capital punishment vs gassing

capital punishment

noun
  • The practice of putting a person to death as a punishment for a crime. 

gassing

noun
  • Poisoning by noxious gas. 

  • boasting; insincere or empty talk 

  • Any similar process of singeing. 

  • The process of passing cotton goods between two rollers and exposing them to numerous minute jets of gas to burn off the small fibres. 

  • The liberation of hydrogen from an overcharged battery due to electrolysis of the electrolyte. 

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