interpose vs unite

interpose

verb
  • To insert something (or oneself) between other things. 

  • To interrupt a conversation by introducing a different subject or making a comment. 

  • To intervene in a dispute, or in a conversation. 

  • To be inserted between parts or things; to come between. 

  • To offer (one's help or services). 

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