Bone, horn, and ivory are, like other organic materials, highly degradable. Because of the nature of their chemical composition, they are well preserved under certain environmental conditions, and decompose quickly in others. The degree of preservation is higher in alkaline and chalky soils than in acidic, water-permeable soils. Artifacts made of bone are affected in much the same way as skeletal material. In order to make it possible to lift an object in one piece, consolidation in situ is necessary in many cases. The method chosen must depend on the condition of the bone, its state of preservation, and on the subsequent treatment. If the object is wet but stable, dehydration under controlled conditions is often sufficient. Brittle, waterlogged objects may have to be stabilized through the application of a bulking agent, such as a wax. Many dry objects do not need treatment by chemical means - a mechanical cleaning may suffice.