Exercitatio anatomica de motu cordis et sanguinis in animalibus
William Harvey (1628)
The English physician William Harvey (1578-1657) is credited
with being the first to correctly describe the properties of blood
being pumped around the body by the heart. His best-known
work, 'An Anatomical Exercise on the Motion of the Heart and the
Blood in Living Beings', investigates the effect of ligatures on
Depicted here is the only illustration in Harvey's treatise on
the circulation. It shows one of his experiments in which he "milks
the vein downward" to demonstrate the one-way action of the veins.
While the heart pumped blood around the body via the arteries, the
veins returned the blood to the heart where it was recycled. The
valves in the veins proved that only a closed, one-way system of
circulation could work.