acetosity vs indignation

acetosity

noun
  • The quality of being acetous; sourness. 

indignation

noun
  • A self-righteous anger or disgust. 

  • An anger aroused by something perceived as an indignity, notably an offense or injustice. 

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