cognoscible vs luminous

cognoscible

adj
  • Capable of being known. 

  • Liable to judicial investigation. 

luminous

adj
  • Clear; enlightening; easy to understand. 

  • Brightly illuminated. 

  • Emitting light; glowing brightly; shining. 

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