伤寒，外感之总名也；《伤寒论》，统论外感之书也。
（注）《难经》云∶伤寒有五。则五种外感，昔人皆谓之伤寒矣。《伤寒论》有治风、治温、治喝。治湿
诸法，则非专论一伤寒矣。
《伤寒论》云∶太阳病，或已发热，或未发热，必恶寒，体痛呕逆，脉阴阳俱紧者，名曰伤寒。是正伤寒
病也。
（注）伤寒无不发热者，此云或未发热者，乃身热未发之时，先见恶寒等证，所谓“无热恶寒发于阴”。
寒为阴邪，故往往先恶寒而后发热也。脉阴阳俱紧，即尺寸皆紧，紧为坎中满之象，坎为寒水之卦，故伤寒之
脉必紧。若已发热，紧必兼浮可知已。
太阳病，头痛发热，身疼腰痛，骨节疼痛，恶风，无汗而喘者，麻黄汤主之。是正伤寒治法。
（注）寒邪凝冱，表气塞实，故无汗气喘而恶风寒。麻黄汤温散发汗之方，设非正伤寒而误用之，则有亡
阳之祸。
伤寒四时皆有，有是脉，有是证，即用是药。谚云∶“对证发药”，旨哉言乎！病势较轻，体气稍弱者，
则羌、防、苏、芷皆可代麻黄用也。若寒伤于外，热伏于内者，温散方中须佐清凉之品，仿长沙大青龙之制可
耳。
（注）四时皆有伤寒，然冬三月乃寒水司令，较三时之寒为
独盛，故昔人以冬月感寒即病者为正伤寒，非谓春夏秋并无伤寒也。医者苟能辨证清楚，用药自不泥于时令矣。
伤寒者，寒伤于外而邪客于表也。若其人阳气素虚，无以捍御，则外寒得以直入于内而犯脏，名曰中寒，
盖阳衰则阴盛也。阴虽盛，却忌温散之法，因阳气既衰，其汗易出，误投温散，更速其危。亟用姜、附回阳破
阴，是为治法。
（注）阳衰则阴盛，可见阴未尝盛，只缘阳衰，故阴盛耳。是以中寒不必隆冬之令，虽盛暑之时亦有之。
昔人有治此而愈者，乃不谓其阳衰饮冷、夏月中寒，而以为静得之阴暑，自误误人，可为叹惜。姜、附回阳破
阴，即兵家强主弱客之法。
《伤寒论》之中风，为《难经》五种伤寒之一，即后世之伤风是也。盖“伤”与“中”字义无殊，如云风
伤卫、寒伤营是矣。后人以寒邪在表者为伤寒，寒邪入里者为中寒，遂疑伤轻而中重，然此不过分别邪之在表
、在里耳。夫入里之寒，何必重于在表之寒耶？实因本阳既衰，故客寒得以直入。发表以取汗，是治标也，其
邪不得为轻；温里以回阳，是治本也，其邪不必较重。病分标本，则本为重而重之，非邪较重而重之也。明乎
此，则越人、长沙之谓风为中，即谓寒为伤之意矣。
（注）后世以外感风邪为伤风，虚风卒倒为中风，庶二病之名目不相混也。然“伤”、“中”二字之义，
弥觉轻重悬殊矣。故昧者泥于越人、长沙之谓风为中，而不知即是伤风，竟与卒倒扑击互相引证者，误矣。
风之伤人也，既为五种伤寒之一，夫岂小病者！且风无定性，不但四时有异、四方不同也。燥湿不齐，雨
迥判，风寒风热，顷刻变迁。感之于人，施治有别。长沙桂枝证，风寒病也；发汗已身灼热者，风热病也。
然昔人往往知有风寒而不知
有风热。《伤寒论》又云∶服桂枝汤，大汗出后，大烦渴不解，脉洪大者，白虎加人参汤主之，合而观之，岂
非误以风寒药治风热病之变证哉？汉代且然，况后人乎！
（注）今人视伤风为轻小之病，其头疼发热者，则曰重伤风，是未知伤风即越人、长沙所谓之中风也。病
源不清，无怪乎有过服温燥以夺其液，早投滋补以锢其邪，延久成劳，尚诿为伤风不醒。噫，医实不醒也。
风热即风温也，四时皆有，冬春为甚。长沙云∶若发汗已身灼热者，风温也。盖言风寒为病，可以桂枝汤
发汗而愈，若发汗而热反灼者，乃风温病，温即热之谓也。后人不为详玩，而谓风温为汗后坏病，抑何固耶？
夫病本热也，加以桂枝之辛热，故液为热迫而汗大出，液去则热愈灼，故大烦渴而脉洪大。二条似论一证，主
以白虎加人参汤，正《内经》风淫热淫治以甘寒之旨也。惟香岩先生独窥其微，谓风温首必犯肺，先卫后气。
治法初用辛凉，继以甘寒。超超元箸，万古开群蒙也。
（注）《伤寒论》病患藏无他病条，发汗则愈，病常自汗出条，复发其汗则愈，并主桂枝汤。可见桂枝汤
是风寒发汗之剂，不过较麻黄汤为和缓耳。《内经》明言辛甘发散为阳，岂可以治风热之病乎？更有谓桂枝汤
止汗者，尧封先生已辨其误矣。
（校）近见淮阴吴氏《温病条辨》一书，以桂枝汤为治温首方，更属可议。
（刊）《医林改错》云∶发热有汗之证，从未见桂枝汤治愈一人。杨素园明府大不以为然，谓尝治风伤卫证，
桂枝汤半剂辄愈。雄按∶《改错》所云者，乃温热证也。若风寒伤卫，岂可不遵圣法？即叶案咳嗽门首列伤风数
条，皆从《伤寒论》变化。
至于中风，《内经·生气通天论》谓之虚邪，是本先虚而后邪中之也。《通评虚实论》谓肥贵人则膏粱之
疾也。此后贤主痰、主火、主气、主虚诸说，皆本于此，细绎经文，则真中风本虚邪中，不可竟以为实证，类
中风肥甘酝酿，未可概以为虚证。必也随其证之虚实而调剂之，治百病无余蕴矣！中风云乎哉？
（注）凡证有大虚者，有大实者，有虚中实、实中虚者，有虚多实少、实多虚少者，诸家之说皆有精义，
既不可废，亦不可执，贵乎用之者适其当耳。
冬春感受风热而病者，名曰风温，前已辨之矣。若冬伤于寒，至春令发泄之时，伏气化热而出，名曰春温，
亦曰温病。其邪自内达外，故发热而渴，不恶寒也。然亦有挟新感之风寒而发者，虽恶风寒而口必渴，若误汗
之，祸不可言。长沙而后知此义者，惟郭白云、刘守真、王安道、张石顽、周禹载、叶香岩数君而已，其书皆
不可不读也。
（注）温者，热之渐也。伏寒化热，口燥而渴，故谓之温。一切温散燥热之药，皆不可犯。奈何以喻氏之
贤，而误指《金鉴》春月伤寒为温病，治虽合法，立论大谬，在泾先生非之是矣，而俞惺斋、毛达可佥极口赞
颂，未免贻误将来。
冬伤于寒，伏于少阴，夏至前发出者，名曰温病矣；若夏至后发出者，名曰热病。以夏至前天气尚温，夏
至后天气已热，皆随时令以名其病也。其名虽异，其病相同，故温热二病，古人往往互称。《内经》则云后夏
至日者为病暑，亦以夏至后炎暑司令，故曰病暑。且在天为热，在地为火，其性为
暑，是暑即热之谓也。第此之病暑，因于伏寒化热，与吸受暑邪而病者，其名虽同，其因则异也。
（注）以温热二字命为病名，似不过分其时令之气耳。然名曰温者，凉之可愈，名曰热者，寒之乃瘳。顾名
思义，治法已无余蕴，故不嫌与感冒之温、吸受之暑同名者，正示人以殊途同归之旨，岂非古圣析义之精耶？
夏令属火，日光最烈，天时乃热，人感其气，名曰伤暑，亦曰中暑。暑字从日，曰炎暑，曰酷暑，皆指
烈日之火而言也。盖日为众阳之宗，日出则爝火无光，阳燧承之，火可立至。《内经》云∶岁火太过，炎暑流
行。若三冬久霁，则生燥火之病，况夏月之暑乎？而长沙名中热曰 ，不曰暑者，所以别于夏至后发之伏气暑
病也。且《说文》∶ ，伤暑也。故暑、热、 三者，皆烈日之气也。后人昧此，遂多歧说，可谓不知
冷热之人矣。暑为离火，离中虚，故暑脉亦虚。暑伤气，故气虚身热为伤暑，所谓壮火食气也。暑为阳邪，天
气通于鼻，鼻为肺窍，肺合皮毛，故暑邪由鼻入肺，肺受火烁则多汗，与风伤卫证相似，亦以渴不渴辨之。渴
者燥也，燥万物者莫 乎火，故温热病长沙皆揭“渴”字以为准鹄。嘉言先生云∶古人以燥热为暑，得其旨矣。
