fitful vs quicksilver

fitful

adj
  • Characterized by sudden bursts of activity with periods of inactivity in between; intermittent, irregular, unsteady. 

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 fitful and quicksilver occurred in a corpus of books? (source: Google Ngram Viewer )