Sir

I was drawn to read P.-L. Chau's letter about the Chinese discovering blood circulation1 by the provocative title “Chinese beat Harvey on blood flow” on the contents page. Chau quoted science historian Joseph Needham2 as saying that, in the medical treatise Su Wên (part of The Yellow Emperor's Classic of Internal Medicine), “Chhi Po says that ‘the flow in the tract and channel runs on and on, and never stops; a ceaseless movement in an annular circuit…’. Clearly the circulation of the blood and chhi was standard doctrine [in the second century BC]”.

But who is Chhi Po? According to Paul Unschuld3, a medical historian and authority on Chinese medicine, Chhi Po or Qí Bó, the most important interlocutor of the Yellow Emperor in The Yellow Emperor's Classic of Internal Medicine, is none other than Hippocrates.

Qí Bó is a man who has no historical background in Chinese history or mythology. This fact, together with the Hàn-period pronunciation of his name, allows speculation that the fame of the Greek physician reached China two centuries after his death — to the extent that he is quoted as a living authority in medical textbooks of the time.