Evidence of nail care in a modern mummy from Sermoneta (central Italy)

Since the first exploration, a pair of hands with clear, white nails was visible in a crypt of the church of San Michele Arcangelo in Sermoneta. They belonged to a partially mummified female of 32-40 years of age at death and displayed all but one (right fifth) of the fingernails. At direct and digital dermoscopic examination, these latter appeared well preserved and diffusely coloured in white, with generally intact cuticles. The left fourth fingernail was carefully extracted from its bed and submitted to stereomicroscopy, scanning electron microscopy (SEM), also with energy dispersive X-ray (EDX) analysis, in order to evaluate its features and establish the chemical composition of white substance, following a conservative approach. Stereomicroscopy allowed to appreciate differences between dorsal (pigmented) and ventral (unstained) surfaces, as well as to closely inspect the nail root and the free edge contours. SEM evidenced further details of such structures, enabling us to select areas for EDX measurements. The following elements were detected: C, O, S, Mg, Cl, K, P and Ca in unstained areas of dorsal surface and in ventral one, indicating the organic structures of the nail; O, S and Ca in the pigmented areas, suggesting the presence of CaSO4 used as a nail polish; Al, Fe and Si in the free edge, referred to remnants from manicure devices. The presence of calcium sulfate (chalk, plaster) allowed the preservation of the fingernails, that often disappear following death. According to the history of nail care, the chemical composition of the polish and the nail shape helped to date back the death of the subject to the very first decades of XX century. At that time women used to stain their nails with tinted powders, buffing them shiny and naturally coloured, even though in this case the procedure could be performed before or after death