水蛭∶味咸，色黑，气腐，性平。为其味成，故善入血分；为其原为噬血之物，故善破血；为其气腐，其
气味与瘀血相感召，不与新血相感召，故但破瘀血而不伤新血。且其色黑下趋，又善破冲任中之瘀，盖其破瘀
血者乃此物之良能，非其性之猛烈也。《神农本草经》谓主妇人无子，因无子者多系冲任瘀血，瘀血去自能有
子也。特是，其味咸为水味，色黑为水色，气腐为水气，纯系水之精华生成，故最宜生用，甚忌火炙。
凡破血之药，多伤气分，惟水蛭味咸专入血分，于气分丝毫
无损。且服后腹不觉疼，并不觉开破，而瘀血默消于无形，真良药也。愚治妇女月闭 瘕之证，其脉不虚弱者，
恒但用水蛭轧细，开水送服一钱，日两次。虽数年瘀血坚结，一月可以尽消。
水蛭、虻虫皆为破瘀血之品。然愚尝单用以实验之，虻虫无效，而水蛭有效。以常理论之，凡食血之物，
皆能破血。然虻虫之食血以嘴，水蛭之食血以身。其身与他物紧贴，即能吮他物之血，故其破瘀血之功独优。
近世方书，多谓水蛭必须炙透方可用，不然则在人腹中，能生殖若干水蛭害人，诚属无稽之谈。曾治一妇
人，经血调和，竟不产育。细询之，少腹有 瘕一块。遂单用水蛭一两，香油炙透，为末。每服五分，日两次，
服完无效。后改用生者，如前服法。一两犹未服完， 瘕尽消，逾年即生男矣。惟气血亏损者，宜用补助气血
之药佐之。
或问，同一水蛭也，炙用与生用，其功效何如此悬殊？答曰∶此物生于水中，而色黑（水色）味咸（水味）
气腐（水气），原得水之精气而生。炙之，则伤水之精气，故用之无效。水族之性，如龙骨、牡蛎、龟板大抵
皆然。故王洪绪《外科证治全生集》谓用龙骨者，宜悬于井中，经宿而后用之，其忌火可知，而在水蛭为尤
甚。特是水蛭不炙，为末甚难，若轧之不细，晒干再轧或纸包置炉台上令干亦可。此须亲自检点，若委之药坊，
至轧不细时，必须火焙矣。西人治火热肿疼，用活水蛭数条，置患处，复以玻璃杯，使吮人毒血，亦良法也。
水蛭：味道咸，颜色黑，气味腐臭，药性平和。因为它的味道咸，所以善于进入血分；因为它原本是吸食血液的生物，所以善于破除瘀血；因为它的的气味腐臭，其气味与瘀血相互感召，不与新鲜血液相互感召，所以只破除瘀血而不损伤新血。而且它的颜色黑且向下趋行，又善于破除冲脉和任脉中的瘀血，大概它破除瘀血的能力是这种生物的本能，并非它的药性猛烈。《神农本草经》说它能治疗妇女不孕症，因为不孕症多由冲任二脉瘀血引起，瘀血去除后自然就能怀孕。只是，它的味咸属于水的味道，色黑属于水的颜色，气腐属于水的气味，纯粹是由水的精华生成，所以最适合生用，非常忌讳用火炙烤。
凡是破除瘀血的药物，大多会损伤气分，只有水蛭味咸专门进入血分，对气分丝毫无损。而且服用后腹部不觉得疼痛，也不觉得有破开的感觉，而瘀血在无形中默默消散，真是良药啊。我治疗妇女闭经、癥瘕（腹内结块）的病症，如果患者脉象不虚弱的，常常只用水蛭轧成细粉，用开水送服一钱，每天两次。即使是数年的坚结瘀血，一个月也可以完全消除。
水蛭、虻虫都是破除瘀血的药物。但我曾经单独使用它们进行实验，虻虫无效，而水蛭有效。按常理推断，凡是吃血的生物，都能破血。然而虻虫是用嘴吸血，水蛭是用身体吸血。它的身体与其他物体紧贴时，就能吮吸其他物体的血液，所以它破除瘀血的功效特别优异。近代方书，大多说水蛭必须炙透才能使用，否则在人腹中，能繁殖出许多水蛭危害人，这确实是无稽之谈。曾治疗一位妇人，月经调和，竟然不能生育。仔细询问后，发现少腹有一块癥块。于是单用水蛭一两，用香油炙透，研成粉末。每次服用五分，每天两次，服完后无效。后来改用生品，按照之前的服法。一两还没有服完，癥块就完全消除了，过了一年就生了男孩。只是对于气血亏损的人，应该用补益气血的药物辅助治疗。
有人问，同样是水蛭，炙用和生用的功效为何如此悬殊？回答说：这种生物生长在水中，颜色黑（水的颜色），味道咸（水的味道），气味腐（水的气味），原本就是得水的精气而生成的。如果炙烤，就会损伤水的精气，所以使用无效。水族药物的性质，如龙骨、牡蛎、龟板大致都是这样。所以王洪绪在《外科证治全生集》中说使用龙骨，宜悬挂在井水中，经过一夜后再使用，由此可知它忌讳火，而对于水蛭来说更是如此。只是水蛭如果不炙烤，研成粉末很难，如果轧得不细，晒干后再轧，或者用纸包好放在炉台上让它变干也可以。这需要亲自检查，如果委托给药坊，等到轧不细的时候，就必须用火焙干了。西方人治疗火热引起的肿痛，用几条活水蛭，放置在患处，再用玻璃杯覆盖，使其吮吸人的毒血，这也是良法。
Shuizhi (Leech, Hirudo nipponia): It has a salty taste, black color, putrid odor, and neutral nature. Due to its salty taste, it is adept at entering the Blood aspect; because it is originally a creature that sucks blood, it is adept at breaking up Blood stasis; due to its putrid odor, its scent resonates with Blood stasis but not with fresh Blood, thus it breaks up only Blood stasis without damaging new Blood. Furthermore, its black color directs downwards, making it effective in breaking up stasis within the Chong and Ren vessels. Its ability to break up Blood stasis is an inherent capability of this creature, not due to a fierce nature. The *Shennong Bencao Jing* states it treats female infertility, as infertility often stems from stasis in the Chong and Ren vessels; once the stasis is removed, conception becomes possible. Specifically, its salty taste corresponds to the flavor of Water, its black color to the color of Water, and its putrid odor to the Qi of Water. It is purely generated from the essence of Water, so it is most suitable for raw use and strongly contraindicated for fire-roasting.
