Jack Ketch vs eternal sleep

Jack Ketch

noun
  • the gallows 

  • death 

  • a public executioner 

  • the devil 

eternal sleep

noun
  • Death 

  • A magical state of suspended animation, a state of ageless, deathless, everlasting sleep. Well-known examples are Endymion, (the lover of the Greek moon goddess, Selene), and the princess from Sleeping Beauty. 

How often have the words Jack Ketch and eternal sleep occurred in a corpus of books? (source: Google Ngram Viewer )