admixture vs immixture

admixture

noun
  • An instance of admixing, a mixing in of something. 

  • a mixture composed of entities retaining their individual properties. 

  • A mixing-in of a biologically or genetically differentiated group to an established stock. 

  • A mixture, in some contexts 

immixture

noun
  • The act, or the result of immixing 

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