1 Introduction to the Prologue Hall: Dong'e Introduction: Tao Hongjing, a famous medical scientist and Taoist in the Southern and Northern Dynasties, once said in his "Famous Doctors": "Donkey-hide gelatin comes from Dong'e, so it is named donkey-hide gelatin. "It can be seen that donkey-hide gelatin is named after it is produced in Dong'e County. Dong'e County has a long and splendid history and culture. It was established as early as the Spring and Autumn Period and the Warring States Period. It was called Keyi at that time and later evolved into Ayi. Beautiful and legendary stories have happened in the land of Dong'a, such as Dayu's flood control, Yanzi's control of A, and Cao Zhi's title of king. But it is a magical Chinese medicinal material - donkey hide gelatin - that makes Dong'a famous all over the world.