Mr. George, who has been looking first at one of them and then at the other, as if he were demented, takes his venerable acquaintance by the throat on receiving this request, and dragging him upright in his chair as easily as if he were a doll, appears in two minds whether or no to shake all future power of cushioning out of him and shake him into his grave.
There are no more uses of "demented" in the book.
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Stay away from her. She’s dangerous and demented.
Some demented killer has declared open season on people in nice cars.