effervescence vs pessimism

effervescence

noun
  • Vivacity. 

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

  • Foment. 

pessimism

noun
  • A general belief that bad things will happen. 

  • The condition of being pessimal. 

  • The doctrine that this world is the worst of all possible worlds. 

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