NEW YORK, NY.- The year was 1791, and while Marie Antoinette may not have had the favor of the people of France, she did have a pen pal. Her confidant, Axel von Fersen, was a Swedish count, and one of the French queen’s close friends.

Between the summers of 1791 and 1792, though the queen was kept under close surveillance after a botched escape attempt, she still managed to sneak letters to von Fersen. He copied the letters, which are now held in the French national archives. But between the time the letters were written and the time they arrived at the archives, some mysterious actor censored the letters, scrawling out words and lines with tightly looped circles of ink.

The content of the censored lines — and the identity of the fastidious scribbler — eluded historians for nearly 150 years. In a paper published Friday in the journal Science Advances, scientists have now revealed the redacted content of eight of the censored letters between Marie Antoinette and von Fersen. The researchers used a technique called X-ray fluorescence spectroscopy, which can detect the chemical signatures of different inks without damaging documents.

The uncensored contents of the letters show the depth of Marie Antoinette’s affections for her close friend during a time of turmoil. But in a blow to gossips, the contents do not clarify whether they were having an affair.

Emeline Pouyet, a researcher at Sorbonne University in France who was not involved with the project, called the lifted redaction “a real technical breakthrough” that contributes to the field of conservation science.

“I think it’s absolutely fantastic,” said Catriona Seth, a professor of French literature at the University of Oxford who was not involved with the research. “Science is teaching us things we couldn’t have guessed.”

Marie Antoinette, who was executed in 1793, wrote many letters in her life.

Though the content of the queen’s later correspondence with the count is frequently political, the letters capture some of the most extreme moments of her life. “She’s under house arrest, she fears for her life, she may be killed,” Seth said. “She is writing with this awareness of her fate.”

But only a few of the letters had redacted content, Seth said. And many historians have wondered whether those censored lines could offer new insights into the French queen’s relationship with the Swedish count.

The letters stayed in von Fersen’s family until 1877, when they were published by the count’s great-nephew, Baron R.M. de Klinckowström. Many historians suspect the baron was the letters’ censor, perhaps to preserve his family’s reputation among rumors that the Swedish count and the French queen had been secret lovers.

In 2014, the National Archives contacted Anne Michelin, an assistant professor at the French National Museum of Natural History, to see whether she might be able to uncover the text.

Researchers can use X-ray tomography, or CT scans, to recover certain hidden texts, such as the inky insides of rolled papyri. These X-rays can visualize the text without damaging the manuscripts.




But the redactions in the Marie Antoinette letters are a different sort of beast. The censor scratched out lines using the same ink as the original writing, creating a black tangle of superimposed ink. The two inks did not have enough chemical contrast for CT scans to detect the underlying text. The researchers brainstormed potential techniques that could break through the censorship; all but one failed to illuminate the redactions.

The method that prevailed was X-ray fluorescence spectroscopy, or XRF, which differentiated the chemical signature of the ink used by the original author and the ink used by the censor. The initial XRF scans revealed that both texts had been etched with metal-gall ink, a common ink made with iron sulfate. “But the iron sulfate is not pure most of the time,” Michelin said. “It contains other metallic elements, like copper and zinc. With that slight difference, we can differentiate the inks.”

In some letters, copper was present only in the original ink, so isolating the element on its own would remove the censor. “So just with the map of the copper, I can read the text,” Michelin said.

Other letters proved trickier. With no single elemental smoking gun, the researchers mapped the ratios of certain elements, such as copper-to-iron, to distinguish between the inks and to reveal the text. And more letters still evaded deciphering entirely, as the original and redacting inks were too similar in composition to be separated.

The ink scans may also have uncloaked the true identity of the redactor: not the grandnephew, de Klinckowström, but von Fersen himself. The scans showed that the count started using the same ink to write and redact after 1791. In one letter, the count redacted a line and added text above it in the same ink to ensure the line would still be readable, changing “the letter of the 28th made my happiness” to the milder “the letter of the 28th reached me.” A handwriting expert confirmed the tweak came from the count himself.

The team ultimately undid the censorship of eight of the 15 total letters, revealing sentimental displays of affection between the French queen and the Swedish count: words like “beloved,” “tender friend,” “adore” and “madly.”

“Very clearly, Marie Antoinette has a very deep affection for von Fersen, who at this stage of her existence is one of the pillars of her affection,” Seth said.

But Seth says these moonstruck effusions are not proof of a love affair. She compared them to the kissy-face emoji.

“You might use it to mean ‘bye’ to a friend, and yet someone who doesn’t know about our emoji culture will assume you must be deeply in love,” she said.

Besides, the count was a busy man.

“He’s still having an affair with another woman at the time,” Seth added.

Before starting the project, Michelin was not familiar with the rumored relationship between von Fersen and Marie Antoinette. Though she now has more compassion for the maligned queen, she is somewhat uninterested in the rumors.

“All the queens and all the kings in France had this love affair,” she said dryly over a Zoom call. “It’s common.”

This article originally appeared in The New York Times.