The Manual also says: 'What we call the vascular system is like dykes and retaining walls forming a circle of tunnels which control the path that is traversed by blood so that it cannot escape or find anywhere to leak away.' The Chinese, always so methodical at measuring and weighing things, carried out investigations in which they removed the blood vessels from corpses, stretched them to their full length, and made measurements of the total distance traveled by the blood in one circuit. This was estimated by these measurements to be 162 feet.

  Once every twenty-four hours, the blood circulation and the ch'i circulation 'met' again in the wrist, having completed fifty blood circuits, so that the circulations coincided. The Chinese thus computed that the blood flowed 8 1 00 feet per day. During this time, 13,500 breaths were supposed to take place; this meant that the blood flowed six inches for every breath. By making all these calculations, the Chinese imagined themselves to be pinning down the phenomenon quite comfortably.

  The heart was clearly conceived of as pumping the blood. Indeed, Chinese doctors used in their classrooms an extraordinary system of bellows and bamboo tubes to pump liquid in demonstrations for their pupils, showing how the heart and blood circulation worked.

  In the calculations of the flow of the blood in the body, each circulation was estimated as taking 28.8 minutes. We know through medical research that this is too slow by sixtyfold, the true time being only thirty seconds. William Harvey had not come to any conclusion about this, speculating that the time taken might be 'half an hour ... an hour, or even ... a day'.

  The Dutch East India physician, Willem ten Rhijne, stated in his book of 1685, Mantissa Schematica de Acupunctura, that the circulation of the blood was one of the basic tenets of the whole of Chinese medicine. He wrote: 'The Chinese physicians ... perhaps devoted more effort over many centuries to learning and teaching with very great care the circulation of the blood, than have European physicians, individually or as a group. They base the foundation of their entire medicine upon the rules of this circulation, as if they were oracles of Apollo at Delphi.'

  In the very same year, the renowned scholar Isaac Vossius wrote that the Chinese had known of the circulation of the blood for four thousand years. As Needham says: 'He was of course taking the legendary date of the Yellow Emperor. But some two thousand years would have been right enough.' We thus see that three hundred years ago, it was widely realized in Europe that th Chinese had originated the idea of the circulation of the blood. But since that time, Europeans have reverted to a state of ignorance on the subject and forgotten this entirely.

Nature Discovery