X-Rays Reveal Ancient Scientific Text Scraped Away And Overwritten With Biblical Hymns


An international, multidisciplinary team is using X-rays to reveal the hidden text of a medical manuscript by the ancient Greek doctor Galen. SLAC

Modern technology is helping us find out more about medicine’s roots and how new science developed and spread across the ancient world.

Technical experts, scientists, and scholars at the Stanford Synchrotron Radiation Lightsource (SSRL) are using high-powered X-ray beams to scan and analyze an ancient text known as the Galen Palimpsest. On the surface of the animal hide parchment is an 11th-century text outlining psalms for the week. Past that, scientists have discovered a 6th-century medical text that had been scraped off and written over to make room for the biblical writings.

Galen's original 16th-century text was written lengthwise. Biblical texts from the 11th century were written in this bi-fold style. SLAC

At a time when paper and writing utensils were hard to come by, scribes would often scrape off original text and write over it, a Medieval form of recycling known today as a palimpsest.

“Underneath the text is a very faint and erased text that you can only see by using this X-ray signal,” physicist Uwe Bergmann told IFLScience.

The team has advanced a technique first developed 12 years ago. As the inks used to write on the manuscript have different compositions, they responded differently to an X-ray beam directed onto them. These differences allowed the scientists to distinguish between them. 

“This very fine beam creates a two-dimensional image like a map, which contains in the fluorescent signals the elements of what is on each page,” said Bergmann. “By doing that, even if the ink is erased, there are still some traces of the metal in the ink that we can bring out.”

The scanned images show minute variations from metals found in the ink. The ink used in the newer religious text reacts to the X-ray beams differently from the residual ink, allowing scientists to tell them apart. SLAC

This technology, known as X-ray fluorescence imaging, has been around for more than a decade. However, it’s the team’s ability to rapidly convert the manuscripts into high-resolution images that sets this project apart. Bergmann said in the past they were only able to record around 10 megabytes of data. They are now able to record up to six gigabytes. Each of the 26 pages takes around 10 hours to convert into files that can be shared with scholars online. 

Written in ancient Syriac, researchers believe the ancient text includes the oldest-known copy of On the Mixtures and Powers of Simple Drugs, a medical text written by Greco-Roman writer, philosopher, and physician Galen of Pergamon, who died in 210 CE. Credited with being the first to investigate the body through dissection, Galen produced theories that dominated European medicine for 1,500 years. He even discovered that arteries carry blood and that urine is formed in the kidneys.  

The palimpsest first turned up in Germany in the early 1900s, according to an emailed statement from the SLAC National Accelerator Laboratory. Research indicated it came from St Catherine’s Monastery on the Sinai Peninsula, Egypt. Almost a century later, a page of the 1,000-year-old text was found in a wealthy collector’s museum of rare scientific material in Baltimore. The discovery launched a global hunt for other lost leaves, which culminated in 2013 with the digitization of the final rediscovered page in Paris.

Now, almost two millennia later, Galen’s text continues to circulate and advance the world of science.

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