苗者，痘之痂也。种痘者，全资乎此，以为胎毒之引导，关系匪轻。选苗时，宜留神
细察，不可轻忽，其中有可用者，有不可用者，惟在痘之顺与不顺别之。痘之不顺者，出
不尖圆，色不红润，浆不充满，所落之痂，黑暗而薄。此天人合病，内外合邪所致，即幸
而得愈，亦不过良工之善为调治，非天然之美，此等痘痂，断不可用。痘之顺者，始终
无夹杂之证，出则尖圆，色则红润，浆则充满，所落之痂，苍蜡光泽，肥大浓实。此得
天地阴阳之正气，极顺之苗也，收而用之，效如附应。但此痂甚少，所遇无多，或不能亲
其事而假手他人，亦必令彼身亲目睹方可。否则宁置而不用，切勿滥用，种者审之。
种痘必资于苗，而苗之所可恃者，在气之相通耳。若遇热则气泄，日久则气薄，触
污秽则气不清，腑不洁则气不正，此蓄苗之法，所以不可不慎也。如遇好苗，须贮新瓷
瓶内，上以物密覆之，置于洁净之所，清凉之处。其所贮之苗，在春天者，一月之痂可
种。冬令严寒，四五十日之痂尚可种。盖寒则气收藏，热则气易泄，故时日有不同也。然
于未收苗时，即当先与出痘之家明言其故，使彼乐从，无所疑忌。彼方肯用心收贮，不致稍有贻误也。
种痘贵得天时，得其时则种，不得其时则不种。夫天时之正，莫过于春。春为万物
发生之际，天气融和，不寒不热，种之则痘自随其气而发生，此正、二、三月之时，所
以可种也。若交夏之后，六阳尽出地上，人之阳气亦皆外浮，暑热烁金，受病者众。斯
时种痘，儿何以堪？此四、五、六月之时，所以必不可种也。至若秋令，天气清肃，收敛
之时，虽遇可种之儿，而无引毒之具，此七、八、九月之时，势有不能种也。至于十月，名
曰小春，虽亦可种，然斯时寒气固结，纯阴用事，不若俟冬至后一阳鼓动，借其生生之
气，种之甚吉。此十月之所以可种，犹不若十一、十二月之尤可种也，然当可种之时，亦
有不可种者，如春应温而反寒，夏应热而反凉，秋应凉而反热，冬应寒而反温，当其时
而非其气，是天地不正之气也。常人感染则成时疫，小儿调理未遑，况敢言种痘乎？倘
或遇此，只宜稍避，俟时气平定，再为议种，方保万全。亦有未种之时，天时甚正，既种
之后，忽尔寒暄不时，此又人事所遇不齐，偶尔变气，出乎意外者也。则宜屋中适其寒温，
顺会天时，常烧辟秽香，饮食起居，更加谨慎，可保无恙。种痘者宜详审而体察之。
痘苗，就是天花痊愈后脱落的痂皮。种痘疗法完全依赖于此，将其作为胎毒的引导，关系非常重大。在挑选痘苗时，应当留心仔细察看，不可轻视疏忽。其中有的可以使用，有的不可以使用，关键在于辨别痘疹是顺证还是逆证。痘疹属于逆证的，出痘形态不尖圆，颜色不红润，浆液不充满，脱落的痂皮黑暗且薄。这是天人合病、内外邪气相合所致，即使侥幸痊愈，也不过是高明医生善于调治的结果，并非天然完美之象，这样的痘痂绝对不可使用。痘疹属于顺证的，从头到尾没有夹杂其他病症，出痘形态尖圆，颜色红润，浆液充满，脱落的痂皮呈苍蜡色且有光泽，肥大浓实。这是因为获得了天地阴阳的正气，是最为顺遂的痘苗，收集起来使用，疗效迅速显著。但是这种好的痘苗很少见，遇到的机会不多，如果无法亲自处理而委托他人，也必须让受托者亲眼目睹方可。否则宁可放置不用，也千万不要滥用，种痘者务必审慎考虑。
种痘必须依靠痘苗，而痘苗之所以可靠，在于气息的相通。如果遇到热天，痘苗的气息就会泄散；时间久了，气息就会变淡薄；接触到污秽之物，气息就不纯净；容器不洁净，气息就不端正。这就是保存痘苗的方法，所以不可不谨慎。如果遇到好的痘苗，必须储存在新的瓷瓶内，上面用物体严密覆盖，放置在洁净的地方、清凉之处。所储存的痘苗，在春季，一个月内的痂还可以用来种痘。冬季天气严寒，四五十天的痂还可以用来种痘。大概是因为寒冷时气息收藏，炎热时气息容易泄散，所以时间长短有所不同。然而在未收取痘苗之前，就应当先向出过天花的人家讲明其中的道理，使他们乐意听从，没有任何疑虑忌讳。他们才肯用心收存保管，不至于稍有延误失误。
种痘贵在顺应天时，遇到合适的时候才种，不合适的时候就不种。天时的正位，莫过于春季。春季是万物发生之际，天气融和，不冷不热，此时种痘，痘疹自然会随着天时之气而发生，这就是正月、二月、三月可以种痘的原因。如果进入夏季之后，六阳之气全部出于地上，人的阳气也都向外浮越，暑热灼烧肺金（指伤及肺气），患病的人很多。这个时候种痘，小孩子怎么能承受得住？这就是四月、五月、六月绝对不能种痘的原因。至于秋季，天气清肃，是收敛的时候，虽然遇到可以种痘的孩子，但没有引导毒邪的工具（指缺乏适宜的生发之气来引毒外出），这就是七月、八月、九月形势上不能种痘的原因。到了十月，名叫“小春”，虽然也可以种痘，然而此时寒气凝结，纯阴之气主事，不如等到冬至之后一阳初动，借助其生生不息的气机，种痘非常吉利。这就是十月的可种性，还不如十一月、十二月更适宜种痘的原因。但是在应该种痘的时候，也有不能种的情况，比如春天本该温暖却反而寒冷，夏天本该炎热却反而凉爽，秋天本该凉爽却反而炎热，冬天本该寒冷却反而温暖，在这个时候却不是这个时候应有的气候，这是天地不正之气。普通人感染就会成为时行疫病，小儿调理尚且来不及，哪里还敢谈论种痘呢？倘若遇到这种情况，只宜稍微避开，等到时气平定之后，再商议种痘，才能确保万无一失。也有在未种痘之前，天时很正，种痘之后，忽然寒暖不时，这又是人事遭遇不齐，偶尔出现的气候变异，出乎意料之外的情况。这时应当在屋内调节好寒温，顺应天时，经常焚烧辟秽香，饮食起居更加谨慎，可以保证平安无事。种痘者应当详细审察并体会观察这些情况。
Miao (seed/graft) refers to the scab of smallpox. Vaccination relies entirely on this, using it as a guide for fetal toxins, which is of significant importance. When selecting miao, one must pay close attention and examine carefully, not taking it lightly. Among them, some are usable, and some are not; it depends on distinguishing whether the smallpox eruption is favorable (Shun) or unfavorable (Bu Shun). Unfavorable eruptions present with shapes that are not sharp and round, colors that are not ruddy and bright, and pustules that are not full. The fallen scabs are dark and thin. This is caused by the combination of heaven and human pathologies, and internal and external evils. Even if recovery occurs by luck, it is merely due to the skillful treatment of a competent physician, not a natural perfection. Such scabs must absolutely not be used. Favorable eruptions have no mixed symptoms from beginning to end; they erupt with sharp and round shapes, ruddy and bright colors, and full pustules. The fallen scabs are pale wax-colored, lustrous, large, thick, and solid. These obtain the righteous qi of heaven and earth's yin and yang, representing the most favorable miao. Collecting and using them yields effects as immediate as an echo. However, such scabs are rare and encounters are infrequent. If one cannot handle the matter personally and delegates it to others, one must ensure those persons witness it themselves. Otherwise, it is better to leave them unused than to abuse them; vaccinators should exercise caution.
