allay vs mollify

allay

verb
  • To make quiet or put at rest; to pacify or appease; to quell; to calm. 

  • To alleviate; to abate; to mitigate. 

noun
  • Alleviation; abatement; check. 

mollify

verb
  • To ease a burden, particularly worry; make less painful; to comfort. 

  • To appease (anger), pacify, gain the good will of. 

  • To soften; to make tender 

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