用朴硝炼玄明粉，原用莱菔。然此法今人不讲久矣。至药局所鬻者，乃风化硝，非玄明粉也。今并载其法，
以备参观。
其法∶于冬至后，用洁净朴硝十斤，白莱菔五斤切片，同入锅中，用水一斗五升，煮至莱菔烂熟，将莱菔
捞出。用竹筛一个，铺绵纸二层，架托于新缸之上，将硝水滤过。在庭露三日，其硝凝于缸边，将余水倾出，
晒干。将硝取出，用砂锅熬于炉上，融化后，搅以铜铲，熬至将凝，用铲铲出。再装以瓷罐，未满者寸许，盖
以瓦片。用钉三个，钉地作鼎足形，钉头高二寸，罐置其上，用砖在罐周遭，砌作炉形，多留风眼，炉砖离罐
三寸。将木炭火置于炉中，罐四围上下都被炭火壅培，以 至硝红为度。次日取出，再用绵纸铺于净室地上，
将硝碾细，用绢罗筛于纸上浓一分。将户牖皆遮蔽勿透风，三日后取出，其硝洁白如粉，轻虚成片。其性最能
降火化痰，清利脏腑。怪证服之可蠲，
狂躁用之即愈。搜除百病，安敛心神。大人服二、三钱，小儿服五分至一钱，用白汤或葱汤融化，空心服之。
服药之日，不宜食他物，惟饮稀粥。服二三次后、自然精神爽健，脏腑调和，津液顿生，百病如失。惟久病泄
泻者，服之不宜。
浓朴∶味苦辛，性温。治胃气上逆，恶心呕哕，胃气郁结胀满疼痛，为温中下气之要药。为其性温味又兼
辛，其力不但下行，又能上升外达，故《神农本草经》谓其主中风伤寒头痛，《金匮》浓朴麻黄汤，用治咳而
脉浮。与橘、夏并用，善除湿满；与姜、术并用，善开寒痰凝结；与硝、黄并用，善通大便燥结；与乌药并用，
善治小便因寒白浊。味之辛者属金，又能入肺以治外感咳逆；且金能制木，又能入肝、平肝木之横恣以愈胁下
掀疼；其色紫而含有油质，故兼入血分，甄权谓其破宿血，古方治月闭亦有单用之者。诸家多谓其误服能脱元
气，独叶香岩谓“多用则破气，少用则通阳”，诚为确当之论。
【附案】一少妇因服寒凉开胃之药太过，致胃阳伤损，饮食不化，寒痰瘀于上焦，常常短气，治以苓桂术
甘汤加干姜四钱、浓朴二钱，嘱其服后若不觉温暖，可徐徐将干姜加重。后数月见其家人，言干姜加至一两二
钱、浓朴加至八钱，病始脱然。问何以并将浓朴加重？谓“初但将干姜加重则服之觉闷，后将浓朴渐加重至八
钱始服之不觉闷，而寒痰亦从此开豁矣。”由是观之，元素谓∶寒胀之病，于大热药中兼用浓朴，为结者散之
之神药，诚不误也。
愚二十余岁时，于仲秋之月，每至申、酉时腹中作胀，后于将作胀时，但嚼服浓朴六七分许，如此两日，
胀遂不作。服浓朴辛以散之，温以通之，且能升降其气化是以愈耳。
愚治冲气上冲，并挟痰涎上逆之证，皆重用龙骨、牡蛎、半夏、赭石诸药以降之、镇之、敛之，而必少
用浓朴以宣通之，则冲气痰涎下降，而中气仍然升降自若无滞碍。
[Appendix: Method for Refining Glauber's Salt into Xuanming Powder]
To refine Glauber's salt (Mirabilite) into Xuanming powder, radish was originally used. However, this method has long been neglected by people today. What is sold in pharmacies now is weathered saltpeter (Fenghua Xiao), not Xuanming powder. The method is recorded here for reference.
