北方炊食都用煤火，以地属坎，足胜其气，且助命门真火。人食煤火，长气于阴
，膂力强壮。南人食之，多发痈毒。受其毒者，以齑汁解之，然煤火处，置大缸水于旁，则
毒从水解。南方炊食都用薪火，人食薪火，长气于阳，气多轻浮不实，不似北方之禀气刚劲
也。凡煎补药，文火缓煎。泻药武火急煎。煎膏用桑柴火最良。抱朴子云∶一切神仙药，不
得桑柴不服。然不若煎收并用文火，则不伤药性。上古炊食都用燧火，是为阳火。今皆击石
取火则阴火也，用以炊食犹之可也。若点艾炷尤非所宜，灸艾宜取太阳真火，否则真麻油灯
，艾茎点于炷上，则灸疮至愈不痛。神针火治寒湿痹、附骨阴疽，凡在筋骨隐痛者针之，火
气直达病所。燔针即烧针，病在经筋所发诸痹，用之其效最捷。经云，治在燔针劫刺，以知
为度，以痛为愈。马矢 煨风痹药，取其性缓，通行经络也。苇薪火炊泻阳药，取其轻扬，
不损药力，二者皆《内经》法也。灯火淬小儿诸惊，及头风脑痛、风痹缓急，以油能解风毒
，火能通经络也。灯花治小儿邪热在心，夜啼不止，以二三颗灯心汤调，抹乳吮之。烛烬治
疔肿，同胡麻、针砂等分为末，和醋敷之。治九漏，与阴干马齿苋等分为末，和腊猪脂敷之
，取乌 之余力，以化歹肉也。至于烟草之火，方书不录，惟《朝鲜志》见之，始自闽人吸
以祛瘴，向后北人借以辟寒，今则遍行寰宇，岂知毒草之气，熏灼脏腑，游行经络，能无壮
火散气之虑乎？近日目科内障丸中，间有用之获效者，取其辛温散冷积之翳也。不可与冰片
同吸，以火济火多发烟毒。不可以藤点吸，恐其有蛇虺之毒也。吸烟之后，慎不得饮火酒，
能引火气熏灼脏腑也。又久受烟毒而肺胃不清者，以砂糖汤解之。烟筒中脂污衣上，涤之
不去，惟嚼西瓜仁揉之即净，其涤除痰垢之力可知也。世以瓜子仁生痰，不亦谬乎。
北方人做饭都用煤火，因为北方地处坎位（五行属水），地气旺盛，且能助长命门中的真火。人食用经煤火烹煮的食物，能使阴气增长，从而体力强壮。南方人食用后，却容易引发痈疽毒疮。受到煤火毒性影响的人，可以用醋汁来解毒；但在烧煤的地方，旁边放置大水缸，毒性就会随水分化解。
南方人做饭都用柴火，人食用经柴火烹煮的食物，能使阳气增长，但气多轻浮不实，不像北方人的禀赋那样刚劲有力。凡是煎煮补益药物，要用文火缓慢煎煮；煎煮泻下药物，要用武火快速煎煮。煎制膏剂用桑柴火最好。抱朴子说：一切神仙药，没有不用桑柴火煎服的。然而，不如采用煎煮与收膏并用文火的方法，这样才不会损伤药性。
上古时代做饭都用燧石取火，这属于阳火。现在都是击石取火，这属于阴火，用来做饭还可以。但如果用来点燃艾炷进行艾灸，就很不适宜了。艾灸宜取太阳真火，或者使用纯麻油灯，将艾茎点在艾炷上燃烧，这样灸疮直到痊愈也不会疼痛。神针火用于治疗寒湿痹证、附骨阴疽，凡是筋骨间有隐痛的症状，用此法针刺，火气能直达病所。燔针即烧红的针，对于病在经筋所引发的各种痹证，使用它效果最快捷。《内经》说：治疗在于燔针劫刺，以症状缓解为度，以疼痛消失为痊愈。用马粪煨制治疗风痹的药物，是取其药性缓和，能通行经络。用芦苇薪火煎煮清泻阳热的药物，是取其性质轻扬，不损伤药力，这两种方法都符合《内经》的法度。
用灯火灼烫治疗小儿的各种惊风，以及头风脑痛、风痹引起的肢体缓急，是因为油能解风毒，火能通经络。灯花可以治疗小儿心经邪热导致的夜间啼哭不止，用二三颗灯心草煎汤调服，或涂抹在乳头上让婴儿吮吸。烛灰可以治疗疔肿，与胡麻、针砂等分研成末，加醋调和敷贴。治疗九漏（一种淋巴结核类疾病），与阴干的马齿苋等分研成末，加腊月猪脂调和敷贴，这是利用乌贼鱼余留的力量，来化除坏死的肌肉。
至于烟草之火，医方书中没有收录，只在《朝鲜志》中见到，起初是福建人吸食以祛除瘴气，后来北方人借用它以抵御寒冷，如今则遍布全球。岂不知烟草是毒草之气，熏灼脏腑，游行于经络之中，怎能没有“壮火散气”的忧虑呢？近日眼科内障丸中，偶尔有用烟草取得疗效的，是取其辛温之性以消散冷积形成的翳障。不可与冰片一同吸食，因为火上加火容易多发烟毒。不可用藤管点吸，恐怕其中含有蛇蝎类的毒素。吸烟之后，务必不要饮用烈性酒，因为酒能引动火气熏灼脏腑。另外，长期受烟毒侵害导致肺胃不清的人，可以用砂糖汤来解毒。烟筒中的油脂弄脏衣服，洗涤不掉，只有咀嚼西瓜仁揉搓即可洗净，由此可知其涤除痰垢的能力。世人认为瓜子仁生痰，难道不是谬论吗？
In the North, cooking is done using coal fire. Since the region belongs to Kan (Water element in Five Phases), the earthly Qi is strong and assists the True Fire of the Mingmen (Gate of Life). People consuming food cooked with coal fire have their Yin Qi enhanced, resulting in robust physical strength. However, when people from the South consume such food, they are prone to developing carbuncles and toxic sores. Those affected by the toxicity can be detoxified with vinegar juice; furthermore, placing large vats of water nearby where coal is burned allows the toxicity to be dissolved by the water.
