Semmelweis set up a basin filled with chlorinated water in the hospital. Those passing from the dissection room to the wards were required to wash their hands before attending to living patients. Mortality rates on the medical students’ ward plummeted. In April 1847, the rate was 18.3 percent. After hand-washing was instituted the following month, rates in June were 2.2 percent, followed by 1.2 percent in July and 1.9 percent in August.
