dampen vs encourage

dampen

verb
  • To lessen; to dull; to make less intense (said of emotions and non-physical things). 

  • To become damped or deadened. 

  • To become damp or moist. 

  • To make damp or moist; to make moderately wet. 

encourage

verb
  • To mentally support; to motivate, give courage, hope or spirit. 

  • To spur on, strongly recommend. 

  • To foster, give help or patronage 

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