In 1876, Robert Koch, then an unknown country doctor in Germany, identified the microbe, Bacillus anthracis, responsible for anthrax. Seven years later, he identified Vibrio cholerae, another bacillus, as the cause of cholera. At long last there was proof that individual microorganisms caused specific diseases. It is remarkable to think that we have had electric lights and telephones for about as long as we have known that germs kill people.
