Thomas Bartholin (; Latinized as Thomas Bartholinus; 20 October 1616 – 4 December 1680) was a Danish physician, mathematician, and theologian. He is best known for his work in the discovery of the lymphatic system in humans and for his advancements of the theory of refrigeration anesthesia, being the first to describe it scientifically. Thomas Bartholin came from a family that has become famous for its pioneering scientists, twelve of whom became professors at the University of Copenhagen. Three generations of the Bartholin family made significant contributions to anatomical science and medicine in the 17th and 18th centuries: Thomas Bartholin's father, Caspar Bartholin the Elder (1585–1629), his brother Rasmus Bartholin (1625–1698), and his son Caspar Bartholin the Younger (1655–1738). Thomas Bartholin's son (1659–1690) became a professor of history at the University of Copenhagen and was later appointed royal antiquarian and secretary to the Royal Archives. Personal life Thomas Bartholin was the second of the six sons of Caspar Bartholin the Elder, a physician born in Malmø, Scania, and his spouse Anne Fincke. Bartholin the Elder published the first collected anatomical work in 1611. This work was later augmented, illustrated and revised by Thomas Bartholin, becoming the standard reference on anatomy; the son notably added updates on William Harvey's theory of blood circulation and on the lymphatic system. Bartholin visited the Italian botanist Pietro Castelli at Messina in 1644. In 1663 Bartholin bought Hagestedgård, which burned down in 1670 including his library, with the loss of many manuscripts. King Christian V of Denmark appointed Bartholin as his physician with a substantial salary and freed the farm from taxation as recompense for the loss. In 1680 Bartholin's health failed, the farm was sold, and he moved back to Copenhagen, where he died. He was buried in Vor Frue Kirke (Church of Our Lady). The Bartholinsgade, a street in Copenhagen, is named for the family. Nearby is the Bartholin Institute (Bartholin Institutet). One of the buildings of the University of Aarhus is named after him. Contributions to medical research In December 1652, Bartholin published the first full description of the human lymphatic system. Jean Pecquet had previously noted the lymphatic system in animals in 1651, and Pecquet's discovery of the thoracic duct and its entry into the veins made him the first person to describe the correct route of the lymphatic fluid into the blood. Shortly after the publication of Pecquet's and Bartholin's