Recovering the past from surfaces and interfaces: experimental and cultural issues

Surface science studies have substantially advanced our knowledge of the physico-chemical characteristics of archaeomaterials and of the modifications produced on them by their surroundings. In the present paper, some experimental aspects encountered in XPS and AES analyses of archaeomaterials will be reviewed, including some cases for which the surface (of Roman bronze) and the interface (of Roman lead pipes) are themselves a source of archaeological evidence. The views on surfaces, as discussed by philosophers, writers and artists, from antiquity up to this day will then be discussed. It will be shown that the account of Pliny the Elder on the surface oxidation of metal surfaces was influenced by the views of the Stoic philosopher Posidonius, and this will be discussed in the light of XPS and AES spectra recorded on relevant surfaces.