Electromotive force: Volta’s forgotten concept

The concept of electromotive force as first presented by Volta seems to be all but forgotten. Introduction of the term often occurs without any definition at all and is often confused with electrostatic potential difference. When a formal definition is given it is usually neither in accord with Volta’s original idea nor conceptually useful or comprehensible. We emphasize Volta’s use of the term to describe nonelectrostatic action on charges. The relationship of emf’s to electrostatic potential differences is presented through the introduction of electrostatic and nonelectrostatic fields (as was described by Abraham in 1904). A failure to note a distinction between these types of electric fields mars some highly important works including J. C. Maxwell’s.