今天之医法失传者，莫如痘疹。痘之源，藏于脏腑骨脉，而发于天时。所谓本于脏腑骨
脉者
，凡人受生之初，阴阳二气，交感成形。其始因火而动，则必有渣滓未融之处，伏于脏腑骨
脉之中，此痘之本源也。然外无感召，则伏而不出，及天地寒暑阴阳之气， 戾日积，与人
身之脏腑气血相尖，则其毒随之而越，此发于天时者也。而天时有五运六气之殊，标本胜复
之异。气体既禀受不同，感发又随时各别，则治法必能通乎造化之理，而补救之。此至精至
微之术也，奈何以寒凉伐之，毒药劫之哉？夫痘之源，不外乎火，固也。然《内经》云∶火
郁则发之。其遇天时炎热，火甚易发者，清解固宜。若冬春之际，气为寒束，则不起发；发
而精血不充，则无浆。浆而精血不继，即不靥。则温散提托补养之法，缺一不可，岂得概用
寒凉？至其用蚯蚓、桑虫、生蝎等毒药，为祸尤烈。夫以毒攻毒者，谓毒瓦斯内陷，一时不能
托出，则借其力以透发之。此绵危笃之症，千百中不得一者，乃视为常用之药，则无毒者，
反益其毒矣。病家因其能知死期，故死而不怨。孰知服彼之药，无有不死，非其识见之高，
乃其用药之灵也。故之生死，全赖气血。当清火解毒者，则清火解毒；当培养气血者，则温
托滋 百不失一矣。呜呼！廖说流传，起于明季，至今尤甚。惟以寒药数品，按日定方，不效
则继以毒药，如此而已。夫以至变至微之病，而立至定至粗之法，于是群以为痘科最易，不
知杀人亦最多也。
附∶种痘说
种痘之法，此仙传也。有九善焉∶凡物欲其聚，惟痘不欲其聚，痘未出而强之出，则毒
不聚
，一也。凡物欲其说，痘欲其少，强之出必少，二也。凡物欲其大，痘欲其小，强之出必小
，三也。不感时痘之戾气，四也。择天地温和之日，五也。择小儿无他病之时，六也。其痘
苗皆取种出无毒之善种，七也。凡痘必浆成十分而后毒不陷，种痘之浆五分以上即无害，八
也。凡痘必十二朝成靥，并有延至一月者，种痘则九朝已回，九也。其有种而死者，深用悔
恨。不知种而死者，则自出断无不死之理，不必悔也。至于种出危险之痘，或生痘毒，此则
医家不能用药之故。种痘之人更能略知治痘之法，则尤为十全矣。
当今的医法中失传的，没有比痘疹（天花）更严重的了。痘的根源，藏匿于脏腑骨脉之中，而发作则与天时气候有关。所谓“本于脏腑骨脉”，是指人在初受胎成形之时，阴阳二气交感融合。其初始因火气而动，必然有未能完全融化的渣滓，潜伏在脏腑骨脉之中，这就是痘的本源。然而，如果没有外感的感召，这些伏邪就不会发作出来；等到天地间的寒暑阴阳之气积聚成戾气，与人身体的脏腑气血相感应，那么其中的毒邪就会随之发散出来，这就是“发于天时”的原因。
而且天时有五运六气的差异，有标本胜复的不同。人的体质禀赋既然不同，感受激发又随着时间各有区别，所以治疗方法必须通晓造化自然的规律，从而进行补救。这是极其精微的技术，为什么反而用寒凉药去攻伐它，用毒药去劫夺它呢？痘的根源，不外乎是火，这确实是事实。但是《内经》说：“火郁则发之。”如果遇到天时炎热，火气旺盛容易发作的情况，清热解固然适宜。如果是冬春季节，气候被寒气束缚，痘就不能起发；如果起了但精血不充足，就没有浆液；如果有浆液但精血不能接续，就不能结痂。那么温散、提托、补养的方法，缺一不可，怎么能一概使用寒凉药呢？至于使用蚯蚓、桑虫、生蝎等毒药，造成的祸害尤其猛烈。所谓“以毒攻毒”，是说毒瓦斯内陷，一时之间不能托举出来，才借助它们的力量来透发痘毒。这是绵重危笃的病症，千百人中难得一例的情况，现在却把它当作常用药物，那么原本无毒的人，反而增加了毒性。病人因为医生能预知死期，所以死了也不怨恨。哪里知道服用那些医生的药，没有不死人的，这不是他们见识高明，而是用药诡诈啊。所以痘的生死，全赖气血。应当清火解毒的时候，就清火解毒；应当培养气血的时候，就温托滋补，这样百无一失。唉！谬论流传，始于明代末年，到现在更加严重。只是用几味寒药，按日子定方子，无效了就继之以毒药，如此而已。用这种至变至微的病，立下至定至粗的法度，于是大家都认为痘科最容易，却不知道杀人也最多。
附：种痘说
种痘的方法，是神仙传授的。它有九大好处：凡是物品都希望聚集，只有痘不希望聚集，痘未发出时强行让它发出，那么毒邪就不聚集，这是一大好处。凡是物品都希望舒展，痘希望稀少，强行让它发出必然稀少，这是第二大好处。凡是物品都希望长大，痘希望细小，强行让它发出必然细小，这是第三大好处。不感染时行痘的戾气，这是第四大好处。选择天地温和的日子，这是第五大好处。选择小儿没有其他疾病的时候，这是第六大好处。痘苗都选取种出后无毒的良好种子，这是第七大好处。凡是自然发的痘必须浆液长到十分满而后毒邪才不会内陷，种痘的浆液长到五分以上就是无害的，这是第八大好处。凡是自然发的痘必须十二天才能结痂，并有拖延到一个月的，种痘则九天就已经回缩结痂，这是第九大好处。其中有种痘而死亡的，人们深表悔恨。不知道种痘而死的，是因为即使自然发出也绝对没有不死之理，不必悔恨。至于种出危险的痘，或者生出痘毒，这是医生不能恰当用药的缘故。种痘的人如果能略微懂得治疗痘的方法，那就更是十全十美了。
Among the medical methods lost today, none is more so than those for variola (smallpox). The origin of smallpox lies hidden within the Zang-Fu organs, bones, and vessels, while its manifestation is governed by celestial timing. What is meant by "rooted in the Zang-Fu organs, bones, and vessels" is that at the initial stage of human conception, when Yin and Yang Qi interact to form the body, there must be some dregs that fail to fully integrate due to the movement of Fire. These dregs lie dormant within the Zang-Fu organs, bones, and vessels; this is the root source of smallpox. However, without external感召 (induction), these latent pathogens will not emerge. When the cold, heat, Yin, and Yang Qi of heaven and earth accumulate into malevolent Qi, and resonate with the Zang-Fu and Qi-Blood of the human body, the toxicity within them will then vent outward. This is what is meant by "manifesting according to celestial timing."
Furthermore, celestial timing varies according to the Five Movements and Six Qi, and differs in the relationships between root and branch, excess and deficiency. Since individual constitution and endowment differ, and the induction and activation vary with time, treatment methods must comprehend the principles of natural creation to provide remediation. This is an extremely refined and subtle art. Why, then, attack it with cold-cooling herbs and劫夺 (rob/capture) it with toxic substances? It is true that the root of smallpox is essentially Fire. However, as stated in the *Nei