2. Rehmannia glutinosa: (1) Take Rehmannia glutinosa, stew it with wine until the wine is completely absorbed, take it out, dry it in the sun until the mucus on the epidermis is slightly dry, cut it into thick pieces or blocks, and dry it. (per 100kg of rehmannia glutinosa, use 30 ~ 50 kg of yellow rice wine. (2) Take Radix Rehmanniae, steam it until it is black and moist, take it out, dry it in the sun until it is about 80% dry, cut it into thick slices or blocks, and dry it.