Attitude of Health Personnel Cholera--history Communicable Disease Control--history Communicable Diseases--etiology Disease Outbreaks--history Engineering--history History, 15th Century History, 16th Century History, 17th Century History, 18th Century History, 19th Century Humans Hungary Malaria--history Physicians--history Plague--history Public Health--history Rivers Soil Microbiology Typhoid Fever--history Water Microbiology Water Pollution--history