black art vs prestidigitation

black art

noun
  • A practice such as witchcraft, sorcery, necromancy, or black magic. 

  • A process that is mysterious or difficult to master. 

prestidigitation

noun
  • A performance of or skill in performing magic or conjuring tricks with the hands. 

  • A show of skill or deceitful cleverness. 

How often have the words black art and prestidigitation occurred in a corpus of books? (source: Google Ngram Viewer )