brittleness vs impotence

brittleness

noun
  • The state of being brittle; aptness to break; fragility. 

  • The property by virtue of which a material is fractured without appreciable deformation by the application of load. 

impotence

noun
  • Powerlessness; incapacity. 

  • Inability to copulate or beget children; sterility, erectile dysfunction, etc. 

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