ABSTRACT
The reason why a group of materials as diverse as leather, beeswax, and alcohol can be classified together as organic, is not that they derive from living organisms, even though this is the case, but that their composition is based on carbon. Today, organic materials such as plastic and pesticides seem far removed from living things, but in antiquity organic materials were mostly derived from organisms which were living or had recently lived; these ranged from mammals to green plants but did include minerals such as bitumen formed from much altered plant debris. Not only was the range of sources wide, but the different types of material obtained were numerous. Thus, structural materials such as wood and ivory, as well as preserving materials such as tannins and adhesives such as resin, were all available from natural sources. Mankind either employed these materials virtually unaltered from their original source in, for example, wooden artefacts, or they carried out considerable work on them in order to make them more suitable for their use in, for example, leather artefacts.
