Louis Pasteur (1822 - 1895) was French chemist and microbiologist. He was significant in his great contribution to the prevention of disease, based on his discovery of the causative agents of these diseases. His greatest discoveries are the principle of vaccination, microbial fermentation and pasteurisation. Thus he created a vaccine against rabies and a way of preserving the quality of milk, based on the process of killing the microbes that spoil the milk. This process is called pasteurisation.
