, ought to be preferred to the greenish yellow; it is not so hard, and answers better for the purpose to which it is destined.

When painters wish to obtain a common color of the ochrey kind, and have no boiled oil by them, they may paint with linseed oil, not freed from its greasy particles, by mixing with the color about 2 or 3 parts of litharge, ground on a piece of porphyry with water, dried, and reduced to fine powder, for 16 parts of oil. The color has a great deal of body, and dries as speedily as if mixed with drying oil.
 

Boil together for 2 hours on a slow and equal fire, 1/2 oz. of litharge, as much calcined ceruse, and the same of terre d'ombre and talc, with 1 lb. of linseed oil, carefully stirring the whole time. It must be carefully skimmed and clarified. The older it grows the better it is. A quarter of a pint of this dryer is required to every pound of color.
 

It is performed with water-colors on fresh plaster, or a wall laid with mortar not dry. This sort of painting has a great advantage by its incorporating with the mortar, and drying along with it becomes very durable.

The ancients painted on stucco, and we may remark in Vitruvius what infinite care they took in making the plastering of their buildings, to render them beautiful and lasting, though the modern painters find a plaster of lime and sand preferable to it.
 

The Genevese employ a kind of stone, known under the name of molasse, for constructing fire-places and stoves, after the German manner. This stone is brought from Saura, a village of Savoy, near Geneva. It has a grayish color, inclining to blue, which is very agreeable to the eye. This tint is similar to that communicated to common whitewashing with lime, chalk, or gypsum, the dullness of which is corrected by a particle of blue extract of indigo, or by charcoal black.
 

Dip a brush in water from a common lye, or in soapy water, or in water charged with a 20th part of the carbonate of potash (pearlash), and draw it over the tiles. This washing thoroughly cleanses them, and disposes all the parts of the pavement to receive the distemper.

When dry, dissolve in 8 pts. of water 1/2 lb. of Flanders glue; and while the mixture is boiling, add 2 lbs. of red ochre; mix the whole with great care. Then apply a stratum of this mixture to the pavement, and when dry apply a second stratum with drying linseed oil, and a third with the same red mixed up with size. When the whole is dry, rub it with wax.
 

Badigeon is employed for giving an uniform tint to houses rendered brown by time, and to churches. Badigeon, in general, has a yellow tint. That which succeeds best is composed of the saw-dust or powder of the same kind of stone and slacked lime, mixed up in a bucket of water holding in solution 1 lb. of the sulphate of alumina (alum). It is applied with a brush.

At Paris, and in other parts of France, where the large edifices are constructed of a soft kind of stone, which is yellow, and sometimes white when it comes from the quarry, but which in time becomes brown, a little ochre de rue is substituted for the powder of the stone itself, and restores to the edifice its original tint.
 

To make it Black.

First, the canvas, linen, or cloth is to be washed with hot or cold water, the former preferable, so as to discharge the stiffening which all new canvas, linen, or cloth contains; when the stiffening is perfectly discharged, hang the canvas, linen, or cloth up to dry; when perfectly so, it must be constantly rubbed by the hand until it becomes supple; it must then be stretched in a hollow frame very tight, and the following ingredients are to be laid on with a brush for the first coat, viz.; 8 qts. of boiled linseed oil, 1/2 oz. of burnt umber, 1/4 oz. of sugar of lead, 1/4 oz. of white vitriol, 1/4 oz. of white lead.

The above ingredients, except the white lead, must be ground fine with a small quantity of the above-mentioned oil, on a stone and muller; then mix all the ingredients up with the oil, and add 3 oz. of lampblack, which must be put over a slow fire in an iron broad vessel, and kept stirred until the grease disappears. In consequence of the canvas being washed and then rubbed, it will appear rough and nappy; the following method must be taken with the second coat, viz. the same ingredients as before, except the white lead; this coat will set in a few hours, according to the weather; when set take a dry paint-brush and work it very hard with the grain of the oanvas; this will cause the nap to lie smooth.

The third and last coat makes a complete jet-black, which continues its color: Take 3 galls. of boiled linseed oil, an ounce of burnt umber, 1/2 oz. of sugar of lead, 1/4 oz. of white vitriol, 1 oz. of Prussian blue, and 1/4 oz. of verdigris; this must be all ground very fine in a small quantity of the above oil; then add 4 oz. of lampblack, put through the same process of fire as the first coat. The above are to be laid on and used at discretion, in a similar way to paint. To make lead color, the same ingredients as before in making the black, with the addition of white lead in proportion to the color you wish to have, light or dark.

To make it Green.

Yellow ochre, 4 oz.; Prussian blue, 3/4 oz.; white lead, 3 oz.; white vitriol, 1/2 oz.; sugar of lead 1/4 oz.; good boiled linseed oil sufficient to make it of a thin quality, so as to go through the canvas.

To make it Yellow.

Yellow ochre, 4 oz.; burnt umber, 1/4 oz.; white lead, 6 or 7 oz.; white vitriol, 1/4 oz.; sugar of lead, 1/4 oz.; boiled linseed oil, as in green.

To make it Red.

Red lead, 4 oz.; vermilion 2 oz.; white vitriol 1/4 oz.; sugar of lead 1/4 oz.; boiled linseed oil as before.

To make it Gray.

Take white lead, a little Prussian blue, according to the quality you want, which will turn it to a gray color; a proportion of sugar of lead and white vitriol, as mentioned in the other colors, boiled linseed oil sufficient to make it of a thin quality.

To make it White.

White lead, 4 lbs.; spirits of turpentine, 1/4 pt.; white vitriol, 1/2 oz.; sugar of lead, 1/2 oz.; boiled oil sufficient to make it of a thin quality.

The above ingredients, of different colors, are calculated as near as possible; but, as one article may be stronger than another, which will soon be discovered in using, in that case the person working the color may add a little, or diminish, as he may find necessary.

The same preparation for wood or iron, only reducing the oil about 3 qt. out of 8, and to be applied in the same manner as paint or varnish, with a brush.
 

On Coloring Materials.

The composition of colors as respects those leading tests of excellence, preservation of general tints, and permanency of brilliant hues, during their exposure for many centuries to the impairing assaults of the atmosphere, is a preparation in which the ancient preparers of these oily compounds, have very much excelled, in their skilfulness, the moderns. It is a fact, that the ancient painted walls, to be seen at Dendaras, although exposed for many ages to the open air, without any covering or protection, still possess a perfect brilliancy of color, as vivid as when painted, perhaps 2000 years ago. The Egyptians mixed their colors with some gummy substance, and applied them detached from each other without any blending or mixture. They appeared to have used six colors, viz., white, black, blue, red, yellow, and green; they first covered the canvas entirely with white, upon which they traced the design in black, leaving out the lights of the ground color. They used minium for red, and generally of a dark tinge. Pliny mentions some painted ceilings in his day in the town of Ardea, which had been executed at a date prior to the foundation of Rome. He expresses great surprise and admiration at their freshness, after the lapse of so many centuries. These are, undoubtedly, evidences of the excellence of the ancients in their art of preparing colors. In the number of them there is, probably, not much difference between the ancient and modern knowledge. The ancients seem to have been possessed of some colors of which we are ignorant, while they were unacquainted, themselves, with some of those more recently discovered. The improvements of chemistry have, certainly, in later times, enriched painting with a profusion of tints, to which, in point of brilliancy at least, no combination of primitive colors known to the ancients could pretend; but the rapid fading in the colors of some of the most esteemed masters of the Modern School, proves at least there is something defective in their bases or mode of preparing them. This fault is peculiarly evident in many of the productions from our esteemed master, Sir Joshua Reynolds, which, although they have not issued from his pallet more than 40 years, carry an impoverishment of surface, from the premature fading of their colors, so as almost to lose, in many instances, the identity of the subjects they represent. On this head (and a most important one it is), the superiority of the ancient compounders completely carries away the palm of merit.
 

Separate from the stone the most apparent parts of the ultramarine, reduce them to the size of a pea, and, having brought them to a red heat in a crucible, throw them in that state into the strongest distilled vinegar. Then grind them with the vinegar, and reduce them to an impalpable powder; next take of wax, red colophonium, and lapis lazuli, an equal quantity, say 1/2 oz. of each of these three substances; melt the wax and the colophonium in a proper vessel, and add the powder to the melted matter, then pour the mass into cold water, and let it rest eight days. Next take two glass vessels filled with water, as hot as the hand can bear, knead the mass in the water, and when the purest part of the ultramarine has been extracted remove the resinous mass into the other vessels, where finish the kneading to separate the remainder; if the latter portion appears to be much inferior, and paler than the former, let it rest for 4 days, to facilitate the precipitation of the ultramarine, which extract by decantation, and wash it in fair water.

Ultramarine of four qualities may be separated by this process. The first separation gives the finest, and as the operation is repeated, the beauty of the powder decreases.

Kinckel considers immersion in vinegar as the essential part of the operation. It facilitates the division, and even the solution of the zeolitic and earthy particles soluble in that acid.

Another Method.

Separate the blue parts, and reduce them, on a piece of porphyry, to an impalpable powder, which besprinkle with linseed oil, then make a paste with equal parts of yellow wax, pine resin, and colophonium, say, 8 oz. of each; and add to this paste 1/2 oz. of linseed oil, 2 oz. of oil of turpentine, and as much more mastic.

Then take 4 parts of this mixture, and 1 of lapis lazuli, ground with oil on a piece of porphyry, mix the whole warm, and suffer it to digest for a month, at the end of which knead the mixture thoroughly in warm water, till the blue part separates from it, and at the end of some days decant the liquor. This ultramarine is exceedingly beautiful.

These two processes are nearly similar, if we except the preliminary preparation of Kinckel, which consists in bringing the lapis lazuli to a red heat and immersing it in vinegar. It may be readily seen, by the judicious observations of Morgraff on the nature of this coloring part, that this calcination may be hurtful to certain kinds of azure stone. This preliminary operation, however, is a test which ascertains the purity of the ultramarine.

To Extract the Remainder of Ultramarine.

As this matter is valuable, some portions of ultramarine may be extracted from the paste which has been kneaded in water; nothing is necessary but to mix it with four times its weight of linseed oil, to pour the matter into a glass of conical form, and to expose the vessel in the balneum maria of an alembic. The water of which must be kept in a state of ebullition for several hours. The liquidity of the mixture allows the ultramarine to separate itself, and the supernatant oil is decanted. The same immersion of the coloring matter in oil is repeated, to separate the resinous parts which still adhere to it; and the operation is finished by boiling it in water to separate the oil. The deposit is ultramarine; but it is inferior to that separated by the first washing.

To Ascertain whether Ultramarine be Adulterated.

As the price of ultramarine, which is already very high, may become more so on account of the difficulty of obtaining lapis lazuli, it is of great importance that painters should be able to detect adulteration. Ultramarine is pure if, when brought to a red heat in a crucible, it stands that trial without changing its color; as small quantities only are subjected to this test, a comparison may be made, at very little expense, with the part which has not been exposed to the fire. If adulterated, it becomes blackish or paler.

This proof, however, may not always be conclusive. When ultramarine of the lowest quality is mixed with azure, it exhibits no more body than sand ground on porphyry would do; ultramarine treated with oil assumes a brown tint.

Another Method.

Ultramarine is extracted from lapis lazuli, or azure stone, a kind of heavy zeolite, which is so hard as to strike fire with steel, to cut glass, and to be susceptible of a fine polish. It is of a bright blue color, variegated with white or yellow veins, enriched with small metallic glands, and even veins of a gold color, which are only sulphurets of iron (martial pyrites); it breaks irregularly. The specimens most esteemed are those charged with the greatest quantity of blue.

Several artists have exercised their ingenuity on processes capable of extracting ultramarine in its greatest purity; some, however, are contented with separating the uncolored portions of the stone, reducing the colored part to an impalpable powder, and then grinding it for a long time with oil of poppies. But it is certain that, in consequence of this ineffectual method, the beauty of the color is injured by parts which are foreign to it; and that it does not produce the whole effect which ought to be expected from pure ultramarine.

It may be readily conceived that the eminent qualities of ultramarine must have induced those first acquainted with the processes proper for increasing the merit and value of it, to keep them a profound secret. This was indeed the case; ultramarine was prepared long before any account of the method of extracting and purifying it was known.

Artificial Ultramarine.

Sulphur, 2 parts; dry carbonate of soda, 1 part. Put them into a Hessian crucible, cover it up, and apply heat until the mass fuses, then sprinkle into it gradually a mixture of silicate of soda and aluminate of soda (the first containing 72 parts of silica, the second, 70 parts of alumina); lastly, calcine for 1 hour, and wash in pure water.
 

Having reduced the ore to powder, calcine it in a reverberatory furnace, stirring it frequently. The chimney of the furnace should have a strong draught, in order that the calcination may be perfect, and the arsenical and sulphurous acid vapors may be carried off. The calcination is to be continued until these vapors cease to be disengaged, which is easily ascertained by collecting in a ladle a little of the gas in the furnace; the presence or absence of the garlic odor determines the fact. When calcined, boil the result slightly in an excess of weak nitric acid, in a glass matrass, decant the supernatant liquor, and evaporate the solution thus obtained, nearly to dryness, in a capsule of platina or porcelain. This residuum is to be thrown into boiling water and filtered, and a solution of the subphosphate of soda to be poured into the clear liquor, which precipitates an insoluble phosphate of cobalt. After washing it well on a filter, collect it while yet in a gelatinous form, and mix it intimately, with eight times its weight of alumina, in the same state - if properly done the paste will have a uniform tint, through its whole mass. This mixture is now to be spread on smooth plates and put into a stove; when dry and brittle, pound it in a mortar, enclosed in a covered earthen crucible, and heat it to a cherry-red for half an hour. On opening the crucible, if the operation has been carefully conducted, the beautiful and desired product will be found. Care should be taken that the alumina in the gelatinous form be precipitated from the alum by a sufficient excess of ammonia, and that it is completely purified by washing with water filtered through charcoal.
 

Saxon blue may be successfully imitated by mixing with a divided earth prussiate of iron at the moment of its formation and precipitation.

Into a solution of 144 grs. of sulphate of iron pour a solution of yellow prussiate of potash.

At the time of the formation of iron add, in the same vessel, a solution of 2 oz. of alum, and pour in with it the solution of potash, just sufficient to decompose the sulphate of alumina, for a dose of alkali superabundant to the decomposition of that salt might alter the prussiate of iron. It will, therefore, be much better to leave a little alum, which may afterwards be carried off by washing

As soon as the alkaline liquor is added, the alumina precipitated becomes exactly mixed with the prussiate of iron, the intensity of which it lessens by bringing it to the tone of common Saxon blue. The matter is then thrown on a filter, and, after being washed in clean water, is dried. This substance is a kind of blue verditer, the intensity of which may vary according to the greater or less quantity of the sulphate of alumina decomposed. It may be used for painting in distemper.
 

