concept of correlation as a component of science; Louis may have drawn upon these concepts during his studies. Legacy Louis conducted other, similar pre-epidemiological work, dividing patients into exposed/affected versus unexposed/unaffected groups to determine similar relationships between illness and etiology, deducting for instance the heritable nature of emphysema. For his work on the numerical method, Louis was elected the president in perpetuity of the Society for Medical Observation, a society formed by his students. Louis is also credited by some for standardizing the patient history, starting with questions about general health and narrowing down to specific symptoms. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1849. Louis was mentor to Oliver Wendell Holmes Sr. during the younger man's training in Paris and strongly influenced his skeptical outlook. References External links Pierre Charles Alexandre Louis, Red Gold. Recherches sur les effets de la saignée dans quelques maladies inflammatoires, et sur l'action de l'émétique et des vésicatoires dans la pneumonie (French) 1787 births 1872 deaths 19th-century French physicians Fellows of the American Academy of Arts and Sciences People from Marne (department)