Puzzle No. 32: Chain

In 1628 the English physician William Harvey, physician to King Charles I, published at Frankfurt his short Latin treatise Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (An Anatomical Exercise on the Motion of the Heart and Blood in Animals), known simply as De Motu Cordis. Drawing on dissection, vivisection of animals, careful observation and quantitative reasoning, Harvey showed that the heart is a muscular pump that drives the blood in a continuous one-way circuit around the body, with the arteries carrying blood out and the veins returning it. He estimated the volume of blood expelled with each beat and demonstrated that the quantity was far too great for the body to manufacture and consume it anew, as Galenic doctrine had held for some 1,500 years. His conclusions overturned the prevailing belief that blood was constantly produced in the liver and consumed in the tissues. Though initially met with scepticism, and some who thought him 'crackbrained', Harvey's experimental method and his demonstration of circulation became a model of physiological investigation and a landmark of the Scientific Revolution in medicine.

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Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

Before William Harvey demonstrates the circulation of the blood

After William Harvey demonstrates the circulation of the blood

After William Harvey demonstrates the circulation of the blood

After William Harvey demonstrates the circulation of the blood