appetite vs longing

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. 

longing

noun
  • An earnest and deep, not greatly passionate, but rather melancholic desire. 

  • The buying of a financial instrument with the expectation that its value will rise 

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