acerbate vs get someone's Irish up

acerbate

verb
  • To make bitter or sour. 

  • To exasperate; to irritate. 

adj
  • Embittered; having a sour disposition or nature. 

get someone's Irish up

verb
  • To anger or annoy someone. 

How often have the words acerbate and get someone's Irish up occurred in a corpus of books? (source: Google Ngram Viewer )