平脉法脉阴阳俱紧，至于吐利，其脉独不解；若脉迟，至六七日不欲食，此为晚发，水
停故
也，为未解。成注晚发者，后来之疾也。泉案∶《外台》卷一张文仲疗晚发伤寒，三月至年
末为晚发，方生地、栀子、升麻、柴胡、石膏、五味。若头面赤，去石膏用干葛，无地用豉
。然则晚发云者，乃伤寒最晚所发，以意逆之，感寒热而至半年发者曰晚发。三月晚发者，
其感在冬至前，不论时气、正气也；年末晚发者，其感在夏至后，不论时气，正气也。以
寒热在身，蓄至半年必发也。何以言之？自秋分至春分，正气之寒，当以冬至为界，冬至前
伤寒者，其晚发至三月末而极，以距秋约半年也；若冬至后伤寒，至五月后发，则为病热，
不称晚发，为其兼新感也。凡寒热至二至后而木偏，最易有新感；有新感则病两歧，故不得
称晚发。自春分至秋分时气之寒，当以夏至为界，夏至前伤寒至九月发，则为温疟，不称晚
发，为其兼新感也；若夏至后伤寒至年末发者，则为晚发，以相距半年也。自秋分至春分时
气之热，以冬至为界，冬至前感热者，其晚发在三月末，法与正气同；若冬至后感热者，至
夏末发则为温热，不称晚发，法与正气同。自春分至秋分正气之热，亦以夏至为界，夏至前
感热者，至九月发则为温疟，不称晚发，法与正气同；若夏至后感热至年末发，则为晚发，
法与正气同。然则晚发云者，是从温热两病中别出言之，亦对时气、正气之即发者言之，盖
冬至后感之年末发，与夏至前感之六月发，皆即发也。“即”字与“晚”字正相对。若专以
冬月正气言之，恐未能迟至次年末始发也。《活人书》因此改为三月至夏，殆未达其旨，所
以如是晚者，以积受寒邪，寒搏于液，液停为水，邪不得发故也。凡邪伏不发者，多由水停
。《外台》卷四温病，冬温未即发，至春被积寒所折不得发，至夏得热，其春寒解，冬温毒
始发出肌中，斑烂隐轸如锦文，壮热咳闷，呕吐清水。据此知冬温被春寒折时，先有水停，
故至夏发时，必呕吐出水而后疹见。此冬至后感时气发于夏末者，不称晚发之证。彼方用麻
、杏、葛、橘，与此方皆是提出寒水之意。又《录验》载温毒此条下，又云已自得下利，宜
服黄连橘皮汤。然则停水之毒，吐利皆有，与晚发同法。即谓《外台》、《录验》两温毒为
晚发之温也，亦无不可。
平脉法中，若脉象阴阳俱紧，出现呕吐和腹泻，但脉象依然紧而不解；如果脉象迟缓，到了六七天不想吃东西，这称为“晚发”，是因为水饮停聚的缘故，病邪尚未解除。成无己注释说，“晚发”是指后来发作的疾病。我的案语是：《外台秘要》卷一中，张文仲治疗晚发伤寒，从三个月到一年末发病的称为晚发，方药用地黄、栀子、升麻、柴胡、石膏、五味子。如果头面部发红，去掉石膏改用干葛根，没有地黄就用豆豉。那么所谓“晚发”，是指伤寒中最晚发作的，推测其意，感受寒热之邪直到半年后才发作的称为晚发。三个月后晚发的，其感受邪气在冬至之前，不论属于时行之气还是正气；年末晚发的，其感受邪气在夏至之后，不论属于时行之气还是正气。因为寒热之邪在体内蓄积，到半年必然发作。为什么这样说呢？从秋分到春分，正气的寒邪，应当以冬至为界限，冬至前感受伤寒的，其晚发最迟到三月末达到极点，因为距离秋天大约半年；如果冬至后感受伤寒，到五月后发作，则称为热病，不称为晚发，因为它兼有新感邪气。凡是寒热之邪到二至（冬至、夏至）之后而木气偏盛时，最容易兼有新感；如果有新感，则病情两歧，所以不能称为晚发。从春分到秋分，时气的寒邪，应当以夏至为界限，夏至前感受伤寒到九月发作，则称为温疟，不称为晚发，因为它兼有新感邪气；如果夏至后感受伤寒到年末发作，则称为晚发，因为相距半年。从秋分到春分，时气的热邪，以冬至为界限，冬至前感受热邪的，其晚发在三月末，治法与正气相同；如果冬至后感受热邪，到夏末发作则称为温热病，不称为晚发，治法与正气相同。从春分到秋分，正气的热邪，也以夏至为界限，夏至前感受热邪的，到九月发作则称为温疟，不称为晚发，治法与正气相同；如果夏至后感受热邪到年末发作，则称为晚发，治法与正气相同。那么所谓“晚发”，是从温热两类疾病中特别提出来说的，也是相对于时气、正气即时发作而言的，大概冬至后感受邪气到年末发作，与夏至前感受邪气到六月发作，都属于即时发作。“即”字与“晚”字正好相对。如果专门以冬季正气的情况来说，恐怕未必会延迟到次年才发作。《活人书》因此将其改为三个月到夏季，大概没有理解其中的旨意。之所以这样晚发，是因为积聚了寒邪，寒邪搏结于津液，津液停聚成为水饮，邪气不得发散的缘故。凡是邪气潜伏不发作的，多由水饮停聚引起。《外台秘要》卷四记载温病，冬温未即时发作，到春天被积寒所遏制不能发作，到夏天得到热气，春天的寒气消散，冬天的温毒才开始发出肌表，斑疹隐现如锦纹，高热咳嗽胸闷，呕吐清水。据此可知，冬温被春寒遏制时，先有水饮停聚，所以到夏天发作时，必定先呕吐出水然后疹子才出现。这是冬至后感受时气在夏末发作的，不称为晚发的证候。那个方子用麻黄、杏仁、葛根、橘皮，与此方都是提出寒水之意。又《录验方》记载温毒这一条下，又说已经自行得下利的，宜服用黄连橘皮汤。那么停聚水饮的毒邪，呕吐和下利都有，与晚发的治法相同。即使称《外台秘要》、《录验方》中的两种温毒为晚发的温病，也没有不可以的。
In the *Ping Mai Fa* (Method of Assessing Pulse), if the pulse is tight in both yin and yang positions, accompanied by vomiting and diarrhea, yet the pulse remains tight and unresolved; if the pulse is slow, and after six or seven days there is a lack of appetite, this is termed "Late Onset" (Wan Fa). This is due to the retention of fluid-dampness, indicating that the pathogen has not yet been resolved. Cheng Wuji annotated that "Late Onset" refers to diseases that manifest later. My commentary states: In Volume 1 of *Waitai Miyao* (Prescriptions from the Imperial Cabinet), Zhang Wenzhong treats late-onset cold damage. Manifestations occurring from three months to one year after infection are called late onset. The formula uses Sheng Di Huang (Rehmanniae Radix), Zhi Zi (Gardeniae Fructus), Sheng Ma (Cimicifugae Rhizoma), Chai Hu (Bupleuri Radix), Shi Gao (Gypsum Fibrosum), and Wu Wei Zi (Schisandrae Fructus). If the head and face are red, remove Shi Gao and use Gan Ge Gen (Puerariae Lobatae Radix); if Sheng Di Huang is unavailable, use Chi Dou (Sojae Semen Praeparatum). Thus, "late onset" refers to the latest manifestation of cold damage. By inferring the intent, contracting cold-heat pathogens and manifesting symptoms half a year later is called late onset. For late onset at three months, the infection occurred before the Winter Solstice, regardless of whether it was seasonal qi or normal qi; for late onset at year-end, the infection occurred after the Summer Solstice, regardless of seasonal or normal qi. This is because cold-heat pathogens accumulate within and must manifest after half a year. Why is this so? From Autumn Equinox to Spring Equinox, regarding the cold of normal qi, the Winter Solstice serves as the boundary. Cold damage contracted before the Winter Solstice manifests its late onset peak by the end of March, approximately half a year after autumn. If cold damage is contracted after the Winter Solstice and manifests after May, it is termed heat disease, not late onset, because it involves a new contraction of pathogenic factors. Whenever cold-heat pathogens persist until after the two solstices (Winter/Summer) when Wood Qi becomes dominant, new contractions are most likely; with new contractions, the pathology bifurcates, thus it cannot be called late onset. From Spring Equinox to Autumn Equinox, regarding the cold of seasonal qi, the Summer Solstice serves as the boundary. Cold damage contracted before the Summer Solstice and manifesting in September is termed warm malaria, not late onset, due to concurrent new contraction. If cold damage is contracted after the Summer Solstice and manifests at year-end, it is called late onset, as it is separated by half a year. Regarding the heat of seasonal qi from Autumn Equinox to Spring Equinox, the Winter Solstice is the boundary. Heat contracted before the Winter Solstice manifests its late onset at the end of March, following the same method as normal qi; heat contracted after the Winter Solstice and manifesting at summer's end is termed warm-heat disease, not late onset, following the same method as normal qi. Regarding the heat of normal qi from Spring Equinox to Autumn