Northwestern University scientists and students are working to unravel the mysteries of a small female mummy, including how her body was prepared 1,900 years ago in Egypt, what items she may have been buried with, the quality of her bones and the composition of a foreign material present in her brain cavity. As part of the investigation, the university team transported the mummy to Argonne National Laboratory on Nov. 27 for an all-day X-ray scattering experiment. It was the first study of its kind performed on a human mummy.

“This is a unique experiment, a 3-D puzzle,” says Stuart R. Stock, research professor of cell and molecular biology at Northwestern University Feinberg School of Medicine, who led the synchrotron experiment. “We have some preliminary findings about the various materials but it will take days before we tighten down the precise answers to our questions. We have confirmed that the shards in the brain cavity are likely solidified pitch, not a crystalline material.”

Thirteen materials science and humanities students are examining the materials and methods used to create both this intact portrait mummy and a well-preserved collection of Roman-Egyptian mummy portraits for an upcoming exhibition at Northwestern’s Block Museum of Art. Such mummies have a lifelike painting of the deceased individual incorporated into the mummy wrappings and placed directly over the person’s head. The Roman-Egyptian mummy from Northwestern is one of approximately 100 known portrait mummies in the world.

“Intact portrait mummies are exceedingly rare, and to have one here on campus was revelatory for the class and exhibition,” says Marc Walton, a research professor of materials science and engineering at Northwestern’s McCormick School of Engineering. “This is a once-in-a-lifetime opportunity for our undergraduate students—and for me—to work at understanding the whole object that is this girl mummy. Today’s powerful analytical tools allow us to nondestructively do the archaeology scientists couldn’t do 100 years ago.”

He says the synchrotron experiment at Argonne is a modern-day version of 19th-century England’s “mummy unwrapping” parties. The Northwestern team collaborated with scientists at Argonne and used the extremely brilliant high-energy synchrotron X-rays produced by Argonne’s Advanced Photon Source to probe the materials and objects inside the mummy, while leaving the mummy and her wrappings intact. “From a medical research perspective, I am interested in what we can learn about her bone tissue,” Stock says. “We also are investigating a scarab-shaped object, her teeth and what look like wires near the mummy’s head and feet.”

Prior to its trip to Argonne, the mummy had a CT scan at Northwestern Memorial Hospital in August, also led by Stock. The scan gave the researchers a 3-D map of the structure of the mummy and enabled them to confirm the girl was approximately five years old.

At the Advanced Photon Source, Stock and his team shined the pencil-shaped X-ray beam (about twice the diameter of a human hair) on areas of high density in the mummy that were identified by the CT scan. The team will now use the X-ray diffraction patterns as “fingerprints” to identify each crystalline material. For example, is the black rounded object seen on the CT scan a gold object or a rock?

The findings from the synchrotron experiment, CT scan and other scientific analyses and studies of history conducted by the students will help researchers and historians better understand the context in which the mummy was excavated in 1911 as well as Roman-period mummification practices. Conservators will also use the information to determine how to best preserve the mummy.

“We’re basically able to go back to an excavation that happened more than 100 years ago and reconstruct it with our contemporary analysis techniques,” Walton says. “All the information we find will help us enrich the entire historic context of this young girl mummy and the Roman period in Egypt.” http://www.anl.gov