Generally, drugs that break up Blood stasis tend to damage the Qi aspect, whereas Shuizhi (Leech), being salty and specifically entering the Blood aspect, causes no harm to the Qi. Moreover, after ingestion, there is no abdominal pain nor sensation of rupture, yet the Blood stasis silently dissipates invisibly; truly a good medicine. In my treatment of women with Amenorrhea (absence of menstruation) and Jia Masses (abdominal masses), if the pulse is not weak, I often use only Shuizhi (Leech) ground into fine powder, taken with boiled water, one qian per dose, twice daily. Even firm stasis accumulated over years can be completely eliminated within one month.
Both Shuizhi (Leech) and Mengchong (Horsefly) are agents for breaking up Blood stasis. However, in my experiments using them separately, Mengchong was ineffective while Shuizhi was effective. By general reasoning, any creature that feeds on blood can break up blood. Yet, Mengchong feeds on blood with its proboscis, whereas Shuizhi feeds with its body. When its body adheres tightly to another object, it can suck the blood from that object, hence its efficacy in breaking up Blood stasis is superior. Modern formularies often claim that Shuizhi must be thoroughly roasted before use; otherwise, it will reproduce inside the human abdomen and harm the patient. This is indeed nonsense. I once treated a woman whose menstruation was regular but who failed to conceive. Upon detailed inquiry, a Jia Mass was found in the lower abdomen. I prescribed solely one liang of Shuizhi, roasted thoroughly in sesame oil, and powdered. Each dose was five fen, taken twice daily. After finishing the course, there was no effect. Subsequently, I switched to raw Shuizhi, administered as before. Before the full liang was consumed, the mass had completely dissipated, and she gave birth to a son the following year. However, for those with Qi and Blood deficiency, it is advisable to supplement with herbs that tonify Qi and Blood.
One might ask: Why is there such a drastic difference in efficacy between roasted and raw Shuizhi? The answer is: This creature lives in water, possesses the color black (color of Water), taste salty (flavor of Water), and odor putrid (Qi of Water), having been born from the essence of Water. Roasting damages this essence of Water, rendering it ineffective. This characteristic applies generally to aquatic substances such as Longgu (Fossilized Bones), Muli (Oyster Shell), and Guiban (Turtle Shell). Therefore, Wang Hongxu in *Waike Zhengzhi Quansheng Ji* stated that when using Longgu, it should be suspended in a well overnight before use, indicating its aversion to fire, which is even more pronounced with Shuizhi. However, grinding raw Shuizhi into powder is difficult. If not ground finely enough, it can be sun-dried and re-ground, or placed in paper packets on the stove top to dry. This requires personal supervision; if entrusted to a pharmacy, by the time it needs further grinding, it would inevitably be baked with fire. Westerners treat heat-induced swelling and pain by placing several live leeches on the affected area, covering them with a glass cup to suck out toxic blood, which is also a good method.