7 Ancient Technologies That Used Amazingly Advanced Science

6. Brass - Ancient Disinfectant

You know in the olden days when everything was dirty and smelly? How on Earth did anyone stay alive long enough to reproduce before dropping dead of some horrible infection? Well, despite our prejudices about grimy people from The Olden Days, as we sit smugly atop our tower of bleach and antibacterial hand gel, they knew a thing or two about killing germs using something called the oligodynamic effect.

Brass doorknobs made an unlikely cover story a few years ago, as it was found that copper and some of its alloys were actually capable of killing bacteria, including the scary superbug, MRSA. Rather embarrassingly, an ancient Egyptian medical text known as the Edwin Smith Papyrus recommends the use of copper, as well as silver, magnesium and arsenic, as medical disinfectants. It was also a well known practice for settlers in North America to drop copper and silver coins in their containers of water, milk and wine to keep it fresh.

How this actually works is still unclear, but it's thought that metal ions damage proteins or interfere with the metabolic processes of the bacteria. As a result, a brass doorknob will disinfect itself in around eight hours, whereas a flashing stainless steel one never will.