The Mystery of Blood (Discovered 1628)
William Harvey’s 1628 discovery showed how blood circulates through our bodies, with the heart pumping nearly 2,000 gallons daily through a complex network of vessels. Scientists later revealed blood’s intricate makeup – each cubic millimeter contains roughly 5 million red blood cells, with hundreds of millions of hemoglobin molecules transporting oxygen. The book of Leviticus stated, “the life of the flesh is in the blood,” long before microscopes existed.