Ibn al-Nafis and the pulmonary circulation

Galen had taught that blood crossed from the right ventricle of the heart to the left through a passage in the wall between them. Ibn al-Nafis rejected this in his Commentary on Anatomy in Avicenna's Canon, which he published when he was 29. There is no passage between the two cavities, he wrote, visible or invisible. Blood from the right ventricle must reach the left by way of the lungs. He added that there must be small openings, which he called manafidh, between the pulmonary artery and the pulmonary vein, 400 years before Marcello Malpighi found the pulmonary capillaries.

He was born in or near Damascus in 1213 and studied medicine at the Nuri hospital there. At 23 he moved to Cairo, worked at the Nasiri hospital and then at the Mansuri, and became its chief physician. He was also an authority on religious law and a specialist in eye disease. His Concise Book, a digest of Ibn Sina's Canon, became the most popular of all the epitomes of that work. He wrote a separate commentary on the anatomy because Ibn Sina had scattered it through different sections of the Canon. When he died in 1288 he left his house and library to the Mansuri hospital.

A copy of the anatomical sections of the Canon finished by an unnamed scribe on 13 July 1584, now in the National Library of Medicine, has marginal notes that quote his commentary. They call him al-Qurashi, the name by which earlier writers knew him. His fellow student Ibn Abi Usaybi'a left him out of a biographical dictionary of more than 380 physicians, although it gave two chapters to contemporaries in Syria and Egypt; Emilie Savage-Smith of Oxford guessed at a rivalry between the two men.

In Europe the passage of blood through the lungs was described three centuries later by Michael Servetus, in 1553, and by Realdo Colombo, who died in 1559. Andrea Alpago's Latin translation of 1547 was of a different work by Ibn al-Nafis, a commentary on compound drugs, and apparently said nothing about the pulmonary transit. Muhyo al-Deen el-Tatawi, a young Egyptian physician, came across a manuscript in the Prussian State Library in Berlin and translated its account of the pulmonary circulation for his medical dissertation at Freiburg in 1924.