阉法与前项大略相同，惟仅阉牡兽，牝兽则不可阉，其阉割时期，亦随其类而异。大抵
马生后一年至半年，牛生后六月至九月，羊生后一月，过迟恐有妨生命，施术者不可不留意
也。
公鸡生后二、三月，即可阉割。阉割之前，自朝至暮，宜先令绝食。然后紧缚两翅，置
鸡身于阉割台上，台以竹木制之，有枢机能固定鸡身，使不得动。乃于其末一肋骨之前，去
毛纵剖之，约寸许，取出其肾子，缝其伤口。释使安居巢中，越日即如常。
元明粉最能降火化痰，清利脏腑，危症服之可蠲，狂躁用之即愈。炼法宜于冬至后取净
朴硝十斤，以水一斗五升，白萝卜五斤，同硝入锅内煮化。俟沸足，捞去萝卜，乃以绵纸二
层，摊竹丝箕内，乘热过滤。将其汁置露天中三日，其硝即逐渐凝结，沥去余水，干之。将
硝取下，再用砂锅倾炭炉上，将硝一碗，化开煎沸，以铜匙铲搅，将成凝结时，铲入小鱼酢
罐内，上空寸许，再下硝炼，如此已毕。每一罐下以三钉如品字形，钉入地中，上留半寸在
外，将罐浮顿钉头上，以瓦覆口，周遭以砖砌成百眼炉，围绕离罐寸许，以着火之炭，安入
炉内，四围及顶火、底火，须同时相护，俟罐硝红为度。次日将罐取出，预以绵纸平铺洁净
阴地上，将硝自罐中倾出碾细，以绢筛于棉纸上，浓约一钱。三日后其硝复活，色白如粉，
轻虚成片。再以钵盛之，除去潮气，收藏候用。
阉割的方法与前文所述大致相同，只是仅对雄性牲畜进行阉割，雌性牲畜则不可阉割。其阉割的时期，也随着物种的不同而有所差异。大体而言，马在出生后一年至半年内，牛在出生后六月至九月内，羊在出生后一个月内进行。如果时间过迟，恐怕会妨碍生命，施术者不可不留意这一点。
公鸡在出生后两三个月，即可进行阉割。阉割之前，从早晨到傍晚，应当先让鸡禁食。然后紧紧绑住双翅，将鸡身放置在阉割台上。阉割台由竹或木制成，带有枢轴机构可以固定鸡身，使其无法动弹。接着在其最后一根肋骨前方，去除毛发并纵向剖开，约一寸左右，取出其睾丸（肾子），缝合伤口。释放后让其安住在巢穴中，过一天便恢复正常。
元明粉最能降火化痰，清利脏腑，危重病症服用它可以消除，狂躁症状使用它即可痊愈。炼制方法适宜在冬至后取纯净朴硝十斤，用水一斗五升、白萝卜五斤，同硝一起放入锅内煮化。等到沸腾足够时，捞出萝卜，然后用两层绵纸，摊开在竹丝箕内，趁热过滤。将滤出的汁液置于露天处三天，其中的硝就会逐渐凝结，沥去剩余的水分，将其弄干。将硝取下，再用砂锅放在炭炉上，将一碗硝熔化煎沸，用铜勺铲搅拌，当快要凝结时，铲入小鱼酢罐内，上方留出一寸左右的空隙，再下硝炼制，如此完成。每一个罐子下面以三枚钉子呈品字形钉入地中，上面留出半寸在外面，将罐子浮顿在钉头上，用瓦片覆盖口部，周围用砖砌成百眼炉，围绕距离罐子一寸左右，将着火的炭安置入炉内，四周及顶部、底部的火，必须同时相互保护，等到罐内的硝变红为止。第二天将罐子取出，预先用绵纸平铺在洁净的阴凉地上，将硝从罐中倒出碾细，用绢筛筛在棉纸上，厚度约为一钱。三天后硝复活，颜色白如粉末，轻虚成片。再用钵盛装它，除去潮气，收藏起来备用。
The castration method is roughly the same as the previous item, except that only male animals are castrated, while female animals are not. The timing of castration also varies by species. Generally speaking, horses should be castrated between half a year and one year after birth, cattle between six and nine months after birth, and sheep within one month after birth. If performed too late, it may endanger life; practitioners must pay close attention to this.
Roosters can be castrated two to three months after hatching. Before castration, they should be fasted from morning until evening. Then, bind both wings tightly, place the chicken on the castration table, which is made of bamboo or wood and features a pivot mechanism to fix the chicken's body, preventing movement. Next, remove feathers and make a longitudinal incision of about one cun anterior to the last rib, extract the testicles (referred to as "kidneys"), and suture the wound. Release the bird into its coop; it will return to normal the following day.
Hua Tuo’s Divine Formulas for Preparing Various Medicines
Yuanming Powder (Refined Mirabilite) is most effective in descending fire, resolving phlegm, and clearing and benefiting the zang-fu organs. It can eliminate critical conditions when taken, and cure mania and restlessness upon use. The refining method is suitable for use after the Winter Solstice: take ten jin of pure Puxiao (Natrii Sulfas), one dou five sheng of water, and five jin of white radish. Boil them together in a pot until fully dissolved. Once sufficiently boiling, remove the radish. Filter the liquid while hot using two layers of cotton paper spread over a bamboo winnowing basket. Place the filtrate outdoors for three days, during which the mirabilite will gradually crystallize. Drain the remaining water and dry it. Remove the mirabilite, place a clay pot on a charcoal stove, melt one bowl of mirabilite until boiling, and stir with a copper spoon. When it begins to congeal, scoop it into a small fish-vinegar jar, leaving about one cun of space at the top. Repeat the refining process. For each jar, drive three nails into the ground in a triangular formation, leaving half a cun exposed above ground. Rest the jar on these nails, cover the mouth with tiles, and build a hundred-eye furnace around it with bricks, leaving about one cun distance from the jar. Place burning charcoal inside the furnace, ensuring that the fire surrounding the sides, top, and bottom protects each other simultaneously. Continue until the mirabilite in the jar turns red. The next day, remove the jar. Spread clean cotton paper flat on a cool, shaded surface. Pour the mirabilite out of the jar, grind it finely, and sieve it through silk gauze onto the cotton paper to a thickness of approximately one qian. After three days, the mirabilite "revives," becoming white like powder, light, and forming flakes. Store it in a mortar, remove moisture, and keep it for future use.