acumen vs marbles

acumen

noun
  • Quickness of perception or discernment; penetration of mind; the faculty of nice discrimination. 

  • A bony, often sharp, protuberance, especially that of the ischium. 

  • A sharp, tapering point extending from a plant. 

marbles

noun
  • Sanity. 

  • Bits of rolled-up rubber shed by the tires of race cars that accumulate at the edges of the track, especially at the corners. 

  • Any of several children's games played with small balls (made of marble or more commonly glass). 

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