The French chemist and microbiologist Louis Pasteur (1822-1895). He is considered the greatest physician of all time and the insfatherins of the germ theory of diseases. He strongly believed that diseases were caused by tiny organisms and transmitted from individual to individual. His researches brought him to the development of two vaccines: the first against anthrax, a major disease of cattle and the second against rabies. Pasteur also recognised that wine and beer, under gentle heating, could be preserved from souring. This process is now known as pasteurization and widely applied in the food industry.