（注）暑从日，日为天上之火，故日字在上；寒从 ， 为地下之水，故 字在下。暑为阳邪，易入心经，
寒为阴邪，先犯膀胱。霄壤不同，各从其类也，或有以暑为阴邪者，岂非坐井观天、不见日面之语耶？
湿土分旺四季，长夏是其正令，土润溽暑，故暑湿二气最易相合。人受其感，名曰湿温，亦曰湿热，即暑
湿相兼之病，为五种伤寒之一，《难经》已详其脉证。而昧者逞其臆说，谓
湿与热合，始名为暑。然则湿与寒合，又将何名乎？天夫寒地冻，天暑地热，阴阳之对待也。暑必湿热相合而
始为暑，寒将何气相合而始为寒乎？若亢旱之年，流金烁石，禾苗欲槁，河裂井枯，不名酷暑而何名乎？盖湿
无定体，风也寒也暑也，无不可合，故治湿者须察其相合，治暑者亦必审其有无兼湿，庶无遗憾也。然湿热之
病为独多，而变证甚易，疗治颇难。惟香岩先生之法，可谓空前绝后，学人宜奉为金科玉律也。
（注）暑也湿也，皆五气之一也。暑属火，湿属土，各居五行之一。火土合德，故暑湿每易相兼，亦理之常
也。若谓暑中有湿，是析一行为二也；若谓湿热合而始为暑，则并二气为一也。岂五行之理未知，而五气之名
未闻乎？自误误人，莫此为甚。
温病、热病、湿温病，治不得法，皆易致死。流行不已，即成疫疠。犹之治盗不得其法，则贼党众而为流
寇也。因热气、病气、尸气互相胶葛，即成毒疠之气而为疫，岂真天地之间另有一种异气哉？故疫之流行，必
在都会人烟繁萃之区，若山乡僻壤、地广人稀之处，从无大疫。如果另是一种不正之气，何必择地而行哉？其
盛行于兵荒之后者，兵荒之死亡，亦在人烟繁萃之区也。盖人气最热，纪晓岚先生杂诗云∶万家烟火暖云蒸，
销尽天山太古冰。自注曰∶迪化自设郡县以后，婴儿出痘与内地同。盖彼处气候极寒，数载以来渐同内地，
人气盛也。于戏！纪氏此言可谓先得我心。夫上古无痘，至汉始有，今则罕有不出痘者矣。何也？生齿日繁，
地气日热，所以古人最重伤寒，今世偏多温热也。费建中以治疫之法治痘，岂非千古只眼？治疫之法，惟清热、
解毒、宣气六字为扼要，而宣气尤为首务，未有气不宣而热能清、毒能解者，质诸宗匠，然乎
否耶？
（注）温病虽能成疫，而治温治疫有殊。吴又可混同论治，未免粗疏，且不知暑热亦能成疫。乾隆甲子，
都中暑疫，热死者无算。徐后山《柳崖外编》尝言之。嗣有余师愚专论热疫，惜其书未甚流行耳。
（校）宣气之法，不但用药为然，如衣被宣洁净，饮食宜澹泊，卧房宜宽绰，窗户宜开爽，侍人勿杂，灯火少燃，
清风徐来，疫气自然消散，反是则热气、浊气益为疫气树帜矣。病家医家，皆宜识此。
（刊）痘为疫气。万密斋、王勋臣皆知之；疹为疫气，惟余师愚知之，故所着书名曰《疫疹一得》。治疫专用大剂
石膏，晓岚先生目击其技之神，加载《阅微草堂笔记》。道光间，归安江笔花宗其法，《医镜》载尝治一时疫发斑，用石
膏至十四斤而斑始透，因叹师愚之道为不孤。曩客东瓯，适多温证，而彼处风俗，病戒谷食，专啖番薯。余谓温邪初发，
如何可食实脾补气之物。土人以为相传如是，不之听也。且医者用药，辄尚温补，遂致死亡接踵，百无一生。人皆
谓之天行时疫，余叹曰∶此药酿为疫，非天有不正之气，乃人有不正之治耳。当名其病曰药疫。比至宜黄。杨素园明府
述江西飞尚亦类是。然则天下之大，疫疠之频，吾恐酿成于药者，不止所见所闻之两地也。比之养成寇患，的是确喻。
寒暑燥湿风，乃五行之气合于五脏、行于四时者也。惟火旺于夏，特以暑称。暑字从日，明其为烈日之气炎炎在上
也。然三时之暖燠，无非离照之光，因不可以暑称，故有六气之名焉。其实火即暑之焰，犹水即寒之质耳。非五气外另
有一气也。而人之火病独多者，以风寒燥湿悉能化火，五志过动无不生火，何报之先生论之甚详。愚谓此皆不可以暑称
者，故圣人于五气之下赘一火字，其旨深矣。若以五行论，言暑则火在其中矣，而医者往往不知，故反复述之。
（注）何氏论火云∶丹溪谓气有余便是火，此一火也，治宜清凉；气不足亦郁而成火，东垣所谓阳虚发热
也，又一火也，治宜甘温以补其气，少佐甘凉以泻其火，外感暑热燥气，增助内气成热，此一火也，治宜甘润
清凉，外感风寒湿气，闭郁表气成热，亦一火也，治宜辛温发散；内伤饮食辛热之物，致火得热愈炽，此一火
也，宜用苦寒之剂消导之；内伤饮食生冷之物，致火彼遏愈怒，又一火也，治宜辛热之剂消导之，肾水虚，致
令下焦之火上炎，此一火也，治宜六味丸之类补水制火，此水涸火炎之证，上下皆热，医者动用桂、附，辄云
引火归元，不知引归何处，以致酷烈中上，烁涸三阴，杀人如麻，为祸甚火；肾阴盛，逼其浮游之火上升，又
一火也，治宜八味丸之类引火归元，此下寒上热之证，故用附、桂补火，不可误投于阴虚证也。
（校）上论六气。
君子观夫劳字，可得治劳之法。况《难经》、《金匮》论之最精，《理虚元鉴》阐发甚详，读此三书已无遗义。虽脉大
伤寒，是外感疾病的总称；《伤寒论》是一部统论外感疾病的著作。
（注）《难经》说：伤寒包括五种类型。那么这五种外感疾病，古人都称之为伤寒。《伤寒论》中有治疗风邪、温邪、暑邪、湿邪等诸法，说明它并非专门论述一种伤寒病。
《伤寒论》说：太阳病，有的已经发热，有的尚未发热，但必定恶寒，身体疼痛，呕吐气逆，脉象寸关尺三部都紧的，称为伤寒。这是典型的正伤寒病证。
（注）患伤寒没有不发热的，这里说“尚未发热”，是指身体热象尚未显现的时候，先出现恶寒等症状，这就是所谓“无热恶寒发于阴”。寒属于阴邪，所以往往先恶寒而后发热。脉象寸关尺三部都紧，即尺寸脉皆紧，紧脉是坎卦中满的形象，坎卦代表寒水，所以伤寒的脉象一定是紧脉。如果已经发热，紧脉必然兼有浮象，这是可以推知的。
太阳病，头痛发热，身体疼痛，腰痛，骨节疼痛，怕风，无汗且气喘的，用麻黄汤主治。这是正伤寒的治疗方法。
（注）寒邪凝结闭塞，体表之气壅实，所以无汗、气喘且恶风寒。麻黄汤是温散发汗的方剂，如果不是正伤寒而误用此方，就会有阳气亡脱的祸患。
伤寒四季都有，只要有相应的脉象和症状，就使用相应的药物。谚语说：“对证发药”，这话很有道理！病情较轻，体质稍弱的患者，那么羌活、防风、紫苏、白芷都可以代替麻黄使用。如果寒邪伤于体表，热邪伏于体内，在温散方剂中必须佐以清凉的药物，仿效张仲景大青龙汤的制方原则即可。
（注）四季都有伤寒，然而冬季三个月是寒水当令，比另外三个季节的寒气更为独盛，所以古人把冬季感受寒邪随即发病的称为正伤寒，并不是说春夏秋三季没有伤寒。医生如果能够辨证清楚，用药自然就不会拘泥于时令了。
伤寒，是寒邪伤于体表而邪气客居在表。如果其人阳气素来虚弱，无法抵御外邪，那么外寒就能直接侵入体内而侵犯脏腑，称为中寒，这是因为阳气衰微则阴气盛。阴气虽然盛，却忌讳使用温散的方法，因为阳气既然衰微，其汗液容易外出，误投温散药物，会加速其危重。急需使用干姜、附子来回阳破阴，这才是治疗方法。
（注）阳气衰微则阴气盛，可见阴气并未真正盛，只是由于阳气衰微，所以表现为阴盛。因此中寒不一定发生在隆冬时节，即使在盛夏也有发生。过去有人治愈此类病症，却不认为他是因阳虚饮冷、夏季感受寒邪所致，反而认为是静处所得的阴暑，这种看法自误误人，令人叹息。使用姜、附回阳破阴，就是兵家中加强主力削弱客军的策略。
