necropsy vs vivisection

necropsy

noun
  • The pathological examination of a corpse, particularly to determine cause of death. 

verb
  • The act of performing a necropsy. 

vivisection

noun
  • The action of cutting, surgery or other invasive treatment of a living organism for the purposes of physiological or pathological scientific investigation. 

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