permeation vs suffusion

permeation

noun
  • The movement of a fluid through a porous or permeable solid. 

  • The spreading of something (especially something malignant) through the body via blood vessels etc. 

suffusion

noun
  • The act of pouring a liquid over or soaking something. 

  • coat, coating, film, plating. 

  • The state of becoming red on the surface. 

  • The state of being wet. 

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