Trasformazione della materia e dubbi giurisprudenziali: una rilettura di Gai. 2.79

The essay represents the first piece of a larger study. It analyzes Gai. 2.79, investigates the context and the expository scheme and goes through the reasons why Gaius considers problematic to found the juridical discipline of the specification on the naturalis ratio. The recognition of the examples of specification given by the jurist represents a mean for the comparison with the systematics of the Res Cottidianae, in which the criterion of reversibility appears, stated in close connection with the consequences of fluvial changes.