The first Chinese herbal book, the Shennong Ben Cao Jing, compiled during the Han Dynasty but dating back to a much earlier period, possibly 2700 BC, lists 365 medicinal plants and their uses. Succeeding generations augmented on the Shennong Ben Cao Jing, as in the Yaoxing Lun (Treatise on the Nature of Medicinal Herbs), a 7th century Tang Dynasty treatise on herbal medicine. The Huangdi neijing, the most important classic in the history of Chinese medicine, had an enormous influence on medical thought in later centuries. It records the dialogues between a Chinese Emperor and some of his sage physicians on medical issues. While the emperor’s questions encompass every possible aspect of diagnostics, pathology, acupuncture, and moxibustion, including both theory and practice, the sage teachers give detailed explanation of each topic.