ardency vs warmth

ardency

noun
  • Intensity of feelings. 

  • Intensity of devotion. 

  • Intensity of light. 

  • Intensity of heat or burning. 

warmth

noun
  • Fervor, intensity of emotion or expression. 

  • Friendliness, kindness or affection. 

  • A moderate degree of heat; the sensation of being warm. 

  • The effect of using mostly red and yellow hues. 

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