夫百病之生，莫不乘虚而发，即如痘疮一症。凡元气壮实，调理得宜。则虽有时行
不能感触，否则，或因外感，或因内伤，新病而具出旧邪矣。然内伤虚人，中气即虚，
外感虚入，略缓时日，况邪之所凑，其正已虚，既受客病，更伤正气，痘疮乘虚感动，
益虚其虚矣。治者，切须审其或阴或阳，或表或里，因所因而调之，使气血鼓舞，自能
逐毒，气血合德，邪无容地。如筛米而转运不停，则糠秕腾然起聚，自作一团而不混杂
于米。如气血和畅而互相为用，则鼓舞营运不息，其为阴翳之毒，自出自化于肌肉之
表，而难伏匿于脏腑经络之中，惟有重感风寒，闭塞腠理者，方可荆、防、羌、葛、微
开毛孔，疏毒外达。所谓有病病当之也。如一概疏表解肌，以毒攻毒为事，倘外无强暴
之寒邪。又值重帏不密之腠理，且芽儿柔脆，正气无力主持，一任药力猛锐，毒势奔
溃，一齐涌出，其形如麸如 者，即不足之气逼而成之也。其色如疹如丹者，即不足之
血竭而华之也。然中气荣卫泄越于表，枯竭于里，邪在未解之秋，正无续运之势，定有
复陷干枯无脓之患，治者能明至理，当此邪毒出表，毒瓦斯外泄，其热其势，姑在少缓之
时，火盛者，重用滋阴以化阳，仍宜鼓舞而勿滞。火衰者，便倍中气以固本，仍兼润药
而勿燥，托毒之中，寓入培本之药预为地步，则到灌脓朝限，有此气血而为酿脓之
具。若到灌脓之期，用之已无及矣。但虚凭脉，则药不得阴阳错补，人谓毒盛难于早
补，殊不知毒盛而无气血，将何逐毒化毒耶，张深悯其厄，梦寐求之，得此至情，尚
可十有一，活。盖痘疮一拥而出，临时毒尽在外，当此只有正虚。所谓应犯而犯似乎无
犯之时也。乘势急以扶正，却邪之饵也。邪气受我正气之节制则何往不宜。若至灌脓之
期。气血不能接续，荣卫之力转穷，毒瓦斯何从化泄，乘虚陷入，尚有何法可救哉！更人
但知以毒为火，清火以解毒，殊不知毒即是火，毒化而火亦清，毒凝而火愈郁，然毒之
化必由脓，脓之来必由气血，气血之化必由火也。岂可以寒凉清解之乎？即使火之有
余，亦由水之不足，滋水便可以化火，更能养血之根，而为脓之本矣，况寒凉解毒，仅
可施于腑毒疮疡，至于痘，属脏毒，属阴最深，必仗气血送出于皮肤，运化于窠囊，收
结成痂，还元而后已，宁有内消者乎。宁有不成脓者乎！然痘之成形华色者，皆后天气
血有形之用也。运气血以成形华色，化脓结 者，皆先天水火无形之德也。惟其无形，
故能致其有形，故有形之疾病难除，必求无形水火之真药可化，试思痘出之红而白，白
而黄，黄而黑者，岂非水火无形之化欤，况凡痘疮，及一切痈疽肿毒，皆因气血不和，
偏阴偏阳，留结所致，偏于阴而气不足，在痈疽则谓阴毒，在痘疮则谓气虚。偏于阳而
血不足，在痈疽则谓阳毒，在痘疮则谓血热。故本是气血中阴阳偏胜所致，原非气血
外另有恶气所成，焉得作有形之相，寒凉克削而攻无形之虚。故《经》曰∶营气不从，
逆于肉里，乃生痈肿者，此也。既属无形阴阳偏胜之所化，盒饭据脉察候，以阴阳之所
偏以调之，将此有形之实，化作无形之虚，借此无形之水火，以作有形之妙用，自无而
有，自有而无，挽回造化之神功，默运于内，而莫测其微矣。
大凡各种疾病的发生，没有不是趁着人体正气虚弱而发作的，就拿痘疮这一病症来说。凡是元气壮实、调理得当的人，即使遇到时行疫气，也不能被感染；否则，或者因为外感邪气，或者因为内伤正气，新病与潜伏的旧邪一同发作。然而，如果是内伤导致的虚损之人，中气本就虚弱，若是再感受外邪，稍微拖延时日，况且邪气聚集之处，正气已经虚弱，既然遭受了客邪侵袭，更会损伤正气，痘疮趁机乘虚而动，使得虚者更虚。治疗者，必须仔细审察病情是属于阴证还是阳证，属于表证还是里证，根据病因进行调理，使气血振奋鼓舞，自然能够驱逐毒邪，气血和谐共济，邪气便无处容身。就像筛米一样，转运不停，糠秕就会腾然聚集成一团，而不混杂在米粒之中。如果气血和畅并互相为用，那么鼓舞营运不息，那些阴翳之毒，自然会从肌肉表面排出化解，而难以潜伏在脏腑经络之中。只有当再次感受风寒，导致腠理闭塞时，才可以使用荆芥、防风、羌活、葛根等药物微微开启毛孔，疏泄毒邪使其向外达出。这就是所谓“有病则病受之”。如果一概使用疏表解肌、以毒攻毒的方法，倘若外部没有强暴的寒邪，又正值腠理疏松不密，且婴儿柔嫩脆弱，正气无力主持，一旦任由药力猛锐，毒势奔溃，一齐涌出，其形态像麸皮或碎屑一样的，就是不足之气逼迫而成的。其颜色像疹子或丹毒一样的，就是不足的血液枯竭而华现出来的。然而中气和营卫之气泄越于体表，内部枯竭，在邪气尚未解除的时候，正气没有继续运行的势头，必定会有再次陷入、干枯无脓的祸患。治疗者如果能明白至理，当此邪毒出于体表，毒瓦斯向外排泄之时，其热势可以暂时稍加缓和。火盛者，重用滋阴药物以化除阳亢，仍宜鼓舞正气而不要壅滞。火衰者，加倍补益中气以固根本，仍兼用润药而不要燥烈，在托毒的过程中，寓入培补本元的药物预作打算，那么到了灌脓的关键期限，有了这些气血作为酿脓的工具。如果到了灌脓的时期，再用这些方法就已经来不及了。但是判断虚实凭靠脉象，用药就不能阴阳错补。人们常说毒盛时难以早补，殊不知毒盛而无气血，将用什么来驱逐和化解毒邪呢？张深怜悯其困境，梦寐以求寻求良方，得到这种至情至理的方法，还可以挽救十分之一二。大概痘疮一拥而出，临时毒气尽在于外，当此之时只有正气虚弱。这就是所谓“应当犯病却犯了病，看起来好像没犯病的时候”。趁此形势急以扶正，这是驱除邪气的药剂。邪气受到我正气的节制，那么往哪里不宜呢？如果到了灌脓的时期，气血不能接续，营卫之力转穷，毒瓦斯从哪里化泄？乘着虚陷进去，还有什么办法可救呢！世人只知道把毒当作火，清火来解毒，殊不知毒即是火，毒化解了火也就清了，毒凝结了火就更郁结，然而毒的化解必然通过脓，脓的到来必然依靠气血，气血的化生必然依靠火啊。怎么可以用寒凉清解的药物呢？即使火有余，也是由于水不足，滋补水液就可以化除火邪，更能养血之根，作为成脓的根本。况且寒凉解毒，仅可施用于腑毒疮疡，至于痘疮，属于脏毒，属阴最深，必须依靠气血将其送出于皮肤，运化于窠囊，收结成痂，还元而后停止，哪里有内消的呢？哪里有不成脓的呢！然而痘疮形成形状和华美色泽的，都是后天气血有形作用的结果。运用气血来形成形状和华美色泽，化脓结痂的，都是先天水火无形德性的体现。正因为无形，所以能成就有形，所以有形的疾病难除，必须求得无形水火的真药才能化解。试思考痘出后红而白，白而黄，黄而黑的变化，难道不是水火无形变化的体现吗？况且凡是痘疮，以及一切痈疽肿毒，都是因为气血不和，偏阴偏阳，留结所致。偏于阴而气不足，在痈疽则称为阴毒，在痘疮则称为气虚。偏于阳而血不足，在痈疽则称为阳毒，在痘疮则称为血热。所以本是气血中阴阳偏胜所致，原本并非气血之外另有恶气所成，怎么能做成有形的相状，用寒凉克削的方法来攻伐无形的虚损。所以《内经》说：“营气不从，逆于肉里，乃生痈肿”，就是这个道理。既然属于无形阴阳偏胜所化，就应当依据脉象察候，根据阴阳之所偏来调理，将此有形的实证，化作无形的虚证，借此无形的水火，以作有形的妙用，自无而有，自有而无，挽回造化之神功，默默运行于内，而不可测度其微妙之处。
