明堂下经云。古来灸病。忌松柏枳 榆枣桑竹八木。切宜避之。有大珠曜日。以艾承之
得火
有此火镜曜日。亦以艾引得火。此火皆良。诸番部落。用镔铁击KT 石。得火出以艾引之。
凡人卒难备。即不如无木火青麻油点灯。灯上烧艾茎点灸是也。兼滋润灸疮至愈不疼痛。用
蜡烛更佳。良方云。凡取火者。宜敲石取火（今舟行人以铁钝刀击石。先以纸灰为火。纸在
下承之亦得火）。或用水晶镜。于日得太阳火为妙。太阴则以槐木取火。
凡下火点灸。欲令艾炷根下亦辉广三分。若不三分。孔穴不中。不合经络。缘荣卫经脉
气血通流。各有所主。灸穴不中。即火气不能远达。而病未能愈也。
凡灸头与四肢。皆不令多灸。缘人身有三百六十五络。皆归于头。头者。诸阳之会也。
若灸
多。令人头旋目眩。远视不明。缘头与四肢肌肉薄。若并灸。则气血滞绝于注下。宜歇火气
少时。令气血遂通。再使火气流行。候主数足。自然除病。宜详察之。
古来用灸病。忌八般木火。切宜避之。八木者。松木火难瘥增病。柏木火伤神多汗。竹
木火
伤筋目暗。榆木火伤骨失志。桑木火伤肉肉枯。枣木火内伤吐血。柘木火大伤气脉。橘木火
伤荣卫经络。
凡灸发际。如是患人有发际正齐。根据明堂所说。易取其穴。如是患人先因疾患。后脱落
尽发
际。或本人额项无发。难凭取穴。今定患人两眉中心直上三寸为发际。后取大椎直上三寸为
发际。以此为准。明堂上经云。如后发际亦有项脚长者。其毛直至骨头。亦有无项脚者。毛
齐至天牖穴。即无毛根。如何取穴。答曰。其毛不可辄定。大约如此。若的的定风府正相当
即测量相去各二寸。此为定穴。
《明堂下经》记载：自古以来，艾灸治病时，忌讳使用松、柏、枳、榆、枣、桑、竹这八种树木的木材生火，务必避开这些。有一种名为“大珠曜日”的工具，将艾草置于其下即可引燃取火；还有这种火镜映照太阳，也能用艾草引火。这些取火方式都很好。各少数民族部落，用镔铁敲击碙石（燧石），迸出火星后用艾草引燃。普通人难以备齐这些工具，不如不用木柴生火，而是点燃青麻油灯，在灯上烧灼艾茎进行点灸，这样既能滋润灸疮直至痊愈且不疼痛，使用蜡烛效果更佳。《良方》记载：凡是取火，宜敲击石头取火（如今乘船的人用钝铁刀击打石头，先在纸灰中引火，纸张在下承接也能取到火）；或者用水晶镜，在阳光下取得太阳之火最为巧妙；若是阴天，则用槐木钻木取火。
凡是施灸点火，希望艾炷根部燃烧范围也达到三分宽。如果不足三分，穴位就不准确，不合经络。因为营卫经脉的气血流通，各有其主治部位。如果灸穴不准确，火气就不能远达病所，疾病也就不能痊愈。
凡是灸头部和四肢，都不宜多灸。因为人身有三百六十五络脉，都汇聚于头部，头是诸阳经交会的地方。如果灸得过多，会导致头晕目眩，视物不清。因为头部和四肢肌肉较薄，如果同时多处施灸，气血就会阻滞不通，应当暂停施灸片刻，让气血恢复通畅，再使火气流行，等到规定的壮数灸足，自然能祛除疾病。应当仔细考察这一点。
自古以来用艾灸治病，忌讳八种木材的火，务必避开。这八种木材中：松木火难愈且加重病情；柏木火损伤神志导致多汗；竹木火损伤筋脉导致视力昏暗；榆木火损伤骨骼导致意志丧失；桑木火损伤肌肉导致肌肉枯瘦；枣木火内伤导致吐血；柘木火大伤气脉；橘木火损伤营卫经络。
凡是灸发际处，如果患者发际线整齐，根据《明堂》所说，容易选取穴位。如果患者先因病痛，后头发全部脱落至发际线，或者本人额头颈部无发，难以凭借发际取穴。现在确定以患者两眉中心直上三寸为发际，向后取大椎穴直上三寸为发际，以此为准。《明堂上经》记载：如后发际也有颈项较长者，毛发一直长到骨头，也有没有颈项者，毛发齐平至天牖穴，即没有毛根，如何取穴？回答是：毛发不可轻易作为定穴标准，大约如此。如果确实风府穴位置相当，就测量相距各二寸，此为确定的穴位。
The *Mingtang Xiajing* (Lower Classic of the Acupuncture Mounds) records: Since ancient times, when using moxibustion to treat diseases, it is taboo to use firewood from eight types of trees: pine (*Pinus*), cypress (*Cupressus*), zhi (*Ziziphus jujuba var. spinosa*), elm (*Ulmus*), jujube (*Ziziphus jujuba*), mulberry (*Morus*), bamboo (*Bambusoideae*), and others. One must strictly avoid these. There is a tool called "Da Zhu Yang Ri" (Great Pearl Reflecting the Sun); placing mugwort (*Artemisia argyi*) beneath it can ignite fire. Similarly, using a fire mirror to reflect sunlight can also ignite mugwort. These methods are all excellent. Various ethnic tribes use bin-tie (wrought iron) to strike kong-shi (flint), producing sparks which are then used to ignite mugwort. Ordinary people find it difficult to prepare such tools; therefore, it is better not to use wood fire, but rather to light a lamp with green hemp oil, burn the stem of mugwort on the lamp flame for point-moxibustion. This method moistens the moxa sore until it heals without pain. Using candles is even better. The *Liangfang* (Good Prescriptions) records: Whenever obtaining fire, one should strike stone to get fire (today, boatmen use a dull iron knife to strike stone, first creating fire in paper ash, with paper underneath to catch the spark). Or, use a crystal mirror to obtain solar fire under the sun, which is optimal. On cloudy days, one should use locust wood (*Robinia pseudoacacia*) to generate fire by friction.
