As early as the ancient dynasties of Egypt, silver coins were placed in the drinking vessels of the nobility to protect them from harm.聽聽Of course, this was not the result of any scientific investigation, the practice probably originated from some superstitious belief about the magical properties of precious metals.聽聽Over the years it became apparent that the silver coins really did have an effect, they kept water from becoming slimy.聽聽Storage of water in silver vessels was an obvious extension of this observation, affording the well-to-do some protection from water-borne diseases that were common before the introduction of chlorination.聽聽As recently as the twentieth century, when Maharaja Sawai Madho Singh II journeyed to England, he carried holy water from the Ganges River in two sterling silver vessels acclaimed to be the world's largest silver containers.聽聽聽
You do not have to be as rich as a Maharaja to experience this effect.聽聽The metal can be incorporated into urinary catheters and endotracheal breathing tubes to reduce infections and fabrics can be formulated with small amounts of silver to control the bacteria responsible for churning out odorous compounds when they feast on sweat.聽聽The antimicrobial effect is actually due to silver ions, in other words, silver atoms that have lost an electron.聽聽These ions are produced whenever silver atoms at the surface of the metal react with either oxygen or hydrogen sulphide, the 鈥渞otten egg鈥� compound that is always present in the air and water in trace amounts.聽聽Indeed the 鈥渢arnish鈥� on silver is silver sulphide, the product of the reaction between silver and hydrogen sulphide.聽聽聽
Silver ions inactivate enzymes that are essential for bacterial life.聽聽That鈥檚 why bacteria are killed when contaminated water is stored in a silver container.聽聽But in this case, the extent of disinfection is unreliable because the concentration of silver ions in the water cannot be controlled.聽聽The purity of the silver, the size of the container, whether the water is shaken, are all important determinants of the concentration of silver ions.聽聽However, techniques have been worked out to produce just the right concentration of ions by immersing a pair of silver electrodes connected to a direct current into water that needs to be purified.聽聽This was the method used to produce drinking water aboard the Apollo space flights and is used in hospital plumbing systems to deactivate Legionella bacteria.聽聽Often copper is alloyed with silver in the electrodes to take advantage of its oligodynamic effect as well.聽聽Swimming pool disinfection systems using copper-silver ionization that allow for reduced use of chlorine are also available.聽
Unfortunately, quackery often rides along the coattails of science.聽聽And so it is in this case.聽聽Numerous websites promote the use of 鈥渃olloidal silver鈥� as a cure for cancer, diabetes, HIV infection, herpes and now, COVID-19.聽聽Colloids refer to a system in which finely divided particles are dispersed within a continuous medium without settling out.聽聽In the case of colloidal silver, these particles can be elemental silver or particles of silver compounds.聽聽Indeed they may well have an antimicrobial effect in a Petri dish, but that is a long way from having an effect when taken internally.聽聽No scientific evidence supports the benefit of ingesting any form of colloidal silver.聽聽Making health claims on its behalf is illegal, but colloidal silver can be sold as a dietary supplement.聽聽That is a curiosity because humans have no dietary requirement for silver and there is no such thing as a silver deficiency.聽
But there certainly is such a thing as silver excess.聽聽The metal can deposit in the skin as well as in internal organs with the result being a condition known as 鈥渁rgyria.鈥澛犅營ts hallmark is gray-blue skin, a condition that is irreversible.聽聽One of the most famous cases was that of the Blue Man who was a featured attraction in Barnum and Bailey鈥檚 circus in the early years of the twentieth century.聽聽He had apparently tried to cure his syphilis by ingesting silver nitrate but succeeded only in making himself blue.聽聽More recently, Stan Jones, an American Libertarian who twice ran unsuccessfully for the Senate as well as for Governor of Montana did succeed in becoming blue.聽聽Back in 2000, he was worried that computers would stop functioning and that this would somehow make antibiotics unavailable.聽聽He decided to take preventative action and started to take a colloidal silver preparation that he made himself by passing an electric current through a solution equipped with silver electrodes.聽Unfortunately, he didn鈥檛 know what he was doing, used too high a voltage and his solution contained a great deal of silver.聽聽He turned blue.聽聽But he is not singing the blues, maintaining that he is healthy and still dopes himself with colloidal silver.聽聽Pretty dopey actually.