Dissolve the copper, cold, in nitric acid (aquafortis), and produce a precipitation of it by means of quicklime, employed in such doses that it will be absorbed by the acid, in order that the precipitate may be pure oxide of copper, that is, without any mixture. When the liquor has been decanted, wash the precipitate and spread it out on a piece of linen cloth to drain. If a portion of this precipitate, which is green, be placed on a grinding-stone, and if a little quicklime, in powder, be added, the green color will be immediately changed into a beautiful blue. The proportion of the lime added is from 7 to 10 parts in 100. When the whole matter acquires the consistence of paste, desiccation soon takes place.

Blue verditer is proper for distemper, and for varnish, but it is not for oil painting, as the oil renders it very dark. If used it ought to be brightened with a great deal of white.
 

To a solution of bichromate of potassa add a solution of nitrate of lead as long as a precipitate falls. Wash and dry it.
 

Is a compound of cadmium and sulphur. It is obtained by precipitation from a salt of cadmium by a current of sulphuretted hydrogen gas, or by an alkaline sulphide.
 

Is a chromate of baryta, made by mixing hot saturated solutions of bichromate of potassa and nitrate of baryta. Wash and dry the precipitates. It is considered superior to chrome yellow.
 

Twelve oz. of ceruse, 2 oz. of the sulphuret of antimony, 1/2 oz. of calcined alum, 1 oz. of sal ammoniac. Pulverize these ingredients, and having mixed them thoroughly, put them into a capsule or crucible of earth, and place over it a covering of the same substance. Expose it at first to a gentle heat, which must be gradually increased till the capsule is moderately red. The oxidation arising from this process requires, at least, 5 hours' exposure to heat before it is completed. The result of this calcination is Naples yellow, which is ground in water on a porphyry slab with an ivory spatula, as iron alters the color. The paste is then dried and preserved for use. It is a yellow oxide of lead and antimony.

There is no necessity of adhering so strictly to the doses as to prevent their being varied. If a golden color be required in the yellow, the proportions of the sulphuret of antimony and muriate of ammonia must be increased. In like manner, if you wish it to be more fusible, increase the quantities of sulphuret of antimony and calcined sulphate of alumina.
 

Take 4 lbs. of litharge, well sifted, divide it into 4 equal portions, and put it into as many glazed earthen vessels. Dissolve also 1 lb. of sea-salt in about 4 lbs. of water. Pour a fourth part of this solution into each of the 4 earthen vessels, to form a light paste; let the whole rest for some hours, and when the surface begins to grow white stir the mass with a strong wooden spatula. Without this motion it would acquire too great hardness, and a part of the suit would escape decomposition. As the consistence increases dilute the matter with a new quantity of the solution, and if this is not sufficient recourse must be had to simple water to maintain the same consistence. The paste will then be very white, and in the course of 24 hours becomes uniform and free from lumps; let it remain for the same space of time, but stir it at intervals to complete the decomposition of the salt. The paste is then well washed, to carry off the caustic soda (soda deprived of carbonic acid) which adheres to it: the mass is put into strong linen cloth and subjected to a press. The remaining paste is distributed in flat vessels, and these vessels are exposed to heat, in order to effect a proper oxidation (calcination), which converts it into a solid, yellow, brilliant matter, sometimes crystallized in transverse striae.

This is Montpellier yellow, which may be applied to the same purposes as Naples yellow.
 

This kind of fecula, so fertile in gradation of tone by the effect of mixtures, and so grateful to the eye in all its shades, so useful to the painter, and so agreeable to the delicate beauty, is only the coloring part of a kind of dried insect known under the name of cochineal.

A mixture of 36 grs. of chosen seed, 18 grs. of autour bark, and as much alum thrown into a decoction of 5 grs. of pulverized cochineal, and 5 lbs. of water, gives, at the end of from 5 to 10 days, a red fecula, which, when dried, weighs from 40 to 48 grs. This fecula is carmine. The remaining decoction, which is still highly colored, is reserved for the preparation of carminated lakes.
 

Heat 6 buckets of rain-water, and when it commences to boil throw in 2 lbs. of finely-powdered cochineal; continue boiling 2 hours, and then add 3 oz. of pure water, and immediately afterwards 4 oz. of binoxalate of potash. Boil again 1 minute, then remove the vessel from the fire, and let the decoction stand 4 hours. Draw off the supernatant liquid with a syphon into numerous basins, and put them aside upon a shelf for about 3 weeks, at the end of which time a mouldy pellicle will be formed, which is to be carefully removed with a whalebone, or by means of a small sponge attached to the end of a stick. The water is then run off through a syphon, which must reach to the bottom of the pans, the carmine being so compact that it adheres. This carmine is dried in the shade, and is of an intensely brilliant hue.
 

Boil the stems of woad in alum-water, and then mix the liquor with clay, marl or chalk, which will become charged with the color of the decoction. When the earthy matter has acquired consistence, form it into small cakes and expose them to dry. It is under this form that the Dutch pinks are sold in the color shops.
 

The small blackthorn produces a fruit which when collected green, is called yellow berries. These seeds, when boiled in alum-water, form a Dutch pink superior to the former. A certain quantity of clay or marl, is mixed with the decoction, by which means the coloring part of the berries unites with the earthy matter and communicates to it a beautiful yellow color.
 

Boil for an hour in 12 lbs. of water 1 lb. of yellow berries, 1/2 lb. of the shavings of the wood of the Barberry shrub and 1 lb. of wood-ashes. The decoction is strained through a piece of linen cloth. Pour into this mixture, warm, and at different times, a solution of 2 lbs. of the sulphate of alumina in 5 lbs. of water; a slight effervescence will take place, and the sulphate being decomposed, the alumina which is precipitated will seize on the coloring part. The liquor must then be filtered through a piece of close linen, and the paste which remains on the cloth, when divided into square pieces, is exposed on boards to dry. This is brown Dutch pink, because the clay in it is pure. The intensity of the color shows the quality of the pink, which is superior to that of the other compositions.
 

By substituting for clay a substance which prevents a mixture of that earth and metallic oxide, the result will be Dutch pink of a very superior kind.

Boil separately 1 lb. of yellow-berries and 3 oz. of the sulphate of alumina in 12 lbs. of water, which must be reduced to 4 lbs. Strain the decoction through a piece of linen, and squeeze it strongly. Then mix up with it 2 lbs. of ceruse, finely ground on porphyry, and 1 lb. of pulverized Spanish white. Evaporate the mixture till the mass acquires the consistence of a paste; and, having formed it into small cakes, dry them in the shade.

When these cakes are dry, reduce them to powder, and mix them with a new decoction of yellow-berries. By repeating this process a third time a brown Dutch pink will be obtained.

In general the decoctions must be warm when mixed with the earth. They ought not to be long kept, as their color is speedily altered by the fermentation. Care must be taken also to use a wooden spatula for stirring the mixture.

