excite vs instigate

excite

verb
  • To arouse or bring out (e.g. feelings); to stimulate. 

  • To cause an electron to move to a higher than normal state; to promote an electron to an outer level. 

  • To energize (an electromagnet); to produce a magnetic field in. 

  • To stir the emotions of. 

instigate

verb
  • to incite; to bring about by urging or encouraging 

  • to goad or urge (a person) forward, especially to wicked actions; to provoke 

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