《伤寒论》中的中风，是《难经》五种伤寒之一，也就是后世的伤风。大概“伤”与“中”字义没有区别，比如常说风伤卫气、寒伤营血。后人认为寒邪在表的叫伤寒，寒邪入里的叫中寒，于是怀疑伤轻而中重，但这不过是分别邪气在表、在里罢了。进入体内的寒邪，何必比在表的寒邪更重呢？实在是因为本元阳气既已衰微，所以客寒得以直接侵入。发表取汗，是治标，其邪气并不轻；温里回阳，是治本，其邪气不必较重。病分标本，则本为重而加重之，并非邪气本身较重而加重之。明白了这一点，就知道越人（秦越人）、长沙（张仲景）所说的风为中，即谓寒为伤的意思了。
（注）后世将外感风邪称为伤风，将虚风卒然昏倒称为中风，这样两种病的名称才不会混淆。然而“伤”、“中”二字的含义，越发觉得轻重悬殊。所以愚昧的人拘泥于越人、长沙说风为中，却不知道这就是伤风，竟然与卒然昏倒扑击互相引证，这是错误的。
风邪伤人，既然是五种伤寒之一，难道是小病吗！况且风没有定性，不仅四季不同、四方各异。燥湿不均，雨晴迥异，风寒与风热，顷刻间就会变迁。感染于人，施治方法有别。张仲桂枝汤证，是风寒病；发汗后身体灼热的，是风热病。然而古人往往只知道有风寒而不知道有风热。《伤寒论》又说：服用桂枝汤后，大汗出之后，大烦渴不解，脉象洪大的，用白虎加人参汤主治，合起来看，这难道不是误用治风寒的药来治疗风热病的变证吗？汉代尚且如此，何况后人呢！
（注）今人视伤风为轻小之病，那些头疼发热的，就说成重伤风，这是不知道伤风就是越人、长沙所谓的中风。病因不清，难怪有过服温燥药物耗伤津液，过早投用滋补药物禁锢邪气，拖延日久成为劳损，还推诿说是伤风不醒。唉，其实是医生自己不醒悟。
风热就是风温，四季都有，冬春两季尤为严重。张仲景说：如果发汗后身体灼热的，是风温。意思是风寒为病，可以用桂枝汤发汗而愈，如果发汗后热反而更灼烈，乃是风温病，温就是热的意思。后人不为详细研读，而说风温是发汗后的坏病，这也太固执了。病本属热，加上桂枝的辛热，所以津液被热逼迫而大汗出，津液去则热更灼烈，所以大烦渴而脉洪大。这两条条文看似论述同一证候，主方用白虎加人参汤，正是《内经》中“风淫热淫，治以甘寒”的宗旨。只有叶天士先生独自窥探到其中的微妙，说风温首先侵犯肺脏，先犯卫分后犯气分。治疗方法初期用辛凉，继用甘寒。见解高超，万古以来开启蒙昧啊。
（注）《伤寒论》中病患脏腑无其他病变条文，发汗则愈；病常自汗出条文，复发其汗则愈，都主用桂枝汤。可见桂枝汤是治疗风寒发汗的药剂，不过比麻黄汤较为和缓罢了。《内经》明确说辛甘发散为阳，怎么能用来治疗风热病呢？更有说桂枝汤能止汗的，尧封先生已经辨明其错误了。
（校）近来见到淮阴吴氏的《温病条辨》一书，以桂枝汤作为治疗温病的首方，更是值得议论。
（刊）《医林改错》说：发热有汗的证候，从未见桂枝汤治愈一人。杨素园明府非常不以为然，说曾治疗风伤卫气证，桂枝汤半剂就痊愈了。雄按：《改错》所说的，乃是温热证。如果是风寒伤卫，怎能不遵循圣人的法则？即使叶天士案咳嗽门首列伤风数条，都是从《伤寒论》变化而来。
至于中风，《内经·生气通天论》称之为虚邪，是本先虚而后邪气乘中之。《通评虚实论》说肥贵人则是膏粱之疾。此后贤者主张痰、主张火、主张气、主张虚的各种说法，都基于此，仔细推究经文，则真中风本是虚邪中伤，不可竟当作实证；类中风由肥甘酝酿而成，未可一概当作虚证。必须根据证候的虚实来调剂治疗，治百病就没有遗漏了！中风这个话题怎么样呢？
（注）凡是证候有大虚的，有大实的，有虚中夹实、实中夹虚的，有虚多实少、实多虚少的，各家学说都有精义，既不可废弃，也不可固执，贵在使用者用得恰当罢了。
冬春感受风热而发病的，称为风温，前面已经辨析过了。如果冬季感受寒邪，到了春季发泄之时，伏气化热而出，称为春温，也称为温病。其邪气从内达外，所以发热而口渴，不恶寒。然而也有挟带新感的风寒而发的，虽然恶风寒但口中必渴，如果误用发汗法，祸患不可言说。张仲景之后知晓此义的，只有郭白云、刘守真、王安道、张石顽、周禹载、叶天士这几位先生而已，他们的书都不可不读。
（注）温，是热的渐进。伏寒化热，口燥而渴，所以称为温。一切温散燥热的药物，都不可触犯。为何像喻嘉言那样贤能的人，却错误地将《医宗金鉴》中春季伤寒称为温病，治疗虽然合法，立论却大谬，泾川先生批评他是正确的，而俞惺斋、毛达可极力称赞颂扬，未免贻误将来。
冬季感受寒邪，伏藏于少阴，夏至前发出的，称为温病；若夏至后发出的，称为热病。因为夏至前天气尚温，夏至后天气已热，都是随着时令来命名疾病。名称虽然不同，病机相同，所以温热二病，古人往往互称。《内经》则说夏至日后的称为病暑，也是因为夏至后炎暑当令，所以称为病暑。且在天上为热，在地上为火，其性质为暑，所以暑就是热的意思。只是这里的病暑，是因为伏寒化热，与吸入受暑邪而病的，名称虽然相同，病因则不同。
（注）用温热二字作为病名，似乎不过是区分其时令之气罢了。然而名为温的，用凉法可愈；名为热的，用寒法乃瘳。顾名思义，治疗方法已无遗漏，所以不嫌弃与感冒之温、吸入之暑同名，正是示人以殊途同归的宗旨，这难道不是古圣分析义理的精妙吗？
夏令属火，日光最烈，天时乃热，人感受其气，称为伤暑，也称中暑。暑字从日，曰炎暑，曰酷暑，都指烈日之火而言。盖太阳是众阳之宗，日出则小火无光，阳燧承接阳光，火可立即生起。《内经》说：岁火太过，炎暑流行。如果三冬久晴，则生燥火之病，何况夏月的暑呢？而张仲景将中热称为暍，不称为暑，是为了区别于夏至后发出的伏气暑病。且《说文解字》：暍，伤暑也。所以暑、热、暍三者，都是烈日之气。后人不明此理，遂有多种歧说，可谓不知冷热之人。暑为离火，离卦中虚，所以暑脉亦虚。暑伤气，所以气虚身热为伤暑，所谓壮火食气。暑为阳邪，天气通于鼻，鼻为肺窍，肺合皮毛，所以暑邪由鼻入肺，肺受火烁则多汗，与风伤卫气证相似，也以渴不渴来辨别。渴的是燥，燥万物者没有比火更厉害的了，所以温热病张仲景都揭出“渴”字作为准则。嘉言先生说：古人以燥热为暑，得其旨意了。
（注）暑从日，日为天上之火，所以日字在上；寒从仌（冰），仌为地下之水，所以仌字在下。暑为阳邪，易入心经；寒为阴邪，先犯膀胱。霄壤不同，各从其类。或许有认为暑为阴邪的，岂不是坐井观天、不见日面的话吗？
湿土分旺于四季，长夏是其正令，土润溽暑，所以暑湿二气最容易相合。人感受其邪，称为湿温，也称湿热，即暑湿相兼的病，为五种伤寒之一，《难经》已详述其脉证。而愚昧之人逞其臆说，谓湿与热合，始名为暑。那么湿与寒合，又将叫什么名字呢？天寒地冻，天暑地热，是阴阳的对待。暑必湿热相合始为暑，寒将何气相合始为寒呢？若遇亢旱之年，流金烁石，禾苗欲枯，河裂井枯，不叫酷暑叫什么？盖湿无定体，风也寒也暑也，无不与之相合，所以治湿者须察其相合，治暑者亦必审其有无兼湿，才无遗憾。然而湿热之病为独多，而变证甚易，疗治颇难。只有叶天士先生的方法，可谓空前绝后，学人宜奉为金科玉律。
