NO OTHER scientist has so aptly earned the title of "father" of his branch of science than Robert Koch. While Pasteur is regarded as the greatest applied bacteriologist, it was Koch who first perfected the pure techniques of cultivating and studying bacteria. When Koch succeeded in isolating the dreaded anthrax bacillus, he became the first to prove that a specific bacterium was the cause of a specific disease. He also developed four famous rules-still in use today-for relating one kind of bacteria to one kind of disease. Later, he succeeded in growing pure cultures of bacteria, an essential technique in modern bacteriology. In 1882, Koch astounded the scientific world by first isolating the tubercle bacillus-the cause of tuberculosis. Later he discovered tuberculin, a substance used in diagnosing tuberculosis today. A tireless worker, Koch went on to save thousands of lives, both human and animal, through his investigation of Asiatic cholera, sleeping sickness, malaria, Texas fever, rinderpest, and Rhodesian red water fever.