Sticking with our theme of microbial nasties, let's all hear it for Louis Pasteur. During his time, the prevailing theory was "spontaneous generation" and scientists generally believed that bacteria kinda sprouted from nowhere to spoil your milk and your day. Pasteur was not convinced though, and began to experiment. He took flasks of sterile culture mediums, opened some in the dirty, bustling streets of Paris, and one in the fresh clean air of the Alps. The former cultures quickly grew and multiplied, whereas the ones that had been kept sterile remained untouched. In doing this, Pasteur was able revolutionised our ideas about germ theory and proved that it was possible to keep disease and decay at bay. Whilst he is perhaps best known for inventing the pasteurisation process to which he gave his name, Pasteur's discoveries were further reaching than that. Germ theory is essential the foundation on which we have built pretty much all of our ideas about hygiene and safety in everywhere from restaurants to hospitals. Pasteur also built on Jenner's work with vaccination, opening the door to the development of numerous life-saving vaccines.
