Links to related information on other sites:
The Care of Silver
http://www.bishopmuseum.org/research/pdfs/cnsv-silver.pdf
The Care and Preservation of Historical Silver
http://www.thehenryford.org/explore/artifacts/silver.asp
2.11 Evaluation of Abrasive Materials for the Cleaning of Silver Objects
http://www.getty.edu/conservation/science/abstracts/2.11.html