Acid medicine can converge, and it has the function of convergence. For example, Schisandra chinensis with spontaneous sweating and nocturnal emission, gallnut with chronic diarrhea and dysentery, ebony with chronic cough, and Cornus officinalis with sweating and bleeding are all sour. In addition, acid can also promote fluid production and moisturize skin, such as papaya and ebony. Sour medicine can control evil spirits, and should be used with caution if the evil spirits are not finished.