《素问·平人气象》长夏软弱有石曰冬病，石甚曰今病。（从《脉经》及《甲乙》。）案石
之义
，似当为坚，而经与软弱并举，则石脉之象，从此可推已。盖坚为长属，去来相引；石为短
属，去来皆断∶两者固别。《素·玉机真脏》真肾脉至搏而绝，如以指弹石辟辟然。绝谓去
来绝也。一曰如夺索。（“夺”古“脱”字，见《说文》。夺索即绝也。）是石脉取义于绝，
不取于坚，故得与软弱并举。第辟辟之石无胃气，软弱之石有胃气，故在彼为死脉，在此为
病脉耳！所以长夏忌石者，脾平脉相离，如鸡践地，则离而不甚觉其离也；石则离之显焉者
矣。夫离之为言，犹断也。以不甚觉离者，而忽显见为离，脾气弱而肾气强矣，故病。
玉屏风之止汗，非如圬者之于墙然也。其谓汗之因风得之者，恒至虚其卫气而久恋，卫
则不
收，风恋则不纯，以不纯乘不收，则汗出自易。故必以防风从外发之，白术从中守之，而黄
则居其间而托之。 之为言致也，（《诗·皇矣》上帝耆之，耆致也。）推致卫气使风不得
留，则卫自收而汗自止。方义如此。人见其汗止也，而以为黄 固表，亦盍观其方下有治风
邪久留不散，自汗不止两语乎？《本草经》曰∶黄 治大风。此方本之，故其义与金匮血痹
黄汗黄胆诸用黄 方不同而同，以彼症亦由卫虚挟风故也，其防术并用，取诸金匮桂芍知母
汤方中，亦以彼症由风汗之故，以彼证此，断可知已，必其人之症，如方下所云，始可用之
，倘其汗不由于风，或微有风而属在表虚里实之体，即不可服，服之则卫以被托而益虚，表
虚而里益形其实，诸气不和，虽本无汗，且可使有汗，奈何忌汗而藉此止汗耶，且屏风之名
，兼有屏绝屏挡之义，若专以屏藩屏蔽为言，则艳其名而没其实矣，大抵古今名方，苟得
仲景之一端，即非望文而可晓，读者当以意逆志焉。
《素问·平人气象论》中提到：“长夏季节脉象软弱却带有石脉（肾脉，主冬令之气），称为冬季的疾病；如果石脉象明显，则称为当下的疾病。”（此句依据《脉经》及《甲乙经》）。
考察“石”字的含义，似乎应当解释为坚硬，但经文将“石”与“软弱”并列提及，那么石脉的形象，从此就可以推知了。大概而言，“坚”属于长气（连绵不断），去来相互牵引；“石”属于短气（断绝），去来都断绝：两者固然不同。《素问·玉机真脏论》中说：“真肾脉至，搏动而绝，像用手指弹石头一样辟辟作响。”所谓“绝”，是指去来断绝。另一种说法是像争夺绳索一样紧绷。（“夺”是古“脱”字，见于《说文解字》，夺索即断绝之意。）由此可见，石脉取义于“断绝”，而非取义于“坚硬”，所以能够与“软弱”并列。只是那种辟辟作响的石脉没有胃气，而软弱中兼有石意则有胃气，所以在前文中被称为死脉，在此处被称为病脉罢了！之所以说长夏季节忌讳石脉，是因为脾的平脉（正常脉象）与石脉相离，像鸡踩在地上那样轻灵，这种分离并不容易被察觉；而石脉则是分离得很明显的表现。所谓“离”，意思就是断绝。以不太容易察觉的分离，突然变成明显可见的分离，说明脾气虚弱而肾气强盛，所以生病。
玉屏风散止汗的道理，不像粉刷匠对待墙壁那样简单。它认为，因为风邪导致的出汗，往往会耗伤卫气并使其长久滞留，卫气不能固摄，风邪留恋而不纯粹，以不纯之风乘卫气不收之时，出汗自然容易。因此，必须用防风从外部发散风邪，白术在内部守持中气，黄芪居于中间托举正气。黄芪的“芪”字，意为“致”（推致、达到）。（《诗经·皇矣》中“上帝耆之”，耆即致的意思。）通过推致卫气，使风邪不得停留，那么卫气自然收敛，汗液自然停止。方剂的义理就是这样。人们看到它止住了汗，就以为黄芪是固表止汗，何不看看方剂下方写着“治疗风邪久留不散，自汗不止”这两句话呢？《神农本草经》说：“黄芪主治大风。”本方正是依据这一点制定的，所以它的义理与《金匮要略》中血痹、黄汗、黄疸等使用黄芪的方剂既有不同又有相同之处，因为那些病症也是由卫虚挟带风邪引起的。其中防风和白术并用，取自《金匮要略》桂枝芍药知母汤方中的配伍，也是因为那些病症是由风邪导致出汗的缘故。以此证彼，完全可以推断出来。必须是患者的症状如方剂下方所述那样，才可以服用此方。如果出汗不是由于风邪引起，或者虽然有轻微风邪但属于表虚里实的体质，就不可服用。服用了就会使卫气被托举而更加虚弱，表虚而里实更加明显，各种气机不和，即使原本不出汗，也可能导致出汗，怎么能为了忌汗而借此来止汗呢？况且“屏风”这个名字，兼有屏蔽、阻挡的含义。如果仅仅把它理解为屏障遮挡，那就是只看重名字而忽略了其实质了。大抵古今的名方，只要得张仲景学术思想的一方面，就不是望文生义所能明白的，读者应当用心去揣测其志向和用意。
The *Suwen: Pingren Qixiang Lun* states: "If the pulse in late summer is weak and soft yet exhibits a 'Stone' quality (Kidney pulse, associated with winter Qi), it indicates a disease of winter; if the Stone quality is pronounced, it indicates a current disease." (This passage is based on the *Maijing* and *Jiayi Jing*).
