liquefaction vs merging

liquefaction

noun
  • The liquid or semiliquid that results from this process. 

  • Process of being, or state of having been, made liquid (from either a solid or a gas) 

merging

noun
  • The act, or the result, of being merged. 

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