（注）暑也湿也，都是五气之一。暑属火，湿属土，各居五行之一。火土合德，所以暑湿每易相兼，也是常理。如果说暑中有湿，是将一行分为二；如果说湿热合而始为暑，则是将二气合为一。这岂是未知五行之理，而未闻五气之名吗？自误误人，没有比这更严重的了。
温病、热病、湿温病，治疗不得法，都容易致死。流行不止，就成疫疠。就像治盗不得其法，则贼党众多而为流寇。因热气、病气、尸气互相胶葛，即成毒疠之气而为疫，难道真是天地之间另有一种异气吗？所以疫的流行，必在都会人烟繁萃的区域，若山乡僻壤、地广人稀之处，从无大疫。如果另是一种不正之气，何必选择地点而行呢？其盛行于兵荒之后的，兵荒的死亡，也在人烟繁萃的区域。盖人气最热，纪晓岚先生杂诗云：万家烟火暖云蒸，销尽天山太古冰。自注说：迪化自设郡县以后，婴儿出痘与内地相同。盖彼处气候极寒，数年以来渐同内地，人气盛也。唉！纪氏此言可谓先得我心。上古无痘，至汉始有，今则罕有不出痘者了。为什么呢？生齿日繁，地气日热，所以古人最重伤寒，今世偏多温热。费建中以治疫法治痘，岂非千古只眼？治疫之法，惟清热、解毒、宣气六字为扼要，而宣气尤为首务，未有气不宣而热能清、毒能解的，请问各位宗师，是这样吗？
（注）温病虽能成疫，而治温治疫有区别。吴又可混同论治，未免粗疏，且不知暑热也能成疫。乾隆甲子年，京都中暑疫，热死者无数。徐后山《柳崖外编》曾提及此事。嗣后有师愚专论热疫，可惜其书未甚流行耳。
（校）宣气之法，不但用药如此，如衣被宣洁净，饮食宜澹泊，卧房宜宽绰，窗户宜开爽，侍人勿杂，灯火少燃，清风徐来，疫气自然消散，反是则热气、浊气益为疫气树帜矣。病家医家，皆宜识此。
（刊）痘为疫气。万密斋、王勋臣皆知之；疹为疫气，惟余师愚知之，故所著书名曰《疫疹一得》。治疫专用大剂石膏，晓岚先生目击其技之神，加载《阅微草堂笔记》。道光年间，归安江笔花宗其法，《医镜》载尝治一时疫发斑，用石膏至十四斤而斑始透，因叹师愚之道为不孤。从前客居东瓯，适逢多温证，而彼处风俗，病戒谷食，专啖番薯。我说温邪初发，如何可食实脾补气之物。土人以为相传如是，不听。且医者用药，辄尚温补，遂致死亡接踵，百无一生。人皆谓之天行时疫，我叹曰：此药酿为疫，非天有不正之气，乃人有不正之治耳。应当名其病曰药疫。等到宜黄，杨素园明府述江西飞尚亦类似。然而天下之大，疫疠之频，我恐怕酿成于药的，不止所见所闻的两地也。比之养成寇患，确实是确切的比喻。
寒暑燥湿风，是五行之气合于五脏、行于四时的。只有火旺于夏，特以暑称。暑字从日，明其为烈日之气炎炎在上。然而三时之暖燠，无非离照之光，因不可以暑称，故有六气之名焉。其实火即暑之焰，犹水即寒之质耳。并非五气外另有一气也。而人之火病独多者，以风寒燥湿悉能化火，五志过动无不生火，何报之先生论之甚详。我认为这些都不可以暑称，所以圣人于五气之下赘一火字，其旨深矣。若以五行论，言暑则火在其中矣，而医者往往不知，故反复述之。
（注）何氏论火说：丹溪谓气有余便是火，这是一火，治宜清凉；气不足亦郁而成火，东垣所谓阳虚发热也，又一火，治宜甘温以补其气，少佐甘凉以泻其火，外感暑热燥气，增助内气成热，此一火，治宜甘润清凉，外感风寒湿气，闭郁表气成热，亦一火，治宜辛温发散；内伤饮食辛热之物，致火得热愈炽，此一火，宜用苦寒之剂消导之；内伤饮食生冷之物，致火彼遏愈怒，又一火，治宜辛热之剂消导之，肾水虚，致令下焦之火上炎，此一火，治宜六味丸之类补水制火，此水涸火炎之证，上下皆热，医者动用桂、附，辄云引火归元，不知引归何处，以致酷烈中上，烁涸三阴，杀人如麻，为祸甚火；肾阴盛，逼其浮游之火上升，又一火，治宜八味丸之类引火归元，此下寒上热之证，故用附、桂补火，不可误投于阴虚证也。
（校）以上论述六气。
君子观察“劳”字，可得治劳之法。况且《难经》、《金匮》论之最精，《理虚元鉴》阐发甚详，读此三书已无遗义。虽脉大
Shanghan (Cold Damage), is the general term for exogenous diseases; *Treatise on Cold Damage* (*Shanghan Lun*) is a book that comprehensively discusses exogenous diseases.
(Note) The *Classic of Difficult Issues* (*Nan Jing*) states: "Shanghan includes five types." Thus, these five types of exogenous diseases were all referred to as Shanghan by ancient people. *Treatise on Cold Damage* contains methods for treating wind, warm, summerheat, and dampness pathogens, indicating that it does not exclusively discuss one type of Shanghan.
*Treatise on Cold Damage* states: In Taiyang disease (disease pattern of the Bladder channel), whether fever has already appeared or not, there will definitely be aversion to cold, body pain, vomiting, and reversal of qi, with pulse tightness at both yin and yang positions (cun and chi). This is named Shanghan. This is the typical Zheng Shanghan (True Cold Damage) disease pattern.
(Note) There is no case of Shanghan without fever. The phrase "has not yet developed fever" here refers to the time before the heat manifestation appears, when symptoms such as aversion to cold appear first. This is what is meant by "aversion to cold without fever originates from Yin." Cold belongs to Yin pathogen, so it often presents with aversion to cold first, followed by fever. Pulse tightness at both yin and yang positions means the cun and chi pulses are both tight. The tight pulse resembles the image of fullness in the center of the Kan trigram (☵), which represents cold water. Therefore, the pulse in Shanghan must be tight. If fever has already appeared, the tight pulse must also be floating, which can be deduced.
