How does silver staining work?

[Bernard Khoo]

One of those simple questions...

How does silver staining work? In particular, why do proteins bind
silver?

In a related question, how does Coomassie staining work?

Reason for asking: plain curiosity, that's all.

Thanks for any help...

Bernard Khoo   Wellcome/CRC Institute, Cambridge, UK.
               bcek1 at cus.cam.ac.uk or @mole.bio.cam.ac.uk