acidulous vs olfactory

acidulous

adj
  • Slightly sour; sub-acid; sourish. 

  • Sharp; caustic. 

  • Containing carbonic acid. 

olfactory

adj
  • Concerning the sense of smell. 

noun
  • The sense of smell. 

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