1 INTRODUCTION

Over the past 50 years, conservators and conservation scientists have focused increasingly on identifying materials in the museum environment that contribute to the deterioration of works of art and the mechanisms by which they work. Much of the initial research was generated by the packing industry (Packman 1957, 1960; Rance and Cole 1958; Clarke and Longhurst 1961;Arni et al. 1965; Donovan and Moynehan 1965) with conservation scientists and conservators supplementing and refining the scope to reflect the specific needs and conditions of the museum community. The susceptibility of silver and metals generally to the effects of acidic pollutants generated by the materials used in their display and storage has been a subset of that research (Thomson 1965, 1978; FitzHugh and Gettens 1971;Weyde 1972;Oddy 1975;Blackshaw and Daniels 1978, 1979; Hnatiuk 1981; Leveque 1986; Berndt 1987; Craddock 1988; Brimblecombe et al. 1992; Green and Thickett 1994; Lee and Thickett 1996; Hatchfield 2002;T�treault 2002). As a result, the understanding of the “ideal” macroand microenvironments for the exhibition of metals has grown substantively over time; however, economic and aesthetic concerns often inhibit museums' abilities to create the model environment. Such constraints have necessitated the development and institution of a variety of less costly but effective measures that are either object or exhibition case specific. A historical overview of the different approaches taken during the past 25 years by the Metropolitan Museum of Art to the exhibition of silver is illustrative of the techniques utilized by conservators to enhance the safekeeping of silver on display or in storage.