The onset of all diseases invariably takes advantage of deficiency to manifest. Take smallpox as an example. If the Yuan Qi (Primordial Qi) is robust and regulation is appropriate, even during an epidemic season, one cannot be infected. Otherwise, due to external contraction or internal injury, new illnesses may emerge alongside latent pathogens. However, in individuals with internal injury and deficiency, the Middle Qi (Spleen and Stomach Qi) is already deficient. If they contract external pathogens and time is allowed to pass, considering that where pathogens gather, Zheng Qi (Upright Qi) is already weak, having suffered from exogenous illness further damages Zheng Qi. Smallpox takes advantage of this deficiency to move, exacerbating the deficiency. The practitioner must carefully examine whether the condition is Yin or Yang, exterior or interior, and regulate according to the etiology, so that Qi and Blood are stirred and encouraged, naturally driving out toxins. When Qi and Blood act in harmony, pathogens have no place to reside. It is like sifting rice; as the movement continues, chaff gathers into a clump without mixing with the grains. If Qi and Blood are harmonious and mutually supportive, their circulation remains unceasing. The Yin-shrouded toxins will naturally emerge and transform on the surface of the muscles, making it difficult for them to hide within the Zang-Fu organs and meridians. Only when re-contracted by wind-cold, closing the Cou Li (skin pores and interstices), should one use Jing Jie (Schizonepetae Herba), Fang Feng (Saposhnikoviae Radix), Qiang Huo (Notopterygii Rhizoma et Radix), and Ge Gen (Puerariae Lobatae Radix) to slightly open the pores and disperse toxins outward. This is what is meant by "when there is disease, the disease bears the brunt." If one indiscriminately uses methods to release the exterior and resolve the muscle layer, aiming to attack toxin with toxin, yet there is no severe cold pathogen externally, and the Cou Li are loose and not tight, and the infant is tender and fragile with insufficient Zheng Qi to govern, allowing the fierce medicinal force to cause the toxic momentum to collapse and surge out together, the form