Abstract
In his treatise On Generation and Corruption I 10, Aristotle introduces the new concept of "mixture"(mixis) to explain the constitution of the homogeneous substances of which all complex beings - natural and artificial - in the sublunary world are composed. In the mixture, the ingredients "react" reciprocally to give rise to a new, qualitatively different substance with its own formula, but they also remain there, potentially, and can be separated again. But how do they potentially persist in the compound, and how can they be separated again? In Book IV of the Meteorologicals, Aristotle sketches out the possibility of performing a "diagnose" of these bodies on the basis of certain passive and technical properties, such as the fusibility or ductility of metals. This is an essentially theoretical cognitive operation, aimed at understanding the causal structure, material composition and genesis of the formation of these bodies. But it does not exclude, even if only occasionally and subordinately, experimental procedures such as distillation.
