HMHistoria MedicaHistory of medicine, examined.

Source / Experimental anatomical book

De Motu Cordis

Published at Frankfurt in 1628, William Harvey's Exercitatio anatomica de motu cordis et sanguinis in animalibus—An Anatomical Exercise on the Motion of the Heart and Blood in Animals—argued that the contracting heart drove the same blood outward through arteries and back through veins in a repeated, whole-body circuit.

Its historical importance lies in the coordination of evidence, not a solitary “eureka” experiment or a timeless account of the cardiovascular system. Harvey made comparative anatomy, interventions on living animals, arm ligatures, venous valves, and deliberately rough arithmetic support one another, while leaving the artery-to-vein connection unseen and retaining early modern ideas about heat, spirits, nourishment, and purpose.

First edition
Frankfurt am Main, 1628; published by William Fitzer
Form
A 72-page Latin quarto in seventeen chapters, with two leaves of engraved plates
Argument
Chapters 1–7 analyse cardiac motion; chapters 8–17 argue for circulation
Historical scope
Early seventeenth-century anatomy and natural philosophy—not modern blood chemistry, oxygen physiology, or clinical cardiology
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The problem inherited

Harvey revised a learned physiology; he did not begin with an empty map.

“Galenic medicine” was not one unchanging formula, but influential university accounts commonly distinguished venous blood associated with the liver and nutrition from arterial blood associated with the heart, heat, and vital spirit. They allowed blood to move between organs and parts without making all of it return in one continuous systemic circuit. Harvey repeatedly used Galen's observations even while rejecting features such as invisible pores through the wall between the heart's ventricles (French 1994; Harvey 1628).

Pulmonary transit had a longer, plural history

In thirteenth-century Damascus and Cairo, Ibn al-Nafīs denied interventricular pores and described blood passing through the lungs in his commentary on the anatomy of Avicenna's Canon. That was pulmonary transit within a medieval Islamic physiological and theological project, not Harvey's whole-body circulation. Sixteenth-century writers including Michael Servetus and Realdo Colombo also discussed passage through the lungs; Harvey cited Colombo, but no evidence establishes that he knew Ibn al-Nafīs's account. A priority contest erases these different texts, settings, and problems (Fancy 2013).

Padua supplied questions, not a ready-made answer

Harvey studied medicine at Padua and graduated in 1602. His teacher Girolamo Fabrici (Fabricius ab Aquapendente) had described the small flap-like ostiola, or “little doors,” in veins, but interpreted them within an outward movement of venous blood. Harvey did not discover these valves. He reassigned their function by asking which direction a probe, finger, or column of blood could pass (Bertoloni Meli 2013).

The printed book followed years of demonstration

In his address to the president and fellows of the College of Physicians in London, Harvey said that he had demonstrated his position publicly for more than nine years and had answered objections before publishing. This is the author's retrospective account of his preparation, not a dated laboratory log; it supports development before 1628 without proving that the complete argument existed at the start of his Lumleian lectures (Harvey 1628).

How the argument works

No single test carries the circulation.

The book first establishes what the heart and arteries do, then asks where the volume of expelled blood can go, and finally argues that veins return it. Its sequence turns observations made under different conditions into three mutually supporting propositions (Harvey 1628, chapters 1–17; Bertoloni Meli 2013).

Slower hearts make sequence visible

Harvey opened living animals and compared many species. The beats of toads, frogs, serpents, fishes, crustaceans, and molluscs were slow enough to follow; in dogs and pigs he watched as the heart weakened and motion slowed near death. He concluded that systole—the heart's hardening and contraction—was the active phase that expelled blood, and that the arterial pulse followed the ventricular contraction. These observations depended on altered, injured, and dying bodies, a methodological condition the published conclusions cannot erase (Harvey, chapters 2–5; Bertoloni Meli 2013).

Intervention tests inflow, outflow, and direction

In a snake, obstructing the vena cava below the heart left the heart pale and depleted; obstructing the artery on the other side made it engorged. On a human arm, a very tight band stopped the arterial pulse, whereas a less tight band admitted arterial blood but impeded venous return, swelling the veins below it. Pressing a raised vein between two fingers then showed that its valves resisted blood pushed away from the heart. Ligatures were old surgical tools; Harvey's systematic use of different tensions to investigate direction was the significant move (Harvey, chapters 10–13; Bertoloni Meli 2013).

