真珠，气寒，无毒。镇心神，润颜色。点目去膜，塞耳治聋，治小儿惊痫，尤堪止渴，
亦能
坠痰。然内治绝少，存之以为外治之需。
真珠，生肌最良，疮毒中必用之药。然内毒未净，遽用真珠以生肌，转难收口。
牡蛎，味咸，气平、微寒，无毒。左顾者良，火 末用。入少阴肾经。软积癖，消结核，
去
胁下硬，泻热掀肿，益精，遗尿可禁，敛阴汗如神，摩宿血，消老痰，绝鬼交，收气滞。但
只可为佐使。佐之补则补，佐之攻则攻，随药转移，不能自主也。
或疑牡蛎乃涩精之药，先生独削而不谈，何也？曰∶盖牡蛎涩精，而精愈遗，虽非牡蛎
之故
，殊不知牡蛎涩精，而精必利而后可止，非涩精之可止也。
或谓牡蛎非涩药也，使牡蛎为止涩之药，如何仲景张公伤寒书中载大病瘥后，腰以下有
水气
者，用牡蛎泽漆散之乎？曰∶嗟乎。大病之后，水不能下行，原宜用补以消水。但伤寒经汗
、吐、下之余，元气不能骤生，补之则功缓，故宜因势利导，而用泽泻。又恐水势甚大，单
用泽泻未免太泄其水，而元气随水而尽泄。故用牡蛎于利之中以涩之也。利中带涩，则水泄
而元气无亏，是泄中有补之道存焉，真善用利耳。谁谓牡蛎非涩药哉。
或疑牡蛎既可于利中用涩，安在止精不可与利水并用耶？曰∶水可于利中用涩，而精不
可于
涩中兼利也。盖精愈涩而愈遗，补精而带涩，则徒补无益，故遗精之病，断不可用牡蛎耳
。（〔批〕辨涩精反致遗精，实见到之语。）然亦有用之而效者，乃玉关大开，不得已而用之
，以闭精于一时，而终不可恃之为长服之剂也。
或问牡蛎之肉，味甘性温，即鲍鱼肉也。牡蛎用之而止梦遗，若鲍鱼多食，使丈夫无髭
须，
何
也？曰∶牡蛎，即鲍鱼之壳，二者同气，皆止涩之味也。食之过多，则任督之路断，二经之
气不能上升于唇口，故须髯渐少。其实，多食牡蛎，亦能令人少髭也。
真珠，性寒，无毒。能镇安心神，润泽容颜。点眼可去除翳膜，塞耳可治疗耳聋，治疗小儿惊风癫痫，尤其能够止渴，也能坠痰。然而内服治疗极少见，保留它作为外治法的需要。
真珠，生肌效果最好，是疮毒中必须使用的药物。然而如果体内毒素未清除干净，就急于使用真珠来生肌，反而难以收口愈合。
牡蛎，味咸，气平、微寒，无毒。左侧生长的品质较好，需煅烧后使用。入少阴肾经。能软化积块癖疾，消除结核，去除胁下的硬结，泻热消肿，益精，遗尿可以控制，敛汗（特别是盗汗）效果如神，磨碎可消宿血，消除老痰，杜绝鬼交（指梦遗滑精等虚损症状），收敛气滞。但只能作为佐药或使药使用。配合补药则起补的作用，配合攻下药则起攻的作用，随其他药物的变化而变化，不能自主发挥作用。
有人怀疑牡蛎是涩精的药物，先生唯独删去不谈，为什么呢？回答说：大概牡蛎虽然具有涩精作用，但会导致精气更加遗泄，这虽然不是牡蛎的过错，但不了解的是，牡蛎涩精，必须先通过利小便等方式通利之后才能停止遗精，不是单靠涩精就能止住的。
有人说牡蛎不是涩药，如果牡蛎是为止涩的药物，为什么张仲景在《伤寒论》中记载大病痊愈后，腰部以下有水气者，使用牡蛎泽漆散呢？回答说：唉！大病之后，水液不能下行，原本应该用补法来消除水气。但是经过伤寒发汗、催吐、泻下之后，元气不能迅速恢复，如果用补法则见效慢，所以适宜顺势利导，而使用泽泻。又担心水势很大，单用泽泻未免过于泄水，导致元气随着水液一起泄尽。所以在使用泽泻利水的同时加入牡蛎以涩之。利中带涩，则水液排泄而元气不亏损，这是泄中有补的道理存在，真是善于利用利法啊。谁说牡蛎不是涩药呢。
有人怀疑牡蛎既然可以在利水中使用涩法，为什么在止精时不可以与利水并用呢？回答说：水可以在利水中使用涩法，而精不能在涩精中兼有利水作用。大概精越涩越容易遗泄，补精同时带有涩性，则徒然进补而无益，所以遗精的病，绝对不可使用牡蛎。（批注：辨析涩精反而导致遗精，确实是见识深刻的言论。）然而也有使用有效的情况，那是由于玉关大开（指精关不固严重），不得已才使用它，以暂时闭精，但最终不可依赖它作为长期服用的药剂。
有人问牡蛎的肉，味甘性温，就是鲍鱼肉。牡蛎使用后能止梦遗，如果多吃鲍鱼，会使男子不长胡须，为什么呢？回答说：牡蛎，就是鲍鱼的壳，二者同气，都是止涩的味道。食用过多，则任脉和督脉的路径阻断，这两条经脉的气不能上升到达唇口，所以胡须逐渐减少。其实，多吃牡蛎，也能让人胡须变少。
Zhenzhu (Pearl), cold in nature, non-toxic. It calms the heart spirit (Shen) and moistens the complexion. Applied to the eyes, it removes ocular membranes; inserted into the ears, it treats deafness; used for pediatric convulsions and epilepsy; especially effective in quenching thirst; also capable of descending phlegm. However, its internal use is rare; it is preserved for external therapeutic needs.
