the art of spreading or covering a thing with gold, either in leaf or liquid.

We have this advantage over the ancients, in the manner of using and applying the gold, that the secret of painting in oil, lately discovered, furnishes us with means of gilding works, capable of enduring all the violence of time and weather, which theirs could not. There are several methods of gilding in use among us, as gilding in water, gilding in oil, gilding by fire, &c.

The method of water-gilding. Water-gilding requires more preparation than oil gilding, and is chiefly on wooden works, and those made of stucco; and these too must be sheltered from the weather. A size is used for this way of gilding made of shreds, &c. of parchment or gloves boiled in water to the consistence of a jelly. If the thing to be gilt be of wood, it is first washed with this size, boiling hot, and then set to dry; and afterwards with white paint mixed up with the same size. Some use Spanish white for this purpose, and others plaster of Paris, well beaten and sifted. This sized paint must be laid on with a stiff brush; which is to be repeated seldom or oftener according to the nature of the work, as ten or twelve times in flat or smooth works; but seven or eight times will be sufficient in pieces of sculpture. In the former case they are applied by drawing the brush over the work, in the latter by daubing it. When the whole is dry, they moisten it with fair water, and rub it over with several pieces of coarse linen, if it be on the flat; if not, they beat or switch it with several slips of the same linen, tied to a little stick, to make it follow and enter all the cavities and depressures thereof.

Having thus finished the white, the next thing to be done, is to colour it with yellow ochre: but if it be a piece of sculpture in relievo, they first touch it up, and prepare the several parts, which may have happened to have been disfigured, by the small iron instruments, as gouges, chisels, &c. The ochre used for this purpose must be well ground and sifted, and mixed up with the size before-mentioned. This colour is to be laid on hot; and in works of sculpture, supplies the place of gold, which sometimes cannot be carried into all the depressures and cavities of the foliages and ornaments. A lay is also applied over this yellow, which serves for the ground on which the gold is to be laid: this lay is usually composed of Armenian bole, bloodstone, black-lead, and a little fat; to which some add soap, and oil of olives; others, burnt bread, bistre, antimony, glaas of tin, butter, and sugar-candy. These ingredients being all ground down together with hot size, three lays of this composition is applied upon the yellow, the one after the other has been dried; being cautious not to put any into the cavity of the work to hide the yellow.

The brush used for this purpose, must be a soft one; and when the matter is become very dry, they go over it again with a stronger brush, to rub it down, and take off the small grains that stick out, in order to facilitate the burnishing of the gold.

To be prepared for gilding, you must have three sorts of pencils; one to wet, another to touch up and amend, and a third to flatten; also a gilding cushion, for spreading the leaves of gold on when taken out of the book; a knife to cut them, and a squirrel's tail fitted with a handle; or else a piece of fine soft stuff on a stick, to take them up directly and apply them. You are first to begin with wetting your pencils; by which the last lay laid on with water is moistened, that it may the better receive and retain the gold. Then you are to lay the leaves of gold on the cushion; and if whole, you must take up with the squirrel's tail, but, if in pieces, with the other instrument, or the knife wherewith they are cut, and lay and spread them gently on the parts of the work you had moistened before. If the leaves, as they frequently do, happen to crack or break in laying on, these breaches must be made up with small bits of leaf, taken up upon the repairing pencil, and the whole work is to be smoothed either with the same pencil, or another something larger; the gold being pressed into the dents, into which it could not be so easily carried by the squirrel's tail.

The work having been thus far gilded, must be set to dry, in order to be burnished and flattened. See Burnishing.

The last operation is the applying the vermeil in all the little lines and cavities; and to stop and amend any little faults with shell-gold. The composition called of vermeil is made of gum guttae, vermilion, and a little of some ruddy-brown, ground together with venetian varnish and oil of turpentine. Some gilders, instead of this, make shift with fine lacca, or dragon's blood, with gum-water.

Sometimes, instead of burnishing the gold, they burnish the ground or composition laid on the last before it, and only afterwards wash the part over with the size. This method is chiefly practised for the hands, face, and other nudes in relievo: which, by this means, do not appear so very brilliant as the parts burnished, though much more so than the parts perfectly flat.