When applying moxibustion, the base of the moxa cone should spread approximately three *cun* (Chinese inches) wide. If it does not reach this width, the acupoint will be inaccurate and not align with the meridians. This is because the flow of Ying-Wei (Nutritive and Defensive) Qi and Blood through the meridians has specific governing areas. If the moxa point is inaccurate, the heat energy cannot reach far enough, and the disease will not be cured.
When treating the head and four limbs, one should not apply excessive moxibustion. This is because the human body has 365 collaterals that all converge at the head, which is the meeting place of all Yang meridians. Excessive moxibustion here can cause dizziness, vertigo, and blurred vision. Since the muscles of the head and limbs are thin, simultaneous extensive moxibustion can cause stagnation and blockage of Qi and Blood. It is advisable to pause the application of heat for a short time to allow Qi and Blood to circulate freely again, then resume until the prescribed number of cones is completed. The disease will naturally be eliminated. This requires careful observation.
Since ancient times, eight types of wood fires have been taboo for moxibustion and must be avoided. Among these eight woods: Pine fire leads to non-healing and worsening of symptoms; Cypress fire damages the Spirit (*Shen*) and causes excessive sweating; Bamboo fire damages tendons and causes dim vision; Elm fire damages bones and leads to loss of will; Mulberry fire damages flesh causing emaciation; Jujube fire causes internal injury and hematemesis (vomiting blood); Zhe wood fire severely damages Qi and vessels; Orange wood fire damages Ying-Wei (Nutritive and Defensive) systems and meridians.
When treating the hairline: If the patient has a regular hairline, acupoints can be easily selected according to the *Mingtang*. However, if the patient lost their hair due to illness or was born without hair on the forehead or neck, it is difficult to rely on the hairline for point location. Currently, it is determined that the hairline is located three *cun* vertically above the midpoint between the two eyebrows. Posteriorly, the hairline is three *cun* vertically above the Dazhui (*GV14*) acupoint. This serves as the standard. The *Mingtang Shangjing* (Upper Classic of the Acupuncture Mounds) notes: Some individuals have long napes where hair grows down to the bone, while others lack a nape entirely, with hair ending level with the Tianyou (*TE16*) acupoint, having no root. How should points be located? The answer is: Hair growth cannot be rigidly fixed as a standard. Generally, it is so. If the Fengfu (*GV16*) acupoint position is confirmed, measure two *cun* distance from it; this determines the point.