HENRY JAFFE, a gray-bearded man in a brown suit, stands in the center of a room full of ``Treasures From the Fitzwilliam Museum'' and tries to decide which will mean most to American viewers. He's entitled. Mr. Jaffe is director of the Fitzwilliam, considered one of the finest small museums in Europe, and road manager of the lustrous new show that opened here recently at the National Gallery. He nods at a small, lush Renoir, ``La Place Clichy,'' showing a red-haired woman in a Victorian bonnet, her head and shoulders as sharply focused as a close-up, the street crowd above her in soft focus as though seen through a rainy windowpane. He compares it to Renoir's larger ``Le Dejeuner des canotiers'': ``That's exactly the period (1880-81), but, of course, this is much smaller. It's the same superb quality, but we haven't got immense space; so we go for very high-quality things of a smaller size.''
From another portrait, this one painted by Joseph Derby Wright, the calm hazel eyes of the Hon. Richard Fitzwilliam (1745-1816) gaze out on this British exhibit. It was Richard, seventh Viscount Fitzwilliam of Merrion, who founded the museum with a handsome bequest to his alma mater, Cambridge University. The legacy included his art collection, library, and 90,000, to be used ``for the purpose of promoting the increase of learning and other great objects of that noble foundation.'' That phrase is the subtitle of the show.
The exhibit includes more than 160 objects from the Cambridge museum, ranging from an image of a reindeer, dating back to 12,000 BC and incised on limestone in France, to a 1919 drawing by Modigliani of a woman in a picture hat. In between are paintings by Rubens, Degas, Delacroix, Van Dyck, Hogarth, and Hals, as well as drawings by William Blake, Rembrandt, Tiepolo, and Puvis de Chavannes.
The highly eclectic collection also includes a smiling turquoise monkey ewer from 12th-century Persia; an amiable-looking black and gray jade horse, hoofs tucked under him, from 17th-century China; and a variety of rare coins, medals, decorative arts, and illuminated manuscripts. In a miniature of the Pentecost from a Book of Hours done about 1485, a dove hovers in a small rainbow halo above a wondering group of the Apostles and the Virgin Mary.
Amid all these riches, Mr. Jaffe wheels around toward a huge Titian painting and says, ``We do have a few larger pictures.'' In ``Tarquin and Lucretia,'' Tarquin threatens his blond victim with a dagger. ``That marvelous Titian ... ought to mean something for American viewers, because, if your National Gallery had started in the middle of the 19th century, you could have had that,'' Jaffe explains. ``It was offered, but you didn't have a National Gallery.''
He turns again, points toward a dramatic ``Stormy Landscape,'' by Diaz de la Pena, full of yellow and gray light. ``That's very stunning. We have a very, I think, restricted view of Diaz; then you suddenly see a great big furious storm like that, and it changes one's view of Diaz. It reminds everybody of El Greco [``View of Toledo''], but I don't think Diaz ever saw that. He arrived independently at it.''
Another turn: ``And then there's a much smaller painting,'' Jaffe says, stopping before Richard Parkes Bonington's ``Boccadasse, Genoa, with Monte Fasce in the Background,'' a luminous view of mountains, clouds, and bay. ``He was a very short-lived artist, who lived 26 years only, a genius. So many of his paintings have been overcleaned,... but this is in dazzling condition. A real pearl.''
The remaining objects in the show range from the ridiculous (a lavender hen-and-chickens tureen garnished with sunflowers from England, ca. 1755) to the sublime (Rembrandt's drawing, ``The Supper at Emmaus''). In this inspired depiction of Christ Jesus' appearance before his disciples after the Resurrection, Rembrandt shows the Master transformed into a being of light as he ``vanished out of their sight.''
``Treasures From the Fitzwilliam'' will be on view at the National Gallery's East Building through June 18 before starting a national tour that will take it to the Kimbell Art Museum in Fort Worth, Texas (July 15-Oct. 8); the National Academy of Design in New York (Nov. 5-Jan. 28, 1990); the High Museum of Art in Atlanta (Feb. 20-May 6, 1990); and the Los Angeles County Museum of Art (June 21-Sept. 9, 1990).