pierce vs put under a microscope

pierce

noun
  • A pierced earring. 

verb
  • To penetrate; to affect deeply. 

  • To get to the heart or crux of (a matter). 

  • To create a hole in the skin for the purpose of inserting jewelry. 

  • to break or interrupt abruptly 

  • To puncture; to break through. 

put under a microscope

How often have the words pierce and put under a microscope occurred in a corpus of books? (source: Google Ngram Viewer )