coagulate vs vitrify

coagulate

verb
  • To become congealed; to convert from a liquid to a semisolid mass. 

  • To cause to congeal. 

noun
  • A mass formed by means of coagulation. 

vitrify

verb
  • To convert into glass or a glass-like substance by heat and fusion. 

  • To be converted into glass, especially through heat. 

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