patchy vs quicksilver

patchy

adj
  • Not constant or continuous; intermittent or uneven. 

  • Full of, or covered with, patches; abounding in patches. 

quicksilver

adj
  • Unpredictable, erratic or fickle; mercurial. 

verb
  • To overlay with quicksilver. 

  • To treat with quicksilver. 

noun
  • The metal mercury. 

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

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