demonology

from The Collaborative International Dictionary of English v.0.48

Demonology \De`mon*ol"o*gy\ (?; 277), n. [Demon + -logy: cf. F.
   d['e]monologie.]
   A treatise on demons; a supposititious science which treats
   of demons and their manifestations. --Sir W. Scott.
   [1913 Webster]