BONE POROSITY AND THE USE OF MERCURY INTRUSION POROSIMETRY IN BONE DIAGENESIS STUDIES*

Porosity measurements made on archaeological bones have revealed very-close relationships between changes in the porosity, remaining protein content and mineral alterations. The results have important implications for models that attempt to quantify the rates and extent of chemical reaction between bone and its geochemical environment. We report here on a novel application of an established technique, mercury intrusion porosimetiy, to investigate in more detail the pore size distribution of archaeological bones. Mercury intrusion porosimetry measures an ‘intermediate’range of bone porosity, ‘mesoporosity’, and produces data which permit the observation of significant structure characteristics in the porosity of modern laboratory altered and diagenetically altered bones.     

Estimation of the Production Parameters of Very Large Medieval Bricks from St. Urban,Switzerland

The aim of the present study is to determine the production technology of a particular type of large medieval brick. The firing temperature and their soak times are estimated using a combination of colour and fabric, as well as mineralogical, microstructural and open porosity analysis. A replication experiment was carried out in order to validate the estimated predictions, and to give a realistic idea of the time needed to dry and fire each large brick. The experiment also suggests the temperature distribution and firing atmosphere in the kiln, as well as providing an estimate of fuel consumption. Analytical results and replication both provide information to assess the production technology, the time parameters and the firing temperatures involved in the production of the medieval bricks of St. Urban.     

AMALGAM TINNING OF CHINESE BRONZE ANTIQUITIES*

This paper investigates the question whether or not amalgam tinning was used for the plating of bronze objects in pre‐Han and Han dynasty China. The relevant literary sources are reviewed and amalgam tinning is characterized experimentally with regard to its micro‐structure and residual mercury content using metallography and electron microprobe analysis. Examination of a tinning sample from a Warring States dagger previously assumed to be amalgam tinned demonstrates that this was probably not the case, but that a trace of mercury found in the plating is likely to be the result of contamination.