derived vs firsthand

derived

adj
  • A product of derivation 

  • Of, or pertaining to, conditions unique to the descendant species of a clade, and not found in earlier ancestral species. 

firsthand

adj
  • Not previously owned or used; contrasted with secondhand. 

  • Direct, without intermediate stages. 

adv
  • Directly or from personal experience. 

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