Heavy Metal Antibiotics: The Oligodynamic effect and Homeopathy
That silver, copper, and possibly germanium (and many other metals) have antibiotic properties is known as the oligodynamic effect, and is widely used in sterile gauze and other mainstream medical applications. Interestingly, these same toxic metals may have growth-stimulating effects in ultra-low doses; known as the Arndt-Schultz law ("small doses stimulate; medium doses inhibit; large doses kill"), from homeopathy.
On a related note, what is the shiny stuff on the new $20 bill? Copper? Gold? Plastic?