caseation vs thickening

caseation

noun
  • A necrotic degeneration of tissue to a cheese-like condition. 

thickening

adj
  • Beginning to thicken, becoming thicker. 

noun
  • The process of making something, or becoming, thick or viscous. 

  • A thickened part of a structure. 

  • A substance, usually a source of starch, used to thicken a sauce. 

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