STOCKHOLM.- At an ordinary public auction this past April, Nationalmuseum purchased a magnificent terracotta sculpture by French artist Claude Michel, known as Clodion. The piece, thought to date from the 1780s, depicts a satyr embracing a young nymph. Clodions superb attention to detail and perfect balancing of the two figures makes this one of his most significant works. Claude Michel, known as Clodion, was two years the senior and a colleague of the Swedish sculptor Johan Tobias Sergel during his time in Rome. Clodion never completely abandoned the graceful rococo style. Not surprisingly, he was popular with collectors, but he was never elected to the Académie in his native France. The terracotta sculpture of a satyr embracing a nymph, purchased by Nationalmuseum at a public auction held by Stockholms Auktionsverk in April, typifies Clodions work in many respects. This piece, which probably dates from the