purpural vs purpuric

purpural

adj
  • Synonym of purpuric 

purpuric

adj
  • Derived from or forming purpuric acid. 

  • purple in colour; derived from or forming a substance which is purple; especially 

  • Pertaining to or affected with purpura (skin discoloration from blood inside it). 

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