quicksilver vs tranquil

quicksilver

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. 

adj
  • Unpredictable, erratic or fickle; mercurial. 

tranquil

adj
  • Calm; without motion or sound. 

  • Free from emotional or mental disturbance. 

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