Arithmetic makes continual replacement untenable

Harvey did not directly measure a modern cardiac output. He assumed possible ventricular capacities and fractions expelled per beat, then multiplied even low estimates by more than 1,000 beats in half an hour. The result exceeded what the body could contain or food could continually replace, making return and recirculation an arithmetical necessity within his argument. Historians have also shown that his Latin draws on the language of reckoning, intake, and expenditure familiar in early modern accountancy (Harvey, chapters 8–9; Neuss 2018).

The plates ask the reader to perform

The labelled views of an arm show a ligature, prominent veins, and finger pressure at successive points. They do not picture an entire circulatory system or record one self-contained experiment. Their evidential force depends on a reader reproducing the manipulation, seeing and feeling changes, and accepting that the local direction of venous flow belongs to the proposed circuit (1628 facsimile; Bertoloni Meli 2013).

What remained unresolved

A necessary connection was inferred before it was seen.

Arteries to veins: Harvey argued that blood must cross in the tissues through tiny connections or through the “porosities” of flesh, but he did not observe a capillary bed. In 1661 Marcello Malpighi described a microscopic vascular network in the lungs of frogs. That observation supplied visible evidence of pulmonary artery-to-vein continuity; it should not be projected backward as something already pictured in De Motu Cordis (West 2013).

Function: The circuit was not a modern account of oxygen exchange, blood cells, pressure, or metabolism. Harvey still described blood as nutritive and spirit-bearing, returning to recover heat and perfection, and compared the heart to the sun of the body's microcosm. Those claims locate the book in Aristotelian and Galenic natural philosophy even where its account of motion challenged received physiology (Harvey, chapter 8; French 1994).

Clinical change: Demonstrating circulation did not by itself test remedies or abolish humoral practice and bloodletting. Two surviving prescriptions written by Harvey for John Aubrey in 1653 and 1655 use Galenic purges, evidence that an experimental approach to physiological motion could coexist with conventional therapeutics (Williams, O'Dell, and Aronson 2021).

Animal suffering: The evidence repeatedly came from cutting, restraining, bleeding, and observing living or dying animals. The book describes what such interventions made visible far more fully than the animals' pain or the number of failed and unreported trials. Historians can study its technical ingenuity without treating suffering as an incidental footnote (Bertoloni Meli 2013).

Publication and dispute

Circulation became credible through print, repetition, and argument.

1628: The compact Latin quarto appeared at Frankfurt under the name of English publisher William Fitzer. Its international learned language and place of publication carried the case beyond the London College of Physicians, although the first edition was cheaply made, typographically faulty, and accompanied in some copies by an errata leaf. A surviving copy must therefore be read as a particular material witness, not an immaculate vehicle for Harvey's intentions (Boyle 2008; Heidelberg copy).

1630s: James Primrose published an early rebuttal in 1630; Caspar Hofmann and Jean Riolan the Younger also resisted parts of the doctrine. Their objections were not all refusals to look. Critics asked where the unseen vascular connection was, what purpose a circulation served, and how it could fit a physiology and medical practice organised around the production, alteration, and evacuation of humours (French 1994).

1641: At Leiden, Johannes Walaeus published experiments after moving from opposition to support. His ligatures reproduced directional filling in arteries and veins, and his work joined circulation to investigations of the newly described lacteal vessels. Repetition altered and extended Harvey's programme rather than merely declaring it true (Bertoloni Meli 2013).

1649: Harvey published two anatomical exercises addressed to Riolan, answering a critic who accepted only a limited circulation. The exchange shows that “acceptance” had degrees: a reader might grant recurrent movement while disputing its speed, extent, physiological purpose, or consequences (French 1994).

1661: Four years after Harvey's death, Malpighi's observations of frog lungs gave microscopic evidence for vessels joining the arterial and venous sides. Later reputation often turns this into the last missing piece of one inevitable discovery; in its own setting it was a new observation made with different instruments, organisms, and questions (West 2013).

Using the source

Read a staged case, not a transparent laboratory record.

