diffuseness vs superfluity

diffuseness

noun
  • The state or quality of being diffuse. 

  • The result or product of being diffuse. 

superfluity

noun
  • The quality or state of being superfluous; overflowingness. 

  • Something superfluous, as a luxury. 

  • Collective noun for a group of nuns. 

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