cognac vs libation

cognac

noun
  • A brandy distilled from white wine in the region around Cognac in France. 

libation

noun
  • The wine or liquid thus poured out. 

  • A beverage, especially an alcoholic one. 

  • The act of pouring a liquid, most often wine, in sacrifice on the ground, on a ritual object, or on a victim, in honor of some deity. 

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