Inventor Frederick de Moleyns of England is granted the first patent for an incandescent lamp.
German physicist Gustav Kirchhoff introduces his laws of electric circuits, which have since been named in his honor.
British chemist Michael Faraday observes that the plane of polarization of light traveling through glass is affected by magnetic lines of force, a clear indication that magnetism and light are related. The phenomenon produced experimentally by Faraday is referred to as the Faraday effect or Faraday rotation.
Physicist and mathematician Franz Neumann of Germany publishes his deductions of the mathematical laws for induction of electric currents.
German physicist Wilhelm Weber attempts to unify the analysis and experimental results of André-Marie Ampère, Michael Faraday and others in his development of an electromagnetic theory that involves forces between charged particles in motion. Though his theory is later discounted, Weber’s work would precede many other advances in the field of electromagnetic theory.
Wilhelm Weber puts forward the idea that diamagnetism is simply an example of Faraday’s law impinging upon molecular circuits and suggests that diamagnetism exists in paramagnetic and ferromagnetic substances, but is masked due to the comparative strength of the permanent molecular currents the possess.
Hermann von Helmholtz, a German physicist and physician, reads his paper On the Conservation of Force to the Physical Society of Berlin, providing one of the earliest and clearest accounts of the principle of the conservation of energy that governs electrostatic, magnetic, chemical and all other forms of energy.