disperse vs unite

disperse

verb
  • To disseminate. 

  • To break up and disappear; to dissipate. 

  • To scatter in different directions. 

  • To separate rays of light, etc., according to wavelength; to refract. 

  • To distribute throughout. 

adj
  • Scattered or spread out. 

unite

verb
  • To bring together as one. 

  • To come together as one. 

noun
  • A British gold coin worth 20 shillings, first produced during the reign of King James I, and bearing a legend indicating the king's intention of uniting the kingdoms of England and Scotland. 

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