Guillaume de Baillou

Guillaume de Baillou (also Ballonius; * 1538 in Paris, † 1616 ) was a French physician and founder of modern epidemiology.

He was a pupil of Jean Fernel (1497-1558), the personal physician of Henry II Baillou worked in this position for Henry IV later

The terms rheumatism and rheumatism were first used in his 1642 published work Liber de Rheumatismo et Pleuritide dorsali. He believed by the former doctrine of the humors ( humoral ) that cold mucus flowed from the brain down to the extremities and the corresponding triggering complaints.