世有一等孩重，生得体质恢肥，似血气有余也。何患痘疮则囊房空虚，不至灌浆澄
脓，八九日而死者何欤？盖天元不可以形拘气血宁堪以质滞，彼形体虽瘦小而元气充
盈，则痘自然起灌成功，如形体虽恢大而元气薄劣，则痘必至枯涩难长，故治痘看人元
气，不可拟人形体，况痘有经络部位不同，多寡大小之不一，气运时令之不齐，调摄受
养之得失，岂可以形体论哉！故痘之经络既正，颗粒稀朗，气运淑顺，调摄合宜，枭毒
原浅，则瘦小而元气实者固不为害，即瘦小而元气弱者亦有生矣。如痘之经络错犯，点
数密，此时令乖逆，调护戾常，枭毒禀盛，则肥胖而气血衰者，固罹其危，即肥胖而气
盛者，亦有死者矣，况疮黑者，骨坚肉硬，且气固于中，骨胜肉也，出痘多吉。肥白
者，骨脆肉松，且气居于表，肉胜骨也，出痘多凶，盖肾主骨，痘为肾毒耳。
《经》曰∶春夏阳气在上，人气亦在上，秋冬阳气在下，人气亦在下，故春夏出
痘，血气随阳气上运而行疾，秋冬出痘，血气随阳气下陷而行迟，痘以头面为主，春夏
得发生之气。秋冬为闭藏之司。故曰∶春夏为顺，秋冬为逆，然有处春夏凶而秋冬吉
者，盖由禀气之壮弱；受毒之浅深，而后赖乎时令耳。又曰∶春脓 ，夏黑陷，秋斑冬
疹，皆为逆候，此以五脏所属，合时令而言也。虽然黑陷即处冬令，总非佳候，故不可
不知也。以宜存其略也，不可尽准者，以其犹有谬也。
世间有一种孩童，生得体质宽大肥胖，看似血气有余。为何患痘疮时囊房空虚，不能灌浆化脓，在第八九日就死亡呢？这是因为先天元气不能被形体所拘束，气血又怎能被形质所滞碍呢？那些形体虽然瘦小但元气充盈的，痘疮自然能起发灌浆而成功；如果形体虽然宽大肥胖但元气薄弱低劣的，痘疮必定干枯涩滞难以生长。所以治疗痘疮要看人的元气，不可根据人的形体来判断，何况痘疮有经络部位的不同，多少大小的不一，运气时令的差异，调摄养护的得失，怎么可以单凭形体来论断呢！
所以痘疮的经络既正，颗粒稀疏明朗，运气和顺，调摄适宜，毒邪原本浅薄，那么瘦小但元气充实的人固然不会受害，即使是瘦小但元气虚弱的人也有生机。如果痘疮的经络错乱触犯，点数密集，此时令乖逆，调护违背常理，毒邪禀受旺盛，那么肥胖但气血衰弱的人固然遭受危险，即使是肥胖但气盛的人，也有死亡的。何况疮色黑的，骨骼坚硬肌肉结实，且气固守于中，骨胜于肉，出痘多吉利。肥胖皮肤白的人，骨骼脆弱肌肉松弛，且气居于体表，肉胜于骨，出痘多凶险，这是因为肾主骨，痘疮是肾毒所致。
《内经》说：春夏阳气在上，人气也在上；秋冬阳气在下，人气也在下。所以春夏出痘，血气随着阳气向上运行而行动迅速；秋冬出痘，血气随着阳气向下陷落而行动迟缓。痘疮以头面为主，春夏得到发生之气，秋冬为闭藏之司。所以说：春夏为顺，秋冬为逆。然而有处于春夏凶险而秋冬吉利的，这是由于禀赋之气的壮弱、感受毒邪的浅深，而后依赖于时令。又说：春季脓疱不干，夏季黑陷，秋季斑疹，冬季疹出不畅，都是逆候，这是从五脏所属与合时令而言的。虽然黑陷即使处于冬令，总归不是佳兆，所以不可不知道。应当保留其大概原则，不可完全拘泥，因为其中还有谬误之处。
There are children in the world who are born with a broad and obese constitution, seemingly having an abundance of Xueqi (Blood and Qi). Why do they suffer from empty pustule sacs when contracting smallpox, failing to fill with pus and suppurate, leading to death on the eighth or ninth day? This is because congenital Yuanqi (Primal Qi) cannot be constrained by physical form, nor can Xueqi be stagnated by material substance. Those whose bodies are thin and small but possess abundant Yuanqi will naturally have their smallpox erupt, fill, and succeed. Conversely, those whose bodies are large and obese but have weak and inferior Yuanqi will inevitably experience dryness and difficulty in growth. Therefore, treating smallpox requires observing the patient's Yuanqi, not judging based on physical appearance. Moreover, smallpox involves different meridians and locations, varying numbers and sizes, differing Qi movements and seasonal timing, as well as gains and losses in care and nourishment; how can it be judged solely by physical form?
Thus, if the smallpox follows the correct meridians, presents with sparse and clear lesions, aligns with favorable Qi movements, receives appropriate care, and originates from shallow toxin levels, then even a thin and small individual with solid Yuanqi will not be harmed, and even one with weak Yuanqi may survive. However, if the smallpox invades incorrect meridians, presents with dense spots, occurs during adverse seasons, involves improper care contrary to norms, and stems from intense inherited toxin levels, then even an obese individual with strong Qi may die, let alone one with deficient Xueqi and Yin. Furthermore, those with black sores have firm bones and hard flesh, with Qi secured internally where bone dominates flesh, indicating a generally auspicious outcome for smallpox. In contrast, those who are obese and pale have brittle bones and loose flesh, with Qi residing superficially where flesh dominates bone, indicating a generally ominous outcome. This is because the Kidney governs bones, and smallpox is considered a toxin of the Kidney.
The *Classic* states: "In spring and summer, Yang Qi is above, and human Qi is also above; in autumn and winter, Yang Qi is below, and human Qi is also below." Therefore, when smallpox erupts in spring and summer, Xueqi follows the ascending Yang Qi and moves rapidly; when it erupts in autumn and winter, Xueqi follows the descending Yang Qi and moves slowly. Smallpox primarily manifests on the head and face. Spring and summer correspond to the energy of generation, while autumn and winter correspond to the function of storage. Thus, it is said that spring and summer are favorable (Shun), while autumn and winter are unfavorable (Ni). However, there are cases where spring and summer are ominous and autumn and winter are auspicious, depending on the strength of inherited Qi and the depth of toxin exposure, which then rely on seasonal timing. It is also stated that "spring pustules fail to dry, summer lesions become black and sunken, autumn presents with macules, and winter presents with rashes," all of which are unfavorable signs, discussed in terms of the Five Zang Organs' correspondence to seasonal timing. Although black sunken lesions occurring in winter are still not a good omen, this must be understood. One should retain the general principles but not apply them rigidly, as there are exceptions and errors.