Ancient Translation of Historic Greek Medical Text Rediscovered Using X-Ray Vision

There are lost ancient texts hiding before our very eyes. Writers weren't always intending their words for long-term preservation, and the need to reuse precious resources, like animal hide, sometimes meant erasing an old text to make room for the new. 

But modern technology can recover these secret texts, as research taking place this week at the Stanford Synchrotron Radiation Lightsource (SSRL), an instrument housed at a U.S. Department of Energy laboratory in California, shows. The payoffs are worth it: a team began their analysis on Friday and have already identified a previously unreadable page as part of a preface.

"The first initial results are incredibly mind-blowing," Peter Pormann, a classicist who studies connections between ancient civilizations at the University of Manchester in the U.K., told Newsweek. "This is a unique witness to this particular text."

03_12_galen_palimpsest_synchrotron Researchers preparing a page of the palimpsest for examination. Robert Kish/SLAC

The text the team is focused on was erased a millennium ago, after the book was written on animal skin, or parchment, in the 500s. Parchment is expensive, and it turns out it's surprisingly easy to erase an entire book by scratching the ink off the hide. That gives later writers a clean enough surface to reuse without finding another goat or sheep to skin.

But a faint ghost of the erased text remains. And although that shadow can be extremely difficult to see, modern physicists have just the tool to highlight it: a super-powerful beam of x-rays the width of a human hair. The instrument, a cyclic particle accelerator housed at the Department of Energy's SLAC National Accelerator Laboratory, is usually used by scientists for projects ranging from building electronics to developing medicines.

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But every once in a while, it's called in to examine manuscripts, fossils, and other more eclectic targets. By scanning the manuscript pages with that beam, scientists can map where individual chemical elements lie on the page, allowing them to map older and newer inks separately.

This isn't the first time the book has been photographed under a range of wavelengths of light to try to catch the erased text. Previous work has used ultraviolet, visible, and infrared wavelengths on the text. But sections have remained impossible to decipher. "We're continuing to do that, but we hit the limits of those darn laws of physics optically," said Michael Toth, whose business coordinates manuscript imaging projects.

By Saturday, the team intends to have scanned 26 pages of the manuscript using this x-ray beam. Before the project could begin, those pages had to be carefully extracted from the modern binding of the manuscript and flattened for examination. Each page takes about 10 hours to scan, which means the team is carefully switching pages out sometimes at midnight to make the most of their time with the instrument.

03_12_galen_palimpsest_syriac The visible writing, which dates to the 11th century, is a religious text written in Syriac. Farrin Abbott/SLAC

If the effort is successful, they'll end up with a much clearer idea of what writing is hidden on those 26 pages, which were chosen out of about 226 pages total of erased text. Both the erased and the visible texts are writted in Syriac, a form of ancient Aramaic. Syriac ended up being a key resource for later Arabic and thereby European cultures trying to tap into ancient knowledge. While the visible letters are a religious text written in the 11th century, the erased text was written in the sixth century and contains a medical treatise. The team believes it was written at St. Catherine's Monastery on the Sinai Peninsula, which is famous for its library.

That erased text is a translation of even older Greek writings by a physician called Galen of Pergamum, plus an introduction from the translator, the new text identified earlier this week. "Galen is the most important and most influential physician arguably of all time," Pormann said. His beliefs—like the idea that the body was governed by four liquids called humors and that sickness was the result of those liquids being out of balance—remained the cornerstone of medicine in Europe. That's part of why the team is so determined to crack the manuscript's secrets. "This is basically our history, this is how medicine developed," Pormann said.

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