leach vs percolate

leach

verb
  • To purge a soluble matter out of something by the action of a percolating fluid. 

  • To part with soluble constituents by percolation. 

noun
  • A tub or vat for leaching ashes, bark, etc. 

  • A jelly-like sweetmeat popular in the fifteenth century. 

  • A quantity of wood ashes, through which water passes, and thus imbibes the alkali. 

percolate

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

  • To make (coffee) in a percolator. 

  • To drain or seep through a porous substance. 

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

noun
  • A liquid that has been percolated. 

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