Pasteur was a French chemist and biologist who proved the germ theory of disease and invented the process of pasteurisation.
Louis Pasteur was born on 27 December 1822 in Dole in the Jura region of France. His father was a tanner. In 1847, he earned a doctorate from the École Normale in Paris. After several years research and teaching in Dijon and Strasbourg, in 1854, Pasteur was appointed professor of chemistry at the University of Lille. Part of the remit of the faculty of sciences was to find solutions to the practical problems of local industries, particularly the manufacture of alcoholic drinks. He was able to demonstrate that organisms such as bacteria were responsible for souring wine and beer (he later extended his studies to prove that milk was the same), and that the bacteria could be removed by boiling and then cooling the liquid. This process is now called pasteurisation.
Pasteur then undertook experiments to find where these bacteria came from, and was able to prove that they were introduced from the environment. This was disputed by scientists who believed they could spontaneously generate. In 1864, the French Academy of Sciences accepted Pasteur's results. By 1865, Pasteur was director of scientific studies at the École Normale, where he had studied. He was asked to help the silk industry in southern France, where there was an epidemic amongst the silkworms. With no experience of the subject, Pasteur identified parasitic infections as the cause and advocated that only disease-free eggs should be selected. The industry was saved.
Pasteur's various investigations convinced him of the rightness of the germ theory of disease, which holds that germs attack the body from outside. Many felt that such tiny organisms as germs could not possibly kill larger ones such as humans. Pasteur now extended this theory to explain the causes of many diseases - including anthrax, cholera, TB and smallpox - and their prevention by vaccination. He is best known for his work on the development of vaccines for rabies. In 1888, a special institute was founded in Paris for the treatment of diseases. It became known as the Institut Pasteur. Pasteur was its director until his death on 28 September 1895. He was a national hero and was given a state funeral.