Art: Momentous Diptych

Two little pieces of canvas slightly bigger than a man's shirtfront last week raised the entire Metropolitan Museum of Art high in the list of the world's repositories. Bursting with pride Director Herbert Eustis Winlock placed on exhibition the most important purchase the museum has ever made out of its own funds, two panels joined together by hinges, bought after four years of stealthy negotiation from the Soviet Government: "The Crucifixion" and the "Last Judgement," generally attributed to Hubert van Eyck. Belittlers have insisted that the small panels (each 22¼ by 7¾ in.)...