Jean-Baptiste BIOT (1774-1862), astronomer and physicist, pioneer in the use of polarised light, member of the Académie française. Autograph manuscript signed "B..t", 10 pp. in-4, with numerous erasures and corrections. Superb article on Volta for Michaud's Biographie universelle. "Our feeling for Volta's genius is so strong and so deep that we hardly think we should mention a few of the particular instruments he devised, which have come into general use in all physics cabinets and chemistry laboratories [...]. We hasten to move on to the great discovery of the development of electricity by the mutual contact of bodies, an absolutely new and unforeseen principle that Volta recognised with extreme sagacity, that he brought to light by a series of experiments as skilfully as they were wisely conducted, and from which he deduced an application so happy and extraordinary that it is still, if it is possible, a greater discovery than the very principle from which it was derived. This is Volta's true, great claim to immortality [...]".