In Taiyang disease, if there is headache, fever, body ache, lower back pain, joint pain, aversion to wind, anhidrosis (absence of sweating), and wheezing, Mahuang Tang (Ephedra Decoction) should be used as the primary treatment. This is the treatment method for Zheng Shanghan.
(Note) Cold pathogen condenses and blocks, causing stagnation and excess in the exterior qi, resulting in anhidrosis, wheezing, and aversion to wind and cold. Mahuang Tang is a formula for warming, dispersing, and inducing sweating. If used mistakenly in cases other than Zheng Shanghan, it could lead to the disaster of Yang collapse.
Shanghan occurs in all four seasons. If the corresponding pulse and symptoms are present, the corresponding medicine should be used. As the proverb says: "Prescribe medicine according to the syndrome," this statement is profound! For patients with milder disease severity and slightly weaker constitution, Qianghuo (Notopterygii Rhizoma et Radix), Fangfeng (Saposhnikoviae Radix), Zisu (Perillae Folium), and Baizhi (Angelicae Dahuricae Radix) can all be used to replace Mahuang (Ephedrae Herba). If cold pathogen injures the exterior while heat pathogen lies latent within, cooling agents must be added to the warming and dispersing formulas, following the principle of Zhang Zhongjing's Da Qing Long Tang (Major Green Dragon Decoction).
(Note) Shanghan occurs in all seasons, but during the three months of winter, Cold Water rules, making the cold more intense than in the other three seasons. Therefore, ancients called Shanghan contracted and immediately manifesting in winter "Zheng Shanghan," not implying that Shanghan does not occur in spring, summer, or autumn. If physicians can clearly differentiate syndromes, their medication will naturally not be constrained by the season.
Shanghan refers to cold injuring the exterior and the pathogen lodging in the exterior. If a person's Yang qi is inherently deficient and unable to defend against external pathogens, the external cold can directly enter the interior and invade the zang organs, named Zhong Han (Mid-Cold). This is because Yang deficiency leads to Yin excess. Although Yin is excessive, warming and dispersing methods are contraindicated. Since Yang qi is already deficient, sweat comes out easily; mistakenly administering warming and dispersing drugs will accelerate the danger. It is urgent to use Sheng Jiang (Zingiberis Rhizoma) and Fu Zi (Aconiti Lateralis Radix Praeparata) to restore Yang and break Yin. This is the treatment method.
