downer vs soporific

downer

noun
  • A drug that has depressant qualities. 

  • A livestock animal that has collapsed. 

  • A negative drug trip. 

  • A form of industrial action in which workers down tools and refuse to work. 

  • Something or someone disagreeable, dispiriting or depressing; a killjoy. 

soporific

noun
  • Something inducing sleep, especially a drug. 

  • Something boring or dull. 

adj
  • Boring, dull. 

  • Tending to induce sleep. 

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