Lead ink used on Herculaneum scrolls will make them readable

Posted Mar 22, 2016 by Karen Graham
Metallic ink has been found on some fragments of papyrus scrolls carbonized in the eruption of Mount Vesuvius in 79 AD. Scientists now entertain the possibility that many of the 800 Herculaneum scrolls in the ancient library may be readable.
In 1752  an ancient library was discovered at Herculaneum  buried beneath the ashes of Mount Vesuviu...
In 1752, an ancient library was discovered at Herculaneum, buried beneath the ashes of Mount Vesuvius. Astonishingly, nearly 2000 carbonized papyrus rolls were preserved, though some were so badly burned they looked like pieces of charcoal.
The Romans
Researchers relied on synchrotron X-ray based techniques at the European Synchrotron Radiation Facility in Grenoble, France that revealed a high concentration of lead was used in the ink on some of the ancient scrolls.
Vito Mocella, a physicist with the National Research Council’s Institute for Microelectronics and Microsystems (CNR-IMM) in Naples, told Discovery News, “We are reasonably certain that lead was intentionally used. It doesn’t come from contamination of water from Roman aqueducts or from a bronze container."
At left is a photo of a fragment of the incinerated papyrus. At right  lead is visible in the this X...
At left is a photo of a fragment of the incinerated papyrus. At right, lead is visible in the this X-ray fluorescence image.
Emmanuel Brun et al
The finding of large amounts of lead in the Graeco-Roman ink proves that metal-bearing ink was used several centuries earlier than previously thought. Until now, it was assumed that both Greek and Latin literary papyri were written in carbon-based inks obtained from soot from wood fires, reports New Scientist.
Mocella, along with Emmanuel Brun at the Grenoble Institute of Neurosciences, Daniel Delattre, papyrologist from the CNRS-IRHT- Institut de Recherche et d’Histoire des Textes, and other colleagues, examined two multilayered fragments that had been handed to Napolean Bonaparte as a gift in 1802. The two fragments had been held at the Institute of France in Paris.
“We do not know their exact dating. Most of the papyri in the villa date from the first century B.C., though the oldest one goes back to the 3rd century B.C.,” Mocella said.
The Herculaneum papyri
Workers accidentally discovered the library while digging in the ancient Roman city of Herculaneum in 1752, in a site that is now known as the Villa of the Papyri. In the 18th century, under the patronage of Charles III of Spain, excavation of Herculaneum commenced. More than 1.800 papyri were discovered.
The Villa of the Papyri was the largest Roman villa ever found. It stretched down toward the sea on ...
The Villa of the Papyri was the largest Roman villa ever found. It stretched down toward the sea on four terraces. The villa housed one of the finest libraries of antiquity. The scrolls consisted mainly of Epicurean philosophical texts and were carefully stored in shelves covering the walls.
It was only by sheer luck that as many of the scrolls survived the unearthing because they were totally carbonized by the intense heat of the pyroclastic flows when Mount Vesuvius erupted in 79 AD. The parching didn't take very long in the intense heat, and deprived of oxygen and covered by layers of cement-like rocks, the fragile blocks of scrolls were preserved.
Most of the scrolls have been attributed to the Epicurean philosopher and poet Philodemus of Gadara. Other scrolls are thought to hold Aristotle’s lost 30 dialogues, philosophical works, erotic poems by Philodemus, Virgilius, scientific work by Archimedes and lesbian poetry by Sappho. Over 200 scrolls are in such delicate shape they have never been read.
European Radiation Synchrotron Facility helped in research
A massive X-ray microscope at the Synchrotron facility allowed researchers to see what was written on the papyri fragments using a technique called scanning X-ray fluorescence (XRF) to see wisps of lead in the outlines of letters. Regular imaging techniques would not have revealed anything.
Not only did the XRF reveal the metallic ink, but it also revealed how ancient scribes were able to make such tidy, even lines. Using XRF scanning of a number of manuscript fragments, researchers discovered that scribes actually followed the perfect, straight lines created by natural ridges in papyrus leaves. It could be said that papyrus leaves were a form of naturally lined paper.
The team of researchers are excited at the prospects of future discoveries to be found in the scrolls. “It will allow us to optimize the next experiments on the reading of the invisible text within the scrolls,” lead author Brun said. Mocella and his team will start X-raying scrolls from the National Library in Naples in July, with the scanners looking for lead.
This very interesting piece of research, "Revealing metallic ink in Herculaneum papyri," was published in the journal Proceedings of the National Academy of Sciences on March 21, 2016.