The Cairo doctor who described the lungs' circulation 300 years early

Around 1242 CE, the physician Ibn al-Nafis, working in Cairo, described how blood passes from the right side of the heart through the lungs before returning to the left side — the pulmonary circulation. He set this down in his commentary on the anatomy of Ibn Sina's Canon, more than three centuries before the English physician William Harvey (1578–1657) published his own account of the circulation in his 1628 De Motu Cordis. The Arabic manuscript only resurfaced in the 20th century.

One of many fact-checked wonders across eight traditions at The Spring of Wisdom.