蜚虻，味苦，气微寒，有毒。逐瘀血血闭，寒热酸 。止两目赤疼， 伤泪出。通血脉
九窍
，治喉痹，破积血，症瘕痞坚亦治。此物视之可憎，用之以治瘀血之症，实救命之药也，药
笼中断宜预备。
畜血之症，必须水蛭以消之，否则瘀血硬痛，必变发黄之症。今人畏惧水蛭，谢绝不用。
当
以虻虫代水蛭，则畜血病可解也。
或问蜚虻食人之血，何仲景夫子以治伤寒之症？曰∶伤寒之变症不同，失于不汗，有气
结、
血结之病。气结，可用草木之药以散气。而血结，必须蜚虻、水蛭以散血也。但气结与血结
，何以辨之？气结者，小便必不利；血结者，小便必利也。
又问血结者，必须用蜚虻矣，然何以知是血结之病？曰∶大约气结、血结，身大热，肠
中俱
有燥屎作痛。但血结者，止小便利，异于气结也。舍蜚虻，又何物以散其瘀血哉。
僵蚕，味咸、辛，气平，无毒，升也，阴中阳也。逐风湿殊功，口噤失音者必用，拨疔
毒极
效，肿突几危者急敷。主小儿惊痫夜啼，治妇人崩中赤白，止阴痒，去三虫，灭黑 及诸疮
瘢痕，面色令好。散风痰并结滞痰块，喉痹使开，驱分娩，罢余疼，解伤寒后阴易。功用虽
多，而不宜多服，少为佐使可也。
或问僵蚕功多，亦有过乎？夫僵蚕安得无过。多服则小腹冷痛，令人遗溺，以其性下行，
利
多而成寒也。
蜚虻，味道苦，气性微寒，有毒。能驱除瘀血和血闭证，治疗因寒热引起的酸痛。能止住两眼红肿疼痛，以及外伤导致的流泪。能疏通血脉及九窍，治疗喉痹（咽喉肿痛闭塞），破除积血，症瘕痞坚（腹内结块坚硬）也能治疗。这种药看起来令人厌恶，但用来治疗瘀血病症，实在是救命的药物，药箱中断然应该预备。
蓄血证，必须用水蛭来消除它，否则瘀血硬痛，必定转变为发黄的病症。现在的人畏惧水蛭，拒绝使用。应当用虻虫代替水蛭，那么蓄血病就可以解除了。
有人问：蜚虻吸食人的血液，为什么张仲景先生用它来治疗伤寒病症？回答说：伤寒的变证不同，如果失于发汗，会有气结、血结的病证。气结，可以用草木类药物来疏散气滞。而血结，必须用蜚虻、水蛭来消散瘀血。但是气结与血结，如何辨别呢？气结的人，小便一定不通利；血结的人，小便一定通利。
又问：血结证，必须用蜚虻了，然而怎么知道是血结的病证呢？回答说：大致上气结和血结，身体都大热，肠中都有燥屎导致疼痛。但血结证，只是小便利，这与气结不同。除了蜚虻，又有什么药物能消散它的瘀血呢？
僵蚕，味道咸、辛，气性平，无毒，具有升散之性，属于阴中之阳。在驱逐风湿方面有特殊功效，口噤失音（牙关紧闭、不能说话）者必须使用，拔除疔毒极有效，肿胀突起几乎危及生命时紧急外敷。主治小儿惊痫夜啼，治疗妇人崩中赤白（月经量多或带下异常），止阴痒，去除三虫（寄生虫），消除黑斑及各种疮疡瘢痕，使面色变好。能疏散风痰并化解结滞的痰块，开通喉痹，辅助分娩，停止产后余疼，解除伤寒后发生的阴易（伤寒愈后复感邪气或房劳复发）。功用虽然多，但不宜多服，少量作为佐使药即可。
Feimeng (Menshiae Herba, 虻虫), bitter in taste, slightly cold in nature, and toxic. It expels blood stasis and treats blood obstruction, alleviates soreness and pain caused by alternating chills and fever, stops redness and pain in both eyes, and halts tearing due to trauma. It unblocks the blood vessels and the nine orifices, treats throat bi (sore throat with obstruction), breaks up accumulated blood, and also treats zheng jia pi jian (hard abdominal masses). Although this substance appears repulsive, when used to treat blood stasis syndromes, it is truly a life-saving medicine and should always be prepared in the medicine cabinet.
For blood accumulation syndromes, Leech (Shuizhi, 水蛭) must be used to dissipate them; otherwise, hard and painful blood stasis will inevitably transform into jaundice. Nowadays, people fear Leech and refuse to use it. One should substitute Feimeng (Menshiae Herba, 虻虫) for Shuizhi, so that blood accumulation diseases can be resolved.
Someone asked: Feimeng (Menshiae Herba, 虻虫) sucks human blood; why did Master Zhang Zhongjing use it to treat Shanghan (Cold Damage) syndromes? The answer is: The complicated syndromes of Shanghan vary. If sweating therapy is neglected, qi stagnation and blood stasis may occur. For qi stagnation, herbal plants can be used to disperse the qi. However, for blood stasis, Feimeng (Menshiae Herba, 虻虫) and Shuizhi (Hirudo, 水蛭) are required to dissipate the blood. But how can one distinguish between qi stagnation and blood stasis? In cases of qi stagnation, urination is invariably difficult; in cases of blood stasis, urination is invariably free.
Another question arose: Since blood stasis requires Feimeng (Menshiae Herba, 虻虫), how does one know it is a blood stasis syndrome? The answer is: Generally, both qi stagnation and blood stasis present with high fever and pain in the intestines due to dry stool. However, in blood stasis, urination is free, which differs from qi stagnation. Apart from Feimeng (Menshiae Herba, 虻虫), what other herb can dissipate its blood stasis?
Jiangcan (Bombyx Batryticatus, 僵蚕), salty and pungent in taste, neutral in nature, and non-toxic. It has an ascending property and belongs to yang within yin. It excels at dispelling wind-dampness and is essential for treating trismus and aphonia (lockjaw and loss of voice). It is extremely effective in extracting toxin from ding sores (furuncles) and should be applied urgently as a poultice when swelling protrudes dangerously. It primarily treats pediatric convulsions and night crying, manages women's metrorrhagia and leukorrhea (abnormal vaginal bleeding or discharge), stops genital itching, eliminates three parasites, removes black spots and scars from various sores, and improves complexion. It disperses wind-phlegm and resolves stagnant phlegm nodules, opens throat bi, assists in childbirth, alleviates postpartum residual pain, and resolves Yin Yi (recurrence after recovery from Shanghan, often related to sexual activity). Although its functions are numerous, it should not be taken in large doses; a small amount as an assistant drug is sufficient.
Someone asked: Jiangcan (Bombyx Batryticatus, 僵蚕) has many merits; does it have no faults? How could Jiangcan (Bombyx Batryticatus, 僵蚕) be without faults? Taking too much causes cold pain in the lower abdomen and leads to urinary incontinence, because its nature descends, and its draining effect creates coldness.