When only one decoction of wood or yellow berries is employed to color a given quantity of earth, the Dutch pink resulting from it is of a bright-yellow color, and is easily mixed for use. When the coloring part of several decoctions is absorbed the composition becomes brown, and is mixed with more difficulty, especially if the paste be argillaceous; for it is the property of this earth to unite with oily and resinous parts, adhere strongly to them, and incorporate with them. In the latter case the artist must not be satisfied with mixing the color; it ought to be ground, an operation equally proper for every kind of Dutch pink, and even the softest, when destined for oil painting.
 

Boil 4 oz. of the raspings of Brazil-wood in 15 pts. of pure water till the liquor is reduced to 2 pts. It will be of a dark-red color, inclining to violet, but the addition of 4 or 5 oz. of alum will give it a hue inclining to rosecolor. When the liquor has been strained through a piece of linen cloth, if 4 oz. of the carbonate of soda be added with caution, on account of the effervescence which takes place, the color, which by this addition is deprived of its mordant, will resume its former tint, and deposit a lake, which, when washed and properly dried, has an exceedingly rich and mellow violet red color.

Another. - If only one-half of the dose of mineral alkali be employed for this precipitation, the tint of the lake becomes clearer, because the bath still retains the undecomposed aluminous mordant.

Another. - If the method employed for Dutch pinks be followed by mixing the aluminous decoction of Brazil-wood with pure clay, such as Spanish white and white of Morat, and if the mixture be deposited on a filter to receive the necessary washing, a lake of a very bright dark rose-color will be obtained from the driers.

Lakes from other Coloring Substances.

By the same process a very beautiful lake may be extracted from a decoction of logwood. In general, lakes of all colors, and of all the shades of these colors, may be extracted from the substances which give up their coloring part to boiling water, because it is afterwards communicated by decomposition to the alumina precipitated from sulphate of alumina, by means of an alkali, or the tincture may be mixed with a pure and exceedingly white argillaceous substance, such as real Spanish white, or white of Morat.
 

Carmine united to talc, in different proportions, forms rouge employed for the toilette. Talc is distinguished also by the name of Briancon chalk. It is a substance composed in a great measure of clay, combined naturally with silex.

Carmine, as well as carminated lakes, the coloring part of which is borrowed from cochineal, is the most esteemed of all the compositions of this kind, because their coloring part maintains itself without degradation. There are even cases where the addition of caustic ammonia, which alters so many coloring matters, is employed to heighten its color. It is for this purpose that those who color prints employ it.
 

Are made with extract of safflower (carthamus), obtained by digesting it, after washing with cold water, in a solution of carbonate of soda, and precipitating by citric acid. It dyes silk and wool without a mordant. The extract is evaporated upon saucers as a dye-stuff, and, mixed with powdered talc, forms a variety of rouge.
 

Boil 1 part of madder in from 12 to 15 pints of water, and continue the ebullition till it be reduced to about 2 lbs. Then strain the decoction through a piece of strong linen cloth, which must be well squeezed; and add to the decoction 4 oz. of alum. The tint will be a beautiful brightred, which the matter will retain if it be mixed with proper clay. In this case, expose the thick liquor which is thus produced on a linen filter, and subject it to one washing, to remove the alum. The lake, when taken from the driers, will retain this bright primitive color given by the alum.

Another Method.

If, in the process for making this lake, decomposition be employed, by mixing with the bath an alkaline liquor, the alum, which is decomposed, deprives the bath of its mordant, and the lake, obtained after the subsequent washings, appears of the color of the madder bath, without any addition: it is of a reddish brown. In this operation 7 or 8 oz. of alum ought to be employed for each pound of madder.

This kind of lake is exceedingly fine, but a brighter red color may be given to it, by mixing the washed precipitate with alum-water, before drying.

Improvement on the above.

If the aluminated madder bath be sharpened with acetate of lead, or with arseniate of potash, the operator still obtains, by the addition of carbonate of soda, a rosecolored lake of greater or less strength
 

Dragon's blood, infused warm in varnish, gives reds, more or less dark, according to the quantity of the coloring resin which combines with the varnish. The artist, therefore, has it in his power to vary the tones at pleasure.

Though cochineal, in a state of division, gives to essence very little color in comparison with that which it communicates to water, carmine may be introduced into the composition of varnish colored by dragon's blood. The result will be a purple red, from which various shades may be easily formed.
 

A mixture of carminated varnish and dragon's blood, added to that colored by prussiate of iron, produces violet.
 

Boil stick-lac in water, filter the decoction, and evaporate the clear liquor to dryness over a gentle fire. The occasion of this easy separation is, that the beautiful red color here separated adheres only slightly to the outsides of the sticks broken off the trees along with the gum-lac, and readily communicates itself to boiling water. Some of this sticking matter also adhering to the gum itself, it is proper to boil the whole together; for the gum does not at all prejudice the color, nor dissolve in boiling water; so that after this operation the gum is as fit for making sealing-wax as before, and for all other uses which do not require its color.
 

Take any quantity of cochineal, on which pour twice its weight of alcohol, and as much distilled water. Infuse for some days near a gentle fire, and then filter. To the filtered liquor add a few drops of the solution of tin, and a fine red precipitate will be formed. Continue to add a little solution of tin every 2 hours, till the whole of the coloring matter is precipitated. Lastly, edulcorate the precipitate by washing it in a large quantity of distilled water and then dry it.
 

The sediment of cochineal that remains in the bottom of the kettle in which carmine is made, may be boiled with about 4 qts. of water, and the red liquor left after the preparation of the carmine mixed with it, and the whole precipitated with the solution of tin. The red precipitate must be frequently washed over with water. Exclusively of this, 2 oz. of fresh cochineal, and 1 of crystals of tartar, are to be boiled with a sufficient quantity of water, poured off clear, and precipitated with the solution of tin, and the precipitate washed. At the same time 2 lbs. of alum are also to be dissolved in water, precipitated with a lixivium of potash, and the white earth repeatedly washed with boiling water. Finally, both precipitates are to be mixed together in their liquid state, put upon a filter and dried. For the preparation of a cheaper sort, instead of cochineal, 1 lb. of Brazil wood may be employed in the preceding manner.
 

Inclose 2 oz. troy of the finest Dutch madder in a bag of fine and strong calico, large enough to hold three or four times as much. Put it into a large marble or porcelain mortar, and pour on it a pint of clear soft water cold. Press the bag in every direction, and pound and rub it about with a pestle, as much as can be done without tearing it, and when the water is loaded with color pour it off. Repeat this process till the water comes off but slightly tinged, for which about 5 pts. will be sufficient. Heat all the liquor in an earthen or silver vessel till it is near boiling, and then pour it into a large basin, into which 1 oz. of alum, dissolved in 1 pt. of boiling soft water, has been previously put: stir the mixture together, and while stirring pour in gently about 1 1/2 oz. of a saturated solution of subcarbonate of potash; let it stand till cold to settle; pour off the clear yellow liquor; add to the precipitate a quart of boiling soft water, stirring it well; and when cold separate by filtration the lake, which should weigh an oz. Fresh madder-root is superior to the dry.

To give Various Tones to Lake.

A beautiful tone of violet, red, and even of purplered, may be communicated to the coloring part of cochineal by adding to the colored bath a solution of chloride of tin.

Another. - The addition of arseniate of potash (neutral arsenical salt), gives shades which would be sought for in vain with sulphate of alumina (alum).

To make a Carminated Lake by Extracting the Coloring Part from Scarlet Cloth.

