Richard Lower, M.D., physician and surgeon (1631-1691).

Richard Lower (1631-1691) was a follower of William Harvey and conducted extensive studies of the physiology of the cardiovascular and respiratory systems. He employed surgery as a key component of his experimental work. He described and employed cardiac massage and maintained arterial oxygenation through positive-pressure respiration. Making good use of these procedures, he established the role of the lungs in the "admixture of air" to the blood. Lower performed exchange transfusion in dogs and transfused the blood of a sheep into a human. He recognized the role of blood transfusion in replacing blood lost from hemorrhage or other causes. In his work on exchange transfusion, he employed extracorporeal vascular conduits, including arterial heterografts. Through surgical experiments he established that all mesenteric lymph passes through the thoracic duct to the subclavian vein. He performed a variety of procedures through an open thorax, closed the thoracotomy, and observed the animals over a period of days. Lower has not received the recognition he deserves as a pioneer surgical investigator.