expatiate vs talk to oneself

expatiate

verb
  • To write or speak at length; to be copious in argument or discussion. 

  • To range at large, or without restraint. 

talk to oneself

verb
  • To say one's thoughts aloud, particularly while also not conversing with anyone else. 

How often have the words expatiate and talk to oneself occurred in a corpus of books? (source: Google Ngram Viewer )