Mystery of How the Ancient Hebrews Created the Longest of the Dead Sea Scrolls Solved by Scientists

The ancient Hebrews who created the longest of the Dead Sea Scrolls did so using unique technology that may have helped the parchment survive so well over the last 2,000 years, researchers have discovered.

By analyzing the Temple Scroll—one of the largest, best preserved of all the scrolls—scientists found the parchment had been processed in an unexpected and unusual way, providing an insight into how to preserve it in future.

The Dead Sea Scrolls are a collection of 981 Hebrew texts found between 1946 and 1956 in caves in the Judean desert. They are believed to have been hidden just under 2,000 years earlier to protect them from Roman invaders. According to a statement from Massachusetts Institute of Technology (MIT), they were buried under a few feet of debris and bat guano by members of the Essenes sect.

Since their discovery, the scrolls have been studied extensively. They contain documents, letters and religious writings—and new details are still being found. Last year, researchers using new imaging techniques found hidden text on a seemingly blank piece of document. In 2017, archaeologists with the Hebrew University of Jerusalem announced the discovery of a 12th cave where the scrolls had been stowed.

However, as well as storing historical information, the Dead Sea Scrolls also contain information about the materials and processing techniques that would have been used at the time.

Parchment is normally made by removing the hair and fat from animal skin, then soaking it in a lime solution. It is then cleaned and stretched thinly across a frame. Once dry, it is sometimes rubbed with salts.

A team of researchers, led by Admir Masic from MIT, was provided an inch-sized fragment of the Temple Scroll to study. At almost 25 feet in length, this document is one of the largest of the scrolls. It is also one of the thinnest, measuring about a tenth of a millimeter. Yet the Temple Scroll is also one of the best preserved of all these historic texts, having the clearest and whitest writing surface.

Masic and his team carried out a chemical analysis of the text to find out how the parchment was made using specially developed, non-invasive techniques that allowed them to identify thousands of elements on the surface of the text.

temple scroll
Section of the Temple Scroll. Scientists have analyzed the chemical composition and found the parchment was rubbed with a specific mix of salts that gave it its unusual brightness. VCG Wilson/Corbis via Getty Images

Their findings, published in scientific journal Science Advances, shows the Temple Scroll has a layered structure and was processed with a mix of salts left over from the evaporation of brines—a mix different to what was used on other scrolls. Elements found include calcium, sodium and sulfur. The concentrations of these elements were "at completely unexpectedly high concentrations," Masic said in a statement.

Researchers say this salt coating is what gave the Temple Scroll its bright white surface and may have helped preserve it. The significance of the text may be why it was treated with a different mix of salts. In an email to Newsweek, Masic and co-author Ira Rabin said: "The Temple Scroll was very special. Not just holy text. Some considered it to be a sixth book of Moses. It is conceivable that this very costly and unusual preparation of the Temple Scroll was done to produce a specifically beautiful scroll."

Where the salts came from is unknown—the composition does not match what would come from the Dead Sea, so it must have come from another source of brine from another location.

By finding out what the parchment was coated in, researchers say it should be easier to identify forgeries, as well as find ways to preserve the ancient text in the future.

"There could be an unanticipated sensitivity to even small-scale changes in humidity," Masic said. "The point is that we now have evidence for the presence of salts that might accelerate their degradation."