One of the first people to postulate the presence of some kind of disease causing substance was Ignaz Semmelweis, a Hungarian doctor, practicing in an obstetrics ward in the 1840s. He noticed that the death rate of the impoverished women attended by the nurse midwives was many times less than that of the wealthier women attended by the doctors. His observations led him to conclude that it was a matter of cleanliness. The doctors, on their schedules, went directly from the morgue to the obstetrics ward without wash their hands. When he tried to present his findings to his fellow doctors, they discounted his theory, unable to believe in what they could not see. It wasn't until the 1880s and the work of Louis Pasteur and Joseph Lister that the truth of germs finally surfaced and was accepted by the scientific community.