"There are no words to express the result" was the beaming reaction of Belgium's Royal Institute for Cultural Heritage, after a 15th-century masterpiece -- painted over shortly after completion -- was restored to its former glory. And they were right -- commentators have been left speechless by one particular aspect of the newly revealed painting. The latest panel of the "Ghent Altarpiece," a large work by Hubert and Jan van Eyck, was unveiled in December as part of an ongoing project to restore the painting to its original design. The painting -- also known as "The Adoration of the Mystic...