insulate vs unite

insulate

verb
  • To separate a body or material from others, e.g. by non-conductors to prevent the transfer of electricity, heat, etc. 

  • To separate, detach, or isolate. 

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 insulate and unite occurred in a corpus of books? (source: Google Ngram Viewer )