De Praetistigiis
 The book also contains a famous appendix also circulated independently as the Pseudomonarchia daemonum, a listing of the names and titles of infernal spirits, and the powers alleged to be wielded by each of them. Weyer relates that his source for this intelligence was a book called Liber officiorum spirituum, seu liber dictus Empto Salomonis, de principibus et regibus demoniorum ("The book of the offices of spirits, or the book called Empto, by Solomon, about the princes and kings of demons.) Weyer's reason for presenting this material was not to instruct his readers in diabolism, but rather to "expose to all men" the pretensions of those who claimed to be able to work magic, men who "are not embarrassed to boast that they are mages, and their oddness, deceptions, vanity, folly, fakery, madness, absence of mind, and obvious lies, to put their hallucinations into the bright light of day." Weyer's source alleged there were estimated to be 7,451,926 devils, divided into 1111 legions and obeying 72 infernal princes. Weyer's source claimed that Hell arranged itself hierarchically in an infernal court which is divided into princes, ministries and ambassadors.