housse of slytherin
in the first book it references how dark wizards come from slytherin. Do those wizards and witches come only from that house when at hogwarts, does ne one think a gryffindor or hufflepuff would practice the dark arts??? I also realize that their are other schools such as Durmstrang that have probably produced dark wizards in the past, so its possible that their have been dark wizards from the other houses, isn't it?