(Note) Yang deficiency leads to Yin excess; thus, Yin is not truly excessive, but appears so due to Yang deficiency. Therefore, Zhong Han does not necessarily occur only in deep winter; it can also happen in midsummer. In the past, some cured such cases but did not attribute them to Yang deficiency and drinking cold fluids, nor to midsummer cold injury, but rather considered them "Yin Summerheat" obtained from stillness. This self-deception and deceiving others is lamentable. Using Ginger and Aconite to restore Yang and break Yin is akin to the military strategy of strengthening the host and weakening the guest.
The "Zhong Feng" (Wind Strike) in *Treatise on Cold Damage* is one of the five types of Shanghan in *Nan Jing*, which corresponds to "Shang Feng" (Wind Injury) in later generations. Essentially, the characters "Shang" (Injure) and "Zhong" (Strike/Mid) have similar meanings, as seen in phrases like "Wind injures Wei Qi" and "Cold injures Ying Blood." Later generations believed that cold pathogen in the exterior is Shanghan, while cold pathogen entering the interior is Zhong Han, leading to the suspicion that Shang is mild and Zhong is severe. However, this merely distinguishes whether the pathogen is in the exterior or interior. Why would interior-entering cold be heavier than exterior-located cold? It is actually because the original Yang is already deficient, allowing the invading cold to penetrate directly. Releasing the exterior to induce sweating treats the branch (symptoms); the pathogen is not light. Warming the interior to restore Yang treats the root (cause); the pathogen is not necessarily heavy. Differentiating disease into root and branch makes the root heavy, not because the pathogen itself is heavy. Understanding this, we see that Yue Ren (Qin Yueren) and Changsha (Zhang Zhongjing) referring to Wind as Zhong implies Cold as Shang.
(Note) Later generations distinguished "Shang Feng" (Wind Injury) as exogenous wind pathogen and "Zhong Feng" (Wind Stroke) as sudden collapse due to deficient wind, so the names of the two diseases do not mix. However, the meaning of "Shang" and "Zhong" feels increasingly disparate in terms of severity. Therefore, ignorant people stick to Yue Ren and Changsha saying Wind is Zhong, not realizing it is just Shang Feng, and even cite sudden collapse and falling as mutual evidence, which is erroneous.
Since Wind pathogen injuring humans is one of the five types of Shanghan, how could it be a minor illness! Moreover, Wind has no fixed nature; it differs not only among the four seasons but also among the four directions. Dryness and humidity vary, rain and clear skies differ greatly, and Wind-Cold and Wind-Heat change in an instant. Upon infecting humans, treatment methods differ. Zhang Zhongjing's Guizhi Syndrome (Cinnamon Twig Pattern) is Wind-Cold disease; after sweating, if the body becomes burning hot, it is Wind-Heat disease. However, ancients often knew of Wind-Cold but not Wind-Heat. *Treatise on Cold Damage* also states: After taking Guizhi Tang, if profuse sweating occurs followed by severe irritability and unrelenting thirst, with a surging-large pulse, Bai Hu Jia Ren Shen Tang (White Tiger Plus Ginseng Decoction) should be used. Viewing these together, is this not mistakenly using Wind-Cold medicine to treat the transformed syndrome of Wind-Heat disease? Even in the Han Dynasty it was like this, let alone later generations!
(Note) Modern people view Shang Feng as a minor illness. Those with headache and fever are said to have "Severe Shang Feng," unaware that Shang Feng is exactly the Zhong Feng mentioned by Yue Ren and Changsha. Unclear disease origins explain why there is overuse of warming-drying drugs depleting fluids, and premature use of tonifying drugs trapping pathogens, prolonging until becoming consumption, yet blaming it on "Shang Feng not waking up." Alas, it is the physician who is not awake.
Wind-Heat is the same as Wind-Warmth. It occurs in all seasons, especially in winter and spring. Changsha said: If after sweating the body becomes burning hot, it is Wind-Warmth. This means Wind-Cold disease can be cured by Guizhi Tang inducing sweat; if sweating makes the heat more burning, it is Wind-Warmth disease. Warmth means heat. Later generations failed to study this in detail and claimed Wind-Warmth is a damaged disease after sweating, which is too rigid. The disease is originally heat; adding the acrid-warmth of Guizhi causes fluids to be forced out by heat, leading to profuse sweating. Loss of fluids makes heat more burning, causing severe irritability, thirst, and surging-large pulse. These two clauses seem to discuss one syndrome, primarily using Bai Hu Jia Ren Shen Tang, which aligns with the *Inner Classic* principle: "For wind and heat excess, treat with sweet-cold." Only Mr. Xiangyan (Ye Tianshi) uniquely perceived its subtlety, stating that Wind-Warmth first attacks the Lung, affecting Wei Qi first then Qi level. Treatment initially uses acrid-cool, followed by sweet-cold. His insights are superlative, opening the eyes of the world for millennia.
(Note) In *Treatise on Cold Damage*, the clause "patient's zang organs have no other disease, sweating cures it" and the clause "patient constantly sweats, re-sweating cures it" both prescribe Guizhi Tang. This shows Guizhi Tang is a sweating agent for Wind-Cold, merely milder than Mahuang Tang. *Inner Classic* explicitly states "Acrid and Sweet disperse and are Yang"; how can it treat Wind-Heat disease? Furthermore, those claiming Guizhi Tang stops sweating, Mr. Yao Feng has already refuted this error.
(Correction) Recently, I saw Mr. Wu of Huaiyin's *Systematic Identification of Warm Diseases* (*Wen Bing Tiao Bian*), using Guizhi Tang as the first formula for treating Warm diseases, which is even more debatable.
(Publication) *Correcting Errors in Medical Forest* (*Yi Lin Gai Cuo*) states: "I have never seen Guizhi Tang cure a single case of fever with sweating." Prefect Yang Suyuan strongly disagreed, stating he treated Wind injuring Wei Qi patterns, cured with half a dose of Guizhi Tang. Xiong notes: What *Correcting Errors* describes are Warm-Heat patterns. If Wind-Cold injures Wei Qi, how can one not follow the Sage's method? Even in Ye Tianshi's records under the Cough section, the first few clauses on Wind Injury are all variations of *Treatise on Cold Damage*.
As for Zhong Feng (Wind Stroke), *Inner Classic · Treatise on Living Qi and Heavenly Counterattack* calls it Xu Xie (Deficient Evil), meaning deficiency exists first, then evil strikes. *Treatise on Evaluating Excess and Deficiency* states that fat and noble people suffer from Gao Liang (rich food) diseases. Later scholars' theories focusing on Phlegm, Fire, Qi, and Deficiency all stem from this. Carefully analyzing the classic text, True Zhong Feng is indeed caused by deficient evil striking, and cannot be simply regarded as an Excess pattern. Lei Zhong Feng (Category Wind Stroke) is brewed from rich and sweet foods, and cannot be generally regarded as a Deficiency pattern. One must adjust treatment based on the excess or deficiency of the syndrome, and there will be no omission in treating hundred diseases! How about Zhong Feng?
