PARIS (Reuters) - A French schoolboy has dug up a glass jar containing severed human fingers preserved in alcohol which police believe may belong to a local carpenter who lost four digits in an accident 30 years ago. The boy, aged seven, made the gruesome discovery on Monday when he was playing behind the gymnasium of his school in Chilly-Mazarin, just south of Paris, and noticed a jar poking out of the earth, a police spokeswoman said. He dug out the liquid-filled jar and saw the partially decomposed fingers inside. With time the jar must have risen to the surface and the fingers were found in well-preserved condition, the police spokeswoman said.