This dissertation explores the intersection between scientific practices and political economy from the time of Maria Theresa's and Joseph II's reforms in the Habsburg State of Milan to the Cisalpina and Italian Republics. It is structured in four parts, corresponding to the themes of "appropriations", "technologies", "spaces" and "soils". Each of these parts comprises of two chapters, with the exception of the last one on "soils". Part I, named "Appropriations", explores how the Società Patriotica took on board the practices and debates which originated in the context of French Physiocracy, such as economic milling and the question of the scale of land-holdings, and analyses how they were appropriated to fit the political economy of the State of Milan. Part II, titled "Technologies", takes into account the attitudes of Milanese reformers, public officers and naturalists towards mechanical arts and, in general, towards technology for the achievement of the felicità and utilità pubblica. Part III of the dissertation has been named "Spaces". It focuses on the travels of naturalists Domenico Vandelli, Paolo Sangiorgio and Lazzaro Spallanzani, using them as starting points to examine the significance of natural history practices, such as travelling and collecting, for an understanding of contemporary political economy. Part IV, titled "Soils", examines a series of texts about the management and making of salnitro, showing their relevance in the context of the newly founded Italian Republic. Overall, the thesis aims to acknowledge the complexity, as well as the intellectual debts, of the production of political economy and scientific knowledge in the State of Milan, and pushes forward the debate on the Italian Enlightenment, by opposing those narratives which have represented it as a marginal and peripheral case in the broader and more "international" European Enlightenment.