Rembrandt “Danae” / acid, knife
(In 1985, a museum visitor attacked the painting, slashing the canvas twice with a knife before splashing it with sulfuric acid. The entire central part of the composition was reduced to a “dark, bubbling, foul-smelling mass that trickled down to the bottom of the the frame and from there onto the floor.” The man was later judged legally insane. The damage was restored over the course of the next twelve years, and the painting was returned to public viewing in 1997.)