If you are interested in traditional Chinese medicine, these photographs are not to be missed. These photographs capture some of the earliest surviving texts to outline a theory of meridians – the channels through which qi, or vital energy, is thought to flow, forming the basis of acupuncture. Archaeologists discovered them in 1972 in the tomb of a noble family in southern China, dated to around the 160s BC. Rendered on silk cloth, the meridian system depicted here is markedly more rudimentary than the one known today, suggesting an early conceptual framework still in the process of taking shape.