The lost Leonardo

On Nov. 9, London’s National Gallery will open a highly anticipated exhibition, “Leonardo da Vinci: Painter at the Court of Milan.” While Leonardo shows are reliable blockbusters, this one will have a particular appeal because it will feature what many believe to be a “lost” Leonardo painting.

“Salvator Mundi” (Savior of the World) shows a distinctly spooky half-length image of Christ against an amorphous dark background. His features are slightly ghosted, an effect called sfumato that Leonardo brought to the fore, in which a dry brush is swept over nearly dry paint in order to gently blur lines and meld colors. Christ has ginger-tinged ringlets, a cleft chin, bee-stung lips and slightly protruding dark eyes, lightly red and moist, as if he has just been crying. His garment, of loose blue cloth with delicate strips of decorative embroidery, and a gemstone over his sternum are handled in a more precise manner. With his raised right hand he gestures in benediction, while his left hand cups a transparent orb, symbolizing the world.

But is it by Leonardo?

In art history, “lost” is a term applied to works that have been destroyed, stolen or misattributed. Occasionally, a lost work surfaces seemingly from nowhere. More often, works are lost in plain sight. In 1993, Caravaggio’s “Taking of Christ” was discovered hanging in a dark corner of a Jesuit seminary in Dublin, grimy with age and long thought a copy rather than the original it proved to be.

Only a few scholars have had access to “Salvator Mundi” so far, but it looks good from photographs. The quality of the work is clear, and stylistically, it could be a lost Leonardo. But Leonardo was so famous during his lifetime that flocks of artists, from his own circle and elsewhere, sought to imitate his style. (An excellent 16th century copy of the “Mona Lisa” was boxed up and shipped around southern France during World War II, leading the Nazis on a wild goose chase. They finally seized their prize, unaware that the real thing, hidden by Louvre staff, never left Paris.)

Five decades ago, “Salvator Mundi” was just another more or less excellent “school of” artwork. It sold for the equivalent of about $125 in 1958. If the new attribution holds up, however, its worth might be as high as $200 million, a record. What did the art world see in 2011 that it missed in 1958? How does one go about establishing authenticity?

The first step is almost inevitably connoisseurship, the exceptional expertise of scholars who spend their lives studying the work of a master and have an almost innate sense for whether a work looks right or wrong. As Martin Kemp, the world’s leading Leonardo expert, told the Daily Telegraph after seeing “Salvator Mundi,” “Once you walked into the room, it had the uncanny presence that Leonardos have.”

Kemp is one of a handful of international scholars, including the director of the restoration of Leonardo’s “Last Supper,” Pietro Marani, who have inspected the oil-on-wood painting since it was purchased in 2005. The buyers, an American consortium, apparently gambled that under centuries of grime and botched restoration efforts lay a masterpiece. “It was in a bad state, covered by old layers of paint,” Marani told the Telegraph. “During the restoration, the quality of the painting emerged.”

Such testimony alone, however, won’t authenticate art in the 21st century — and connoisseurs themselves aren’t likely to weigh in without backup from objective evidence.

Provenance — the documented history of an object — is one of the best ways to determine that a work is what it purports to be.

In the case of “Salvator Mundi,” estimated to have been painted around 1500, the ownership history can be dated back to Britain’s King Charles I; the painting is mentioned as being in his collection in 1649. In 1763 it was bought at auction by the son of the Duke of Buckingham. The painting’s history is unknown between 1763 and 1900. It was acquired by British art collector Frederick Cook in 1900. It was Cook’s descendant who sold it at auction in 1958 for only £45 (about $125 at the then-exchange rate); at the time it was considered to be by a pupil of Leonardo’s, Giovanni Antonio Boltraffio. A representative of the current owners says it was part of an American collection through the 20th century.

The problem with provenance is that it relies on a chain of historical documents that rarely survives the centuries. Could you locate the receipt from the last mattress you bought? And with legitimate, known-quantity works sometimes having no provenance to speak of, the system is still a porous one. In the case of the Leonardo, the provenance primarily shows that the work had a long ownership history, and therefore cannot be a modern fake, and that it had been attributed to Leonardo in past centuries.

The newest approach to authentication is scientific analysis. Developed largely as a response to early 20th century Van Gogh forgeries, forensic investigations can examine the age of organic materials such as wood or canvas and the chemical composition of paints, and the results can be compared with undisputed Leonardos. With infrared,

ultraviolet and X-ray technology in an ever-growing scientific arsenal, science can rarely prove a specific attribution, but it can eliminate the possibility that the work was faked. Because the examination of “Salvator Mundi” showed that the pigments look right for Leonardo and that the wood it’s painted on dates to the correct era, it could be by Leonardo, but that does not necessarily mean that it is by Leonardo.

Many art forgers come from a background in conservation and therefore know the tests their forgeries will need to overcome. There are examples of faked ancient Chinese pottery that forgers injected with a radioactive isotope so that carbon dating would be fooled.

Which brings us back to where we started: Is “Salvator Mundi” by Leonardo? The decision by the august National Gallery to display the painting in its Leonardo show is something of a seal of approval. But even the museum has hedged its bet, telling the media: “This will obviously be the moment to test this important new attribution by direct comparison with works universally accepted as Leonardo’s.”

In the end, the treasure hunt requires that all the evidence line up: the scientific, the historical and the visceral reactions of connoisseurs. One more challenge will follow: the test of time.

Noah Charney is a founder and president of the Italian-based Assn. for Research into Crimes Against Art. He writes The Secret History of Art for ARTINFO.com. His latest book is “The Thefts of the Mona Lisa: On Stealing the World’s Most Famous Painting.”