Scientists in California have used X-rays to reveal hidden text from a medical manuscript by an ancient Greek doctor which was written on 6th-century parchment but later overwritten with religious text hundreds of years later.
Uncovered at the U.S. Department of Energy’s SLAC National Accelerator Laboratory, scientists used high-powered X-rays to analyze the text from St Catherine’s Monastery on the Sinai Peninsula, Egypt.
On the surface were 10th-century psalms covering writings by an ancient Greek doctor called Galen which had been translated a few hundred years after his death into the ancient Syriac language.
Galen, who lived from 129 to around 216 CE, studied medicine by dissecting apes and made some important discoveries, among them the fact that arteries do not carry air, but blood. His work remained influential into the Middle Ages.
The Stanford Synchrotron Radiation Lightsource used to make the discovery is a common particle accelerator.
It works by accelerating electrons to nearly the speed of light and keeps them travelling around a many-sided polygon.
Magnets change the electrons’ directions, producing a beam of high-energy X-rays, which successfully revealed the ink that had been scraped off on the parchment.