Deviation of the magnetic needle by current of battery. Hans Christian ?rsted (August 14, 1777 - March 9, 1851) was a Danish physicist and chemist who discovered that electric currents create magnetic fields, an important aspect of electromagnetism. In 1820 ?rsted noticed a compass needle deflected from magnetic north when an electric current from a battery was switched on and off, showing a relationship between electricity and magnetism. His initial interpretation was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. He began more intensive investigations and published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire. In 1825, ?rsted made a significant contribution to chemistry by producing aluminium for the first time isolating the element via a reduction of aluminium chloride. The unit of magnetic induction (oersted) is named for him. He died in 1851 at the age of 73.