effervescence vs unhappiness

effervescence

noun
  • Vivacity. 

  • The escape of gas from solution in a liquid, especially the escape of carbon dioxide from a carbonated drink. 

  • Foment. 

unhappiness

noun
  • The feeling of not being happy 

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