今西京作畦种，有长三尺者最佳。与苁蓉浸酒服，益肾。竹木刺入肉，嚼烂罨之，即
出。
细辛用根，今惟华州者佳，柔韧，极细直，深紫色，味极辛，嚼之习习如椒。治头面
风痛，不可阙也。叶如葵叶，赤黑，非此，则杜蘅也。杜蘅叶形如马蹄下，故俗云马蹄香。
盖根似白前，又似细辛。襄、汉间一种细辛，极细而直，色黄白，乃是鬼督邮，不可用。
《本经》并无一字治劳，今人治劳方中鲜有不用者。呜呼！凡此误世甚多。尝原病劳
，有一种真脏虚损，复受邪热，邪因虚而致劳，故曰劳者牢也。当须斟酌用之，如《经验方
》中，治劳热青蒿煎丸，用柴胡正合宜耳，服之无不效。热去，即须急已。若或无热，得此
愈甚，虽至死，人亦不怨，目击甚多。《日华子》又谓补五劳七伤。《药性论》亦谓治劳乏
羸瘦。若此等病，苟无实热，医者执而用之，不死何待！注释本草，一字亦不可忽，盖万世
之后，所误无穷耳。苟有明哲之士，自可处治。中下之学，不肯考究，枉致沦没，可不谨哉
？可不戒哉！如张仲景治寒热往来如疟状，用柴胡汤，正合其宜。
此李商隐《太仓铭》中所谓“薏苡似珠，不可不虞”者也，取仁用。《本经》云∶
“微寒，主筋急拘挛”。拘挛有两等，《素问》注中“大筋受热，则缩而短，缩短故挛急不
伸”。此是因热而拘挛也，故可用薏苡仁。若《素问》言因寒则筋急者，不可更用此也。凡
用之，须倍于他药。此物力势和缓，须倍加用，即见效。盖受寒即能止人筋急。受热，故使
人筋挛。若但热而不曾受，又亦能使人筋缓。受湿则又引长无力。
现在西京地区采用起垄种植的方法，其中有长达三尺的牛膝品质最佳。将牛膝与肉苁蓉一起浸泡在酒中服用，可以补益肾脏。如果有竹木刺扎入肌肉，嚼烂牛膝敷在伤口上，刺就能立即取出。
使用细辛时要用根部，现在只有华州出产的品质最好，质地柔韧，极其纤细笔直，颜色深紫，味道极辛辣，咀嚼时有像花椒一样的麻感。细辛是治疗头面部风邪疼痛不可缺少的药物。它的叶子像葵菜叶，呈赤黑色，如果不是这种叶子，那就是杜蘅了。杜蘅的叶子形状像马蹄的下部，所以俗称“马蹄香”。杜蘅的根看起来像白前，又有点像细辛。襄阳、汉水之间有一种被称为细辛的植物，极其细小笔直，颜色黄白，这实际上是鬼督邮，不能使用。
《神农本草经》中并没有一个字提到细辛能治疗虚劳，但现在人治疗虚劳的方剂中很少有不使用细辛的。唉！像这样误导世人的情况非常多。我曾经推究导致虚劳的病机，有一种是真脏气虚损，又感受了邪热，邪气因为正气虚弱而致病，所以叫作“劳”，意思是牢固难愈。应当仔细斟酌使用细辛，比如在《经验方》中，治疗虚劳发热的青蒿煎丸，使用柴胡就非常合适，服用后没有不有效的。热退之后，就必须立即停止服用。如果患者本身没有热象，用了细辛反而病情加重，即使导致死亡，人们也不会怨恨，这种情况我亲眼目睹过很多。《日华子本草》又说细辛能补五劳七伤。《药性论》也说它能治疗因虚劳导致的疲乏羸瘦。如果是这类疾病，假如患者体内没有实热，医生却固执地使用细辛，不死还等什么！注释本草，每一个字都不能忽视，因为万世之后，被误导的人无穷无尽啊。如果有明智之士，自然能够正确处理。学识中等以下的人，不肯考究医理，白白地导致自身沉沦埋没，怎么能不谨慎呢？怎么能不警惕呢？比如张仲景治疗寒热往来像疟疾症状的情况，使用柴胡汤，就非常合适。
这就是李商隐在《太仓铭》中所说的“薏苡仁像珍珠一样珍贵，不能不慎重对待”的意思，取用其种子（薏苡仁）。《神农本草经》记载：“（薏苡仁）微寒，主治筋脉拘挛。”拘挛有两种情况，《素问》注中说：“大筋受热，就会收缩变短，缩短所以导致拘挛伸展不开。”这是因热引起的拘挛，所以可以使用薏苡仁。如果《素问》说的是因寒引起的筋脉紧急，就不能再使用薏苡仁了。凡是用薏苡仁，剂量必须是其他药物的两倍。这是因为薏苡仁的药力温和缓和，必须加倍使用才能见效。大概是因为受寒会导致筋脉拘急，受热则导致筋脉挛缩。如果只是受热而没有受寒，又能使筋脉松弛。受湿邪则会导致筋脉引长而无力。
Currently, in the Western Capital region, ridge planting is adopted; those reaching a length of three chi are considered the best. When soaked in wine with Cistanche (Roucongrong) and taken orally, it benefits the Kidney. If bamboo or wooden splinters penetrate the flesh, chewing the Achyranthes root into a paste and applying it externally will cause the splinter to emerge immediately.
