allay vs touch off

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. 

touch off

verb
  • To start; to cause, especially used for unstable situations that may magnify if disturbed. 

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