admix vs mongrelize

admix

verb
  • To mingle with something else; to mix. 

noun
  • The mixture that results from admixing, especially an alloy. 

  • The act of admixing. 

mongrelize

verb
  • To cross-breed 

  • To breed a mongrel 

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