Oldest Glue Discovered	May 21, 1998
by Amélie A. Walker

An 8,000-year-old decorated skull from Nahal Hemar Cave (The Israel Museum) [LARGER IMAGE]

The oldest glue in the world, carbon dated to 8,310-8,110 years before present, has been found in Nahal Hemar Cave, located on a cliff near the Dead Sea just northwest of Mt. Sedom in Israel. Excavated in 1983 by Ofer Bar-Yosef of Harvard University and David Alon of the Israel Antiquities Authority, the cave yielded objects for daily use such as rope baskets, embroidered fabrics, nets, wooden arrowheads, and bone and flint utensils, and ritual objects including stone masks and decorated human skulls. Many of the artifacts were covered with what was thought to be asphalt from deposits nearby. Analysis conducted by Arie Nissenbaum of the Weizmann Institute of Science in Rehovot, Israel, and J. Connan of Elf-Aquitaine in Pau, France, however, showed the substance to be collagen, a fibrous protein found in skin, sinews, and cartilage. In addition to the artifact-associated material, small pieces of free collagen were found. The study also suggested that the collagen was derived from animal skins.

The glue was used as a protective, waterproof lining on rope baskets, containers, and embroidered fabrics, and was used to hold together utensils. It was also used to make a crisscross design on human skulls. Collagen normally converts quickly into gelatin, but, due to the region's extremely dry climate, the Nahal Hemar specimens were well-preserved.

A collagen-based adhesive was used by the Egyptians about 4,000 years ago as a binder in painting and possibly in the construction of wooden furniture. The Israeli glue is more than twice as old, and shows remarkable technology for a group of people who had not yet begun to produce pottery. Native Americans used a similar substance in the production of bows 1,500 years ago.

It is not known how the collagen adhesive found in Israel was produced, but the Egyptians made their glue by heating and treating skins with an alkaline solution. The Nahal Hemar collagen was supplemented with plant tissue, probably to give it the desired texture.

Not much is known about the Neolithic people who concocted the glue. They may have been using the collagen on objects for outdoor ceremonies, as is done among some nomadic Middle Eastern groups today.

© 1998 by the Archaeological Institute of America www.archaeology.org/online/news/glue.html