Introduction of green paper

According to Chen Shou's "History of the Three Kingdoms", Hua Tuo devoted his life to "Qingnangshu". This book records Hua Tuo's life's hard work and medical experience one by one, but it is said that due to the unfavorable protection of his disciples, this book was eventually burned. As a result, Qingnangshu was lost, and only a few pages were saved at that time, so the history books of junior high school and senior high school had Wuqinxi and Leprosy San.