The 1639 Leiden edition of Harvey's De Motu Cordis & sanguinis in animalibus, anatomica exercitatio present in the Lane Library is the second complete edition of the work published originally in Frankfurt, 1628. In De Motu Cordis William Harvey published his discovery and experimental proof of the circulation of the blood. Harvey's work fundamentally changed concepts about the heart and blood vessels, eventually leading to a reform of all physiology. The 1639 edition has the full text and illustrations, along with refutations, including those of Primrose, who was the first to go into print against Harvey in 1630, a year after Harvey had passed him as a licentiate of the College of Physicians.--J. Norman, 2006.