 Complete the following phrase:  As realism in art gained ground, the positive method in criticism kept pace with it. History returned to its spirit of learned research, as is shown in such works as the Archivio storico italiano, established at Florence by Giampietro Vieusseux, the Storia dItalia nel medio evo by Carlo Troya, a remarkable treatise by Manzoni himself, Sopra alcuni punti della storia longobardica in Italia, and the very fine history of the 