resembling bran or fragments is caused by insufficient Qi being forced out. The color resembling macules or erythema is caused by insufficient Blood drying up and manifesting. However, if Middle Qi and Ying-Wei (Defensive and Nutritive Qi) leak to the exterior and dry up internally, while the pathogen is unresolved and Zheng Qi lacks the momentum for continuous operation, there will inevitably be the risk of sinking again, becoming dry with no pus. If the practitioner understands this profound principle, when the pathogenic toxin emerges to the exterior and toxic vapors dissipate outward, the heat and momentum can be temporarily moderated. If Fire is excessive, heavily employ Yin-nourishing herbs to transform Yang hyperactivity, still encouraging but avoiding stagnation. If Fire is deficient, double the dosage to tonify Middle Qi and secure the root, still incorporating moistening herbs to avoid dryness. Within the method of supporting toxins, incorporate herbs that cultivate the root to prepare ahead. Then, when the critical period of pus formation arrives, these Qi and Blood will serve as the tools for generating pus. If one waits until the pus formation period, it will be too late. However, determining deficiency relies on pulse diagnosis, so medications must not tonify Yin and Yang incorrectly. People say that when toxin is excessive, early tonification is difficult. They do not realize that with excessive toxin but lacking Qi and Blood, what would drive out and transform the toxin? Zhang Shen pitied their plight, seeking desperately in dreams, and obtaining this profound understanding, one could save one or two out of ten. Generally, when smallpox erupts all at once, the toxin is entirely on the exterior at that moment, leaving only Zheng Qi deficiency. This is the situation where "one commits the error that should be committed, appearing as if no error was made." Taking advantage of this momentum to urgently support Zheng Qi is the way to expel pathogens. If pathogens are controlled by our Zheng Qi, there is nowhere they cannot be managed. But if one reaches the pus formation period, Qi and Blood cannot connect, and Ying-Wei strength becomes exhausted, from where can toxic vapors be transformed and discharged? Falling into deficiency, what method remains for rescue! People generally know to treat toxin as Fire and clear Fire to detoxify, not realizing that toxin is Fire itself; when toxin transforms, Fire clears; when toxin coagulates, Fire becomes more stagnant. Yet, the transformation of toxin must occur through