William Harvey

William Harvey (1578-1657) studied at the same university as Copernicus namely University of Padua, founded 1222, and still in operation in Italy. He then returned to England and married, but got no children, and worked in London as a physician. He left money in his will to a boy school in his native town Folkestone which opened 1674 and was called Harvey Grammar School and is still in continuous operation.

After the discovery of the blood circulation 1616 he lived dangerously as the personal physician to James I (1618-1625) who became ill and Harvey failed to cure him and became a scapegoat among a supposed Catholic plot to kill James I. He was saved by the personal protection of Charles I to whom he was also the personal physician (1625-1647).

His teacher at Padua Hieronymus Fabricius had discovered venous valves but his explanation of their function did not satisfy Harvey who went on to discover the circulation of the blood in 1616 which was published 1628 as An Anatomical Exercise on the Motion of the Heart and Blood in Animals.

The heart-lung circulation was discovered earlier by Ibn al-Nafis, born 1213 and Michael Servetus, born 1511. al-Nafis did discuss the possible existence of a link between arteries and veins in the pulmonary circulation and is by some called the father of circulatory physiology.

Galen, born 129, had discovered the different colours of arterial and venous blood and hypothesized that venous blood originated in the liver and arterial blood in the heart. Harvey changed this concept.

Harvey also laid down that the heart was a pump operating the pulmonary and systemic circulations rather than that it, and the liver, was sucking blood as was the theory at the time. The reason al-Nafis did not think of the systemic circulation was probably that even at Harvey's time metabolism was unknown. His theory was eventually accepted during his life time but was attacked and he had to defend himself with a publication from 1649. There was, however, no effect on medical practice at this time. People continued to practice bloodletting ad modum Galen.

It should be noted that capillaries where not known at the time of Harvey and were discovered 1661 by Marcello Malpighi in a paper on frog lung.