In the carpets still woven in Asia Minor, Kurdistan, Khorassan and Persia there are colours at once brilliant and soft that are a constant delight to the eye of the connoisseur. We may point, for instance, to certain reds and greens at which the manufacturers of Europe gaze in despair, in spite of the resources of modern chemistry. This freshness and solidity of tint is explained by the almost exclusive use of vegetable dyes. These the Kurd or Turkoman extracts from mountain plants, sometimes from the stem or the root, sometimes from the blossom or the seed.[350] These inventions and recipes have been handed down from generation to generation through many ages; the secret of many dyes must have been discovered long before the fall of Nineveh or the beginning of the Babylonian decadence. Down to the very last days of antiquity the dyers of Mesopotamia were famous for their processes and the harmonious splendour of their colours. Since the days of Nebuchadnezzar the people of that region have forgotten much, while they have learnt nothing, perhaps, but how to hasten the depopulation of their country by the use of gunpowder. All the professional skill and creative activity of which they still can boast they owe to the survival of this ancient industry, whose traditions and practical methods are preserved in the hut of the mountaineer, under the tent of the nomad, and in those bazaars where so many agile weavers repeat, with marvellous rapidity of hand and sureness of eye, the designs and motives of thirty or forty centuries ago. Among the colouring materials still in use in the woollen fabrics of the Levant there can be very few with which the ancients were not acquainted, and perhaps they used some of them in their distemper paintings; but the latter were no more than feeble shadows when discovered, and they soon vanished when exposed to the air. It was different with those that had been subjected to the action of fire. They could be removed and analyzed. But the enameller confined himself almost exclusively to mineral colours, of which alone we can now describe the composition. The two colours most frequently used were blue and yellow. Backgrounds were nearly always blue (Plates XIII. and XV.), and most of the figures yellow. Certain details were reinforced by touches of black and white. In the brick representing the king followed by his servants (Plate XIV., Fig. 1), the royal tiara is white, the hair, beards, bows, and sandals are black. Red only appears in a few ornamental details (_Ibid._, Fig. 2). Green is still more rare. It has been found at Khorsabad. In a fragment of painting upon stucco it affords the ground against which the figures are relieved;[351] and in the enamelled brick decoration on the harem wall (Vol. I., Fig. 101), it is used for the foliage of a tree that looks at first sight like an orange tree; its leaves however are rather those of an apple (see Plate XV., Fig. 3).