A patient wandered out of her room and ended up in an unused wing of the hospital. When the staff eventually found her, the cold dry conditions of the building had turned her dead body into soap. This is the permanent stain left behind on the top floor of the abandoned wing.
Suffragette, Mary Richardson walked into the National Gallery in 1914 and attacked the canvas with a meat cleaver protesting the arrest of Emmeline Pankhurst the day before. Richardson was sentenced to 6 months imprisonment, the maximum allowed for destruction of an artwork.