(December 27, 1822 – September 28, 1895)
Despite lacking a medical license or any formal training in medicine and surgery, Louis Pasteur revolutionized medicine in a way that no one envisaged. The sterilization method he devised, known as pasteurization, saved uncountable lives by reducing infections in an era when antibiotics were unknown. It also helped to prolong the shelf-lives of perishable foods (such as milk and beverages). This same pasteurization, alongside John Tyndall’s tyndallization, helped debunk the age-long myths surrounding the Theory of Spontaneous Generation. Although his famous accomplishments were in the fields of microbiology and medicine, Louis Pasteur was actually a chemist, who held professorial chairs at both Strasbourg and Lille universities (in France). His works on Molecular Asymmetry enabled scientists understand the optical and crystallographic nature of various organic salts. His determination to explore beyond the boundaries of chemistry brought occasional criticisms from medics who were unnerved by his daring vaccination experiments. He conceded by working alongside doctors, who oversaw that his procedures did not do more harm than good. Undeterred, he pioneered the developments of both rabies and anthrax vaccines. Pasteur’s versatility is evident on how easily he navigated between physical and biological sciences. His revolutionary works in microbiology often overshadow his lofty contributions to chemistry, physics and geology. For instance, he was the first person who accurately explained the concepts of isomerism and molecular chirality. He also published numerous works, won several awards, and served for a decade as the Director of Scientific Studies at the École Nationale Supérieure in Paris.