What was the nationality of the novelist whose eighteenth novel was published in 1976? 
Henry and Cato:  Published in 1976, it was her eighteenth novel. Iris Murdoch: Dame Jean Iris Murdoch ( ; 15 July 1919 – 8 February 1999) was an Anglo-Irish novelist and philosopher, best known for her novels about good and evil, sexual relationships, morality, and the power of the unconscious.
i don't know