demonstration vs obscurity

demonstration

noun
  • A public display of group opinion, such as a protest march. 

  • A proof. 

  • Expression of one's feelings by outward signs. 

  • The act of demonstrating; showing or explaining something. 

  • A prisoner's act of beating up another prisoner. 

  • An event at which something will be demonstrated. 

  • A show of military force. 

obscurity

noun
  • The state of being unknown; a thing that is unknown. 

  • The quality of being difficult to understand; a thing that is difficult to understand. 

  • Darkness; the absence of light. 

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