Art: Sounding the Unplucked String

In Washington, the glowing, meticulous paintings of Watteau

Some exhibitions seem to be beyond full criticism. They redefine their subject, the image of an artist, for a generation, and do it with the utmost sympathy and scholarly passion. The presentation of paintings and drawings of Antoine Watteau that opened last month at the National Gallery in Washington, and will be seen (with various additions and subtractions) at the Grand Palais in Paris during the winter and in Berlin through the spring of 1985, is such an event. So much of the work is fragile,...