There was much hidden away at the time of the Revolution, sayss S.Ananthanarayanan.

Records of the colourful 18th Century French court and nobility were hastily painted over to avoid scrutiny during the Revolution. And rightly so, it appears, from what analysis reveals.

The AAAS journal, Science Advances, carries a paper by Anne Michelin, Fabien Pottier and Christine Andraud, from the Centre of Conservation Research, Sorbonne, which describes how secret correspondence of Marie Antoinette, queen of France, which was over-written, has been recovered. And the journal, Heritage Science carries a paper by Silvia A. Centeno, Dorothy Mahon, Federico Carò and David Pullins, from the Metropolitan Museum of Art, New York, which shows that a portrait of the scientist Antoine Lavoisier, and his wife, Marie Anne, was altered, to make it look more secular!

Marie Antoinette, daughter of the Emperor of Austria, married the crown prince of France in 1770, when she was 14. Four years later, when her husband ascended as Louis XVI, she became Queen of France, and was queen till monarchy was abolished in 1792. Popular sentiment was already incensed by the excesses of French aristocracy, and Marie Antoinette made it positively worse. Her lavish lifestyle, reputation of affairs and immorality, opposition to social reforms, and suspicions of allegiance to the Austrian state, made her an obvious target of the Revolution. The plan of the royal couple to flee was aborted, they were imprisoned, and finally sentenced to the guillotine.

But during the troubled period, Marie Antoinette managed a secret correspondence with the Swedish diplomat, Count Alex Von Fersen, a close friend and believed to be a lover. The letters exchanged, which are now with the French National Archives, contains sections which look like they were over-written by a censor. What lies beneath the changes, why changes were made, has puzzled historians for the last 150 years, the Science Advances paper says.

Recovering obscured graphical content of historical documents is part of cultural historical research. Modern techniques, mostly using different kinds of radiation, which do not damage the fragile and limited historical samples, have often been successful. X-Ray fluorescence, absorption or reflection of infra-red or longer wave radiation, thermal imaging, are modern methods that can reveal concealed or degraded contents of documents. So far, the paper says, these methods have been used mainly to extract the text in rolled or folded, but brittle papyri or parchment, and documents, even, for instance Luigi Cherubini’s 1797 musical score, in a sheet blacked out by the composer, the paper says.

The Antoinette-Fersen letters present a similar challenge, in the sense that the task is to entangle the visible text from something that is hidden. While the hidden text has not been erased, the paper says, the edited version is placed exactly over the older text and the ink used is dark and opaque. A brace of methods was hence tried out, microscopy, spectroscopy, thermal imaging – and x-ray fluorescence, which, the paper says, was found to work.

The inks used had left deposits of sulphur, potassium, manganese, iron, copper and zinc. And differences in the proportions of these components of the original writing and the over-writing should help tell them apart. When x-rays fall on some elements, atoms absorb x-rays of specific frequencies and re-emit light, again of specific colours. This property, of fluorescence, using different frequencies of x-rays, hence enables identification and estimation of elements.

While this could be straightforward if there were clear difference in the proportions, this was generally not the case with the Antoinette letters. Where an element in the original writing was also there in the overlay, but in greater quantity, the overlay could conceal the original. Data of several components of the samples, physical and chemical, was hence acquired and analysed statistically. This often became intractable and the number of components had to be kept down, to what is known as ‘principle components’. And with complex analysis, the originals of 8 of the 15 altered

Antoine Lavoisier

The paper in Heritage Science describes a similar exercise, carried out on a celebrated portrait, completed in 1788, just before the Revolution. The painting, by Jacques-Louis David, who may be the most important painter of the period, is of Antoine Lavoisier and his wife, Marie-Anne Paulze. Lavoisier was a renowned scientist, who identified oxygen, discovered the nature of combustion, and created methods of experimental science. And his partner and supporter in his work was his wife, Marie Anne.

Lavoisier was also a nobleman, a land owner’s son. And apart from his interest in science and public affairs, where he made important contribution, he was a part of the ‘Ancien Regime’, the aristocracy that was overthrown in the French Revolution. He is known to have benefitted from Ferme Génerale, an organisation that undertook tax collection for the state, and kept a part of the collection as remuneration. This association marked him as an oppressor of common people, and his eminence in science or his public work could not save him from the guillotine.

In the portrait, however, the couple are depicted as progressive, rational people engaged in scientific pursuit, quite unlike the rich and privileged ruling class of the time. The simplicity of Marie-Anne’s gown, the practical sash and sleeve, Lavoisier with a pen in hand, scientific apparatus on the table, the evident collaboration of the couple, “has come to epitomize a modern couple born of the Enlightenment,” says the paper in Heritage Science.

Soon after its completion, the painting was to be presented at a salon, in 1789. But it was withdrawn, and the reason was that it was thought politically not suitable to be shown, as it may have heightened the rising resentment of aristocracy. And it remained under wraps for a century, till the Exposition Universelle, in 1889. The painting was finally acquired by the Metropolitan Museum of Art, New York, in 1977, and has been seen as a showpiece of the art of its period.

Till, in 2019, that the painting was moved to the Museum’s conservation lab for attention to a coat of varnish that protects the paint. And during this process, it was noticed that the paint seemed to cover another composition. The painting was hence examined by infra-red reflectography, and then with x-ray fluorescence, which revealed what the authors of the paper call,” an entirely unknown version.” The original version, which was perhaps what was to be shown in 1789, was of the couple in near regal splendour – the lady in a bright coloured hat with ribbons and a sprig of flowers. And the gentleman in breeches that were the height of fashion, a red cloak that came down to his knees, and no sign of scientific apparatus!

The composition was understandably seen as a projection of the decadence of the oppressor regime, and was rightly withdrawn from display. And the painting may have been worked over by Jacques-Louis David, who later prospered under the French Republic.

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