It documents public persuasion

The specified 1628 edition shows how Harvey ordered demonstrations for a Latin-reading medical and philosophical audience, addressed royal and collegiate patrons, anticipated objections, and made embodied tests portable in print.

It does not preserve every trial

The book cannot establish how many animals were used, how demonstrations varied, who assisted, which trials failed, or what every observer concluded. Its first-person narrative is selected evidence arranged for publication.

Translations are later witnesses

The linked English text is a nineteenth-century translation reproduced with an 1894 facsimile. It assists reading but can flatten technical and rhetorical meanings in Harvey's Latin; claims about wording should be checked against the 1628 copy.

Across the collection

Continue from De Motu Cordis

William Harvey

Follow Harvey's education, lectures, court medicine, experiments, publications, supporters, and critics.

History of anatomy

Connect dissection and structure to experiment, motion, instruments, illustration, and physiological explanation.

References

Primary source and historical scholarship

  1. William Harvey, Exercitatio anatomica de motu cordis et sanguinis in animalibus

    Frankfurt am Main: William Fitzer, 1628. Heidelberg University Library digitised first edition, DOI: 10.11588/diglit.20133. The primary witness for title, dedications, chapter sequence, Latin terminology, plates, and the published argument. It is a persuasive authorial account, not a complete record of experimental practice.

  2. William Harvey, An Anatomical Dissertation upon the Movement of the Heart and Blood in Animals

    Canterbury: G. Moreton, 1894; translation by Robert Willis, with a facsimile of the 1628 Latin edition. Wellcome Collection catalogue record and complete digitisation. Used to identify chapter-level examples; the translation postdates Harvey and is not treated as his exact English wording.

  3. Domenico Bertoloni Meli, “Early Modern Experimentation on Live Animals”

    Journal of the History of Biology 46 (2013): 199–226. DOI: 10.1007/s10739-012-9327-7. Peer-reviewed analysis of Harvey's comparative observations, ligatures, vivisection, reuse of established techniques, and the experimental work of Walaeus and other successors.

  4. Michael J. Neuss, “Blood Money: Harvey's De motu cordis (1628) as an Exercise in Accounting”

    British Journal for the History of Science 51, no. 2 (2018): 181–203. DOI: 10.1017/S0007087418000250. Interprets the quantitative argument through the Latin vocabulary and social practice of early modern accountancy rather than presenting it as a modern measurement protocol.

  5. Marjorie O'Rourke Boyle, “William Harvey's Anatomy Book and Literary Culture”

    Medical History 52, no. 1 (2008): 73–91. DOI: 10.1017/S0025727300002064. Examines the first edition's title page, poor production, errata, Latin address to a transnational “literary republic,” and Harvey's positioning of anatomical demonstration against bookish authority.

  6. Roger French, William Harvey's Natural Philosophy

    Cambridge: Cambridge University Press, 1994. ISBN 978-0-521-45535-0. A book-length study of Harvey's anatomical and philosophical sources, the structure of De Motu Cordis, early objections, and the uneven formation of a European consensus.

  7. Nahyan Fancy, Science and Religion in Mamluk Egypt: Ibn al-Nafīs, Pulmonary Transit and Bodily Resurrection

    London and New York: Routledge, 2013. ISBN 978-0-415-62200-4. Contextualises Ibn al-Nafīs's account as pulmonary transit within thirteenth-century Islamic medicine, philosophy, and theology, rather than relabelling it as Harvey's later systemic circulation.

  8. John B. West, “Marcello Malpighi and the Discovery of the Pulmonary Capillaries and Alveoli”

    American Journal of Physiology—Lung Cellular and Molecular Physiology 304, no. 6 (2013): L383–L390. DOI: 10.1152/ajplung.00016.2013. Reviews Malpighi's 1661 letters to Giovanni Alfonso Borelli and the observations of frog lungs that made a pulmonary capillary network visible.

  9. Andrew N. Williams, Fred J. O'Dell, and Jeffrey K. Aronson, “Was William Harvey's Commitment to Experimentation Reflected in His Clinical Practice?”

    Journal of the Royal Society of Medicine 114, no. 6 (2021): 313–322. DOI: 10.1177/01410768211021335. Uses two surviving prescriptions to distinguish Harvey's experimental physiology from his continued use of conventional Galenic therapeutics.