ichor vs vital fluid

ichor

noun
  • A blood-like fluid. 

  • The blood of human beings or animals; also (obsolete) the clear, fluid portion of blood; blood plasma, plasma. 

  • The liquid said to flow in place of blood in the veins of the gods. 

vital fluid

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