Alessandro Volta (18.02.1745-5.03.1827) was an Italian physicist, chemist and physiologist, and the inventor of the source of direct electric current. He was born in Como. He was educated at a school of the Jesuit order, but in his early years became interested in natural science. In 1774—79 he taught physics at the gymnasium in Como, from 1779 he was professor at the University of Pavia, and in 1815—19 director of the faculty of philosophy of the University of Padua.
His research in physics was in the field of electricity. Having become interested in L. Galvani's experiments with “animal” electricity, in 1792 he began to repeat them and soon came to the conclusion that the cause of the brief electric current in the muscles of frogs was not an “animal” electricity of their own, as Galvani believed, but the presence of a circuit of conductors of two classes (two dissimilar metals and a liquid). After long experiments to strengthen the effects that arise when several dissimilar conductors are joined, at the end of 1799 he constructed the first source of a continuous galvanic (electric) current, the voltaic pile. The first voltaic pile consisted of 20 pairs of copper and zinc discs separated by discs of cloth soaked in salt water. He also discovered (1795) the mutual electrification of dissimilar metals in contact (contact electricity) and arranged the metals in the so-called voltaic series (1801). He explained the galvanic polarisation of cells. He built a resin electrophorus (1775), a sensitive straw electroscope (1781), a capacitor (1783), an electrometer and other instruments, and described a design for a telegraph. He also studied the thermal expansion of air and observed (1790) diffusion. He established the conductivity of flame (1787). He discovered methane (1776).
A Fellow of the Royal Society and a member of the Paris Academy of Sciences. Copley Medal (1794).