Abstract

Scanning electron microscopy, with x-ray capture, showed layered distributions of sulphur in parchment cross sections. In artificially aged parchments (exposed to SO, at 25 ppm) sulphur accumulated in layers that were less dense (i.e. showing low electron backscatter). Historical parchments showed layered distributions of sulphur. some of which was deep in the parchment profi]e. Surprisingly, calcium appeared not to be associated with sulphur in artificially aged samp]es. However in degraded historical leathers and parchments there was often a close association between sulphur, calcium, iron and copper. These metals may well increase the rate of collagen degradation by catalysing the formation of sulphuric acid,