Using X-rays to reveal words within scrolls

Scientists really do have X-ray vision and can use it to read otherwise inaccessible historic writings such as fragments of the…

Scientists really do have X-ray vision and can use it to read otherwise inaccessible historic writings such as fragments of the Dead Sea Scrolls. Beams of light that are 100 billion times brighter than a standard X-ray are being used in the analysis and conservation of ancient parchments.

For millennia, written records have been made using iron gall ink on parchment made from specially treated cow, goat or sheep skin. These records include the Dead Sea Scrolls, the Doomsday Book and Magna Carta.

"There is a rich vein of cultural heritage in written records recorded on parchments that need to be preserved, and there are a number of historical documents of great value and we do not know what they contain yet," Prof Tim Wess told the BA festival in York yesterday.

Prof Ross from Cardiff University has been using the new Diamond synchrotron light source in south Oxfordshire as a non-invasive technique to "look" through layers of rolled-up parchment and scrolls.

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"We can use X-ray tomography to recover information on the structure of scrolls and to see the words within," explained Prof Wess.

"There are a number of collections of samples in archives, such as the National Archive, that we are not able to open up to read due to fears of damaging them as they are unfolded or unrolled."

The technique scans layers through the papers and scrolls from different sides, to build up a three-dimensional image.

The difference in the structure of molecules in the iron gall ink and the layers of parchment allow visualisation of the letters and words contained within.

A computer can then be used to simulate unrolling of the scroll and reveal the text contained.

"The system can be used like a hospital X-ray, scanning the scrolls from different angles, obtaining images [ image slices] one micron apart through the sample. Computer algorithms are then applied to allow 3-D visualisation of the scrolls and open them out," explained Prof Wess.

They currently have 80 per cent accuracy in reading the 18th-century test scrolls - old legal documents from Scotland - and once this technique has been validated it will be used on more precious artefacts such as fragments of the Dead Sea Scrolls that Prof Wess has access to.

"There are a number of samples in libraries worldwide that could be looked at in this way. Due to pollution and preservation problems with these documents there are less and less year on year," stated Prof Wess.

Prof Wess is particularly concerned about the risk that some written history could, with time and pollution, degrade to "jelly".

His work is also concentrating on analysing the deterioration process of parchments so that he can give advice on how they can be preserved for future generations.

"Parchments contain collagen [ from the skin] and this can turn to gelatine. Using the X-ray scattering we can analyse the state of the collagen on the surface and through the layers to see how much has turned to gelatine and has degraded," said Prof Wess.

"This will help us understand the degradation process and learn how best to preserve documents for the future."

The group will also use the technique to scan books, although this will be more difficult, but Prof Wess predicts that it could be possible in three to four years.