脉之难，古今之所病也。至虚有盛候，大实有羸状。差之毫厘疑似之间，便有死生祸福
之异，此古今所病也。病不可不谒医，而医之明脉者，天下盖一二数。骐骥不时有，天下未
尝徒行；和扁不世出，病者终不徒死，亦因其长而护其短尔。士大夫多秘所患，以求诊，以
验医之能否。使索病于冥漠之中，辨虚实冷热于疑似之间。医不幸而失，终不肯自谓失也。
则巧饰掩非以全其名，至于不救。则曰是固难治也。间有谨愿者，虽或因主人之言，亦复参
以所见。两存而杂治，以故药不效，此世之通患，而莫之悟也。吾平生求医，盖于平时，默
验其工拙，至于有疾而求疗，必先尽告以所患，而后求诊，使医了然知患之所在也。然后求
之诊，虚实冷热先定于中，则脉之疑不能惑也。故虽中医治吾病常愈，吾求疾愈而已，岂以
困医为事哉！
药至贱而为世要用，未有如苍耳者。他药虽贱，或地有不产。惟此药不为间南北夷夏，
山泽斥卤，泥土沙石，但有地则产。其花叶根实皆可食。食之如菜，亦治病无毒。生熟丸散
无适不可，多食愈善。久乃使人骨髓满，肌理如玉，长生药也。杂疗风痹瘫痪，癃疟疮痒，
不可胜言，尤治瘿金疮，一名鼠粘子，一名羊负菜，诗谓之卷耳，疏谓之 耳，俗谓之道人
头，海南无药，惟此药生舍下，多于茨棘，迁客之幸也。己卯二月望日书。
脉诊的困难，是古今以来人们共同的困扰。极度虚弱的病症可能表现出强盛的假象，极度实邪的病症可能表现出羸弱的表象。在毫厘之间、似是而非的判断差异下，就会产生生死祸福的巨大不同，这是古今以来的通病。生病不能不寻求医生诊治，然而精通脉诊的医生，天下大概只有寥寥一二。千里马不是随时都有，但天下人从未因此就徒步行走；名医和（秦越人）与扁鹊并非每代都能出现，但病人终究不会白白死去，这也是因为利用医生的长处来弥补其短处罢了。士大夫阶层大多隐瞒自己的病情以求得诊断，以此来验证医生的能力高低。这就像是在幽暗模糊之中寻找病因，在虚实冷热似是而非之间进行辨别。如果医生不幸诊断失误，最终也绝不肯承认自己失误。于是便用巧妙的言辞掩饰错误以保全名声，直到无法救治时，才说这本来就是一种难治之症。偶尔有谨慎诚实的医生，虽然有时依据主人的陈述，但也结合自己的观察见解。将两者并存而混杂治疗，因此药物往往无效，这是世间的普遍弊病，却无人醒悟。我平生求医的经验，大抵是在平时默默验证医生的技艺高低，等到有病需要治疗时，必定先详尽告知医生我的所有症状，然后再让医生诊脉，使医生清楚地知道病灶所在。然后在进行脉诊时，虚实冷热的判断心中已有定见，那么脉象的疑惑就不能迷惑我了。所以即使是普通的医生治疗我的病也常常痊愈，我所追求的只是疾病痊愈罢了，哪里会把难为医生当作一回事呢！
药性极其低廉却是世间急需用的药物，没有比得上苍耳的。其他药物虽然便宜，或许有些地方不产。唯独这种药不分南北夷夏之地，无论是山地、沼泽、盐碱地还是泥土沙石地，只要有土地就能生长。它的花、叶、根、果实都可以食用。食用时像蔬菜一样，而且治病无毒。制成生品、熟品的丸剂或散剂，没有不适合的用法，多吃反而更好。长期服用能使人骨髓充盈，肌肤纹理如玉石般光洁，是长生不老之药。用于杂疗风痹瘫痪、癃闭疟疾、疮疡瘙痒等症，多得说不完，尤其擅长治疗瘿瘤和金创（刀箭创伤），又名鼠粘子，又名羊负菜，《诗经》中称之为卷耳，《本草疏》中称之为 耳，俗称为道人头。海南地区缺乏药材，唯有这种药生长在房舍之下，多于荆棘丛中，这是被贬谪之人的幸事。己卯年二月十五日书写。
The difficulty of pulse diagnosis has been a concern for people since ancient times. Extreme deficiency may present with excess-like symptoms, and extreme excess may present with deficiency-like appearances. A discrepancy of mere hair's breadth in such ambiguous situations can lead to vastly different outcomes regarding life and death, fortune and misfortune; this is a universal concern throughout history. When ill, one cannot but seek medical help, yet physicians who are proficient in pulse diagnosis are few, numbering perhaps only one or two in the world. Fine horses do not appear constantly, yet people do not walk everywhere on foot; He Qi (Bian Que) and Qin Yueren do not emerge every generation, yet patients do not simply die without recourse, for they rely on utilizing their physicians' strengths to compensate for weaknesses. Scholars and officials often conceal their ailments to solicit diagnoses, thereby testing the physician's competence. This is akin to searching for the disease in obscurity and distinguishing between deficiency/excess and cold/heat amidst ambiguity. If a physician unfortunately makes an error, they are reluctant to admit it at the end. Instead, they employ clever rhetoric to cover up faults and preserve their reputation, until the condition becomes incurable, at which point they claim, "This was inherently difficult to treat." Occasionally, there are cautious and honest physicians who, although relying partly on the patient's account, also incorporate their own observations. By maintaining both perspectives and treating with mixed methods, the medicine often fails to be effective. This is a common malady of the world, yet no one realizes it. In my lifelong experience of seeking medical care, I generally assess a physician's skill quietly during ordinary times. When illness strikes and treatment is sought, I first inform the physician completely of my symptoms before allowing them to take my pulse, so that the physician clearly knows where the ailment lies. Only then do I request pulse diagnosis; with the determination of deficiency/excess and cold/heat already established in my mind, doubts arising from the pulse cannot confuse me. Thus, even average physicians often cure my illnesses when I seek them out. My sole aim is recovery; I have no intention of making things difficult for the physician!
Among medicines, none is as inexpensive yet so essential for worldly use as Xanthium sibiricum (Cang'er). Other cheap medicines may not be produced in certain regions. However, this herb grows regardless of whether the location is north or south, among Han or Yi peoples, in mountains, marshes, saline-alkali lands, mud, sand, or rocks; wherever there is land, it grows. Its flowers, leaves, roots, and fruits are all edible. It can be eaten like vegetables and treats diseases without toxicity. Whether prepared raw or cooked, in pills or powders, there is no unsuitable application; consuming more yields better results. Long-term consumption fills the marrow, makes the skin texture like jade, and serves as a longevity drug. It is used extensively for miscellaneous treatments of wind-bi paralysis, strangury, malaria, sores, and itching, too numerous to mention. It is particularly effective for goiter and metallic wounds. Also known as Shuniuzi (Arctii Fructus), Yangfucai, referred to as Juan'er in the *Classic of Poetry*, as Er in botanical texts, and commonly called Daoren Tou (Daoist's Head). In Hainan, where medicinal herbs are scarce, this herb grows abundantly around houses, often among thorns and brambles, which is fortunate for exiled scholars. Written on the fifteenth day of the second month in the Jiyao year.