calmative vs tranquilizer

calmative

noun

  • A drug with calming effects. 

adj

  • Calming. 

tranquilizer

noun

  • A drug used to reduce anxiety or tension. 

  • That which tranquillizes or soothes. 

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