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Blood History

Status Quo Under Fire

Developments and discoveries ushered in a new world of science. The discovery of pulmonary circulation -- described by an Egyptian centuries before any European reached the same conclusion -- presaged the eventual shattering of many medical beliefs held to be true since ancient Greece. The 17th century witnessed the first known blood transfusions, from animal to animal and, later, from animal to human. (Though animal-to-human transfusion offered no medical benefits, many recipients survived the procedure.) By the end of the century, scientists have observed, described, and even measured red blood cells.

mid-1200s: Eminent Cairo physician and author Ibn al-Nafis discovers and describes pulmonary circulation -- the flow of blood to and from the lungs.

1553: Unaware of al-Nafis' findings, Spanish physician and theologian Michael Servetus suggests that blood flows from one side of the heart to the other via the lungs instead of through the wall between the ventricles, which refutes Galen's theory. He is burned at the stake as a heretic for denying the Trinity.

1555: The Italian Andreas Vesalius criticizes Galen in the second edition of his seven volume work detailing human anatomy, DE FABRICA.

1603: Fabricius, the anatomist from Padua, publishes his work ON THE VALVES IN VEINS, featuring the first drawings of vein valves.

1628: British physician William Harvey publishes his masterwork EXERCITATIO ANATOMICA DE MOTU CORDIS ET SANGUINIS IN ANIMALIBUS (ANATOMICAL TREATISE ON THE MOVEMENT OF THE HEART AND BLOOD IN ANIMALS), in which he explains that blood circulates within the body and is pumped by the heart. DE MOTU CORDIS, which elicits great criticism, is the culmination of Harvey's years of experiments on animals -- and even on the surface veins of arms of living subjects.

1658: Jan Swammerdam, a 21-year-old Dutch microscopist, is thought to be the first person to observe and describe red blood cells.

1661: Using a rudimentary microscope, Italian anatomist Marcello Malpighi observes the capillary system, the network of fine vessels that connect the arteries and the veins.

1665: In England, Richard Lower performs the first recorded blood transfusion in animals. With a crude syringe made of goose quill and bladder, created by famed architect Christopher Wren, he connects the jugular vein of a dog he's bled to the neck artery of second dog, resuscitating the former.

1667: In June, French physician Jean-Baptiste Denis transfuses a teenage boy suffering from a persistent fever with nine ounces of lamb's blood. He attaches the lamb's carotid artery to a vein in the boy's forearm, without the patient suffering any negative consequences. Denis uses the procedure on several other patients, until the death of Antoine Mauroy, whom Denis transfuses twice with calf's blood in December.

On November 23, before the Royal Society in England, Drs. Richard Lower and Edmund King give Arthur Coga, an indigent former cleric, a transfusion of several ounces of sheep's blood for a fee of 20 shillings; the patient recovers nicely.

1670: Dr. Denis sues Antoine Mauroy's widow in 1668 for slandering his reputation. The case precipitates the French Parliament's ban on all transfusions involving humans. Similar actions follow in England and Rome.

1674: Unaware of the work of Swammerdam and Malpighi, Anton van Leeuwenhoek, a Dutch linen draper turned microscopist, provides a more precise description of red blood cells, even approximating their size, "25,000 times smaller than a fine grain of sand."