foment vs percolate

foment

verb
  • To apply a poultice to; to bathe with a cloth or sponge. 

  • To incite or cause troublesome acts; to encourage; to instigate. 

noun
  • Fomentation. 

percolate

verb
  • To drain or seep through a porous substance. 

  • To pass a liquid through a porous substance; to filter. 

  • To make (coffee) in a percolator. 

  • To spread slowly or gradually; to slowly become noticed or realised. 

noun
  • A liquid that has been percolated. 

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