Zhenzhu (Pearl) is excellent for generating tissue and is a necessary drug for treating sores and toxins. However, if internal toxins are not yet cleared, using Zhenzhu (Pearl) prematurely to generate tissue will hinder wound closure.
Muli (Oyster Shell), salty in taste, neutral and slightly cold in nature, non-toxic. Those growing on the left side are of superior quality; it should be calcined before use. It enters the Shaoyin Kidney Meridian. It softens accumulations and masses, resolves tubercles, removes hardness under the hypochondrium, drains heat and reduces swelling, benefits essence, controls enuresis, stops night sweats with miraculous effect, breaks up old blood stasis, eliminates chronic phlegm, prevents nocturnal emissions (ghostly intercourse), and resolves qi stagnation. However, it can only serve as an assistant or guide drug. When combined with tonifying drugs, it tonifies; when combined with attacking drugs, it attacks; it shifts according to other herbs and cannot act independently.
Some doubt that Muli (Oyster Shell) is an astringent for essence, asking why the author omits discussing it. The answer is: Although Muli (Oyster Shell) has astringent properties for essence, it may cause further leakage of essence. This is not necessarily Muli's fault, but one must understand that Muli (Oyster Shell) astringes essence only after the pathways have been cleared (via diuresis); it does not stop leakage merely by astringency.
Some argue that Muli (Oyster Shell) is not an astringent. If it were solely for astringency, why does Zhang Zhongjing record in the *Shanghan Lun* (Treatise on Cold Damage) that for patients recovering from severe illness with water accumulation below the waist, the formula Muli Zexie San (Oyster Shell and Spurge Powder) is used? The response is: Alas! After severe illness, when water cannot descend downward, tonification is originally indicated to resolve water retention. However, after sweating, vomiting, or purging in cold damage, vital qi cannot recover rapidly; tonification would be too slow. Therefore, it is appropriate to follow the path of least resistance and use Zexie (Alisma Rhizome). Fearing that excessive water volume might lead to the loss of vital qi along with the water if only Zexie is used, Muli (Oyster Shell) is added to provide astringency amidst the draining action. Draining with astringency ensures water is expelled without depleting vital qi, embodying the principle of tonification within drainage. Who says Muli (Oyster Shell) is not an astringent?
Some question: If Muli (Oyster Shell) can be used with astringency in draining water, why can't it be combined with draining actions to stop seminal emission? The answer is: Water can be drained while being astringed, but essence cannot be astringed while simultaneously being drained. Essence leaks more when overly astringed; tonifying essence with astringents is futile. Therefore, for seminal emission, Muli (Oyster Shell) is absolutely contraindicated. (Comment: The analysis that astringing essence leads to further emission demonstrates profound insight.) However, there are cases where it is effective; this occurs when the "Jade Gate" (essence gate) is widely open, necessitating temporary closure. It cannot be relied upon as a long-term medication.
Someone asks: The meat of Muli (Oyster) is sweet and warm, which is Abalone meat. Muli (Oyster Shell) stops nocturnal emissions, but eating much Abalone causes men to lose beard hair. Why? The answer is: Muli (Oyster Shell) is the shell of the Abalone; they share the same nature and both possess astringent flavors. Excessive consumption blocks the Ren and Du meridians, preventing their qi from ascending to the lips and mouth, thus causing gradual loss of beard hair. In fact, consuming too much Muli (Oyster Shell) can also reduce beard growth.