Spectroscopy reveals crossed-out passages in Marie Antoinette’s love letters

Entire passages have been crossed out from letters exchanged between famed French queen Marie Antoinette and the Swedish count Axel von Fersen, her rumored lover, during the height of the French Revolution. Someone clearly did not want those passages to be seen. Now, a team of researchers has found them out, uncovering both the redacted contents and the probable identity of the censor (Sci. Adv. 2021, DOI: 10.1126/sciadv.abg4266).

A team of researchers, led by Anne Michelin from the Research Center for Conservation in Paris, tested whether common forensic techniques could differentiate between the inks used to write the passages and those used to cross them out. The composition of the two inks is very similar, which made the project challenging. After exploring analytical techniques, Michelin’s group found they could use the consistent copper-to-iron ratio between the inks in some of the original letters to uncover crossed-out words between the putative lovers.

Using x-ray fluorescence spectroscopy and a suite of data processing tools, they deciphered the redacted text, which included words like “beloved,” “adore,” and “madly.” Historians had hypothesized that the Count’s great-nephew censored the letters to protect the von Fersen family’s reputation. But after analyzing the overlying redaction inks and comparing their composition to the inks that the Count used to write the letters, the researchers found that the inks were nearly identical and are now confident that it was the Count himself who censored the letters. Michelin, reached over email, says that result surprised her: “We didn’t think we would have such strong evidence.”