Wash your hands. Boil your instruments Microbes cause disease and death for patients.
At the start of the movie, a man in distraught murdered Dr. Francois. The reason behind the murder was the fact that the doctor used unsanitary techniques and did not wash his hands while assisting his wife in child birth. The woman later died of child bed fever.
A chemist named Louis Pasteur came up with a theory that microorganisms are everywhere and are the cause of disease. He was seen as a menace to science by many people.
The government had learned that many of the sheep were dying from the Black Plague until Pasteur helped the rest of the sheep become almost immune to the Plague. Pasteur came up with a vaccination against the microbe that causes anthrax.
Due to the governments disbelief about the vaccination, they came up with an experiment. Farmers provided sheep to help with this experiment. So 25 of the new sheep were vaccinated and 25 weren't. The sheep that weren't vaccinate died and the others remained healthy.
A psychotic dog ran through town and proceeded to bight a man and left him on the ground bleeding.
Pasteur began looking for the vaccination for the rabies virus. Pasteur claimed that the disease was due to a deadly microbe and that one drop of this virus on the slightest patch could kill a man.