LEOPOLDO

NOBILI  (1784-18357, Italian physicist, born at Reggio nell' Emilia in 1784, was in youth an officer of artillery, but afterwards became professor of physics in the archducal museum at Florence, the old habitat of the Accademia del Cimento . His most valuable contributions to science consist in the suggestion of the astatic combination of two needles for galvanometers, and in the invention of the so-called thermomultiplier used by him and M . Melloni . In 1826 he described the prismatically-coloured films of metal, known as Nobili's rings, deposited electrolytically from solutions of lead and other salts when the anode is a polished iron plate and the cathode is a fine wire placed vertically above it . His papers were mostly published in the Bibliotheque universelle of Geneva . He died at Florence in August 1835 .