1. Bitumen, as in the Babylonian structures; 2. Common mud or moistened clay; 3. A very firm cement compounded of sand, ashes, and lime, in the proportions respectively of 1, 2, 3, well pounded, sometimes mixed and sometimes coated with oil, so as to form a surface almost impenetrable to wet or the weather. In Assyrian and also Egyptian brick buildings, stubble or straw, as hair or wool among ourselves, was added to increase the tenacity.