The majority of the beliefs held by Han Chinese physicians are known through texts such as the Yellow Emperor's Inner Canon medical corpus, which was compiled from the 3rd to 2nd century BCE and was mentioned in the Book of Later Han. It is clear from this text and others that their metaphysical beliefs in the Five Phases and Yin and Yang dictated their medical decisions and assumptions. The Han Chinese believed that every organ in the body was associated with one of the five phases (metal, wood, water, fire, earth) and had two circulatory qi channels. Disruption of these channels would yield dire consequences, so Han medical texts suggest that one should consume an edible material associated with one of these phases that would counteract the organ's prescribed phase and thus restore one's health. For example, the Chinese believed that when the heart—associated with the fire phase—caused one to become sluggish, then acidic food should be eaten because sour was associated with the wood phase, which promoted fire. The Han Chinese also believed that by using pulse diagnosis, a physician could determine which organ of the body emitted qi and what qualities the latter had, in order to figure out the exact disorder the patient was suffering. In his Essential Medical Treasures of the Golden Chamber, Zhang Zhongjing was the first to suggest that a regulated diet rich in certain vitamins could prevent different types of disease, an idea which to physicians prescribing a diet rich in Vitamin B1 as a treatment for beriberi. Zhang's contemporary and alleged associate Hua Tuo used anesthesia on patients during surgery and created an ointment that was meant to fully heal surgery wounds within a month. In one diagnosis of an ill woman, he deciphered that she bore a dead fetus within her womb which he then removed, curing her of her ailments.