calcify vs congeal

calcify

verb
  • To make something hard and stony by impregnating with calcium salts. 

  • To become hard and stony by impregnation with calcium salts. 

congeal

verb
  • To coagulate, make curdled or semi-solid such as gel or jelly. 

  • To change from a liquid to solid state, perhaps due to cold; called to freeze in nontechnical usage. 

  • To become congealed, solidify. 

  • To make rigid or immobile. 

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