details his medical techniques. Hua Tuo's biography in the Houhanshu explains this mafeisan "numbing boiling powder" decoction was dissolved in jiu (; literally "alcoholic beverage; wine"). His prescription for mafeisan anaesthetic liquor was lost or destroyed, along with all of his writings. The Book of Sui lists five medical books attributed to Hua Tuo and his disciples, but none are extant. The subsequent portion of Hua Tuo's biography in the Sanguozhi lists 16 medical cases: ten internal medicine, three surgical, two gynaecological, and one paediatric case. Hua Tuo's treatment of diseases was centred on internal medicine, but also included surgery, gynaecology and paediatrics. He removed parasites, performed abortions and treated ulcers, sores and analgesia. For example: Cao Cao (155-220), a warlord who rose to power towards the end of the Han dynasty and laid the foundation for the Cao Wei state in the Three Kingdoms period, is probably Hua Tuo's best known patient. He suffered from chronic headaches, which were possibly caused by a brain tumour. Cao Cao's condition has also been translated as "migraine headaches accompanied by mental disturbance and dizziness" and the acupuncture point on the sole as identified as Yongquan (; "bubbling fountain"). Cao Cao ordered Hua Tuo to be his personal physician – a job Hua Tuo resented. In order to avoid treating Cao Cao, Hua Tuo repeatedly made excuses that his wife was ill, but Cao Cao discovered the deception and ordered Hua Tuo's execution. Xun Yu, one of Cao Cao's advisers, pleaded for mercy on behalf of the physician. Hua Tuo wrote down his medical techniques while awaiting execution, but destroyed his Qing Nang Shu (; literally "green bag book", which became a Classical Chinese term for "medical practices text"). This loss to traditional Chinese medicine was irreplaceable. Ilza Veith notes that, "Unfortunately, Hua T'o's works were destroyed; his surgical practices fell into disuse, with the exception of his method of castration, which continued to be practised. Due to the religious stigma attached to the practice of surgery, the social position accorded to the surgeon became increasingly lower and thus made a revival of Chinese surgery impossible." A Liezi legend claims that the renowned physician Bian Que ( 500 BCE) used anaesthesia to perform a double heart transplantation, but the fourth-century text was compiled after Hua Tuo used mafeisan. Cao Cao later regretted executing Hua Tuo when his son Cao Chong (196–208), a child