quicksilver vs varying

quicksilver

noun
  • The metal mercury. 

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

adj
  • Unpredictable, erratic or fickle; mercurial. 

verb
  • To overlay with quicksilver. 

  • To treat with quicksilver. 

varying

noun
  • A kind of variable, used by a fragment shader, that interpolates values across a primitive, so as to produce gradient effects etc. 

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