In the 1560s, the noted gentleman-astronomer Tycho Brahe lost the bridge of his nose in a drunken duel. Brahe may have done astronomical research on a private island, but he also frequented the smartest Danish drawing rooms; so to hide the disfigurement, the story goes, he had a local smith make a replacement nose of silver. The metal was fashionable and, more important, had a reputation for curtailing infection. The only drawback was its obvious metallic color, which forced Brahe to carry jars of foundation makeup to smooth over his nasal prosthesis.
Archaeologists later exhumed Brahe’s body and found a green verdigris crust on the front of his skull, suggesting Brahe used not silver but cheaper, lighter copper. Only the nose knows, but either way the story makes sense. Both silver and copper have a long tradition as folk medicines, and modern chemistry confirms that both do indeed have antiseptic powers.
References to copper in medicine date back more than 4,000 years, to Egyptian papyruses that mention using copper compounds to sterilize wounds. Some ancient civilizations also used vessels of copper (or bronze, a copper alloy) to store water because the metal prevented the buildup of sickening slime. As for silver’s medical pedigree, the famed Greek doctor Hippocrates recommended it for ulcers, and some historians have speculated that Roman military officers enjoyed better health than their grunts partly because they ate meals off silver platters.
These accounts are plausible because both metals display the so-called oligodynamic, or “self-sterilizing,” effect—a property first described in 1893 by Swiss botanist Karl Wilhelm von Nägeli.The two metals kill an incredible variety of microbes, including many fungi, bacteria, molds, and protozoa. Other self-sterilizing metals include lead, mercury, platinum, cobalt, and tin, but copper and silver have become closely associated with the oligodynamic effect because they kill pathogens quickly (sometimes in minutes) and because, unlike some metals, they’re essentially non toxic to higher forms of life.
Scientists don’t know exactly why copper and silver kill microbes so selectively, though there’s no shortage of theories. Some argue that copper and silver atoms denature key metabolic proteins inside microbes. Others have found evidence that the metals destroy the membranes of cells. Still other scientists believe that copper at least disrupts pathogens by conducting too much electricity: it literally short-circuits them.
Regardless of the mechanism, self-sterilizing metals have become important tools in public health: witness the prevalence of metal doorknobs, handles, and railings in public places. And copper specifically became common in building infrastructure like air-conditioning systems after 1976, when bacteria festering in the fetid ducts of a Philadelphia hotel killed 34people, the first known outbreak of Legionnaire’s disease. Copper helps keep money sanitary as well; pennies have been 97.5% zinc since 1982, but they retain a thin copper coat to sterilize the part people touch. (Dimes and quarters are both 91.67% copper, and even so-called nickels contain 75% copper.)
Silver has always been too dear for widespread medicinal use, but many American families in the 1800s and early 1900s, especially on the frontier, kept silver coins in milk or water jugs to keep the drinks fresher. In the past two decades silver has made a comeback as an immunity-boosting supplement. Unfortunately it’s quite easy to overdose on silver, which leads to a condition called argyria. Argyria isn’t fatal and causes no internal damage, but it does turn the skin a ghastly blue grey—think Zombie Smurf—and does so permanently. One argyria victim in the early 1900s toured the country as the “Blue Man” in circus freak shows after overdosing on silver nitrate to cure his syphilis. (It didn’t work.) More recently, Stan Jones, a startlingly blue Libertarian from Montana, ran for the U.S. Senate in 2002 and 2006.
Jones explained that he contracted argyria in the late 1990s after becoming obsessed with the Y2K computer crash. Certain there would be a widespread lack of antibiotics, he began priming his immune system by distilling a heavy-metal moonshine in his backyard. This process involved dipping silver wires attached to 9-volt batteries into tubs of water—a method not even hard-core silver enthusiasts recommend since electric currents that strong will dissolve too many silver ions in the bath. Nevertheless, Jones drank his stash faithfully for over four years, right until the Y2K frenzy fizzled out in January 2000.
To his credit Jones has maintained a sense of humor about his condition. (When asked during his Senate campaigns how he responded to children pointing at him on the street, Jones deadpanned, “I just tell them I’m practicing my Halloween costume.”) But Jones remains unrepentant about drinking silver water, telling a national magazine in 2003, “I still believe [silver] is the best antibiotic in the world. . . . If there were a biological attack on America or if I came down with any type of disease, I’d immediately take it again. Being alive is more important than turning purple.”
Jones may be right, but there are certainly less disruptive—and more attractive—ways to reap the benefits of oligodynamic elements.
Sam Kean is the author of The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements.