ENCAUSTIC

ENCAUSTIC PAINTING is an art of very high antiquity, which, after being lost for many ages, was restored, as is commonly believed, by the celebrated Count Caylus, whose method was greatly improved, first by Mr Josiah Colebrooke, and afterwards by Miss Greenland, who brought the rudiments of her knowledge from Italy (See ENCAUSTIC, Encycl.). In that country encaustic painting had employed the attention of various artists and men of learning, such as Requeno, Lorgna, and Astori, &c.; but the best account of it that has fallen under our notice, is in that valuable miscellany called the Philosophical Magazine, taken from a work of Giov. Fabbroni, published at Rome in the year 1797.

According to this author, "the knowledge and use of encaustic painting is certainly older than the time of the Greeks and the Romans, to whom the learned Requeno seems to assign the exclusive possession of this art; because the Egyptians, who, with the Etruscans, were the parents of the greater part of the inventions known among mankind, and from whom the Greeks learned so much, were acquainted with and employed encaustic painting in the ancient ages of their greatness and splendour, as is proved by the valuable fragments of the bandages and coverings of some mummies which he had examined. No oil-painting (he says), of only two or three hundred years old, exhibits a white paint which has kept so well as that seen on these fragments; and this circumstance sufficiently proves the superiority

of the encaustic method over the common oil-painting, which, notwithstanding the general opinion, cannot, he thinks, have been unknown to the ancients.

"It is impossible (says he) that in Egypt and Phœnicia, where so much use was made of flax, the oil procured in abundance from that plant should have been unknown. Those who have kept oil, or who have spilt any of it, whether nut or linseed oil, must have remarked that it possesses the property of soon drying by the effects of the atmosphere; and therefore it may be easily believed that mankind must soon have conceived the idea of employing it, particularly for ships, which, as Hierodotus says, were painted with red ochre in the earliest periods, and adorned with figures and ornaments. The use of oil afforded painting a much simpler and easier method than that of wax; it must therefore have been first adopted, and the transition from oil to wax must be considered as a step towards bringing the art to perfection; because encaustic painting is not exposed to the irremediable inconveniences that arise in oil-painting, the value of which we extolled through ignorance, and praised as a new invention.

"Oil in general, and in particular drying oil which the painters use, has naturally a strong inclination to combine itself with the vital air or oxygen of the atmosphere, and by imbibing oxygen it becomes dry, and assumes the character of resin; but the colour then becomes darker, as is the case with transparent turpentine, which gradually becomes a black pitch.

Painting. "According to the new and more accurate method of decomposing bodies, oil consists principally of hydrogen and carbon. By coming into contact with the atmosphere, and absorbing its oxygen and light, it undergoes a slow and imperceptible combustion, which is not essentially different from the speedy and violent one which it would undergo in the common mode of burning. It first passes, by imbibing oxygen, into the state of a more or less dark resin; loses gradually its essential hydrogen, which makes a new combination, and afterwards the oxygen itself which has attracted the carbon; and at length leaves behind a thin layer of actual carbon, which in the end becomes black in the course of time, and considerably obscures the oil-painting. By a continuance of the before-mentioned slow combustion, the carbon itself, as it were, burns also: if it be strongly acted upon by the light, it attracts the oxygen of the atmosphere, and again brings forward the carbonic acid or fixed air, which gradually flies off. By this, which I may call the second degree of combustion, the painting must become dusky and friable, like crayon painting.

"Hence it appears (says our author) that one can hope only for a transient or deceitful effect from the refreshing of oil-paintings with oil; because the harmony of the tones, which the painter establishes as suited for the moment, does not proceed with equal steps, and cannot preserve itself in the like measure for the course of a few years, as each tint, as they say, ought to increase, or, to speak more properly, to burn in proportion to its antiquity. It thence follows, that mere washing may be prejudicial to an old painting; and that the method of refreshing paintings, as it is called, by daubing over the surface, from time to time, with new drying oil, is highly prejudicial and ill calculated for the intended purpose, since the oil when it becomes dry contracts in its whole surface, carries with it the paint under it, and occasions cracks in the painting. New oil of this kind gives occasion to mineral paints to be restored; but covers the picture with a new coat of resin, and then of carbon, which arises from the gradual combustion, and always causes more blackness, and the decay of the painting which one wishes to preserve.

"Wax, on the other hand, undergoes a change which is very different from that of drying oil. The wax, instead of becoming black by the contact of the atmosphere, increases in whiteness, and, according to its natural quality, is not decomposed in the air, and it does not strongly attract the oxygen of the calces or metallic ashes which are commonly used in painting. Moreover, the so called earths, which are in themselves white, and are never variable either by the presence or absence of oxygen, cannot be employed in oil-painting, because that fluid makes them almost transparent, and causes them to remain as it were without body, and not to produce the wished-for effect. That beautiful white, which may be observed on the before-mentioned Egyptian encaustic, is nothing else than a simple earth, and according to our author's chemical experiments, a chalk which is also unalterable."

