LONDON.- One of the gems of Catherine the Great’s collection, a small painting by Adam Pynacker, which was and never left the Hermitage palace since the day she bought it in 1772, has just arrived in London at the Dulwich Picture Gallery. The little panel by the Dutch artist, of a shimmering light-drenched sweep of Italian water, was jealously guarded. It has never been loaned before, even to exhibitions in Russia, and is known in the west only from reproductions. It is painted on a panel, which makes it particularly fragile. In Russia it is displayed sealed into in a specially built air-conditioned glass case.

Irina Sokolova, curator at the St Petersburg museum, who came to London with the painting which she calls "the pearl of the Hermitage collection", said they agonized before deciding to lend it to the exhibition "Inspired by Italy: Dutch Landscape Painting 1600 - 1700" - an art movement of which this painting is regarded as the outstanding work. The exhibition charts the delirium of the artists from the flat wet countryside and heavy gray skies of Holland, when they discovered the light and color of Italy. There was a craze for the paintings, and so many went straight into royal and aristocratic collections that few remain in Holland. This view, painted in 1655, was acquired by a great French collector, and was acquired from his heirs by Catherine, a voracious art collector. Dr. Sokolova believes it may depict the outskirts of Venice, where Pynacker is known to have stayed and worked around 1655. The exhibition of Italianate Dutch landscapes has just opened and runs until the end of August at the Dulwich Picture Gallery.