lixiviate vs permeate

lixiviate

verb
  • To separate (a substance) into soluble and insoluble components through percolation; to leach. 

noun
  • leachate 

adj
  • Impregnated with salts from wood ashes. 

  • Of or relating to lye or lixivium; of the quality of alkaline salts. 

permeate

verb
  • To pass through the pores or interstices of; to penetrate and pass through without causing rupture or displacement; applied especially to fluids which pass through substances of loose texture 

  • To enter and spread through; to pervade. 

noun
  • Liquid that has passed through a filtration system. 

  • A watery by-product of milk production. 

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