The research project examines the mortality rate of dysentery in Sweden from 1750 to 1900. Today, the common name is dysentery, and the word red soot came from the symptoms of the disease, often bloody diarrhea. The project is based on Europe's demographic development, with decreasing mortality from several infectious diseases in the 19th century, which contributed to a strong population growth. Measles was one of the most common infectious diseases in the 18th and early 19th century, and Sweden suffered several severe epidemics of measles. For example, nearly 20,000 people in Sweden died of measles in 1773. Moreover, mortality was not evenly distributed across the country, so in some areas the disease had very devastating consequences. Towards the end of the 19th century, a change took place and after the turn of the century red rot was rarely mentioned as a cause of death. Despite its former importance, historical research has paid very little attention to the disease, focusing instead on the most prominent diseases of the time, such as plague, cholera and smallpox. However, the diseases that receive attention do not necessarily correspond to the diseases that have the greatest demographic impact. This project will therefore draw attention to the severe red soot epidemics in Sweden and map when the epidemics occurred and study geographical differences in the spread of the epidemics. The project also aims to discuss possible factors behind the emergence of the epidemics and the subsequent disappearance of the disease.