This is the second edition, and the first to include illustrations, of the seminal work by the monk Giovanni Battista Beccaria (Mondovì, 1716–1781), a leading figure in eighteenth-century science and a professor at the University of Turin. Beccaria was among the first European scholars to embrace and develop the theories of Benjamin Franklin, with whom he engaged in an intense and fruitful correspondence. He was one of the major proponents of a modern conception of electrology as an autonomous scientific discipline and, in this work, even anticipated Faraday in his research on electrical conduction in bodies.