Margareta Snyders (Born de Vos)

In 1910 Henry Clay Frick, the Pittsburgh steel magnate, lent pictures from his collection to the Museum of Fine Arts, and the exhibition drew crowds and wide attention in the press. Among the loans were van Dyck's pair of portraits of the Antwerp animal painter Frans Snyders and his wife Margareta, born de Vos. The pair went back to New York, where they still hang in Frick's house.

In 1931 the museum bought a picture of its own, a canvas about half a metre high showing Margareta's head and shoulders in the same pose. The press greeted it as the original sketch for the portrait Boston had admired 21 years earlier. It came from Sudbury Hall in Derbyshire, where the Vernon family had kept it through four generations of barons, and it cost $19,500.

That confidence has thinned since. The museum now catalogues the study as attributed to van Dyck and gives it no date.