It seems even people in the pre-colonial Americas recycled. For the first time, a palimpsest, or parchment where a previous document was imperfectly scraped away so it could be reused and has some remnants of the earlier document, has been discovered from the Americas. The Codex Selden, also known as the Codex Añute, dates from the mid-16th century.

Even before being revealed as a palimpsest, the document was special, because it is one of fewer than 20 known Mexican codices to have survived from pre-colonial and early colonial Mexico, notes a press release about the discovery. Most of them had been destroyed by Spanish conquistadores. “One Spanish witness of the destruction wrote that people were distraught to see their books – and their history – burn, anguished ‘to an amazing degree, and which caused them much affliction,’” writes Maev Kennedy in The Guardian.

This document is one of only five surviving manuscripts from the Mixtec area, now the Oaxaca region of Mexico, the release notes. “These codices use a complex system of pictures, symbols and bright colors to narrate centuries of conquering dynasties and genealogies as well as wars and the history of ancient cities. In essence these codices provide the best insight into the history and culture of early Mexico.”

Researchers had speculated previously that the document, a five-meter-long strip of deer hide, was a palimpsest, according to the press release. It is covered with gesso, a white plaster made from gypsum and chalk, and folded in a concertina format (like old-style printer paper) into a seemingly blank 20-page document. Where the gesso cracked, bright colors peeped through. “The manuscript underwent a series of invasive tests in the 1950s when one page on the back was scraped, uncovering a vague image that hinted at the possibility that an earlier Mexican codex lay hidden beneath,” the release notes, but that approach was destructive to the parchment.

Instead, scientists used hyperspectral imaging to take pictures through the gesso using different wavelengths of light, and combined those images in different ways to reveal the traces of the imagery still hidden below the gesso. This technique has also been used with other palimpsests, most famously the Archimedes Palimpsest, which contained a number of mathematical proofs.

Researchers needed to use hyperspectral imaging rather than some other techniques because the Mixtec people who created the manuscript used inks made from plant materials rather than from minerals, such as the iron that formed the basis of many medieval inks. “That means there haven’t been any techniques that would give researchers the equivalent of X-ray vision, letting them see a hidden image without destroying the surface of the manuscript as we know it,” writes Meghan Bartel for Business Insider.

“Red pigments showed up particularly strongly,” writes Stewart Wills in Optics & Photonics News. “The hyperspectral technique was also able to tease out yellow pigments, which had previously been difficult to discern at all, as they tended to blend in with the gesso color.”

Of course, the next question is, what did it say? That’s less clear. As with the Voynich Manuscript, it is primarily imagery, and researchers aren’t sure what all the images mean. “Interpretation can’t really happen until the entire manuscript is scanned,” Bartel writes. ”But they were still able to identify individual people in the original text. As they scan more, they may be able to connect those characters with historical figures.” Other images include people walking with sticks and spears, women with red hair or headdresses and place signs containing the glyphs for rivers.

In particular, there’s one individual who appears repeatedly on the document, represented by a glyph consisting of a twisted cord and a flint knife. The name seems to resemble a character found in other Mexican codices, and that character is an ancestor of two lineages connected to two important archaeological sites. However, further analysis is needed to confirm that it is the same individual, the release notes.

What’s also noteworthy is that some pages feature more than 20 characters sitting or standing in the same direction, according to the release. “Similar scenes have been found on other Mixtec manuscripts, representing a King and his council,” notes the release. “But the analysis of this particular text shows that the characters are both male and female, raising interesting questions about what the scene represents.” (Like, perhaps it still represents a King and his council – but he had female councilors as well?)

In addition, researchers have found that the hidden manuscript is a different style from any of the others that have survived, meaning it could offer new perspective on archaeological finds from the area, Bartel writes. Moreover, the hidden text also flows sideways across page spreads, rather than from bottom to top the way the manuscript on the surface does, she adds.

While it’s unfortunate that so many such documents were destroyed in the first place, it’s gratifying that techniques have been developed to help us learn more about the ones we still have. Maybe someone will even be able to decode it someday.





