Giambattista Beccaria (3.10.1716-27.05.1781) was an Italian physicist. He was born in Mondovì. He studied in Rome and Narni. From 1737 he taught in Narni, Urbino, Palermo and Rome, and from 1748 he was head of a chair at the University of Turin, which he held for more than 20 years.
His work concerned the study of electrical and magnetic phenomena, and of atmospheric electricity in particular. He introduced the concept of electrical resistance and so began its study, showed that water is less conducting than solid metals and mercury, and showed that the resistance of metals is proportional to their length. He constructed parallel-plate capacitors with spacers of various materials — sealing wax, sulfur, resin. In 1753 he was the first to show that electric charge in conductors is distributed over the surface. He carried out magnetisation by means of the discharge of a Leyden jar. He put forward the hypothesis that a close connection exists between electrical and magnetic phenomena. He reduced (1769) metal oxides by means of discharges