their anthrax vaccine, and the other 25 were unvaccinated. All 50 sheep were injected with the anthrax bacillus. All 25 vaccinated sheep survived, and all 25 unvaccinated sheep died, just as Pasteur and Roux predicted. Louis Pasteur and Émile Roux were sometimes in disagreement in their approach to disease. Pasteur was an experimental scientist, whereas Roux was more focused on clinical medicine. They also held different religious and political beliefs, with Pasteur being a right- leaning Catholic, and Roux being a left-leaning atheist. Given their many differences, they clashed often as they worked towards vaccines against anthrax and rabies. The main issues between Roux and Pasteur regarded the ethics of human experimentation, specifically, the amount evidence from animal experimentation on the rabies vaccine needed in order to justify giving the vaccine to humans. Roux was more reluctant to give the vaccine to humans without further evidence that it was safe in animals. In 1883, he presented a doctoral dissertation in medicine titled Des Nouvelles Acquisitions sur la Rage, in which he described his research on rabies with Pasteur since 1881, which led to the development of the first vaccination against this fearsome disease. Roux discovered the idea of intracranial transmission of rabies, which paved the road for many more Pastorian milestones in research. Roux was now recognized as an expert in the nascent sciences of medical microbiology and immunology. With Pasteur's other assistants (Edmond Nocard, Louis Thuillier, who died while in Alexandria after contracting the disease, and Straus), Roux traveled in 1883 to Egypt to study a human cholera outbreak there, but they were unable to find the pathogen for the disease, which was later discovered in Alexandria by the German physician Robert Koch (1843–1910). In 1883 and for the following 40 years, Émile Roux became closely involved with the creation of what was to become the Pasteur Institute. Roux is known for developing the concept of combining development, research, and application in a specialized hospital. The most distinctive feature of the Pasteur Hospital was free access to medical care. The hospital was also known for being very hygienic for the time period. He divided his time between biomedical research and administrative duties. In 1888, an important year in his career, he accepted the position of Director of Services, joined the editorial board of the Annales de l’Institut Pasteur, and established the first regular course on microbiological technique, which would