Dr Harvey’s extraordinary discovery

On May 18 1636, a 58-year-old Englishman walked into the anatomical theatre at the University of Altdorf in Bavaria, white dissecting gown billowing in his wake. First William Harvey addressed his audience – professors at the front, students behind and general public at the back – in Latin, the language of scholarship.

Harvey propounded his revolutionary theory that the heart pumped blood vigorously through the body in a unified circulatory system of arteries and veins. It was a bold challenge to the conventional view, enshrined in medical orthodoxy for 1,500 years, that there were two separate venous systems: “nutritive blood” was made in the liver and carried slowly around the body in veins; “vital blood” was concocted in the heart with air drawn in from lungs by the heartbeat and then distributed through arteries.

During the lecture, university porters led a dog into the theatre, tied its jaws together with rope and pinned it down on the dissection table. The poor animal was spreadeagled on its back, legs held apart as its four paws were tied firmly to wooden stakes on the table. Then Harvey told his audience: “It is obviously easier to observe the movement and function of the heart in living animals than in dead men.” He plunged a knife into the dog’s thorax and, as the silenced dog writhed in agony, he exposed its beating heart, showing that “the heart’s active phase is contraction, when it drives out the blood as it were by force, as I shall now demonstrate.”

With that he cut the dog’s pulmonary artery while the heart was contracting and stepped aside as a fountain of blood spurted out. With the audience in uproar, Harvey raised his voice to estimate the vast volumes of liquid discharged by the heart every hour.

An image of the heart, 1603

Everything Harvey said contradicted Galen (130-200AD), the Greek physician who codified the medical wisdom of the classical world and whose writings remained sacrosanct into the 17th century. Galen saw the heart as a mixing chamber that gently sucked blood from veins and air from the lungs but was not an active pump.

This description of Harvey delivering one of many public vivisections to promote his blood circulation theory comes from a new biography by the historian Thomas Wright, announced this week as the winner of the £25,000 Wellcome Trust Book Prize. In Circulation: William Harvey’s Revolutionary Idea, Wright argues that Harvey had more impact on the history of science than any other Englishman apart from Newton and Darwin.

The book alternates elegantly between chronological chapters about Harvey’s rise from the Kentish yeomanry to King’s physician and thematic essays that place his discoveries in the medical, cultural and political context of the late Renaissance. Almost all his personal papers were destroyed – some by Roundheads who ransacked his London home during the Civil War and the rest when the Great Fire of 1666 burnt the College of Physicians – but Harvey was famous enough for many contemporary accounts of his achievements to have survived.

Engraving of a circulation experiment by William Harvey. The bandaged arms show the blood vessels and pressure points

Harvey was born in 1578 to a family of sheep farmers and merchants near Folkestone. His father, encouraged by William’s diligence at school, sent him to Gonville and Caius College, Cambridge – hoping for the social and financial advancement that a successful professional career could bring. The family’s academic investment in William increased when he went on to complete his medical studies at the University of Padua, academic capital of the Venetian Republic.

Padua illustrated the cosmopolitan nature of intellectual life in early 17th-century Europe, in spite of the continental religious divide. The university’s 1,500 members were organised into their various “nations” – and Harvey showed his energy and ambition by running successfully for election in 1600 as Councillor of the English Nation, an influential position normally held by an aristocrat.

His medical degree included extensive reading and discussion of Aristotelian philosophy, as well as gaining practical experience on hospital rounds and attending dissections of executed criminals in Padua’s anatomical theatre (which still stands today). Following the custom of the time, the public were admitted to the upper gallery, with gowned students in the lower tiers, and local civic and academic leaders in robes of purple and gold seated closest to the dissection table. Harvey learnt the art of dissection from Girolamo Fabrizi, known as Fabricius and regarded as Europe’s leading anatomist.

The dissection of a dog

After returning to England, Harvey rose fast through the London medical hierarchy, aided by marriage to Elizabeth Browne, daughter of Lancelot Browne, physician to the recently crowned King James. In 1607 he took the oath as a fellow of the College of Physicians, which included a commitment never to speak disrespectfully of Galen. His medical practice flourished and he treated both King James and his son Charles I, who appointed him as “physician in ordinary” – in effect his chief doctor.

At the same time, “the little perpetual movement Dr Harvey”, as one contemporary called him, was carrying out private research in the dissection chamber of his black-and-white timbered Ludgate home. Next door he maintained a menagerie containing an extraordinary variety of fish, reptiles, amphibians and mammals for him to cut up in what quickly became an obsessive quest to understand how the heart really worked. The cold-blooded creatures were useful subjects because their hearts beat more slowly and therefore were easier to observe than mammals.

Gonville and Caius College, Cambridge c.1690

While Harvey’s enthusiastic experimentation with living animals without anaesthesia may make modern readers flinch, he was following a tradition going back to Galen and earlier. Some anatomists in the 16th and 17th centuries did express regret for the suffering they caused but there is no record of Harvey feeling any compunction. The outcome of his vivisection was an entirely new theory of circulation. Harvey seems to have convinced himself by 1618, and over the following 10 years he “showed” his theory to medical colleagues over countless sessions in his private chamber.

After a decade of intense debate, during which many of his fellow physicians defended the classical wisdom of Galen, Harvey felt confident enough to present his ideas in a book De Motu Cordis (otherwise known as On the Motion of the Heart). Its publication (in Frankfurt) internationalised the argument – and he was happy to travel abroad to promote his ideas.

Many established physicians maintained their opposition, among them Caspar Hofmann, professor of medicine at Altdorf, who had been a fellow student at Padua and was the primary target of Harvey’s 1636 demonstration. Their obduracy had an element of self-interest because many longstanding medical practices were rooted in the ancient idea that the balance between four “humours” governed human health. What was the point of bloodletting, a favoured therapy to restore the balance in an afflicted region, if blood flowed vigorously around the whole body?

But younger anatomists rallied to the circulatory cause. So too did the broader intellectual world. Philosophers, mathematicians, alchemists, astronomers, poets, economists and others took to the simple, powerful imagery of the heart driving circulation. Perhaps the most influential convert was the great French philosopher René Descartes (1596-1650), who used Harvey’s work in his mechanistic description of the human body.

By 1649, when the English monarchy came to a temporary end, Harvey had won the argument. But his old age as a childless widower plagued by ill health was far from happy. As an unrepentant Royalist he suffered reprisals from the Commonwealth, including temporary banishment from London.

Outside his medical sphere, Harvey was deeply conservative – and troubled by the knowledge that his discovery had kindled radical ideas in philosophy and politics. Indeed, on his deathbed in 1657 he showed that he was a medical conservative too, according to Wright, asking his apothecary “to let him blood in the tongue which did little or no good … so he ended his days”. It was a strange end for a man who had done more than anyone to set medicine on a long path towards scientific principles.

‘Circulation: William Harvey’s Revolutionary Idea’, by Thomas Wright, is published by Chatto & Windus (£16.99)

The Wellcome Trust Book Prize celebrates medicine in literature. For further information go to www.wellcomebookprize.org

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