To prepare a carminated lake without employing cochineal in a direct manner, by extracting the coloring matter from any substance impregnated with it, such as the shearings of scarlet cloth.

Put into a kettle 1 lb. of fine wood-ashes with 40 lbs. of water, and subject the water to ebullition for 1/4 of an hour; then filter the solution through a piece of linen cloth till the liquor passes through clear.

Place it on the fire; and having brought it to a state of ebullition, add 2 lbs. of the shearings or shreds of scarlet cloth, dyed with cochineal, which must be boiled till they become white, then filter the liquor again, and press the shreds to squeeze out all the coloring part.

Put the filtered liquor into a clean kettle, and place it over the fire. When it boils pour in a solution of 10 or 12 oz. of alum in 2 lbs. of filtered spring-water. Stir the whole with a wooden spatula till the froth that is formed is dissipated, and having mixed with it 2 lbs. of a strong decoction of Brazil-wood, pour it upon a filter. Afterwards wash the sediment with spring-water, and remove the cloth filter charged with it to plaster dryers or to a bed of dry bricks. The result of this operation will be a beautiful lake, but it has not the soft velvety appearance of that obtained by the first method. Besides, the coloring part of the Brazil-wood which unites to that of the cochineal in the shreds of scarlet cloth, lessens in a relative proportion the unalterability of the coloring part of the cochineal. For this reason purified potash ought to be substituted for the wood-ashes.
 

Dissolve 1 lb. of the best pearlash in 2 qts. of water, and filter the liquor through paper; next add 2 more qts. of water and 1 lb. of clean scarlet shreds, boil them in a pewter boiler till the shreds have lost their scarlet color; take out the shreds and press them, and put the colored water yielded by them to the other. In the same solution boil another lb. of the shreds, proceeding in the same manner; and likewise a third and fourth pound. Whilst this is doing, dissolve 1 1/2 lbs. of cuttle-fish bone in 1 lb. of strong aquafortis in a glass receiver, add more of the bone if it appears to produce any ebullition in the aquafortis, and pour this strained solution gradually into the other; but if any ebullition be occasioned, more of the cuttle-fish bone must be dissolved as before, and added till no ebullition appears in the mixture. The crimson sediment deposited by this liquor is the lake: pour off the water, and stir the lake in 2 galls. of hard spring-water, and mix the sediment in 2 galls. of fresh water; let this method be repeated 4 or 5 times. If no hard water can be procured, or the lake appears too purple, 1/2 an oz. of alum should be added to each quantity of water before it is used. Having thus sufficiently freed the latter from the salts, drain off the water through a filter, covered with a worn linen cloth. When it has been drained to a proper dryness, let it be dropped through a proper funnel on clean boards, and the drops will become small cones or pyramids, in which form the lake must be dried and the preparation is completed.

Another Method.

Boil 2 oz. of cochineal in 1 pt. of water, filter the solution through paper, and add 2 oz. of pearlash dissolved in 1/2 pint of warm water and filtered through paper. Make a solution of cuttlebone, as in the former process, and to 1 pt. of it add 2 oz. of alum dissolved in 1/2 pt. of water. Put this mixture gradually to the cochineal and pearlash as long as any ebullition arises, and proceed as above.

A beautiful lake may be prepared from Brazil wood, by boiling 3 lbs. of it for an hour in a solution of 3 lbs. of common salt in 3 galls. of water and filtering the hot fluid through paper; add to this a solution of 5 lbs. of alum in 3 galls. of water. Dissolve 3 lbs. of the best pearlash in 1 1/2 galls. of water, and purify it by filtering; put this gradually to the other till the whole of the color appears to be precipitated and the fluid is left clear and colorless. But if any appearance of purple be seen, add a fresh quantity of the solution of alum by degrees, till a scarlet hue is produced. Then pursue the directions given in the first process with regard to the sediment. If 1/2 lb. of seed-lac be added to the solution of pearlash, and dissolved in it before its purification by the filter and 2 lbs. of the wood and a proportional quantity of common salt and water be used in the colored solution, a lake will be produced that will stand well in oil or water; but it is not so transparent in oil as without the seed-lac. The lake with Brazil wood may be also made by adding 3 oz. of anatto to each pound of the wood, but the anatto must be dissolved in the solution of pearlash.

After the operation, the dryers of plaster, or the bricks which have extracted the moisture from the precipitate, are exposed to the sun, that they may be fitted for another operation.
 

Dissolve sulphate of iron (copperas, green vitriol) in water; boil the solution. Add nitric acid until red fumes cease to come off, and enough sulphuric acid to render the liquor clear. This is the persulphate of iron. To this add a solution of ferrocyanide of potassium (yellow prussiate of potash), as long as any precipitate is produced. Wash this precipitate thoroughly with water acidulated with sulphuric acid, and dry in a warm place.

Soluble Prussian Blue.

Add ferrocyanide of potassium to a solution freshly made of green vitriol in water. The white precipitate which falls, becomes blue on exposure to the air, and is soluble in water.
 

Melt saltpetre in a crucible heated to dull redness, and throw in gradually chrome yellow until no more red fumes arise. Allow the mixture to settle, pour off the liquid portion, and wash rapidly the sediment. The liquid portion contains chromate of potash, and may be used to make chrome yellow.

To make Blue.

A diluted solution of sulphate of indigo.

To make Pink.

Cochineal boiled with bitartrate of potash and sulphate alumina, or a decoction of Brazil-wood with sulphate alumina; the color may be varied by the addition of carbonate potash.
 

A decoction of Brazil-wood and logwood affords, with carbonate of potash, a permanent purple.
 

Boil 4 oz. of the best anatto and 1 lb. of pearlash, 1/2 an hour, in 1 gall. of water, and strain the solution through paper. Mix gradually with this 1 1/2 lbs. of alum, in another gallon of water, desisting when no ebullition attends the commixture. Treat the sediment in the manner already directed for other kinds of lake, and dry it in square bits or lozenges.
 

Take 1 lb. of turmeric-root, in fine powder, 3 pt. of water, and 1 oz. of salt of tartar; put all into a glazed earthen vessel, and boil them together over a clear gentle fire, till the water appears highly impregnated and stains a paper to a beautiful yellow. Filter this liquor, and gradually add to it a strong solution of alum, in water, till the yellow matter is all curdled and precipitated. After this, pour the whole into a filter of paper and the water will run off, and leave the yellow matter behind. Wash it with fresh water till the water comes off insipid, and then is obtained the beautiful yellow called lacque of turmeric.

In this manner make a lake of any of the substances that are of a strong texture, as madder, logwood, etc., but it will not succeed in the more tender species, as the flowers of roses, violets, etc., as it destroys the nice arrangement of parts in those subjects on which the color depends.

To make another Yellow Lake.

Make a lye of potash and lime sufficiently strong; in this boil, gently, fresh broom-flowers till they are white, then take out the flowers, and put the lye to boil in earthen vessels over the fire; add as much alum as the liquor will dissolve, then empty this lye into a vessel of clean water, and it will give a yellow color at the bottom. Settle, and decant off the clear liquor. Wash this powder which is found at the bottom, with more water till all the salts of the lye are washed off; then separate the yellow matter, and dry it in the shade.
 

Gum guttae and terra merita give very beautiful yellows, and readily communicate their color to copal varnish made with turpentine. Aloes give a varied and orange tint.

