Ai Handan, a 51-year old pharmacist working at a hospital in south China\'s Yunnan province, has been lamenting the decline of his craft in recent years. The type of pharmacology Ai practices is not seen in most hospitals. Ai deals in Dai ethnic pharmacology, a practice that dates back more than 2,500 years and features the use of rare herbs and other botanicals. \"Resources for finding rare herbs have been drained. More worryingly, fewer people are interested in hearing about traditional medicine,\" he said. Ai works at China\'s only Dai ethnic hospital, located in Yunnan\'s Xishuangbanna Dai autonomous region. Dai ethnic medicine is based on a Buddhist belief that both the world and the human body are made up of four basic elements (wind, fire, water and earth). \"(Dai ethnic medicine) is nature\'s gift to the Dai ethnic group,\" Ai said. In the past, formulae for Dai medicines were incribed on palm leaves that were passed on from generation to generation. However, this practice, as well as many other features of Dai ethnic medicine, have largely been lost on younger generations. 23-year-old Ai Kan, Ai\'s eldest son, has refused to follow his father\'s career path, choosing instead to plant rubber on the hillsides surrounding their home city. \"Learning the craft is not easy, and a good return is not promised,\"Ai Kan said. To help preserve the ancient medical practices, Ai has been tutoring 49 students as part of a Dai ethnic medicine program being offered at the Xishuangbanna Vocational and Technical Institute.