The astonishing extensibility of gold, a property in which it far surpasses all other metals, induced mankind, at an early period, to attempt beating it into thin plates, as the value of it led them to the art of covering or gilding things of every kind with leaves of it. It is proved by Herodotus, that the Egyptians were accustomed to gild wood and metals688; and gilding is frequently mentioned in the books of the Old Testament689. The gold plates, however, used for this purpose, as may be readily conceived, were not so thin as those made at present; and for this reason, the gilding on statues, which have lain many centuries in the earth, appears to be still entire. Winkelmann says690, that among the ruins of two apartments in the imperial palace, on the palatine hill, in the Villa Farnese, the gold ornaments were found to be as fresh as if they had been newly applied, though these apartments, in consequence of being buried under the earth, were exceedingly damp. The circular bands of sky-blue, with small figures in gold, could not be seen without admiration. The gilding also is still preserved in the ruins of Persepolis.

But, in the time of Pliny, the art of gold-beating was carried so far at Rome, that an ounce of gold could be beat into seven hundred and fifty leaves and more, each four square inches in size691. I shall not compare this result with what the art can do at present, because the account of Pliny is not the most accurate, and because the conversion of the old measures into the modern standard is always attended with uncertainty. Buonarotti, however, who made some researches on this subject692, is of opinion that the gold used at Rome for fire-gilding in his time, that is, at the end of the seventeenth century, was beat six times as thin; and that the gold employed for gilding wood and other things, without the application of fire, was twenty-two times as thin as the gold leaf made at Rome in the time of Pliny. But this Italian author, as appears to me, has, through too great precipitation, translated the words “septingenÆ et quinquagenÆ bracteÆ” fifty and seventy. Gold, however, at that time, was beat so thin at Rome, that Lucretius compares it to a spider’s web, and Martial to a vapour693.

I have, however, not yet met with any information in regard to the method in which the ancient artists beat the gold, or the instruments and apparatus they employed for that purpose. But the German monk Theophilus, whose real name seems to have been RÜger, and who, as Lessing thinks, lived in the ninth, but, according to Morelli, in the twelfth century, describes the process nearly as it is at present694. The gold, at that time, was beat between parchment, in the same manner as is still practised; and the artists knew how to prevent the gold from adhering to the parchment, by covering it over with burnt ochre reduced to a very fine powder, and then rubbing it smooth with a tooth. With the like view, our gold-beaters rub over with a fine bolus the thin paper used for making the books into which they put their gold leaf, in order to preserve it. But the flatting-mills, between the steel rollers of which cast and hammered ingots of gold are at present reduced to thin leaves, seem not to have been then known, at least this monk makes no mention of them. Lessing, to whom we are indebted for this curious fragment of Theophilus, is of opinion that each artist at that time was obliged to beat the gold leaf which he used, because gold-beating was not then a distinct branch of business. This I will not controvert; but it is no proof of it, that the monk taught the art to his brethren; for in convents the clergy endeavoured to make everything they used, in order that they might purchase as little as possible.

During the progress of the art, it being found that parchment was too thick and hard for the above purpose, workmen endeavoured to procure some finer substance, and at length discovered that the skin of an unborn calf was the most convenient. By means of this improvement, gold leaf was made much thinner than it had ever been before possible; but the art was brought to still greater perfection by employing that fine pellicle which is detached from the gut of an ox or a cow. Lancellotti, who wrote in the first half of the seventeenth century695, says that this invention was made by the German gold-beaters, when, in consequence of the war, they were not able to obtain from Flanders the skins of unborn calves.

I have often heard that the preparation of this pellicle, which the French call baudruche and the Dutch liezen, and which is so thin that two of them must be pasted together, is a secret, and that the best is obtained from England. But in the year 1785, when I paid a visit to a very ingenious gold-beater at Hamburg, he assured me that he prepared this substance himself, and that the case was the same with most of the gold-beaters in Germany. Even in England, in the year 1763, this art was known only to two or three persons, who practised it as a business, but kept it so secret that Lewis was not able to obtain a proper account of it696. In Ireland also this skin is prepared and sent to England697. When the French, in the beginning of the revolutionary war, hoped to out-manoeuvre the Germans by the use of aerostatic machines, it became of some importance to them to obtain a supply of these skins. On this account, the Commission des armes et poudres drew up instructions for preparing them, which they caused to be printed and distributed to all the butchers. At Strasburg they were printed in French, and at the same time in German, but in many parts faulty and unintelligible.