pus, the arrival of pus depends on Qi and Blood, and the transformation of Qi and Blood depends on Fire. How can one use cold and cool clearing and resolving methods? Even if Fire is excessive, it is due to Water insufficiency; nourishing Water can transform Fire, and further nourish the root of Blood, which serves as the foundation for pus. Moreover, cold and cool detoxification is only applicable to Fu-organ toxins and sores/ulcers. As for smallpox, it belongs to Zang-organ toxins, deeply Yin in nature. It must rely on Qi and Blood to send it out to the skin, circulate and transform within the pustule sacs, condense and form scabs, and return to the Primordial State before ending. How could there be internal resolution? How could there be no pus formation! The shaping and coloring of smallpox are the tangible functions of acquired Post-Heaven Qi and Blood. Using Qi and Blood to shape and color, transforming into pus and forming scabs, are the intangible virtues of innate Pre-Heaven Water and Fire. Because it is intangible, it can produce the tangible. Therefore, tangible diseases are hard to eliminate; one must seek the true medicine of intangible Water and Fire to transform them. Consider the changes of smallpox from red to white, white to yellow, and yellow to black; are these not manifestations of the intangible transformation of Water and Fire? Furthermore, all smallpox, as well as carbuncles, ulcers, and swollen toxins, result from disharmony of Qi and Blood, deviation towards Yin or Yang, and stagnation. Deviation towards Yin with Qi insufficiency is called Yin Toxin in carbuncles/ulcers, and Qi Deficiency in smallpox. Deviation towards Yang with Blood insufficiency is called Yang Toxin in carbuncles/ulcers, and Blood Heat in smallpox. Thus, it originates from the excess of Yin or Yang within Qi and Blood, not from some evil Qi existing outside Qi and Blood. How can it take tangible form? Using cold and cool astringent methods to attack intangible deficiency contradicts this. Hence, the *Classic* states: "When Ying Qi does not flow smoothly and reverses within the flesh, abscesses and swellings arise." Since it is transformed by intangible Yin-Yang imbalance, one should observe the pulse and signs, regulating based on the deviation of Yin and Yang. Transform this tangible excess into intangible deficiency, using this intangible Water and Fire to achieve tangible miraculous effects. From non-being to being, from being to non-being, the divine power of restoring creation operates silently within, beyond measure.