Benefits of Colloidal Silver

Why do we wear jewelry? In the 1500's people would put a silver coin in the pale before milking the cow. They would put a silver coin in the baby's bottle as a silver antibiotic. Where does the proverb "every cloud has a silver lining," come from? Why does there exist - in western mythology - the story of the vampire, whom can only be killed by a wooden stake through the heart or with a "silver" bullet? Could it be the case that the vampire is metaphorically - or symbolically - representing the "virus"?