Age When: Louis Pasteur

Louis Pasteur was a French microbiologist who discovered Germ Theory. This being the theory by which disease, infection and illnesses are caused by microbes rather than spontaneous as previously thought. He came up with the method of Pasteurization which involved removing microbes via boiling and then cooling a liquid. He also was one of the primary pioneers for vaccinations against diseases. Many at the time were doubtful of his claims and he had to prove his work time and time again. The success of his Anthrax and rabies vaccines acquired him worldwide fame and many awards from institutes over the world.