Marie Antoinette's love letters laid bare

Let’s step back into the past now to Paris in the late 1700s. It was the time when the French Queen, Marie Antoinette, was under house arrest during the revolution. She corresponded prolifically during that period with the Swedish Count Axel von Fersen, with whom she was alleged to be intimately involved. He kept many of her letters, which now sit in the French national archives, but, ever the tease, someone scribbled out key parts of the text - possibly the bits that might have got him or her into trouble. Now though, researchers have used an X-Ray technique to see through those redactions by subtracting the differing signals of the ink used for the scribbling-out from the one Marie Antoinette wrote with. Anne Michelin, from Sorbonne University, took Harry Lewis through the story...

Anne - This correspondence was separate correspondence between Marie Antoinette and Axel von Fersen in 1791 and 92. It's the end of the life of the queen. She's in jail. We are in the middle of the revolution and it's not really good for the Royal family in France. She realises the situation, she sees that it's not a good time for her and so she writes to Axel von Fersen, which is a very close friend and she writes about the political situation, but also on her feelings. This correspondence is special because some parts of it are redacted. It's very black. You can't see anything. It's impossible to read the text and so it was something that the curator from the national archives asked us if we can read the texts.

Harry - Anne do you have any of those words available? Would you be able to read a short part where something's been redacted?

Anne - It's something like, my dear friend I love you madly and I can't be a moment without adoring you. Something like that. Not exactly, but something like that.

Harry - The big question there is, how do you see underneath the reductions? How do you know what the letters are?

Anne - It's all iron gall ink. Iron gall ink are inks that contain iron sulfate but also other metallic elements like copper and zinc. There is some slight difference between the inks and we use techniques, x-ray fluorescence spectroscopy, that analyse the compositions of the inks. Just the sensor on the paper, and we record the spectrum in each pixel. In each pixel of the letters we record a spectrum.

Harry - Then when you transfer that x-ray to the screen and you put that into a digital format through looking at each pixel you can see where the spectrum changes and the different elements are present. You can build up a visual picture like that?

Anne - Yeah, yeah. Like that. We have some parts where we are only the writing ink, the original ink, and some parts where we are sure there is only the reduction ink. It's like that. We can see if we have the same composition or if we have something really different.