It is an impression of light, movement, dust and death, without pathos. Most surprising to the nonspecialist is the extraordinary difference that could separate drawings in different techniques by the same artist. Pier Francesco Mola's ''Expulsion from Eden'' is a semi-abstract evocation in blobs and streaks of dark brown wash. Nor does the cartoon have much in common with the painting in the Quirinal Palace in Rome. Somehow, the minute the painters took up their brushes, the Baroque draftsmen's freedom vanished, uniformity crept in.
Few exhibitions say as much about the complexities of art history in such enchanting fashion.
This is the perfect teaching show with the lightest possible touch, thanks to the labels written by Hugo Chapman in highly readable form. You want to spend hours, notebook in hand, catching glimpses of cultural history and art as first thought up by its creators, in one of the best-designed prints and drawings cabinets where the lighting is perfect, the display always convenient. They talk a lot about giving full ''access'' to the public in museums. This is it, without demagoguery or Mickey Mouse vulgarity. Fewer and fewer institutions know how to do it.