That the ancients were once acquainted with the use of oil-painting, and neglected it on account of the great

superiority of the encaustic method, our author thinks farther evident from the different accounts which we have of the ancient paintings. "Thus Petronius praises the fresh appearance which the valuable works of Zeuxis and Apelles had, even in his time; but Cicero, on the other hand, speaks of the paintings of the ancients having suffered from blackness. The former speaks of wax-painting, and the latter certainly alludes to paintings in oil. It is well known that paintings with wet chalks or water colours do not become black by age, and that this is the case also with encaustic. Of this any one may be convinced, not only by the expressions of the above quoted authors, but by one's own eyes on surveying the Egyptian fragment alluded to. Galland proves, on various grounds, that a painting was made with oil so early as the reign of Marcus Aurelius; and if no specimens of that period have reached us, this is perhaps to be ascribed to the frail and perishable nature of this species of painting."

Sign. Fabbroni, after some farther observations, calculated to prove that metallic oxyds or calces could not have been employed as pigments on such mummies as still retain their colours fresh, proceeds thus: "Those who are acquainted with the accuracy and certainty of the method not long since introduced into chemical operations, will be convinced, that in 24 grains of the encaustic painting, which I ventured to detach from the above-mentioned Egyptian fragment, in order to subject it to examination, the mixture of an hundredth part of a foreign substance would have been discovered with the greatest certainty; that the resin of Requeno must undoubtedly have been perceptible to me, and that the alkali of Bachelier and Lorgna could not have escaped the counteracting medium. But in this Egyptian encaustic I found nothing except very pure wax, though I varied my analysis in every known method. I must therefore conclude, that modern learned writers, at least in respect to this Egyptian mode of painting, were as far from the truth as the accounts of ancient authors appear to me precise and satisfactory; and that the encaustum with which formerly the fore part of ships and the walls of houses and temples were painted, was something different from soap or resinous crayons.

"I am well aware that it will be asked, In what manner can wax at present be rendered sufficiently liquid for the strokes of the pencil, if it be not converted into powder or soap? This question, in my opinion, can be fully answered from the words of an ancient author, and, in the next place, by experience.

"Vitruvius in particular, book vii. chap. ix. expresses himself in the following clear manner:

"Those (says he) who wish to retain cinnabar on walls, cover it, when it has been well laid on and dried, with Punice wax diluted in a little oil (let this be well remarked); and after they have spread out the wax with a hair brush, they heat the wall by means of a brazier filled with burning coals (hence it is called encaustic painting), and then make it smooth and level by rubbing it with wax tapers and clean cloths, as is done when marble statues are covered with wax. The effect of this wax crust is, that the colour is not destroyed by the light of the sun or the moon (A)."

"It here appears, that the Romans, who copied the Grecian process, which the latter borrowed from the Egyptians, mixed the wax with an oil to make it pliable under the brush; but no mastic, alkali, or honey, as has been ingeniously imagined, and which some have thought might be employed with success. The difficulty now will be confined to point out in what manner this oil was employed. It does not appear that they used those fat oils which are commonly called drying oils; because they could have employed these as we do, without the addition of wax, which, in such a case, would have been entirely superfluous. Fat oils which do not dry would not have been proper for that purpose, as they would have kept the wax continually in the state of a soft pomade or salve. Besides, my experiments (continues the author) would without doubt have shewn me the existence of any oily matter.

"With regard to essential or volatile oils, a knowledge of them is not allowed to the ancients, as the invention of distilling is not older than the eighth or ninth century, and therefore falls in with the period of Geber or Avicenna." Yet it is certain, that, in order to use wax in their encaustic painting, they must have combined it with an ethereal volatile oil, of which no traces should afterwards remain; because this was necessary for the solidity of the work, and because no oil was found in the fragment that was examined. But naphtha is such an oil, much lighter (says our author) than ether of vitriol itself. It is exceedingly volatile, and evaporates without leaving a trace of it behind. On this account it is used when signatures and manuscripts are to be copied; because the paper, which is moistened by it, and so rendered transparent, quickly becomes white and opaque as before by the complete evaporation of the naphtha. That the Assyrians, Chaldeans, and Persians, were well acquainted with the properties of naphtha is known to every scholar; and hence our author thinks it highly probable that it was used by those nations to render wax fit for painting. "It appears to me (says he) that the Greeks, as was the case with many other things, learned encaustic from the Egyptians, who probably derived it from the Assyrians or Chaldeans; and if so, we have discovered the real mixture used for ancient encaustic painting."

To put the matter, however, beyond a doubt, Sign. Fabbroni prepared, for an eminent Saxon painter, a solution of Venetian wax in highly purified naphtha, desiring him to mix up with it the colours necessary for a painting. The artist complied; and both he and our author were astonished, as well as all their friends, at the high tone which the colours assumed, and the agreeable lustre which the painting afterwards acquired when it had been rubbed over with a soft cloth. A similar solution of wax was made for another artist, in which the spirit of turpentine was used instead of naphtha with equal success. Our author therefore concludes, we think with reason, that if he has not discovered the real composition employed by the ancients in their encaustic paintings, he has at least approached much nearer to that discovery than any of his predecessors who have employed their learned labours in the same field of investigation.