Biologists offer new ways to learn human history from old books
For as often as my family checks out books from the library, I don’t think we’ve ever brought home any northern European furniture beetles at the same time. On the other hand, some bookmakers 900 years ago probably didn’t know they were including eggs in the cover they were making from wood and deer skins, so the fauna included in any particular book might not be discovered for some time. The paperback kids’ books we often check out probably can’t hide beetles, but there’s still a lot that could be discovered on their pages. Scientists now have non-destructive ways to sample and analyze proteins, DNA and other microscopic evidence, leading to whole new set of stories is being written about about books, almost completely independent of what’s written in them.
Layers of leather
A thorough study was recently conducted of a 900-year-old copy of The Gospel of Luke. The book was made with a wooden cover bound with deer hide, although DNA analysis revealed that even the cover was more complicated than previously assumed. Aside from the wholes made by Anobium punctatum larvae, the majority of the cover was covered in skin from a Roe deer (Capreolus capreolus), while the strap to close the book was made of fallow (Dama dama) or red deer skin (Cervus elaphus). Aside from revealing a bit more sophistication in the design of the book, this also told researchers about the wildlife that must have been living in England where the book was made. It was probably during a transition where the larger red and fallow deer were beginning to eclipse the native Roe deer, a fact that was even trickling down to book making.
Along similar lines, a gentle rub of a polyvinyl chloride eraser on each page was able to pick up proteins, microbes and DNA from each piece of vellum. Vellum was an early form of parchment made from the skin of young animals, and while that was the expected material to be used in a book like this, the diversity of animals used across different pages was a surprise. Instead of a homogeneous collection of calf skin, sheep and even goat skins were used to make the 156 page manuscript. Previously, goats were thought to have only been used for book making in southern Europe, and researcher wonder if the small number of goat pages in the second half of the text may have been due to a shortage of preferred materials. It also coincided closely with when the primary scribe changed, possibly indicating a bigger disruption to the book’s production before it was completed.
Tainted by touching
The paper books we encounter these days probably aren’t going to turn up with traces of deer or goats, but they are likely to have plenty of human DNA and microbes. Pages with hymns were found to have more human DNA, probably thanks to those pages being accessed, and based on the bacteria on the page, kissed, more frequently than other pages. The most common forms of bacteria on each page were Propionibacterium, which can promote acne, and Staphylococcus, which can cause staph infections if it gets under your skin. Before you worry about picking up a printed page, keep in mind that any popular technology that we put our hands on is likely to have bacteria wiped on it, including your favorite touchscreen.
Researchers have high hopes for these non-destructive ways to study old books. Understanding what lives, or lived, in a book’s pages can help with dating a book’s production, estimating the local availability of resources and even understanding who was doing the reading. A lot of history is recorded in these pages, even if it’s not the history any author intended to document.
Source: Goats, bookworms, a monk’s kiss: Biologists reveal the hidden history of ancient gospels by Ann Gibbons, Science