In the South, cooking is done using firewood. People consuming food cooked with firewood have their Yang Qi enhanced, but this Qi tends to be light, floating, and insubstantial, unlike the sturdy constitution found in the North. When decocting tonifying medicines, a gentle fire (Wen Huo) should be used for slow simmering. For purgative medicines, a fierce fire (Wu Huo) should be used for rapid boiling. For preparing pastes, mulberry wood fire is considered the best. Baopuzi stated: "All immortal medicines must not be taken without being prepared with mulberry wood fire." However, it is better to use gentle fire for both decocting and collecting the paste, so as not to damage the medicinal properties.
In ancient times, cooking was done using fire obtained by friction (sui fire), which is considered Yang Fire. Nowadays, fire is obtained by striking stones, which is considered Yin Fire. While suitable for cooking, it is inappropriate for lighting moxa cones for moxibustion. Moxibustion should utilize the True Fire of the Sun, or alternatively, a pure hemp oil lamp can be used to ignite the moxa stem on the cone; in this case, the moxibustion sore will heal without pain. Shen Zhen Huo (Divine Needle Fire) is used to treat cold-damp Bi syndrome (painful obstruction) and deep-seated yin abscesses (Fu Gu Yin Ju); for any hidden pain in the muscles and bones, needling with fire allows the fire Qi to reach the disease site directly. Fan Zhen (Burning Needle) refers to red-hot needles; for various Bi syndromes originating in the meridians and sinews, its effect is most rapid. The Classic states: "Treatment lies in burning needle robbery puncture, taking symptom relief as the limit, and pain cessation as healing." Ma Shi Wei Feng Bi Yao (Moxa medicine simmered with horse dung) is used because its nature is mild and it promotes circulation through the meridians. Wei Xin Huo (Reed fire) is used to decoct Yang-clearing medicines because its nature is light and ascending, preserving the medicinal power; both methods align with the principles of the *Neijing* (Inner Canon).
Deng Huo Cui (Fire-lamp cauterization) treats various infantile convulsions, head wind and brain pain, and wind-Bi causing flaccidity or spasticity, because oil resolves wind toxicity and fire unblocks the meridians. Deng Hua (Lamp wick ash) treats infantile evil heat in the Heart causing incessant night crying; two or three grains mixed with Deng Xin Tang (Juncus effusus decoction) are administered, or applied to the nipple for the infant to suck. Zhu Jin (Candle residue) treats ding zhong (carbuncles); mixed with equal parts of Sesamum indicum seed (Hu Ma) and iron filings (Zhen Sha), ground into powder, and applied with vinegar. To treat Jiu Lou (nine types of scrofula/lymphatic tuberculosis), mix with equal parts of air-dried Portulaca oleracea (Ma Chi Xian), ground into powder, and applied with lard from the twelfth lunar month; this utilizes the residual power of the cuttlefish (W Yu) to resolve necrotic tissue.
Regarding tobacco fire, it is not recorded in medical formularies, appearing only in the *Choson Ilgi* (Records of Choson). It originated among Fujian people who smoked it to dispel miasma, later adopted by Northerners to ward off cold, and now spreads worldwide. Who would know that the qi of this poisonous herb scorches the Zang-Fu organs and travels through the meridians, raising concerns about "vigorous fire dissipating Qi"? Recently, some internal cataract pills in ophthalmology have shown efficacy with tobacco, utilizing its acrid-warm nature to scatter cold accumulation causing visual obstructions. It should not be inhaled together with Borneolum Syntheticum (Bing Pian), as fire adding to fire generates more toxic smoke. It should not be inhaled via vines, fearing the presence of snake venom. After smoking, one must strictly avoid drinking strong liquor, as alcohol draws fire Qi to scorch the viscera. Furthermore, those whose Lung and Stomach are clouded by long-term tobacco toxicity can be detoxified with sugar water. Grease from the pipe stain clothes and cannot be washed off, but chewing watermelon seeds and rubbing cleans them immediately, demonstrating its power to clear phlegm and dirt. Is it not absurd that the world believes melon seeds generate phlegm?