Many mural paintings of the same character as those at Pompeii have been discovered at Rome, in the Baths of Titus, the Palace of the Cæsars, the tombs and columbaria and other ancient edifices. Most of these have perished, and our only record of them is to be found in the engravings of Bartoli and others. Some interesting specimens, however, still exist in the Museum of the Vatican, of which the finest is the celebrated nuptial scene usually called the Aldobrandini Marriage. As compositions, the mural paintings discovered at Rome are superior to those of Pompeii and Herculaneum, and they are further interesting to us, because it was by the study of these remains that Raffaelle and his successors in the Roman school formed that beautiful style of decorative fresco, which we see with perfection in the Loggie of the Vatican. There is an extensive collection of mural paintings from Pompeii in the Museum at Naples, and there are also some good examples in the British Museum.

Sir W. Gell thus remarks on the painting of the ancients:In grandeur and facility of drawing they warrant all that can be said in their praise; with that feeling for simplicity which distinguishes the ancients from the moderns, many are quite in the taste of the finest bas-reliefs, which, like their tragedies, admitted no under-plot to heighten or embarrass. In colouring they are said to be deficient; want of transparency in the shadows exhibits little knowledge of chiaro-oscuro; each figure has its own light and shade, while none is obscured by the interposition of its neighbour. But if we are called upon to make allowance in some of these points for the lapse of centuries, when viewing the works of a later age, how much more indulgence may be claimed when two thousand years might reasonably have been expected to leave no traces at all."

The walls at Pompeii were carefully prepared for the reception of the fresco painting. They appear to have been prepared in the manner prescribed by Vitruvius, who directs that, after the first rough coat was applied, a second was to be added of arenatum, composed principally of sand and lime; this was afterwards to be covered with marmoratum, in the composition of which the place of sand of the arenatum was supplied by pounded marble. The last coat at Pompeii was put on very thin, and seems to have been well worked and rubbed upon the rough exterior of the arenatum, until a perfectly level, smooth,

and at length polished surface was obtained, nearly as hard as marble. While the last coat was still wet, the colours were laid on, and so done, having, according to Vitruvius, incorporated with the incrustation, were not liable to fade, but retained their full beauty and splendour to a great age. According to Mr. Wornum, the majority of the walls in Pompeii are in common distemper; but those of the better houses, not only in Pompeii, but in Rome and elsewhere, especially those which constitute the grounds of pictures, are in fresco. All the pictures, however, are apparently in distemper of a superior kind, called by the Italians a guazzo; it is a species of distemper, but the vehicle or medium, made of egg gum or glue, completely resists water. He further remarks, "It appears that no veritable fresco painting has been yet discovered, though the plain walls in many cases are coloured in fresco. The paintings upon the walls appear sometimes to have been varnished by an encaustic process; many specimens bearing a polish, or gloss, to which water does not readily adhere."

The Romans divided colours into two classes-florid and grave (floridi, austeri)—the former, on account of their high price, were usually provided for the artist by his employer. These were again divided into natural and artificial or factitious. The florid colours appear to have been six-minium, red; chrysocolla, green; armenium; purpurissimum; indicum; cinnabaris; ostrum; the rest were the austeri.

The natural colours were those obtained immediately from the earth; the others were called artificial, on account of their requiring some particular preparation to render them fit for use.

It is the opinion of Sir Humphry Davy, that the ancient painters, like the best masters of the Roman and Venetian schools, were sparing in the use of the more florid colours, and produced their effects, like them, by contrast and tone.

MOSAIC.-Mosaic, opus musivum, is a kind of painting made with minute pieces of coloured substances, generally either marble, or natural stones, or else glass, more or less opaque, and of every variety of hue which the subject may require, set in very fine cement, and which thus forms pictures of different kinds, rivalling in colour and hue those painted by the brush.

Early nations knew the art of mosaic, and it is supposed to derive its origin from Asia, where paintings of this kind were

composed, in imitation of the beautiful carpets manufactured at all periods in those countries. The Egyptians employed it very probably for different purposes; no traces of it have, however, been found in the temples or palaces, the ruins of which remain. There is in the Egyptian collection at Turin a fragment of a

mummy case, the paintings of which are executed in mosaic with wonderful precision and truth. The material is enamel, the colours are of different hues, and their variety renders with perfect truth the plumage of birds. It is believed to be the only example of Egyptian mosaic.

The Greeks carried the art of mosaic to the highest perfection, assuming after the time of Alexander an importance which entitled it to be ranked as an independent art. Skilfully managing the hues, and giving to the figures in their compositions an exquisite harmony, they resembled at a slight distance real paintings. Different names were given to the mosaics, according as they were executed in pieces of marble of a certain size; it was then lithostroton, opus sectile; or in small cubes, in this case it was called opus tessellatum, or vermiculatum. The name of asaroton was given to a mosaic destined to adorn the pavement of a dining hall. It was supposed to represent an unswept hall, on the pavement of which the crumbs and remains of the repast which fell from the table still remained. It was said to be introduced by Sosus of Pergamus, the first mosaic artist of consequence whom we hear of.

Mosaic was used to adorn the pavements, walls, and ceilings of public and private edifices. The Greeks in general preferred marble to every other material. A bed of mortar was prepared, which served as a base, which was covered with a very fine cement. The artist, having before him the coloured design which he was to execute, fixed the coloured cubes in the cement, and polished the entire surface when it had hardened, taking care, however, that too great a polish, by its reflection, might

not mar the general effect of his work. The great advantage of mosaic is that it resists humidity, and all which could change the colours and the beauty of painting. Painting could not be employed in the pavement of buildings, and mosaics gave them an appearance of great elegance. The mosaic of the Capitol, found in Hadrian's Villa, may give an idea of the perfection which the Greeks attained to in that art. It represents a vase full of water, on the sides of which are four doves, one of which

is in the act of drinking. It is supposed by some to be the mosaic of Pergamus mentioned by Pliny. It is entirely composed of cubes of marble, without any admixture of coloured glass. Mosaics of this kind may be considered as the most ancient; it was only by degrees that the art of colouring marble, enamel, and glass, multiplied the materials suited for mosaics, and rendered their execution much more easy. It was then carried to a very high degree of perfection. The mosaic found at Pompeii, which represents three masked figures playing on

different instruments, with a child near them, is of the most exquisite workmanship. It is formed of very small pieces of glass, of the most beautiful colours, and of various shades. The hair, the small leaves which ornament the masks, and the

eyebrows, are most delicately expressed. What enhances the value of this mosaic is the name of the artist worked in itDioscorides of Samos. Another mosaic found at Pompeii is the beautiful one of Acratus on a Panther. The subjects represented in mosaics are in endless variety, and generally are