The juicy contents of a sealed 300-year-old letter are now available for anyone to enjoy, thanks to a new algorithm that deconstructs x-rays to virtually unfold documents. Researchers at MIT developed the virtual letter-opening method to read unopened letters that, due to wax seals and intense folds, are too fragile to open today.
Hold on, did I say that this letter is juicy? It’s actually a bit mundane. In the letter, dated July 31st, 1697, French lawyer Jacques Sennacques asks his cousin, Pierre Le Pers, to send over a death certificate for a relative named Daniel Le Pers. Unfortunately, the letter never reached Pierre. It instead sat in a trunk nicknamed the Brienne Collection alongside 2,600 other letters, 600 of which remain unopened.
Nosy researchers can’t open these unsealed letters, as they’re all “letterlocked.” Letterlocking, a process where you fold and seal a letter to the point that it can’t be opened without getting torn, was a common trick for hundreds of years in Europe and other continents. It serves as a deterrent for snoops, who by opening a “locked” letter would damage it, leaving evidence that the letter was tampered with.
After 300 years in a dusty French box, the letters are too fragile to “unlock” without causing significant damage. And even in cases where researchers could successfully unfold a letter, doing so erases the letterlock, which is a valuable piece of history in its own right.
Researchers can use this virtual “unlocking” method to reveal the contents of unopened letters, which are quite common given the prevalence of letters before the late-20th century. The technology could also come in handy for researchers studying other fragile documents, like old books and scrolls.