Max Josef von Pettenkofer (1818-1901) was Bavarian chemist, hygienist, principle founder of public health medicine. He was an accomplished chemist; he developed improved methods for the separation of precious metals, for generating illuminating gas from wood and was the first to isolate creatinine in urine and determine its elemental composition. As a hygienist, one of Pettenkofer's chief concerns was that people should consume adequate, but not excessive, amounts of protein and food energy. He was the first to set standards for proper ventilation, particularly for schools and hospitals.During his later years, Pettenkofer was best known for his many studies of the epidemiology of cholera and typhoid. Un fortunately, he reached the incorrect conclusion.