The complete absence of such remains is to be explained by the nature of the materials used in the erection of even the most costly edifices. In the immediate vicinity of Babylon there were no quarries of alabaster, or of limestone, such as existed near Nineveh. The city was built in the midst of an alluvial country, far removed from the hills. Consequently stone for building purposes could only be obtained from a distance. The black basalt, a favorite material amongst the Babylonians for carving detached figures, and for architectural ornaments, as appears from numerous fragments found amongst the ruins, came from the Kurdish mountains, or from the north of Mesopotamia. It was probably floated down the Euphrates and Tigris on rafts from those districts. The Assyrian alabaster could have been brought from Nineveh, and the water communication by the rivers and canals offered great facilities for transport; yet enormous labor and expense would have been required to supply such materials in sufficient quantities to construct an entire edifice, or even to panel the walls of its chambers. The Babylonians were, therefore, content to avail themselves of the building materials which they found on the spot. With the tenacious mud of their alluvial plains, mixed with chopped straw, they made bricks, whilst bitumen and other substances collected from the immediate neighborhood furnished them with an excellent cement. A knowledge of the art of manufacturing glaze, and of compounding colors, enabled them to cover their bricks with a rich enamel, thereby rendering them equally ornamental for the exterior and interior of their edifices. The walls of their palaces and temples were also coated, as we learn from several passages in the Bible, with mortar and plaster, which, judging from their cement, must have been of very fine quality. The fingers of the man's hand wrote the words of condemnation of the Babylonian empire "upon the plaster of the wall of the king's palace."[213] Upon those walls were painted historical and religious subjects, and various ornaments, and, according to Diodorus Siculus, the bricks were enamelled with the figures of men and animals. Images of stone were no doubt introduced into the buildings. We learn from the Bible that figures of the gods in this material, as well as in metal, were kept in the Babylonian temples. But such sculptures were not common, otherwise more remains of them must have been discovered in the ruins.