About the year 1621, Mersenne excited general astonishment, when he showed that the Parisian gold-beaters could beat an ounce of gold into 1600 leaves, which together covered a surface of 105 square feet. But in 1711, when the pellicles, discovered by the Germans, came to be used in Paris, Reaumur found that an ounce of gold, in the form of a cube, five and a quarter lines at most in length, breadth, and thickness, and which covered only a surface of about twenty-seven square lines, could be so extended by the gold-beaters as to cover a surface of more than one hundred and forty-six and a half square feet. This extension, therefore, is nearly one-half more than was possible about a century before.

When these skins are worn out by the hammer of the gold-beater, they are employed, under the name of English skin, for plasters, or properly to unite small wounds. By the English they are called gold-beaters’ skin698; but, since silk covered with isinglass and Peruvian balsam, which in Germany is named English plaster, for the Germans at present call every thing English, has become the mode, this skin is much less used699. I mention this that I might have an opportunity of remarking, that in the middle of the twelfth century, in the Levant at least, a very thin pellicle was in like manner used for wounds. For when the emperor, John Comnenus, accidentally wounded himself in the hand with a poisoned arrow while hunting, a piece of skin, which, from the name and description may be considered the same as that used at present by the gold-beaters, was applied to the wound. The emperor, however, died in consequence of this wound, after it had become inflamed under the pellicle, which, in large wounds, and when the skin is suffered to remain too long, is commonly the case, though the poison alone would have been a sufficient cause of death. Reaumur and others are astonished that artists should have sought for and found a part of their apparatus in the bowels of an ox; but I am of opinion that this pellicle, which is sometimes separated in washing and cleaning the bowels, was first observed by the butchers, and made known by them as a plaster; and that it came into request among the German gold-beaters, as the finest of all the pellicles then known, in the beginning of the seventeenth century.

The art of gilding, and particularly unmetallic bodies, was much facilitated by the invention of oil-painting; but it must be acknowledged that the process employed by the ancients in cold-gilding was nearly the same as that used at present. Pliny says700 that gold leaves were applied to marble with a varnish, and to wood with a certain kind of cement, which he calls leucophoron. Without entering into any research respecting the minerals employed for this cement, one may readily conceive that it must have been a ferruginous ochre, or kind of bole, which is still used as a ground (poliment, assiette)701. But gilding of this kind must have suffered from dampness, though many specimens of it are still preserved. Some of the ancient artists, perhaps, may have employed resinous substances, on which water can produce very little effect.

That gold-leaf was affixed to metals by means of quicksilver, with the assistance of heat, in the time of Pliny, we are told by himself in more places than one. The metal to be gilded was prepared by salts of every kind, and rubbed with pumice-stone in order to clean it thoroughly, and to render the surface a little rough702. This process is similar to that used at present for gilding with amalgam, by means of heat, especially as amalgamation was known to the ancients. But, to speak the truth, Pliny says nothing of heating the metal after the gold is applied, or of evaporating the quicksilver, but of drying the cleaned metal before the gold is laid on. Had he not mentioned quicksilver, his gilding might have been considered as that with gold-leaf by means of heat, dorure en feuille À feu, in which the gold is laid upon the metal after it has been cleaned and heated, and strongly rubbed with blood-stone, or polished steel. Felibien was undoubtedly right when he regretted703 that the process of the ancients, the excellence of which is proved by remains of antiquity, has been lost.

False gilding, that is, where thin leaves of a white metal, such as tin or silver, are applied to the article to be gilded, and then rubbed over with a yellow transparent colour, through which the metallic splendour appears, is much older than I believed it to be in the year 1780. The process for this purpose is given by the monk Theophilus, whose fragments were first printed in 1781704. According to his directions, tin beat into thin leaves was to be rendered of a golden yellow colour by a vinous tincture of saffron, so that other pigments could be applied over it. The varnish or solution of resin in spirit of wine or oil, used for this purpose at present, appears not then to have been known. But in the sixteenth century this art was very common; and instructions respecting it were given by Garzoni705, Cardan706, Caneparius707 and others in their writings. About the same period a pewterer at Nuremberg, named Melchior Koch, was acquainted with the art of communicating a golden colour, in the like manner, to tin goblets and dishes. He died in 1567; and with him, as Doppelmayer says, the art was lost. A method of applying a white metal to paper, and then drawing over it a gold varnish, has been known in China since the earliest periods708. At present this method of gilding is practised more in Sicily than in any other country. It appears also to have been used, at an early period, for gilding leather and leather tapestry; and this perhaps was first attempted at Messina, as we are told by John MatthÆus709, who, however, in another place ascribes the invention to a saint of Lucca, named Cita. But gilt leather was made as early as the time of Lucian, who conjectures that Alexander the impostor had a piece of it bound round his thigh710. The dress of the priests, on the festival of Bacchus, was perhaps of the same kind711.