Researchers Have Read This Sealed Letter Without Opening It

Have you received a sealed letter and looked at it against the sun to see what's inside? Only to find out that you can't understand anything.

Well, these researchers have been successful (unlike us...) in reading an unopened 17th Century letter without breaking the seal.

Image Credit: Unlocking History Research Group archive

The letter, dated 31 July 1697 and sent from French merchant Jacques Sennacques in Lille to his cousin Pierre Le Pers in The Hague, had been closed using “letterlocking”, a process in which the letter is folded to become its own envelope, in effect locking it to keep it private. It is part of a collection of some 2,600 undelivered letters sent from all over Europe to The Hague between 1689 and 1706, 600 of which have never been opened.

Image Credit: The Museum Voor Communicatie

The international team of researchers from universities including MIT, King’s College London, Queen Mary University London, Utrecht and Leiden, worked with X-ray microtomography scans of the letter, which use X-rays to see inside the document, slice by slice, and create a 3D image. They applied computational flattening algorithms to the scans to enable them to virtually unfold the letter without ever opening it, and discovered that Sennacques had been asking his cousin for a certified copy of a death notice of one Daniel Le Pers

For those curious, here's what's written:

“It has been a few weeks since I wrote to you in order to ask you to have drawn up for me a legalised excerpt of the death of sieur Daniel Le Pers, which took place in The Hague in the month of December 1695, without hearing from you,” runs the letter. “I am writing to you a second time in order to remind you of the pains that I took on your behalf. It is important to me to have this extract & you will do me a great pleasure to procure it for me & to send me at the same time news of your health & of all the family.”

Image Credit: Unlocking History Research Group archive