galvanism vs ignition

galvanism

noun
  • The chemical generation of electricity. 

  • The therapeutic use of electricity directly applied to the body. 

ignition

noun
  • The act of igniting. 

  • The phenomenon of a thermonuclear fusion reaction becoming self-sustaining and no longer requiring external heating. 

  • The initiation of combustion. 

  • A system for activating combustion in a combustion engine. 

  • Receptacle for a key used to start the engine in a vehicle. 

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