When Mt. Vesuvius erupted in 79 A.D., the volcanic cataclysm buried the towns of Pompeii and Herculaneum under a thick layer of ash and molten rock. People, pets, and loaves of bread were petrified in place.
So was a library of scrolls, or papyri, in a Herculaneum villa that probably belonged to Lucius Calpurnius Piso Caesonius, Julius Caesar’s father-in-law. A tiny pool of texts remain from the era of Ancient Greece and Rome. When the “Villa of the Papyri” was first discovered in 1754, it represented the only intact library to have survived since antiquity: at least 1,800 texts.
There was one major problem. The hundreds of rolled-up scrolls had been baked by 320-degree volcanic gas into carbonized briquettes, rendering them illegible.
Now European scientists say they have read a handful of words from two of the texts without unrolling them, using a technique that one could be forgiven for describing as X-ray vision.
Classicists called the technique, described in a study in Nature Communications published online Tuesday, as “exciting” and “promising.”
“If they’re able to pull it off, it has the potential to revolutionize the study of the ancient world,” said Jack Mitchell, a professor of Classics at Dalhousie University.
Italian scholars in the 18th century developed a method of reading some of the papyri by suspending the scrolls and letting their own weight slowly unroll them, a process that could take years. In the 20th century, some of the scrolls were picked apart into tiny pieces to read them. But further attempts have been abandoned because so many of the papyri were inadvertently destroyed.
One of the challenges the papyri present is that they are made of strips of plant material with writing of charcoal “ink.” The low contrast between the two materials means that a technique used for reading other ancient materials, which relies on how contrasting materials absorb wavelengths of light or radiation at different rates, is unusable. The rolled-up scrolls also did not allow for those wavelengths to penetrate into the interior.
The new technique, known as X-ray phase contrast tomography, instead exploits variations in how materials with similar absorption rates refract X-rays. The method has been used in medical imaging, but researchers from Italy, France and Germany decided to apply it to two of the villa’s scrolls stored in France. One had been partially unrolled but contained many superimposed layers, the other remained intact.
From a hidden layer of the partially-unrolled papyrus the researchers lifted two Greek words: one translates as “would fall” and the other as “would say.” From the intact scroll, the researchers saw three letters: alpha, nu, and rho, the Greek equivalents of the letters A, N, and R.
The paper is a proof of concept. Mike Sampson, a Classics professor at the University of Manitoba and an expert on papyri, called the announcement “promising” but preliminary. “I’m going to withhold judgment until I see a whole column of text,” Sampson said.
Even if that column of text is blurry, however, Sampson noted that papyrologists are accustomed to untangling faint and degraded words. Dalhousie’s Mitchell called the study a “breakthrough” because of how important the texts are. While most papyri available to classicists come from garbage dumps in Egypt, and mainly consist of grocery lists and other prosaic information, the Villa of the Papyri consists of works of literature and philosophy, particularly from ancient Epicureanism.
Philodemus, the philosopher who is believed to have collected and written many of the texts, also liked to itemize the history of whatever he was writing about before delving into his own beliefs, Sampson and Mitchell both noted, and the texts that have been read so far have filled in huge gaps in Classicists’ knowledge.
“The technology will certainly be improved and refined before it’s put into widespread use and before it bears fruit in the form of full transcriptions and editions,” said Sampson.