English bookbinder who became interested in electricity. He obtained an assistantship in Davy's lab, then began to conduct his own experiments. He wrote a review article on current views about electricity and magnetism in 1821, for which he reproduced Oersted's experiment. He was one of the greatest experimenters ever. Because he was self trained, however, he had no grasp of mathematics and could therefore not understand a word of Ampère's papers. In the course of his experiments, Faraday discovered that a suspended magnet would revolve around a current bearing wire, leading him to propose that magnetism was a circular force. He also discovered magnetic optical rotation, invented the dynamo (a device capable of converting electricity to motion) in 1821, discovered electromagnetic induction in 1831, and devised the laws of chemical electrodeposition of metals from solutions in 1857.

He formulated the second law of electrolysis: "the amounts of bodies which are equivalent to each other in their ordinary chemical action have equal quantities of electricity naturally associated with them." He published many of his results in the three-volume Experimental Researches in Electricity (1839-1855). One of his most important contributions to physics was his development of the concept of a field to describe magnetic and electric forces in 1845. He first suggested that current produces a electric "tension" which produced an "electrotonic state," or polarization of matter molecules, and was responsible for transmitting the electric force. He experimented with dielectrics in a capacitor. After further experimentation, he abandoned the concept of electrotonic forces in favor of "lines of force." He maintained that these lines could be made visible in a magnet using iron filings. Faraday was an advocate of the law of conservation of energy, believing that possibility of "the production of any one [power] from another, or the conversion of into another."

Ampère's, Oersted