quicksilver vs shifting

quicksilver

verb
  • To overlay with quicksilver. 

  • To treat with quicksilver. 

adj
  • Unpredictable, erratic or fickle; mercurial. 

noun
  • The metal mercury. 

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

shifting

noun
  • The phenomenon by which two or more constituents appearing on the same side of their common head exchange positions to obtain non-canonical order. 

  • A shift or change; a shifting movement. 

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