collect vs concentrate

collect

verb
  • To come together in a group or mass. 

  • To get; particularly, get from someone. 

  • To infer; to conclude. 

  • To accumulate (a number of similar or related objects), particularly for a hobby or recreation. 

  • To gather together; amass. 

  • To collect payments. 

  • To collide with or crash into (another vehicle or obstacle). 

adj
  • To be paid for by the recipient, as a telephone call or a shipment. 

noun
  • The prayer said before the reading of the epistle lesson, especially one found in a prayerbook, as with the Book of Common Prayer. 

adv
  • With payment due from the recipient. 

concentrate

verb
  • To bring to, or direct toward, a common center; to unite more closely; to gather into one body, mass, or force. 

  • To focus one's thought or attention (on). 

  • To approach or meet in a common center; to consolidate. 

  • To increase the strength and diminish the bulk of, as of a liquid or an ore; to intensify, by getting rid of useless material; to condense. 

noun
  • A substance that is in a condensed form. 

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