magnetism vs voltage

magnetism

noun
  • The property of being magnetic. 

  • The science which treats of magnetic phenomena. 

  • Animal magnetism. 

  • Power of attraction; power to excite the feelings and to gain the affections. 

voltage

noun
  • The difference in electrostatic potential between two points in space, especially between live and neutral conductors or the earth. 

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