Springing from the “true to nature” ethos of his paintings, Leonardo’s fascination with the human body took him to the morgues and hospitals of Florence, where he performed dissections of corpses, often of executed criminals. His greatest feat was understanding the workings of the heart. After discovering a bulb-shaped swelling at the root of the aorta, he came strikingly close to uncovering the mechanisms of blood circulation more than a century before formal science arrived at it. In fact, he injected melted wax into the heart of an ox, then a glass model of the cast and pumped it with water with a suspension of grass seeds in order to observe the vortexes at work. He then concluded that the swelling made the aortic valve close after each heartbeat, a proposition which cardiologists didn’t arrive at until the early 20th century and didn’t fully confirm until the 1980s.

Perhaps his most famous anatomical drawing was of a 100-year-old man, who had reported being in excellent health mere hours before his death. When Leonardo dissected him to see “the cause of so sweet a death” and found cirrhosis of the liver and a blockage of an artery to the heart, producing the first-ever description of what is now known as coronary vascular occlusion.

As a great artist, Leonardo had two advantages over his contemporary anatomists. First of all, as a sculptor, engineer, architect, he had an intuitive understanding of form — when he dissected a body, he could understand in a very fluid way how the different parts of the body fit together, worked together. And then, having made that understanding, as a supreme draftsman, he was able to record his observations and discoveries in drawings of such lucidity, he’s able to get across the form, the structure to the viewer in a way which had never been done before and, in many cases, has never been surpassed since.

Leonardo intended to publish his drawings as an illustrated treatise on human anatomy, but when he died in 1519, his anatomical papers were buried amongst his private possessions and vanished from public sight. In the early 1600s, around 600 of his surviving drawings were bound in a single collection and by the end of the century, they mysteriously made their way to the Royal Collection. Leonardo da Vinci: Anatomist gathers 90 of these seminal drawings, contextualized in a discussion of their anatomical significance. Accompanying the books is an iPad app, presenting 268 pages of Leonardo’s notebooks in magnificent high resolution.