Li Chunfeng, the Chinese mathematician, astrologer and cosmologist, wearing traditional costume, holding the 'Eight Trigrams' symbol incorporating the 'Yin-yang' symbol. Watercolour, China, 18--.

Licence: Public Domain Mark

Credit: Li Chunfeng, the Chinese mathematician, astrologer and cosmologist, wearing traditional costume, holding the 'Eight Trigrams' symbol incorporating the 'Yin-yang' symbol. Watercolour, China, 18--. Wellcome Collection. Source: Wellcome Collection.