Chloride of lead tinges vitreous matters of a yellow color. Hence the beautiful glazing given to Queen's ware. It is composed of 80 lbs. of chloride of lead, and 20 lbs. of flints ground together very fine, and mixed with water till the whole becomes as thick as cream. The vessels to be glazed are dipped in the glaze and suffered to dry.
 

The acacia, an Egyptian thorn, is a species of mimosa, from which the Chinese make that yellow which bears washing in their silks and stuffs, and appears with so much elegance in their painting on paper. The flowers are gathered before they are fully opened, and put into an earthen vessel over a gentle heat, being stirred continually until they are nearly dry, and of a yellow color: then to 1/2 lb. of the flowers a sufficient quantity of rain-water is added, to hold the flowers incorporated together. It is then to be boiled until it becomes thick, when it must be strained. To the liquor is added 1/2 oz. of common alum, and 1 oz. of calcined oystershells, reduced to a fine powder.

All these are mixed together into a mass. An addition of a proportion of the ripe seeds to the flowers renders the colors somewhat deeper. For making the deepest yellow add a small quantity of Brazil-wood.
 

Largely used as a substitute for white lead, may be made by burning zinc, or by precipitating from a solution by caustic alkali. It is the oxide of the metal, and is not blackened by sulphuretted hydrogen.
 

Pour some distilled water into a solution of nitrate of bismuth as long as precipitation takes place, filter the solution, and wash the precipitate with distilled water as it lies on the filter. When properly dried, by a gentle heat, this powder is what is generally termed pearl white.
 

Mix bichromate of potash with half its weight of muriate of ammonia; heat the mixture to redness, and wash the mass with plenty of boiling water. Dry the residue thoroughly. It is a sesquioxide of chromium, and is the basis of the green ink used in bank-note printing.

Another. - Mix chrome yellow and Prussian blue.
 

Mix 3 parts of boracic acid and 1 part of bichromate of potassa, heat to about redness. Oxygen gas and water are given off. The resulting salt when thrown into water is decomposed. The precipitate is collected and washed. This is a remarkably fine color, solid and brilliant even by artificial light.
 

Dissolve 2 lbs. of blue vitriol in 6 lbs. of water in a copper vessel, and in another vessel dissolve 2 lbs. of dry white potash, and 11 oz. of white arsenic in 2 lbs. of water. When the solutions are perfect pour the arsenical lye into the other gradually, and about 1 lb. 6 oz. of good green precipitate will be obtained.
 

The acetic copper (verdigris) dissolved in acetic acid, forms an elegant green.
 

This is obtained from the solution of a precipitate of copper in tartar and water, which, by evaporation, yields a transparent cupreous tartar which is similar to the superfine Brunswick green.
 

Dissolve in a small quantity of hot water, 6 parts of sulphate of copper; in another part, boil 6 parts of oxide of arsenic with 8 parts of potash, until it throws out no more carbonic acid; mix by degrees this hot solution with the first, agitating continually until the effervescence has entirely ceased; these then form a precipitate of a dirty greenish yellow, very abundant; add to it about 3 parts of acetic acid, or such a quantity that there may be a slight excess perceptible to the smell after the mixture; by degrees the precipitate diminishes the bulk, and in a few hours there deposes spontaneously at the bottom of the liquor entirely discolored, a powder of a contexture slightly crystalline, and of a very beautiful green; afterwards the floating liquor is separated.
 

Some green colors free from the objections which apply to the arsenical greens, are described by Wiener. The first, called "Elsner Green," is made by adding to a solution of sulphate of copper a docoction of fustic, previously clarified by a solution of gelatine; to this mixture is then added 10 or 11 per cent. of protochloride of tin, and lastly an excess of caustic potash soda. The precipitate is then washed and dried, whereupon it assumes a green color, with a tint of blue.

The "Tin-copper Green" is a stannate of copper, and possesses a color which Gentele states is not inferior to any of the greens free from arsenic. The cheapest way of making this is to heap 59 parts of tin in a Hessian crucible, with 100 parts of nitrate of soda, and dissolve the mass, when cold, in a caustic alkali. When clear, this solution is diluted with water, and a cold solution of sulphate of copper is added. A reddish yellow precipitate falls, which, on being washed and dried, becomes a beautiful green.

Titanium Green was first prepared by Elsner in 1846. It is made in the following way: Iserin (titaniferous iron) is fused in a Hessian crucible with 12 times its weight of sulphate of potash. When cold, the fused mass is treated with hydrochloric acid, heated to 50° C. and filtered hot; the filtrate is then evaporated until a drop placed on a glass plate solidifies. It is then allowed to cool, and when cold a concentrated solution of sal ammoniac is poured over the mass, which is well stirred and then filtered. The titanic acid which remains behind is digested at 50° or 70° with dilute hydrochloric acid, and the acid solution, after the addition of some solution of prussiate of potash, quickly heated to boiling. A green precipitate falls, which must be washed with water acidulated with hydrochloric acid, and then dried under 100° C. Titanium green then forms a beautiful dark green powder.

A Green Color which may be employed in Confectionary.

Infuse for 24 hours 0.32 grammes of saffron in 7 grammes of distilled water; take 0.26 grammes of carmine of indigo and infuse in 15.6 grammes of distilled water. On mixing the two liquids a beautiful green color is obtained, which is harmless. Ten parts will color 1000 parts of sugar. It may be preserved for a long time by evaporating the liquid to dryness, or making it into a syrup.

To mix the Mineral Substances in linseed Oil.

Take 1 lb. of the genuine mineral green, prepared and well powdered, 1 lb. of the precipitate of copper, 1 1/2 lbs. of refiners' blue verditer, 3 lbs. of white lead, dry powdered, 3 oz. of sugar of lead powdered fine. Mix the whole of these ingredients in linseed oil, and grind them in a levigating mill, passing it through until quite fine; it will thereby produce a bright mineral pea-green paint, preserve a blue tint, and keep any length of time in any climate without injury, by putting oil or water over it.

To use this color for house or ship painting, take 1 lb. of the green color paint, with 1 gill of pale boiled oil, mix them well together, and this will produce a strong peagreen paint: the tint may be varied at pleasure by adding a further quantity of white lead ground in linseed oil. This color will stand the weather and resist salt water; it may also be used for flatting rooms, by adding 3 lbs. of white lead ground in half linseed oil and half turpentine, to 1 lb. of the green, then to be mixed up in turpentine spirits, fit for use. It may also be used for painting Venetian window blinds, by adding to 1 lb. of the green paint 10 oz. of white lead, ground in turpentine, then to be mixed up in turpentine varnish for use. In all the aforsaid preparations it will retain a blue tint, which is very desirable. When used for blinds, a small quantity of Dutch pink may be put to the white lead if the color is required of a yellow cast.
 

Mix a little white and yellow together, then add a little more red than yellow. These form an excellent imitation of the complexion.
 

Put into a pan 3 qts. of linseed oil, with an equal quantity of brandy and 4 qts. of the best double-distilled vinegar, 3 doz. of whole new-laid eggs, 4 lbs. of mutton suet, chopped small; cover all with a lead plate and lute it well, lay this pan in the cellar for 3 weeks, then take skilfully the white off, and dry it. The dose of this composition is 6 oz. of white to 1 of bismuth.
 

Take the picture out of the frame, lay a coarse towel on it for 10 or 14 days; keep continually wetting it until it has drawn out all the filthiness from the picture, pass some linseed oil, which has been a long time seasoned in the sun, over it, to purify it, and the picture will become as lively on the surface as new.

