Louis Pasteur, founder of microbiology, had an early interest in spontaneous generation. His years of patient and exhaustive research on the germ theory of disease earned for this tireless French chemist a place as one of the true Immortals of Science.Perhaps Pasteur is best known for showing how harmful bacteria could be killed by holding them at a definite temperature for a certain length of time. Later this process acquired its discoverer's name-pasteurization.While Robert Koch, the German bacteriologist, was the first to perfect the pure techniques of studying and cultivating bacteria, Pasteur is regarded as the greatest applied bacteriologist. Through his work he did much to generalize Edward Jenner's process of vaccine innoculation to preventive medicine by discovering many anti-toxins for diseases such as hydrophobia and silkworm diseases. He as also instrumental in opening a breach in the fight against cholera, yellow fever, and diphtheria.