Remnants of the past: high-tech analyses of ancient textiles yield clues to cultures

Science News, Dec 11, 2004 by Diana Parsell

Prehistoric people probably used sumac and bedstraw as dyes, Jakes says, because caches of those seeds have been recovered from archaeological sites although the plants have no known dietary use. In one set of experiments, for example, the researchers made dye baths from sumac berries and bedstraw roots combined with different mineral fixatives. When the researchers tested the baths on fibers from milkweed plants and rabbit hair, only one combination--sumac, bedstraw, and potassium carbonate--produced a deep red that was colorfast.

To estimate the time and skill that early Native Americans may have needed to make textiles, Jakes and her colleagues have done studies replicating yarn production from different plant fibers. In one experiment, several spinners were asked to produce yarns comparable in quality to those of textile artifacts from a Mississippian-period site in Carter County, Ga. The results demonstrated that a spindle technique was more than twice as efficient as hand-spinning methods. The spinning of cotton fibers went much slower than that of flax or hemp because cotton fibers are short and require more twists per turn to hold together the fibers.

These findings and others indicate that the early natives of what is now the eastern United States were highly skilled at cloth making, says Jakes, who presented some of her findings last August in Philadelphia at a meeting of the American Chemical Society.

THREADS BARE ALL Many modern techniques of analytical chemistry are well suited to the study of ancient textiles because they require only small samples of material, Lambert notes. These techniques also enable researchers to investigate other organic materials that may have come in contact with textiles.

Several years ago, James Adovasio and David Hyland of Mereyhurst College in Erie, Pa., analyzed trace residues of blood and other animal tissue on textile remnants found at a prehistoric Indian cemetery in Windover, Fla. To compare these residues with samples of deer and human tissue, the researchers used a technique that relies on antibodies to identify proteins. The results, Adovasio says, indicated that some of the human remains had been wrapped in deer hide as well as textiles.

Richard Evershed of the University of Bristol in England is another pioneer in the chemical analysis of organic archaeological materials. In the Sept. 16 Nature, he and his colleagues describe their study of cloth wrappings from animal mummies of ancient Egypt. The Egyptians preserved millions of mammals, birds, and reptiles as votive offerings. Scholars had assumed that ancient people used relatively simple and inexpensive methods to prepare this multitude of animals for burial.

Evershed's findings call that assumption into question. His team combined mass spectrometry with gas chromatography to analyze samples from cat, hawk, and ibis mummies. The embalming substances turned out to include fairly exotic materials, such as oils, beeswax, sugar gum, and tree resins, and were as complex as those used for human mummification. Evershed suggests that the ancient Egyptians had surprisingly sophisticated knowledge of how to use various preservatives.