galvanism vs hydro

galvanism

noun
  • The chemical generation of electricity. 

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

hydro

noun
  • electrical power supply; specifically, electrical power provided by a utility (as a publicly-owned one); payment or bills for this. 

  • hydroelectric power 

adj
  • hydroelectric 

  • hydroponic 

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