The method is as follows: After the Winter Solstice, take ten jin of clean Glauber's salt and five jin of white radish sliced, put them together in a pot, add one dou and five sheng of water, and boil until the radish is soft and cooked, then remove the radish. Use a bamboo sieve lined with two layers of cotton paper, supported over a new vat, to filter the brine. Leave it exposed to the dew in the courtyard for three days; the salt will crystallize on the sides of the vat. Pour out the remaining water and dry it in the sun. Take out the salt, melt it in an earthenware pot on a stove, stir with a copper spatula, and cook until it is about to solidify, then scoop it out with the spatula. Place it in a porcelain jar, filling it to within one cun of the rim, and cover it with a tile. Drive three nails into the ground in a tripod shape, with the nail heads two cun high, and place the jar on top. Build a furnace shape around the jar using bricks, leaving many ventilation holes, with the furnace bricks three cun away from the jar. Place charcoal fire in the furnace, surrounding the jar completely above and below with the heat, until the salt turns red. Remove it the next day, spread cotton paper on the floor of a clean room, grind the salt into fine powder, sift it through a silk gauze onto the paper to concentrate it slightly. Cover all doors and windows to prevent wind from entering. After three days, take it out; the salt will be white and powdery, light and fluffy in flakes. Its nature is most effective in descending fire and resolving phlegm, clearing and benefiting the zang-fu organs. It can eliminate strange diseases, and cure mania and restlessness immediately. It searches out and removes hundred diseases, and calms and gathers the spirit. Adults take two or three qian, children take five fen to one qian, dissolved in plain water or scallion water, taken on an empty stomach. On the day of taking the medicine, other foods should not be eaten, only thin porridge may be drunk. After two or three doses, one will naturally feel energetic and vigorous, the zang-fu organs will harmonize, body fluids will suddenly generate, and hundred diseases will disappear. However, it is not suitable for those suffering from chronic diarrhea.
Cortex Magnoliae Officinalis (Houpo): Bitter and pungent in taste, warm in nature. It treats rebellious Stomach Qi, nausea, vomiting, and distension and pain due to Stomach Qi stagnation, making it an essential herb for warming the middle and directing Qi downward. Because its nature is warm and its taste is pungent, its force not only moves downward but also upward and outward. Therefore, *Shennong Bencao Jing* states that it treats headache due to Wind-Cold and Cold Damage. In *Jingui Yaolue*, the Houpo Mahuang Decoction is used to treat cough with a floating pulse. When used with Pericarpium Citri Reticulatae (Chenpi) and Rhizoma Pinelliae Preparatae (Banxia), it is good at removing dampness and fullness; when used with Rhizoma Zingiberis Recens (Ganjiang) and Poria (Fuling) or Atractylodis Macrocephalae Rhizoma (Baizhu), it is good at opening cold-phlegm congealation; when used with Glauber's Salt (Puxiao) and Radix et Rhizoma Rhei (Dahuang), it is good at unblocking dry fecal impaction; when used with Rhizoma Linderae (Wuyao), it is good at treating cloudy urine due to cold. The pungent taste belongs to Metal, so it can enter the Lung to treat external contraction-induced cough and wheezing; moreover, Metal controls Wood, so it can enter the Liver to pacify the rampant Liver Wood and heal tearing pain under the ribs. Its purple color and oily content allow it to enter the Blood aspect. Zhen Quan stated that it breaks old blood stasis; ancient formulas for amenorrhea sometimes used it alone. Most schools believe that accidental overdose can deplete Yuan Qi, but Ye Tianshi said, "Large doses break Qi, small doses unblock Yang," which is indeed an accurate judgment.
[Attached Medical Case] A young woman, having taken too much cold-natured herbs to open the appetite, suffered damage to Stomach Yang, leading to indigestion and cold-phlegm stasis in the Upper Jiao, causing frequent shortness of breath. She was treated with Ling Gui Zhu Gan Tang plus four qian of Ginger Root (Shengjiang/Ganjiang - context implies dried ginger given the condition) and two qian of Cortex Magnoliae Officinalis (Houpo). She was instructed that if she did not feel warmth after taking it, she could gradually increase the dose of Ginger Root. Months later, I saw her family member, who said that after increasing Ginger Root to one liang and two qian, and Cortex Magnoliae Officinalis to eight qian, the illness finally disappeared completely. Asked why Cortex Magnoliae Officinalis was also increased, they replied, "Initially, only increasing Ginger Root made me feel stifled after taking it. Later, gradually increasing Cortex Magnoliae Officinalis to eight qian, I no longer felt stifled, and the cold-phlegm was thereby cleared." From this, we see that Li Dongyuan said: For diseases of cold-type distension, using Cortex Magnoliae Officinalis alongside large hot herbs is a divine medicine for dispersing knots, which is indeed correct.
When I was in my twenties, during the mid-autumn month, my abdomen would become distended every day at Shen and You hours (3-7 PM). Later, just before the distension started, I would chew and swallow about six or seven fen of Cortex Magnoliae Officinalis. Doing this for two days, the distension ceased. Taking Cortex Magnoliae Officinalis worked because its pungency disperses and its warmth unblocks, and it regulates the ascending and descending of Qi transformation, thus curing the condition.
In treating cases where Chong Qi rebels upward, accompanied by phlegm-fluids rushing up, I always heavily use Dragon Bone (Longgu), Oyster Shell (Muli), Rhizoma Pinelliae Preparatae (Banxia), and Hematitum (Zhe Shi) to descend, anchor, and gather. However, I must use a small amount of Cortex Magnoliae Officinalis to diffuse and unblock. Then, the Chong Qi and phlegm-fluids descend, while the Middle Qi continues to ascend and descend freely without obstruction.