appetite vs fervor

appetite

noun
  • Any strong desire; an eagerness or longing. 

  • Desire to eat food or consume drink. 

  • The desire for some personal gratification, either of the body or of the mind. 

fervor

noun
  • An intense, heated emotion; passion, ardor. 

  • Heat. 

  • A passionate enthusiasm for some cause. 

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