polymorphous vs unmixed

polymorphous

adj
  • Having, or occurring in, several distinct forms 

  • Crystallizing in two or more different forms; polymorphic 

  • Having, or assuming, a variety of forms, characters, or styles 

unmixed

adj
  • Pure, not mixed or combined. 

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