madcap vs quicksilver

madcap

adj
  • Hasty, impulsive, or reckless; capricious. 

noun
  • An impulsive, hasty, capricious person. 

quicksilver

adj
  • Unpredictable, erratic or fickle; mercurial. 

noun
  • The metal mercury. 

  • An amalgam of mercury and tin applied to the backs of mirrors, quicksilvering. 

verb
  • To overlay with quicksilver. 

  • To treat with quicksilver. 

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