Examining the meaning of "Stone," it seems appropriate to interpret it as firm/hard. However, since the classic text juxtaposes "Stone" with "weak and soft," the imagery of the Stone pulse can be inferred from this. Generally speaking, "Firmness" belongs to long/continuous Qi, where the arrival and departure are mutually connected; "Stone" belongs to short/disconnected Qi, where both arrival and departure are severed: the two are indeed distinct. The *Suwen: Yuji Zhenzang Lun* states: "When the True Kidney pulse arrives, it beats and then cuts off, sounding like striking a stone with a finger—pi pi然." The term "cut off" (Jue) refers to the severance of arrival and departure. Another interpretation is that it feels like pulling a rope taut ("Duo" is an ancient form of "Tuo," seen in the *Shuowen Jiezi*; Duo Suo means severed). Thus, the Stone pulse derives its meaning from "severance/disconnection," not from "firmness," which is why it can be juxtaposed with "weak and soft." However, the Stone pulse that sounds pi pi lacks Stomach Qi, whereas the weak-and-soft pulse containing Stone qualities possesses Stomach Qi. Therefore, the former is termed a death pulse, while the latter is termed a disease pulse! The reason why the Stone pulse is taboo in late summer is that the Spleen's normal pulse separates from the Stone pulse. Like a chicken stepping on the ground, this separation is subtle and not easily perceived; the Stone pulse, however, represents a conspicuous separation. The term "separation" implies disconnection. To go from a barely perceptible separation to a clearly visible one indicates that Spleen Qi is weak and Kidney Qi is strong, hence disease arises.
The mechanism by which Yupingfeng San (Jade Windscreen Powder) stops sweating is not analogous to how a plasterer treats a wall. It posits that sweating caused by wind pathogen often constantly depletes Wei Qi (Defensive Qi) and causes it to linger. When Wei Qi fails to consolidate, and wind lingers impurely, the impure wind exploits the lack of consolidation, making sweating easy. Therefore, Fangfeng (Saposhnikoviae Radix) must be used to disperse wind from the exterior, Baizhu (Atractylodis Macrocephalae Rhizoma) to guard the middle, and Huangqi (Astragali Radix) to support/supportive tonification from within. The character "Qi" in Huangqi implies "to reach/push forward" (as in *Shijing: Huangyi*: "Shangdi qi zhi," where Qi means to reach). By pushing/reaching Wei Qi so that wind cannot remain, Wei Qi naturally consolidates and sweating naturally stops. This is the rationale of the formula. People see that it stops sweating and assume Huangqi merely consolidates the exterior. Why not observe the two phrases under the prescription: "treating wind pathogen lingering for a long time without dispersing, and spontaneous sweating that does not cease"? The *Shennong Bencao Jing* states: "Huangqi treats severe wind." This formula is based on this principle. Thus, its rationale differs from but also shares similarities with formulas using Huangqi for blood bi, yellow sweat, and jaundice in the *Jingui Yaolue*, because those conditions are also caused by Wei deficiency combined with wind. The combination of Fangfeng and Baizhu is taken from the Guizhi Shaoyao Zhimu Tang (Cinnamon Twig, Peony, and Anemarrhena Decoction) in the *Jingui Yaolue*, again because those conditions were caused by wind-induced sweating. Inferring one condition from another, this is clear. One may only use this formula if the patient's symptoms match those described under the prescription. If sweating is not due to wind, or if there is slight wind but the constitution is exterior deficiency with interior excess, it should not be taken. Taking it would cause Wei Qi to be pushed outward and become more deficient, making exterior deficiency worse and interior excess more apparent, leading to disharmony of all Qi. Even if there was no sweating initially, it could induce sweating. How could one seek to avoid sweating by using this to stop it? Furthermore, the name "Pingfeng" (Windscreen) carries the meaning of shielding and blocking. If interpreted solely as a physical barrier, one focuses on the name while missing the substance. Generally, famous formulas of ancient and modern times, if they capture even one aspect of Zhang Zhongjing's thought, cannot be understood merely by looking at the words. Readers should infer the intent through their own understanding.