counterpoison vs preventive

counterpoison

noun
  • A poison used against another poison, serving as an antidote. 

preventive

noun
  • A thing that slows the development of an illness. 

  • A contraceptive, especially a condom. 

adj
  • Carried out to deter military aggression. 

  • Slowing the development of an illness; prophylactic. 

  • Preventing, hindering, or acting as an obstacle to. 

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