(Note) Whenever there are syndromes of great deficiency, great excess, deficiency mixed with excess, excess mixed with deficiency, mostly deficiency with little excess, or mostly excess with little deficiency, each school's theory has profound meaning. Neither should be discarded nor adhered to rigidly; the key lies in appropriate application by the user.
Diseases contracted from Wind-Heat in winter and spring are named Wind-Warmth, as辨析ed earlier. If injured by Cold in winter, and when spring energy releases, latent Qi transforms into Heat and emerges, it is named Chun Wen (Spring Warmth), also called Wen Bing (Warm Disease). The pathogen moves from interior to exterior, so there is fever and thirst, but no aversion to cold. However, some may erupt carrying new Wind-Cold infection; although there is aversion to wind and cold, there must be thirst. Mistaken sweating will bring unspeakable disaster. After Changsha, those who understood this meaning include only Mr. Guo Baiyun, Liu Shouzhen, Wang Andao, Zhang Shiweng, Zhou Yuza, and Ye Xiangyan. Their books must be read.
(Note) Wen (Warmth) is the gradual stage of Heat. Latent Cold transforms into Heat, causing dry mouth and thirst, hence named Wen. All warming-dispersing and drying-hot medicines must not be touched. How can a worthy man like Yu Jia Yan mistakenly point to Spring Shanghan in *Medical Canon Corrected* as Warm Disease? Although the treatment was legal, the theoretical stance was largely erroneous. Mr. Jingchuan criticized him correctly, while Yu Xingzhai and Mao Daku praised him enthusiastically, which unfortunately misleads future generations.
Cold injured in winter, lying latent in Shaoyin, emerging before Summer Solstice, is named Wen Bing (Warm Disease); if emerging after Summer Solstice, it is named Re Bing (Heat Disease). Because weather is still warm before Summer Solstice, and hot after Summer Solstice, diseases are named according to the season. Although names differ, the disease is the same, so ancients often used Warm and Heat interchangeably. *Inner Classic* states those after Summer Solstice day are Bing Shu (Summerheat Disease), also because炎暑 (blazing heat) rules after Summer Solstice, hence named Bing Shu. Furthermore, in Heaven it is Heat, on Earth it is Fire, its nature is Summerheat, so Summerheat is Heat. However, this Bing Shu is due to latent Cold transforming into Heat, whereas contracting Summerheat pathogen through inhalation has the same name but different cause.
(Note) Naming diseases with Warm and Heat seems merely to distinguish seasonal Qi. However, named Warm, coolness can cure; named Heat, coldness brings recovery. By looking at the name, the treatment method leaves nothing to be desired. Thus, not minding being named similarly to Cold-Damage Warmth or Inhaled Summerheat precisely shows people the principle of different paths leading to the same goal. Is this not the exquisite analysis of meaning by ancient sages?
Summer season belongs to Fire, sunlight is most fierce, heavenly time is hot. Humans contracting this Qi are named Shang Shu (Summerheat Injury), also called Zhong Shu (Mid-Summerheat). The character Shu (Summerheat) contains Sun (Ri), called Yan Shu (Blazing Summerheat) or Ku Shu (Bitter Summerheat), all referring to the fire of the scorching sun. The Sun is the ancestor of all Yangs; when the sun rises, small fires lose their light. Using a Yang Sui (fire lens) to catch sunlight, fire can be generated instantly. *Inner Classic* says: "When Year Fire is excessive, blazing summerheat spreads." If there are long sunny days in the three winters, Dry-Fire diseases arise, let alone Summer heat! Yet Changsha named Mid-Heat as Ye (Heat Stroke), not Shu, to distinguish it from the latent Qi Summerheat disease emerging after Summer Solstice. Also, *Shuo Wen*: Ye means Shang Shu. Therefore, Shu, Re, and Ye are all Qi of the scorching sun. Later generations ignorant of this led to many divergent theories, truly showing ignorance of cold and heat. Shu is Li Fire; Li trigram is empty in the middle, so Shu pulse is also deficient. Shu injures Qi, so Qi deficiency with body heat is Shang Shu, known as "Strong Fire consumes Qi." Shu is Yang pathogen. Heavenly Qi connects to the nose; the nose is the orifice of the Lung; Lung governs skin and hair. Thus, Shu pathogen enters the Lung via the nose. Lung scorched by Fire causes profuse sweating, similar to Wind injuring Wei Qi, differentiated by thirst or no thirst. Thirst indicates Dryness. Nothing dries things more than Fire. Hence, in Warm-Heat diseases, Changsha highlights the character "Thirst" as the standard. Mr. Jiayan said: Ancients considered Dry-Heat as Summerheat, grasping the essence.
(Note) Shu contains Sun (Ri); Sun is Fire in Heaven, so Ri is above. Han (Cold) contains Bing (Ice); Bing is Water in Earth, so Bing is below. Shu is Yang pathogen, easily entering Heart Meridian; Han is Yin pathogen, first attacking Bladder. Heaven and Earth differ, each following its kind. Those who consider Shu as Yin pathogen are like sitting in a well looking at the sky, failing to see the sun's face.
Damp Earth prospers in all four seasons, with Chang Xia (Long Summer) being its proper command. Damp earth and humid heat combine, so Summerheat and Dampness Qi easily merge. Humans contracting this are named Shi Wen (Damp-Warmth), also called Shi Re (Damp-Heat), i.e., Summerheat-Dampness combined disease, one of the five types of Shanghan, detailed in *Nan Jing* regarding pulse and syndrome. Ignorant people indulge in speculation, claiming Damp combined with Heat begins to be named Shu. Then, what would Damp combined with Cold be named? Heaven cold and Earth frozen, Heaven hot and Earth warm, are the opposition of Yin and Yang. If Shu must be Damp-Heat combined to be Shu, what Qi combines with Han to make Han? In years of extreme drought, melting metal and scorching stone, crops wither, rivers crack, wells dry up—what else but call it Ku Shu (Bitter Summerheat)? Dampness has no fixed form; it can combine with Wind, Cold, or Summerheat. Therefore, treating Dampness requires observing its combination; treating Summerheat requires examining whether Dampness is concurrent, leaving no regret. However, Damp-Heat diseases are most numerous, transformations are easy, and treatment is difficult. Only Mr. Xiangyan's methods can be described as unprecedented. Students should regard them as golden rules.
(Note) Shu and Shi are both one of the Five Qi. Shu belongs to Fire, Shi belongs to Earth, occupying one of the Five Elements respectively. Fire and Earth combine virtue, so Shu and Shi easily combine, which is normal logic. If saying Shu contains Dampness, it splits one element into two; if saying Damp-Heat combined becomes Shu, it merges two Qi into one. Does this mean unknown Five Element principles and unheard Five Qi names? Self-deception and deceiving others, nothing is worse than this.