Vaccination must rely on miao, and what makes miao reliable is the communication of qi. If exposed to heat, the qi dissipates; over time, the qi becomes weak; contact with filth makes the qi impure; unclean containers make the qi irregular. Thus, the method of storing miao must be handled with extreme care. Upon encountering good miao, it must be stored in a new porcelain bottle, tightly covered with an object, and placed in a clean, cool location. Miao stored in spring can be used within one month. In the severe cold of winter, miao aged forty to fifty days can still be used. This is because cold causes qi to store, while heat causes qi to dissipate easily, hence the difference in timeframes. However, before collecting miao, one must clearly explain the reasons to families who have had smallpox, so they willingly comply without suspicion or fear. Only then will they diligently store it, avoiding any delays or errors.
Vaccination values adhering to heavenly timing: vaccinate when the time is right, do not vaccinate when it is not. The most appropriate season is spring. Spring is the time when all things generate; the weather is mild, neither cold nor hot. Vaccinating then allows the smallpox to occur naturally following the qi. Hence, the first, second, and third lunar months are suitable for vaccination. After entering summer, the six yang energies emerge above ground, and human yang qi floats outward. Summer heat scorches metal (lungs), leading to many illnesses. How could children endure vaccination at this time? Therefore, the fourth, fifth, and sixth lunar months are absolutely unsuitable for vaccination. As for autumn, the weather is clear and solemn, a time of contraction. Although there may be children suitable for vaccination, there is no tool to guide the toxin (lack of generative qi to draw out toxins). Thus, the seventh, eighth, and ninth lunar months are situationally unsuitable. By the tenth month, known as "Little Spring," vaccination is possible, but cold qi is consolidated, and pure yin dominates. It is better to wait until after the Winter Solstice when one yang begins to stir, borrowing its life-generating qi for very auspicious results. Thus, the tenth month is less ideal than the eleventh and twelfth months. However, even during suitable times, there are unsuitable conditions. For example, if spring is cold instead of warm, summer is cool instead of hot, autumn is hot instead of cool, or winter is warm instead of cold, the time does not match the climate. This is the irregular qi of heaven and earth. Ordinary people contracting this develop seasonal epidemics; how much more so for children whose regulation is already insufficient, let alone vaccination? If such situations arise, one should avoid them slightly, waiting for the climate to stabilize before discussing vaccination to ensure safety. There are also cases where the climate was correct before vaccination, but sudden fluctuations in cold and warmth occur afterward. This is due to uneven human circumstances and occasional unexpected climatic changes. In such cases, one should adjust the indoor temperature appropriately, align with the heavenly timing, frequently burn incense to dispel filth, and be more cautious with diet and daily routine to ensure safety. Vaccinators should carefully examine and observe these details.