"Water can be purified using Silver Sol liquid. By applying four drops of Silver Sol liquid into eight ounce glass of water, and letting it stand for about two minutes, it will purifiy even raw river water. Add 32 ounces of liquid Silver Sol to a 55 gallon drum of water to keep your water storage purified for years."

p.155 A Fighting Chance, Dr. Gordan Pedersen

http://www.banditsbuddies.com/focus/silver-shield.shtml