Equinox, the Summer Solstice is also the boundary. Heat contracted before the Summer Solstice and manifesting in September is termed warm malaria, not late onset, following the same method as normal qi; heat contracted after the Summer Solstice and manifesting at year-end is called late onset, following the same method as normal qi. Therefore, "late onset" is distinguished from warm and heat diseases, and is contrasted with the immediate onset of seasonal and normal qi infections. Generally, infection after the Winter Solstice manifesting at year-end, and infection before the Summer Solstice manifesting in June, are considered immediate onsets. The character "Ji" (immediate) stands in direct opposition to "Wan" (late). If discussing only winter normal qi, it is unlikely to delay until the following year to manifest. *Ren Shu* (Book of Vitality) therefore changed it to three months to summer, likely missing the true meaning. The reason for such late onset is the accumulation of cold pathogens, which bind with body fluids, causing fluid retention into water-dampness, preventing the pathogen from dispersing. Pathogens that lie latent without manifesting are mostly due to fluid retention. *Waitai Miyao* Volume 4 records warm disease: Winter-warmth does not manifest immediately; in spring, it is suppressed by accumulated cold and cannot manifest; in summer, upon receiving heat, the spring cold resolves, and winter-warmth toxicity begins to emerge from the muscles. Rashes appear hidden like brocade patterns, accompanied by high fever, cough, chest oppression, and vomiting clear fluid. From this, we know that when winter-warmth is suppressed by spring cold, fluid retention occurs first. Thus, when it manifests in summer, vomiting of fluid must precede the appearance of rashes. This describes a case where seasonal qi contracted after the Winter Solstice manifests at summer's end, which is not classified as late onset. The formula used there includes Ma Huang (Ephedrae Herba), Xing Ren (Armeniacae Semen Amarum), Ge Gen (Puerariae Lobatae Radix), and Ju Pi (Citri Reticulatae Pericarpium), sharing the intent of resolving cold and water-dampness with the current formula. Furthermore, *Lu Yan Fang* (Verified Prescriptions) under the section on warm toxicity adds that if diarrhea has already occurred, Huang Lian Ju Pi Tang (Coptidis and Citri Reticulatae Decoction) should be taken. Thus, toxicity from retained water-dampness presents with both vomiting and diarrhea, treated similarly to late onset. It would be acceptable to classify the two types of warm toxicity in *Waitai Miyao* and *Lu Yan Fang* as warm variants of late onset.