6 CONCLUSION

The need to display silver objects without having to lacquer them has led to the fabrication of a group of sealed vitrines from materials selected to create a benign interior environment. The inclusion of an active filtration system in the design provides a significant degree of protection against pollutants from external sources and from any which might be offgassing from the vitrine materials. The system has functioned successfully for fifteen years in the instance of the Attarouthi Treasure. What is not clear is whether a passive system of adsorption utilizing either activated charcoal or another of the sorbents now being tested (Ankersmit et al. 2000) would be equally successful given the relatively inert environment of the vitrine. Recent developments in accurately recording the dose of hydrogen sulfide or carbonyl sulfide within a closed space (Ankersmit et al. 2000) may help to clarify the question. Certainly, the minimal cost of an active filtration system provides a measure of assurance, as well as providing a potential means for exhibiting unlacquered silver in vitrines built more economically and to different standards.

ACKNOWLEDGEMENTS

The author would like to acknowledge the generosity of the Getty Conservation Institute for making available the results of their material testing; the efforts of Tom Vinton, Principal Departmental Technician in the Medieval department for his assistance in the maintenance of the filtering systems; and the support of Helen Evans, Curator, Department of Medieval Art, Frances Safford, Associate Curator, Department of American Decorative Arts, George Wheeler, Research Chemist, Department of Scientific Research, and Lawrence Becker, Sherman Fairchild Conservator in Charge, Sherman Fairchild Center for Objects Conservation.