The University of Basel has dozens of ancient papyrus texts in its collection, but one has been known for centuries as the Basel Papyrus. The 2,000-year-old work has been in the university’s collection since the 1500s, when it was acquired from a lawyer and art collector named Basilius Amerbach. And throughout those 500 years, no one could decipher it.

The writing on the Basel Papyrus looked like the ancient Greek script commonly used during the waning days of the Roman Empire, around the 3rd century CE, but the letters were reversed, like writing held up to a mirror.

“A few individual letters were readable before, but no sense could be established,” Sabine Huebner, professor of ancient history at the University of Basel, told Ars. “There were several theories circulating [about] why the papyrus was written in mirror script: to hide a secret message? As a joke? A medieval forgery?” Generations of archivists have puzzled over the mystery since the papyrus arrived in the university’s collection, but until recently, they’d all been stumped.

That changed in 2017 when an Italian papyrus expert visited Basel to study another set of ancient documents. While he was there, Huebner and her colleagues asked him to examine the enigmatic text.

“He looked at it with a small ultraviolet lamp,” Huebner said. She and her colleagues had already made digital images of the document as part of a project to digitize the university’s papyrus collection, but typically that kind of recording uses only visible and infrared imaging, not ultraviolet. “Under UV light, it seemed for the first time that there were actually several layers of papyrus bonded together by a white substance—some sort of medieval glue,” she said.

The papyrus hadn’t been written in mirrored script on purpose; instead, the reversed letters were the product of ink blotting from one page onto the back of another.

A new round of digital photography, this time under ultraviolet light, revealed that Huebner and her colleagues had a daunting task ahead of them: the fragile sheets of papyrus would have to be separated without destroying the writing. It took a specialist papyrus restorer three days of “very great care with tweezers” to complete the delicate work of separating the pages so that modern readers could have a good look at an ancient mystery.

Fragments of text

After centuries of fuss, Huebner and her colleagues knew there was a good chance the great mystery of the Basel Papyrus might turn out to be something mundane, like a contract or a receipt; most texts of this sort fall into that category, according to Huebner. But this one turned out to be something much rarer and much more interesting: a medical text that seems to either be written by a well-known ancient Roman physician named Galen or an ancient colleague’s commentary on his work. The text describes a condition called “hysterical apnea,” which Galen—along with another famous ancient physician, Hippocrates—had written about in other texts, notably Galen’s On the Affected Parts.

Today, of course, hysterical apnea isn’t a recognized medical condition, and perusal of ancient texts on the subject is an excellent introduction to the surreal sexism of ancient medicine. According to Galen and Hippocrates, women sometimes became so distressed, upset, or excited—hysterical, in other words—that they temporarily stopped breathing. Apparently this never happened to men, somehow.

Ancient physicians believed widows were particularly at risk, especially (as Galen less-than-delicately put it) "those who previously menstruated regularly, had been pregnant and were eager to have intercourse, but were now deprived of all this." He prescribed remarriage.

It’s impossible to say exactly what the author of the Basel Papyrus wanted to add on the subject of hysterical apnea, because half of each line is missing, leaving only fragmentary phrases on the papyrus. But many of those phrases turn up, word for word, in Galen’s other texts, which is part of the reason Huebner and her colleagues think he could also be the author of this text. Although it’s compelling, the phrasing alone doesn’t prove the Basel Papyrus was the work of an ancient celebrity doctor.

“We will probably never have ultimate proof unless another copy of this work pops up among the papyri which clearly states Galen as its author,” Huebner told Ars.

It looks likely that, with or without celebrity authorship, the Basel Papyrus was recycled for book binding material sometime during the Middle Ages. The Italian papyrus expert had worked with a collection of papyrus texts from the Archdiocese of Ravenna, which included several of Galen’s manuscripts that had been re-used and written over in medieval times. Apparently, respect for celebrity doctors died out over time.