When using Asarum (Xixin), the root should be used. Currently, only the variety from Huazhou is of excellent quality: it is flexible and tough, extremely slender and straight, deep purple in color, and has an intensely pungent taste; when chewed, it produces a tingling sensation similar to that of Zanthoxylum (Jiaojiao). It is indispensable for treating wind-pain in the head and face. Its leaves resemble those of Malva (Kuiye), appearing reddish-black; if not this, then it is Aristolochia debilis (Duheng). The leaf shape of Duheng resembles the underside of a horse's hoof, hence the common name "Horse Hoof Fragrance" (Mati Xiang). Its root resembles Peucedanum praecox (Baiqian) and also somewhat resembles Asarum. In the Xiangyang and Han River regions, there is a plant called Asarum that is extremely slender and straight with a yellowish-white color; this is actually Imperata cylindrica var. major (Guidu You), which must not be used.
The *Shennong Bencao Jing* contains no single word indicating that Asarum treats consumptive diseases (Lao). Yet, in contemporary prescriptions for treating Lao, it is rarely omitted. Alas! Such errors mislead the world greatly. I have traced the pathology of Lao; there is a type involving true Zang-Fu deficiency and damage, compounded by pathogenic heat. Pathogens cause Lao due to deficiency, hence "Lao" implies firmness or stubbornness. One must exercise caution in its use. For instance, in the *Experience Formulas*, the Qinghao Jian Wan for treating heat from Lao uses Bupleurum (Chaihu), which is perfectly appropriate; administration yields invariably effective results. Once the heat subsides, one must stop taking it immediately. If there is no heat, and this herb causes the condition to worsen, even leading to death, people would not blame the physician, as such cases are frequently witnessed. *Ri Hua Zi Bencao* further claims it tonifies the five consumptions and seven injuries. *Yaoxing Lun* also states it treats fatigue, emaciation, and weakness due to Lao. In such conditions, if there is no excess-heat, yet physicians persistently employ this herb, how could death not ensue! Annotating materia medica requires attention to every character, for after ten thousand generations, the number of those misled will be infinite. Wise individuals can naturally manage treatment correctly. Those with mediocre learning, unwilling to investigate thoroughly, bring about their own ruin; how can one not be cautious? How can one not be vigilant? For example, Zhang Zhongjing used Chaihu Tang to treat alternating chills and fever resembling malaria, which was precisely appropriate.
This refers to what Li Shangyin said in his *Tai Cang Ming*: "Coix seeds resemble pearls, one must not neglect them." The seed (Coicis Semen) is used. The *Shennong Bencao Jing* states: "(It is) slightly cold, primarily treating muscle spasm and contracture." There are two types of contracture. The commentary on the *Suwen* states: "When large tendons are affected by heat, they shrink and shorten; thus, shortening leads to spasm and inability to extend." This is contracture caused by heat, so Coix Seed can be used. However, if the *Suwen* refers to tendon urgency caused by cold, Coix Seed must not be used. Whenever used, the dosage must be double that of other herbs. This is because Coix Seed has a mild and gentle potency; doubling the dose ensures efficacy. Generally, cold causes tendon urgency, while heat causes tendon contraction. If there is only heat without cold, it may cause tendons to become lax. If affected by dampness, it leads to elongation and weakness.