Jing* (Inner Canon): "When Fire is constrained, disperse it." If one encounters hot weather where Fire is abundant and easily manifests, clearing heat and resolving toxicity is indeed appropriate. But during winter and spring, if the Qi is constrained by Cold, the eruption will not rise; if it rises but Jing-Blood is insufficient, no pustular fluid will form; if there is fluid but Jing-Blood cannot sustain it, scabbing will not occur. Therefore, methods of warming and dispersing, lifting and supporting, and tonifying and nourishing are indispensable. How can one indiscriminately use cold-cooling herbs? As for using toxic substances such as earthworms (Pheretima), silkworm pupae (Bombyx Batryticatus), and live scorpions (Scorpio), the harm caused is particularly severe. The principle of "using toxicity to combat toxicity" applies only when toxic vapors have collapsed inward and cannot be lifted out temporarily, necessitating their strength to penetrate and erupt the disease. This scenario occurs in critical, life-threatening cases, perhaps one in a thousand. Yet, treating it as a common medication means that those without inherent toxicity inadvertently increase their toxicity. Patients do not resent death because the physician claims to know the time of death. Little do they know that taking such physicians' medicines leads inevitably to death; this is not high insight, but cunning in prescription. Thus, survival or death from smallpox depends entirely on Qi and Blood. When clearing Fire and resolving toxicity is indicated, do so; when tonifying Qi and Blood is indicated, use warming support and nourishment, and you will rarely fail. Alas! These erroneous theories spread since the late Ming Dynasty and remain prevalent today. Physicians simply prescribe a few cold-natured herbs daily according to a fixed schedule, and if ineffective, follow up with toxic substances. To apply such rigid and crude methods to a disease of extreme variability and subtlety leads many to believe smallpox treatment is easy, unaware that it kills the most people.
Appendix: On Variolation
The method of variolation was transmitted by immortals. It possesses nine advantages: First, while most things desire aggregation, smallpox does not; forcibly inducing eruption before it naturally arises prevents toxin aggregation. Second, while most things desire expansion, smallpox desires scarcity; forcibly inducing eruption ensures scarcity. Third, while most things desire growth, smallpox desires smallness; forcibly inducing eruption ensures small lesions. Fourth, it avoids infection by the malevolent Qi of epidemic smallpox. Fifth, it allows selection of days with gentle and harmonious heaven-earth Qi. Sixth, it allows selection of times when the child has no other illnesses. Seventh, the vaccine material is taken from benign seeds that produce non-toxic eruptions. Eighth, in natural smallpox, pus must reach full maturity (ten parts) to prevent toxin collapse; in variolation, pus reaching five parts is harmless. Ninth, natural smallpox requires twelve days to scab, sometimes extending to a month; variolation results in regression and scabbing within nine days. Those who die after variolation deeply regret it, not realizing that even if the disease had erupted naturally, death would have been inevitable, so there is no need for regret. Regarding dangerous eruptions post-variolation or the generation of toxic sores, this is due to the physician's inability to medicate correctly. If the person performing variolation also understands basic smallpox treatment methods, the outcome would be perfect.