effusion vs emission

effusion

noun
  • A liquid outpouring. 

  • Process of gases passing through a hole or holes considerably smaller than the mean free path of the gas molecules. 

  • An outpouring of speech or emotion. 

  • The seeping of fluid into a body cavity; the fluid itself. 

emission

noun
  • The act of emitting; the act of sending forth or putting into circulation. 

  • A show; a program. 

  • Something which is emitted or sent out; issue. 

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