9. Cholera Cocktail
Towards the end of the 19th century, Hamburg was on the verge of an outbreak of cholera. The bacteria the causes the disease had only just been isolated and a man named Robert Koch was working on a cure. However, the gloriously named and fabulously moustached Dr. Max Joseph von Pettenkofer disagreed with Koch on the idea that it is just the bacteria alone that causes the disease. He believed that there were environmental factors at play, and that the fact that most of the population lived in filthy squalor, rarely washed and had never seen a vitamin in their lives, probably had something to do with it.
So he sent off to Dr. Koch for a sample of the pure cholera bacterium with the intention of whipping himself up a tasty, deadly cholera cocktail. In front of witnesses, the good doctor neutralised his stomach acid, took a deep breath and downed the drink.
Over the next few days Pettenkofer became ill (surprise surprise) but, despite having ingested a cool 100,000,000 times the dose required to cause the disease, Pettenkofer never came down with full blown cholera - if he had done he would have needed, at worst, a coffin and, at best, a new pair of breeches.
This experiment began to put the idea in people's heads that it probably wasn't a great idea to live your life swimming in faeces and drinking dirty groundwater (a radical concept, apparently). Despite this, Pettenkofer has since faded in to obscurity, eventually shooting himself in a fit of depression - but without him, we could be living in a very different (much dirtier) world today.