Scientist and statesman — Benjamin Franklin (Boston, 1706 – Philadelphia, 1790) was an American scientist, inventor and statesman, among the founding fathers of the United States. Self-taught, he devoted himself to the study of electricity in the mid-eighteenth century, at a time when the phenomenon was still shrouded in mystery. He introduced the concept of positive and negative charge and the idea of charge conservation, hypothesising that electricity was a single fluid. His famous kite experiment during a thunderstorm demonstrated the electrical nature of lightning and led him to invent the lightning rod. He was also a diplomat and a signatory of the American Declaration of Independence.

Theories and contributions

  • Single-fluid theory of electricity — Electricity is a single fluid; bodies become positively charged through excess and negatively charged through deficiency, a sign convention still in use.
  • Conservation of charge — Electric charge is neither created nor destroyed, but transferred from one body to another.
  • Electrical nature of lightning — Demonstration that lightning bolts are electrical discharges, underlying the invention of the lightning rod.

Linked atoms

1 linked atoms.

13 Forza di Coulomb ed elettrostatica