The bricks which composed the structure of the walls in Chaldæan or Assyrian edifices were nowhere visible. Above the slabs sculptured in bas-relief and under the spring of the vaults a white stucco was applied, made of plaster and lime, like that still used by the Orientals to coat their houses; this custom explains the phrase “whited sepulchres” in the Gospels. It was doubtless on a plaster of this nature that the mysterious hand of which the Book of Daniel speaks traced out Belshazzar’s sentence of condemnation on the night of the ill-famed banquet: the sacred writer says that the hand wrote “on the plaster of the wall.” This stucco was often decorated with paintings in distemper, at any rate in the principal chambers, above the line of the bas-reliefs. Modern explorers have collected some fragments of these frescoes or decorative paintings; at Warka, among the ruins of the temple called Wuswas, Loftus acquired some which belong to the remotest Chaldæan period. At Khorsabad, V. Place found on some pieces of stucco elegant rosettes formed by the application and juxtaposition of very decided colours: white, yellow, green, red, and black. One of the most remarkable examples of this painting is a border of bulls painted white on a yellow ground, their form being relieved by a broad black outline (fig. 87). Above is a row of blue battlements; below festoons of many colours. The effect is harmonious, though the tints are flat, and in spite of the absence of all modelling in the figures.[41] [Illustration: Fig. 87.--Painting on plaster, Nimroud (after Layard).] The application of stucco of different colours is particularly conspicuous in the construction of the staged towers, the terraces of which are, beginning from the lowest, white, black, red, yellow, vermilion, silver and gold. In the interior of the chambers, to avoid the disagreeable contrast between the uniform whiteness of the stone bas-reliefs and the brilliancy of the many-coloured paintings, the fashion was to colour the figures in the bas-reliefs themselves. Some traces of colouring may still be recognised in the sculptures preserved in our museums, and though it is true that they are being gradually effaced, they were quite evident when the slabs were disinterred. The beard, hair, weapons, and even the face and costume of the figures were coloured in a similar manner to the paintings on plaster, so that this painted stucco seemed to be the continuation of the bas-reliefs. There are, for instance, evident traces of vermilion paint[42] on the figures of demons in the Assyrian basement of the British Museum. The Assyrians obeyed the same laws of æsthetics as the mediæval artists, who applied polychrome colouring to their marble or stone statues, to bring them into perfect harmony with the rich decoration which filled their cathedrals from the floor to the keystone of the vault. [Illustration: Fig. 88.--Portion of an enamelled archivolt at Khorsabad (after V. Place).]