Another Method.

Put into 2 qts. of the oldest lye 1/4 lb. of Genoa soap, rasped very fine, with about a pint of spirit of wine, and boil all together; then strain it through a cloth, and let it cool. With a brush dipped in the composition rub the picture all over, and let it dry; repeat this process and let it dry again, then dip a little cotton in oil of nut, and pass it over its surface. When perfectly dry, rub it well over with a warm cloth, and it will appear of a beautiful freshness.

To Restore Discolored White.

In paintings, where the white has become blackened by sulphuretted hydrogen, the application of Thenard's oxygenated water will instantly restore it. Probably a solution of permanganate of potassa would have the same effect. (See CONDY'S SOLUTION).
 

Prof. Pettenkoffer has shown that the change which takes place in old paintings, is the discontinuance of molecular cohesion, which, beginning on the surface in small fissures, penetrates to the very foundation. His process is to expose the picture in a tight box to the vapor of alcohol, ether benzine, turpentine, or other similar solvent. The process has been successfully tried in several instances.

Compound for Receiving the Colors used in Encaustic Painting.

Dissolve 9 oz. of gum arabic in 1 pt. of water, add 14 oz. of finely powdered mastic and 10 oz. of white wax, cut in small pieces, and whilst hot, add by degrees 2 pts. of cold spring-water; then strain the composition.

Another Method.

Mix 24 oz. of mastic with gum-water, leaving out the wax, and when sufficiently beaten and dissolved over the fire, add by degrees 1 1/2 pts. of cold water, and strain.

Or, dissolve 9 oz. of gum arabic in 1 1/2 pts. of water, then add 1 lb. of white wax. Boil them over a slow fire, pour them into a cold vessel, and beat them well together. When this is mixed with the colors, it will require more water than the others. This is used in painting, the colors being mixed with these compositions as with oil, adding water if necessary. When the painting is finished, melt some white wax, and with a hard brush varnish the painting, and, when cold, rub it to make it entirely smooth.
 

Take 1 oz. of white wax and 1 oz. of gum mastic, in drops, made into powder; put the wax into a glazed pan over a slow fire, and when melted add the mastic, then stir the same until they are both incorporated. Next throw the paste into water, and when hard take it out, wipe it dry, and beat it in a mortar; when dry pound it in a linen cloth till it is reduced to a fine powder. Make some strong gum-water, and when painting take a little of the powder, some color, and mix them all with the gum-water. Light colors require but a small quantity of the powder, but more must be put in proportion to the darkness of the colors, and to black there should be almost as much of the powder as of color.

Having mixed the colors, paint with water, as is practised in painting with water colors, a ground on the wood being first painted of some proper color, prepared as described for the picture. When the painting is quite dry, with a hard brush, passing it one way, varnish it with white wax, which is melted over a slow fire till the picture is varnished. Take care the wax does not boil. Afterwards hold the picture before a fire near enough to melt the wax, but not to run, and when the varnish is entirely cold and hard, rub it gently with a linen cloth. Should the varnish blister, warm the picture again very slowly, and the bubbles will subside.

Solvents for India-Rubber and Gutta Percha.

1. Benzine. There are two bodies sold as benzine or benzole: one obtained by distilling coal or coal-tar - the true benzine - used in making coal tar colors; the other, from petroleum, contains but little true benzine. They may be used instead of turpentine in mixing paints and the true benzine for varnishes. Commercial benzine will not generally do for varnishes; that from petroleum is much the cheaper. Either forms an excellent solvent for india-rubber.

2. Bisulphide of Carbon is an excellent rubber solvent; acts in the cold; is made by passing the vapor of sulphur over red-hot charcoal.

3. Chloroform is very good, but costly.

Turpentine acts slowly, and takes long to dry. India rubber should always be cut into fine strings or shreds before being submitted to the action of solvents.

Solvent for Old Paint or Putty.

Caustic soda applied with a broom or brush made of vegetable matter. It is sold in the shops as concentrated lye.
 

Into 3 lbs. of pure water put 1 oz. of sulphate of zinc (white vitriol), and mix the whole with 2 lbs. of oil of pinks, or poppy oil. Expose this mixture, in an earthen vessel capable of standing the fire, to a degree of heat sufficient to maintain it in a slight state of ebullition. When one-half or two-thirds of the water has evaporated, pour the whole into a large glass bottle or jar, and leave it at rest till the oil becomes clear. Decant the clearest part by means of a glass funnel, the beak of which is stopped with a piece of cork. When the separation of the oil from the water is effected, remove the cork stopper, and supply its place with the forefinger, which must be applied in such a manner as to suffer the water to escape, and to retain only the oil.

Poppy-oil, when prepared in this manner, becomes, after some weeks, exceedingly limpid and colorless.
 

Take of nut-oil, or linseed-oil, 8 lbs.; white lead, slightly calcined, yellow acetate of lead (sal saturni), also calcined, sulphate of zinc (white vitriol), each 1 oz.; vitreous oxide of lead (litharge), 12 oz.; a head of garlic, or a small onion.

When the dry substances are pulverized, mix them with the garlic and oil, over a fire capable of maintaining the oil in a slight state of ebullition. Continue it till the oil ceases to throw up scum, till it assumes a reddish color, and till the head of garlic becomes brown; a pellicle will then be soon formed on the oil, which indicates that the operation is completed. Take the vessel from the fire, and the pellicle, being precipitated by rest, will carry with it all the unctuous parts which rendered the oil fat. When the oil becomes clear, separate it from the deposit, and put it into widemouthed bottles, where it will completely clarify itself in time, and improve in quality.

Another Method.

Take of litharge, 1 1/2 oz.; sulphate of zinc, 3/8 of an oz.: linseed or nut-oil, 16 oz. The operation must be conducted as in the preceding case.

The choice of the oil is not a matter of indifference. If it be destined for painting articles exposed to the impression of the external air, or for delicate painting, nut-oil or poppy-oil. Linseed-oil is used for coarse painting, and that sheltered from the effects of the rain and of the sun.

A little negligence in the management of the fire has often an influence on the color of the oil, to which a drying quality is communicated; in this case it is not proper for delicate painting. This inconvenience may be avoided by tying up the drying matters in a small bag; but the dose of the litharge must then be doubled. The bag must be suspended by a piece of packthread fastened to a stick, which is made to rest on the edges of the vessel in such a manner as to keep the bag at the distance of an inch from the bottom of the vessel. A pellicle will be formed as in the first operation, but it will be slower in making its appearance.

Another. - A drying quality may be communicated to oil by treating, in a heat capable of maintaining a slight ebullition, linseed or nut-oil, to each pound of which is added 3 oz. litharge, reduced to fine powder.

The preparation of floor-cloths, and all paintings of large figures or ornaments, in which argillaceous colors, such as yellow and red boles, Dutch pink, etc. are employed, require this kind of preparation, that the dessication may not be too slow; but painting for which metallic oxides are used, such as preparations of lead, copper, etc., require only the doses before indicated, because these oxides contain a great deal of oxygen, and the oil, by their contact, acquires more of a drying quality.

Another. - Take of nut-oil, 2 lbs.; common water, 3 do.; sulphate of zinc, 2 oz.

