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PRESS RELEASE I PARIS I 20 JANUARY 2015
Seeing inside Herculaneum's charred scrolls
An international team1 comprising researchers from the CNRS (Institut de Recherche et
d'Histoire des Textes), CNR (Italy) and ESRF (Grenoble synchrotron) has made a major
breakthrough in the study of the papyrus scrolls buried by the eruption of Vesuvius in 79
AD and discovered in Herculaneum 260 years ago. Using a new non-invasive X-ray
imaging technique, the researchers were able to reveal Greek letters hidden deep inside a
charred scroll. Their findings also enabled them to formulate a hypothesis about the
identity of the text’s author. This interdisciplinary work, published on January 20 in Nature
Communications, raises hopes that it may eventually be possible to decipher all the papyri
in the ancient library of Herculaneum.
During the eruption of Vesuvius that destroyed Pompeii, hundreds of papyrus scrolls were buried under
several layers of volcanic material. An entire library was uncovered 260 years ago in Herculaneum. Some
of the library’s papyri were preserved and have survived to the present day. They form a unique cultural
treasure since there are probably no other copies of the texts they contain.
These carbonized scrolls are extremely fragile. Any attempt to open them and read the contents could
break them up or even destroy them. Over the past few decades, various imaging techniques have been
used to try to read the papyri without unrolling them, but so far to no avail. In this article, the researchers
present a new method that has enabled t hem to decipher several letters and words inside a scroll without
damaging it.
The ink used in antiquity was made from carbon obtained from smoke residues. Its density is therefore
almost identical to that of a carbonized sheet of papyrus, which makes it difficult to distinguish using
conventional X-ray methods. The X-ray phase-contrast tomography (XPCT) technique used in this work
makes it possible to better distinguish the ink from the paper by using the difference in refractive index.
This technique also relies on the fact that the ink does not penetrate into the plant fibers, so that the letters
stand out in very slight relief from the paper’s surface. This difference of a few hundred microns makes it
possible to amplify the contrast between the two components of the scroll and reveal the letters.
(1) This international collaboration is a major development of work carried out from 2006 by W. B. Seales (University of Kentucky) and D.
Delattre.
By using XPCT to study two Herculaneum papyri from the Institut de France’s collection, the researchers
were able to read words buried under several layers of paper or on deformed whorls of the roll that had
adhered to one another. They also successfully reconstructed a nearly complete Greek alphabet from a
papyrus that is still rolled up. By analyzing the writing style and comparing it with a previously studied text,
they were able to put forward hypotheses about the age of the carbonized scroll and about its author: the
roll may contain a text by the Epicurean philosopher Philodemus writing in his school during the first
century BC.
This technical breakthrough, which makes it possible to detect traces of ink within a carbonized papyrus
roll without compromising its integrity, has long been awaited. By developing it further, researchers should
be able to obtain the image of an entire papyrus scroll in just a few hours under a synchrotron beamline —
and eventually decipher all the philosophical texts contained in the scrolls in Herculaneum’s 'Villa of the
Papyri'.
Left: Overall view of the PHerc.Paris.4 scroll (length 16 cm).
© Bibliothèque de l'Institut de France / Photo D. Delattre
Right: Tomographic section through the volume of the papyrus. The sequences of letters discovered are located in a hidden layer of the
fragment.
© CNRS-IRHT UPR 841 / ESRF / CNR-IMM Unité de Naples
Part of the alphabet reconstructed from the PHerc.Paris.4. papyrus scroll.
The letters revealed using X-ray phase-contrast tomography are on the first and second lines. On the third line are the letters obtained
by infrared from another papyrus. By comparing the two alphabets it was possible to identify the writing style of the scroll. The fourth
line shows printed capital letters of the Greek alphabet.
© CNRS-IRHT UPR 841 / ESRF / CNR-IMM Unité de Naples
3D reconstruction of one of the scrolls studied: https://www.youtube.com/watch?v=d3aWBgNYOCU
Reference
Revealing letters in rolled Herculaneum papyri by X-ray phase-contrast imaging; Vito Mocella,
Emmanuel Brun, Claudio Ferrero & Daniel Delattre; Nature Communications; 20 January 2015.
Contact information
CNRS researcher l Daniel Delattre l T 0033 (0)3 20 90 33 61 l [email protected]
Researcher l Emmanuel Brun l [email protected]
CNRS Press Office l Lucie Debroux l T 0033 (0)1 44 96 43 09 l [email protected]