heat of passion vs irascibility

heat of passion

noun
  • An outburst of anger that leads one to commit a criminal act, and is itself influenced by preceding events that might cause a reasonable person to lose self control. 

irascibility

noun
  • The quality of being irascible; irritability of temper. 

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