hellfire vs purgatory

hellfire

intj
  • hell; damn; blast 

adj
  • Of or relating to a violent, apocalyptic and ultimate day of reckoning and judgment; usually characterizing a form of Christian preaching. 

noun
  • The fire of Hell. 

  • Fire produced by the Devil, or a similar supernatural creature connected to Hell. 

  • A fire that burns with unusual heat or ferocity. 

purgatory

noun
  • Any situation where suffering is endured, particularly as part of a process of redemption. 

adj
  • Tending to cleanse; expiatory. 

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