The reunion of two Edouard Manet masterpieces at a Swiss exhibition has shed light on one of the most enduring mysteries about the artist.
The paintings, Au café and Coin de café-concert, started off life on the same canvas, but Manet decided to cut the picture in half to create two separate works.
Art lovers were baffled for years about what the artist originally intended to create, until the paintings were brought together at the Manet meets Manet exhibition at the Oskar Reinhart collection in the town of Winterthur.
This is the first time they have been shown together in 125 years.
Both paintings depict figures seated around opposite sides of a table in a café. The canvas was cut in half when the artist revised his original plan.
Experts Juliet Wilson-Bareau and Malcolm Park were able to peer beneath the paint at the underlying sketches by x-raying each canvas and bringing both frames together for the first time.
They discovered that Manet had intended to paint a singer in the background entertaining the café customers in the original painting, which he was going to call Reichshoffen.
The find was made possible when the National Gallery in London agreed to loan Coin de café-concert to the Oskar Reinhart collection, which already houses Au café at the Am Römerholz villa overlooking Winterthur.
The exhibition runs until January 29, allowing art lovers to view both paintings together for the first time since they were last shown side by side in 1880 in Marseilles.
Curator Mariantonia Reinhard-Felice told swissinfo that the project neatly sidestepped a problem of getting paintings on loan.
"Oskar Reinhart stated in his will that none of the paintings in the collection were to be loaned out to other galleries," she said. "This makes it difficult to get paintings loaned to us."
"By carrying out this research we were able to share our exciting findings about the paintings with the National Gallery, which benefits us both."
Researchers also uncovered a previously unknown 1877 article from the London periodical The Architect which describes the original Reichshoffen painting before it was cut up, confirming the evidence uncovered by the x-rays.
Also on display at the exhibition is a tambourine, painted by Manet, depicting a singer that experts believe was the image the artist intended to paint in Reichshoffen.
Another discovery was a document from 1875 that confirms for the first time the existence and location in Montmartre, Paris, of the Reichshoffen café. This is believed to be the café that inspired Manet's original work, which bears a nearly identical name.
Many of Manet's working sketches for the painting have also been collected at Am Römerholz together with documents revealing how the artist was involved in the intensely political café scene of the time.
The exhibition is the first of its type at the Oskar Reinhart collection, and there are plans to stage similar events at Am Römerholz.
The permanent Oskar Reinhart collection at Am Römerholz contains 200 works from the likes of Goya, Cézanne, Constable, Courbet, Monet, Degas, Renoir, van Gogh and Picasso.
swissinfo, Matthew Allen
Oskar Reinhart was born in Winterthur in 1885 and bequeathed part of his impressive art collection and his Am Römerholz villa to the Swiss public on his death in 1965.
Reinhart bought Manet's Au café painting in 1953.
Au café and its sister painting Coin de cafè-concert have been brought together at Am Römerholz for the first time since 1880.