causticity vs sweetness

causticity

noun
  • The quality of being physically caustic; burning, corrosive. 

  • Being caustic in speech, humour etc. 

sweetness

noun
  • A pleasant disposition; kindness. 

  • Term of address for one's sweetheart. 

  • The condition of being sweet or sugary. 

  • The quality of giving pleasure to the mind or senses, pleasantness, agreeableness. 

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