CONTE GIOVAN MARIA, a learned jurisconsult and biographer, born at Brescia in 1717. The first result of his studies was the *Notizie Storiche e critiche intorno alla vita e agli scritti d'Archimede*, Brescia, 1737, in which he explains the inventions of the celebrated Syracusan, and offers suggestions on the mirrors which are said to have set fire to the ships of the Consul Marcellus, and concludes by doubting the authenticity of the fact; thus anticipating the French academician, who afterwards established mathematically the argument *De falso spectu Archimedico*. The author, encouraged by the success of this work, formed the vast design of including in one work all the literary and scientific achievements of Italy from the earliest times. Accordingly, in 1753, he published at Brescia the first two folio volumes of his work in alphabetical order, which completed the letter A. These were followed by four volumes on the letter B in 1758-63, the last which he survived to finish. He died a few years after, leaving behind him a vast collection of ancient codes, manuscripts, casts, and medals, which were afterwards engraved and given to the world, with a description by the Abbé Pietro A. Gaetani at Milan. The *Dissertazioni Storiche, scientifiche ed erudite*, 2 vols. 4to, Brescia, 1765, were the result of the *litterarie conversazioni*, or literary society, which met at his house. Count Mazzucchelli also wrote the *Vite di Scipione Coppe e di Giusto de' Conti*, Brescia, 1769; *Notizie intorno ad Isotta da Imola*, ibid.; essays published in the literary periodicals of his day; many letters; and an edition of the *Vite d'uomini illustri Fiorentini di Filippo Villani*, with additions, corrections, &c. (See Rodella, *Vita del C.G.B. Mazzucchelli*, Brescia, 1766; and Bragnoi, *Elogi de Bresciani*, ibid., 1785.)