To gild a piece of work, and yet preserve white grounds, they apply a lay of Spanish white, mixed with a weak fish-glue, on all the parts of the ground, whereon the yellow or the last lay might run.

The method of Gilding in oil. This operation requires much less apparatus than that before-mentioned. The basis or matter whereon the gold is laid, in this method, is the remains of colours found settled to the bottom of the pots in which painters wash their pencils. This matter, which is very viscid or sticky, is first ground, and then passed through a linen-cloth, and thus laid on the matter to be gilt, after it is washed once or twice over with size; and if it be wood, with some white paint.

When this is almost dry, but yet is still unctuous enough to catch and retain the gold, the leaf-gold is laid on, either whole, if the work be large, or cut to pieces, if smaller: the leaves of gold are taken up and laid on with a piece of fine, soft, well carded cotton; or sometimes by a pallet for the purpose, or sometimes with the knife with which the leaves were cut, according to the parts of the work that are to be gilded, or the breadth of the gold that is to be laid on. As the gold is laid on, they pass over it a coarse stiff pencil brush, to make it stick and as it were incorporate with the ground; and after this they mend any cracks that may may have happened in it, either with the same pencil or one that is smaller, as has been shown before in water-gilding.

This kind of gilding is chiefly used for domes and roofs of churches, courts, banqueting-houses, &c., and for figures of plaster of Paris, lead, &c.

The method of Gilding with liquid gold. This is performed by gold reduced to a calx and amalgamated with mercury, in the proportion of about an ounce of mercury to a dram of gold. To perform this, they heat a crucible red hot, and then put the gold and mercury into it, stirring them gently about till the gold be found melted, and incorporated into a mass with the mercury. When this is done, they cast them into water, to wash and purify them; and out of that into other waters, where the amalgama, which is almost as liquid as if there were nothing but quicksilver in it, may be preserved a long time for use.

Before they proceed to lay this amalgamated gold on the metal, they first render the metal rough, by washing it over with aqua fortis, or aqua secunda; and afterwards rinse the metal in fair water, and scour it a little with fine sand, and then it is ready for the gold.

They next cover over the metal with the mixture of gold and mercury, taking it up with a slip of copper, or a brush made of brass-wire, spreading it as even as possible, so that they wet the brush from time to time in fair water. Then they set the metal to the fire, upon a grate, or in a sort of cage, under which stands a pan of coals; and in proportion as the mercury evaporating and flying off, discovers the places where gold is wanting, they take care to supply them by adding new parcels of amalgama.

Then the work is rubbed over with the wire-brush, dipped in beer or vinegar, which leaves it in a condition to be brought to a colour which is the last part of the process, and which the gilders keep to themselves as a mighty secret.

The method of Gilding by fire on metal. To prepare the metal, they scratch it well, or rake it; then polish it with a polisher; and afterwards set it to the fire to blue, i.e., to heat, till it appear of a blue colour. When this has been done, they clap on the first lay of leaf-gold, rubbing it lightly down with a polisher; and expose it thus to a gentle fire. They usually give it but three such lays, or four at the most, each lay consisting of a single leaf for common works, and of two for extraordinary ones: after each lay, it is set afresh to the fire; and after the last lay, the gold is in condition to be burnished.

To gild paper. Grind bole-armoniac with rain-water, and give one laying of it; when it is dry, take glair of eggs, and add to it a little sugar-candy and gum-water, which lay over the former; and upon this, when it is dry enough, lay leaf-silver, or leaf-gold.

To gild the leaves of books. Take bole-armoniac, eight penny-weight; sugar-candy, two penny-weight: mix and grind them with glair of eggs: then on a bound book (while it is in the press, after it hath been smeared with glair of eggs, and is dried) smear the said composition; let it dry, then rub it well and polish it; then with fair water wet the edges of the book, and suddenly lay on the gold, press it down gently with cotton, let it dry, and then polish it with a tooth.