Leo Naphta commits suicide after Ludovico  Settembrini refuses to shoot at him in a duel.
Mynheer Peeperkorn kills himself after he learns that he is  becoming impotent. Leo Naphta commits suicide after Ludovico  Settembrini refuses to shoot at him in a duel. Joachim Ziemssen  simply dies of tuberculosis, and Hans Castorp marches off to die in  World War I. These are among the patients at the International  Sanitarium Berghof, in FTP, what novel by Thomas Mann?
Mynheer Peeperkorn kills himself after he learns that he is  becoming impotent.
The {Magic Mountain} or Der {Zauberberg}