Mix these matters, and subject them to a slight ebullition, till little water remains. Decant the oil, which will pass over with a small quantity of water, and separate the latter by means of a funnel. The oil remains nebulous for some time; after which it becomes clear, and seems to be very little colored.

Another. - Take of nut-oil, or linseed-oil, 6 lbs.; common water, 4 lbs.; sulphate of zinc, 1 oz.; garlic, 1 head.

Mix these matters in a large iron or copper pan; then place them over the fire, and maintain the mixture in a state of ebullition during the whole day. Boiling water must from time to time be added, to make up for the loss of that by evaporation. The garlic will assume a brown appearance. Take the pan from the fire, and having suffered a deposit to be formed, decant the oil, which will clarify itself in the vessel. By this process the drying oil is rendered somewhat more colored. It is reserved for delicate colors.
 

In order to avoid the use of oxide of lead in making drying oil for zinc paint, oxide of manganese has been proposed as a substitute. The process to be adopted is as follows:

The manganese is broken into pieces about the size of peas, dried, and the powder separated by means of a sieve. The fragments are then to be introduced into a bag made of iron-wire gauze. This is hung in the oil contained in an iron or copper vessel, and the whole heated gently for 24 or 36 hours. The oil must not be allowed to boil, in which case there is great danger of its running over. When the oil has acquired a reddish color, it is to be poured into an appropriate vessel to clear.

For 100 parts of oil 10 of oxide of manganese may be employed, which will serve for several operations when freshly broken and the dust separated. Experience has shown, that when fresh oxide of manganese is used it is better to introduce it into the oil upon the second day. The process likewise occupies a longer time with the fresh oxide. Very great care is requisite in this operation to prevent accident, and one of the principle points to be observed is that the oil is not overheated. If the boiling should render the oil too thick, this may be remedied by an addition of turpentine after it has thoroughly cooled.
 

When linseed-oil is carefully agitated with vinegar of lead (tribasic acetate of lead), and the mixture allowed to clear by settling, a copious white, cloudy precipitate forms, containing oxide of lead, whilst the raw oil is converted into a drying oil of a pale straw color, forming an excellent varnish, which, when applied in thin layers, dries perfectly in 24 hours. It contains from 4 to 5 per cent. of oxide of lead in solution. The following proportions appear to be the most advantageous for its preparation:

In a bottle containing 4 1/2 pts. of rain-water, 18 oz. of neutral acetate of lead are placed, and when the solution is complete, 18 oz. of litharge in a very fine powder are added; the whole is then allowed to stand in a moderately warm place, frequently agitating it to assist the solution of the litharge. This solution may be considered as complete when no more small scales are apparent. The deposit of a shining white color (sexbasic acetate of lead may be separated by filtration. This conversion of the neutral acetate of lead into vinegar of lead, by means of litharge and water, is effected in about a quarter of an hour, if the mixture be heated to ehullition. When heat is not applied, the process will usually take 3 or 4 days. The solution of vinegar of lead, or tribasic acetate of lead, thus formed, is sufficient for the preparation of 22 lbs. of drying oil. For this purpose the solution is diluted with an equal volume of rain-water, and to it is gradually added, with constant agitation, 22 lbs. of oil, with which 18 oz. of litharge have previously been mixed.

When the points of contact between the lead solution and the oil have been frequently renewed by agitation of the mixture 3 or 4 times a day, and the mixture allowed to settle in a warm place, the limpid straw-colored oil rises to the surface, leaving a copious white deposit. The watery solution, rendered clear by filtration, contains intact all the acetate of lead at first employed, and may be used in the next operation, after the addition to it as before, of 18 oz. of litharge.

By filtration through paper or cotton, the oil may be obtained as limpid as water, and by exposure to the light of the sun it may also be bleached.

Should a drying oil be required absolutely free from lead, it may be obtained by the addition of dilute sulphuric acid to the above, when, on being allowed to stand, a deposit of sulphate of lead will take place, and the clear oil may be obtained free from all trace of lead.
 

Take 10 lbs. of drying nut-oil, if the paint is destined for external articles, or 10 lbs. of drying linseedoil if for internal; resin, 3 lbs.; turpentine, 6 oz.

Cause the resin to dissolve the oil by means of a gentle heat. When dissolved and incorporated with the oil, add the turpentine; leave the varnish at rest, by which means it will often deposit portions of resin and other impurities; and then preserve it in wide-mouthed bottles. It must be used fresh; when suffered to grow old it abandons some of its resin. If this resinous oil assumes too much consistence, dilute it with a little essence, if intended for articles sheltered from the sun, or with oil of poppies.
 

Take picked copal, 16 oz.; prepared linseed oil, or oil of poppies, 8 oz.; essence of turpentine, 16 oz.

Liquefy the copal in a matrass over a common fire, and then add the linseed oil, or oil of poppies, in a state of ebullition; when these matters are incorporated, take the matrass from the fire, stir the matter till the greatest heat is subsided, and then add the essence of turpentine warm. Strain the whole, while still warm, through a piece of linen, and put the varnish into a wide-mouthed bottle. Time contributes towards its clarification, and in this manner it acquires a better quality.

Varnish for Watch Cases in Imitation of Tortoiseshell.

Take copal of an amber color, 6 oz.; Venice turpentine, 1 1/2 oz.; prepared linseed-oil, 24 oz.; essence of turpentine, 6 oz.

It is customary to place the turpentine over the copal, reduced to small fragments, in the bottom of an earthen or metal vessel, or in a matrass exposed to such a heat as to liquefy the copal; but it is more advantageous to liquefy the latter alone, to add the oil in a state of ebullition, then the turpentine liquefied, and in the last place the essence. If the varnish is too thick, some essence may be added. The latter liquor is a regulator for the consistence in the hands of an artist.
 

Take copal in powder, 1 oz.; essential oil of lavender, 2 oz.; essence of turpentine, 6 oz.

Put the essential oil of lavender into a matrass of a proper size, placed on a sand-bath heated gently. Add to the oil while very warm, and at several times, the copal powder, and stir the mixture with a stick of white wood rounded at the end. When the copal has entirely disappeared, add at three different times the essence almost in a state of ebullition, and keep continually stirring the mixture. When the solution is completed, the result will be a varnish of a gold-color, exceedingly durable and brilliant.

Another Method.

To obtain this varnish colorless, it will be proper to rectify the essence of the shops, which is often highly colored, and to give it the necessary density by exposure to the sun in bottles closed with cork stoppers, leaving an interval of some inches between the stopper and the surface of the liquid. A few months are thus sufficient to communicate to it the required qualities. Besides, essence of the shops is rarely possessed of that state of consistence without having at the same time a strong amber color.

The varnish resulting from the solution of copal in oil of turpentine, brought to such a state as to produce the maximum of solution, is exceedingly durable and brilliant. It resists the shock of hard bodies much better than the enamel of toys, which often becomes scratched and whitened by the impression of repeated friction; it is susceptible also of a fine polish. It is applied with the greatest success to philosophical instruments, and the paintings with which vessels and other utensils of metal are decorated.
 

This varnish is destined for articles which require durability, pliableness, and transparency.

Take of pulverized copal, 2 oz.; essential oil of lavender, 6 oz.; camphor, 1/8 oz.; essence of turpentine, a sufficient quantity, according to the consistence required to be given to the varnish.

Put into a phial of thin glass, or into a small matrass, the essential oil of lavender and the camphor, and place the mixture on a moderately open fir