Pasteur shows Martel the anthrax germs in blood. The Academy of Medicine debates, and Pasteur accepts an experiment of injecting sheep with blood of dead sheep. All the sheep not vaccinated die, and all those vaccinated live. Martel and Annette ask Pasteur for permission to marry. Lister congratulate Pasteur.
People run from a rabid dog.
In Paris a year later pregnant Annette worries. A letter from Lister says hospitals are becoming safe. After a month he laughs at Pasteur, who then realizes the germs were weakened by age. Pasteur has Martel inject dogs with old germs. A doctor brings a boy bitten by a rabid dog.