Wen Bing, Re Bing, and Shi Wen Bing, if treated improperly, easily lead to death. Continuous spread becomes Yi Li (Epidemic Pestilence). Just as treating bandits improperly leads to many thieves becoming roaming bandits. Due to Heat Qi, Disease Qi, and Corpse Qi tangling together, they become Toxic Pestilence Qi forming Epidemic. Is it really another kind of abnormal Qi between Heaven and Earth? Therefore, Epidemics spread only in densely populated urban areas. In remote mountains and sparsely populated places, there are never major epidemics. If it were another kind of abnormal Qi, why would it choose locations? Its prevalence after war and famine is because deaths from war and famine also occur in densely populated areas. Human Qi is hottest. Mr. Ji Xiaolan's miscellaneous poem says: "Ten thousand households' smoke and fire warm the clouds, melting away the ancient ice of Tianshan Mountain." Self-note: Since Dihua established prefectures and counties, infant smallpox is the same as inland. That place's climate is extremely cold, but in recent years it has gradually become like inland due to abundant human Qi. Ah! Mr. Ji's words hit the mark. In ancient times, there was no smallpox; it started in Han Dynasty. Now, almost everyone gets it. Why? Population grows daily, Earth Qi heats daily. Thus, ancients feared Shanghan most, while modern times have more Warm-Heat. Fe Jianzhong treating smallpox with Epidemic methods, isn't that a unique insight for millennia? The key to treating Epidemics lies in six characters: Clearing Heat, Resolving Toxicity, and Ventilating Qi. Ventilating Qi is especially the priority. Without ventilated Qi, Heat cannot be cleared, and Toxicity cannot be resolved. Asking the masters, is this correct?
(Note) Although Warm Disease can become Epidemic, treating Warm Disease and Epidemic differs. Wu Keyou conflating them for treatment is somewhat rough, and unaware that Summerheat-Heat can also cause Epidemic. In the Jiazi year of Qianlong, the capital suffered Summerheat Epidemic, countless died of heat. Xu Houshan's *Liuya Waibian* mentioned this. Later, Yu Shiyu specialized in discussing Heat Epidemic, pitying his book didn't circulate widely.
(Correction) The method of Ventilating Qi applies not only to medication. Clothing and bedding should be clean; diet should be bland; bedroom spacious; windows open; attendants not crowded; lights few; gentle breeze blows, Epidemic Qi naturally dissipates. Opposite actions make Heat Qi and Turbid Qi support Epidemic Qi. Patients and physicians should recognize this.
(Publication) Smallpox is Epidemic Qi. Wan Mizhai and Wang Xunchen knew this; Rash is Epidemic Qi, known only by Yu Shiyu, hence his book titled *One Gain from Epidemic Rash*. Treating Epidemic specifically uses large doses of Shi Gao (Gypsum Fibrosum). Mr. Xiaolan witnessed its miraculous skill and recorded it in *Notes from the Yorwei Studio*. During Daoguang era, Jiang Bihua of Gui'an followed this method. *Medical Mirror* records treating a local epidemic with rash, using 14 jin of Gypsum until rash emerged, sighing that Master Yu's way is not lonely. Previously staying in Dong'ou, encountering many Warm patterns, local custom forbade grain food for patients, eating only sweet potatoes. I said: When Warm Evil first emerges, how can one eat solid spleen-tonifying and Qi-nourishing foods? Locals thought it was tradition and didn't listen. Moreover, physicians preferred warming and tonifying drugs, leading to successive deaths, none surviving. People called it Heavenly Traveling Seasonal Epidemic. I sighed: This Epidemic is brewed by medicine, not Heaven having abnormal Qi, but Humans having abnormal treatment. Should name this disease "Medicine Epidemic." Arriving in Yihuang, Prefect Yang Suyuan stated Jiangxi Feishang was similar. Thus, in the vast world, frequent epidemics, I fear those brewed by medicine exceed the two places I've seen and heard. Compared to cultivating bandit troubles, this is an accurate metaphor.
Cold, Summerheat, Dryness, Dampness, and Wind are the Five Elements' Qi combining with Five Zang and moving through Four Seasons. Only Fire prospers in Summer, specifically called Shu (Summerheat). Shu contains Sun (Ri), clarifying it is the Qi of the scorching sun blazing above. However, the warmth of the three seasons is none other than the light of the Li Sun, so it cannot be called Shu, hence the name Six Qi. Actually, Fire is the flame of Shu, just as Water is the substance of Cold. It is not an additional Qi outside the Five Qi. The reason human Fire diseases are particularly numerous is that Wind, Cold, Dryness, and Dampness can all transform into Fire, and excessive movement of Five Emotions all generate Fire. Mr. He Baozhi discussed this in detail. I believe these cannot be called Shu, so the Sage added the character Fire under the Five Qi, its meaning is profound. If discussing Five Elements, speaking of Shu includes Fire, yet physicians often don't know this, hence repeated explanation.
(Note) Mr. He's discussion on Fire: Danxi said "Excess Qi is Fire," this is one Fire, treatment should be cooling; "Qi deficiency also stagnates into Fire," Dongyuan's so-called Yang deficiency fever, this is another Fire, treatment should be sweet-warm to tonify Qi, slightly assisted by sweet-cool to drain Fire. External contraction of Summerheat-Heat-Dryness Qi increases internal Qi heat, this is one Fire, treatment should be sweet-moist and cooling. External contraction of Wind-Cold-Dampness Qi closes exterior and generates heat, this is also one Fire, treatment should be acrid-warm dispersing. Internal injury from spicy-hot food causes Fire to blaze with heat, this is one Fire, should use bitter-cold agents to digest. Internal injury from cold-raw food suppresses Fire, making it angry, this is another Fire, treatment should be acrid-hot agents to digest. Kidney Water deficiency causes Lower Jiao Fire to flare upward, this is one Fire, treatment should be Liu Wei Wan (Six Flavor Pill) etc. to tonify Water and control Fire. This is Water dried up and Fire flaming syndrome, upper and lower both hot. Physicians using Gui Zhi (Cinnamomi Ramulus) and Fu Zi (Prepared Aconite Root) always say "Guide Fire Back to Source," not knowing where to guide it, causing cruel heat in Middle and Upper, scorching Three Yin, killing like flies, bringing great disaster. Kidney Yin excess forces floating Fire to rise, this is another Fire, treatment should be Ba Wei Wan (Eight Flavor Pill) etc. to guide Fire back to source. This is Lower Cold and Upper Heat syndrome, so using Fu Zi and Gui Zhi to tonify Fire, must not be mistakenly given to Yin deficiency syndromes.
(Correction) Above discusses Six Qi.
Observing the character "Lao" (Consumption/Overwork), one can obtain the method for treating Consumption. Moreover, *Nan Jing* and *Jin Gui* discuss it most precisely, *Li Xu Yuan Jian* elaborates in detail. Reading these three books leaves no omitted meaning. Although pulse is large...