丹溪曰∶车螯散，一以轻粉为佐，一以灯心为佐，其散毒消肿，下积安稳，详轻重大小
证候亦可仗之。
（《精要》）车螯散（《本草》云∶车螯，大蛤也，一名蜃，性冷无毒，能攻诸疮肿毒。）
车螯（四个。黄泥固济，火 赤，出火毒一宿） 栝蒌（一两，去壳，瓦上炒香）
灯心（三十根） 甘草节（二钱）
上将瓜蒌、灯心、甘草为粗末，作一服。酒二盏煎一盏，去渣，入蜜一大匙和匀，调
车蝥末二钱，腻粉少许。空心温服，取下恶物。
又方
车熬（一两，制如前） 生甘草（半两） 轻粉（五分）
为细末，每服四钱，浓煎。栝蒌酒调下，五更服，下恶物为度，未下再服，效。
凡治痈疽后，补血气，进饮食，实为切要。盖脓血出多，阴阳两虚，此药可以回生起死，
惜其不分经络时
令，须在识者触而长之。今医以肿平痛宽，遂以为安，漫不加省，往往于结痂后两三月或半
年，虚证乃见。医者不察，而加补养之功，因而转成他病者多矣。一人因脚弱，详见后条。
《精要》云∶大法痈疽不可舍五香汤。丹溪曰∶吾不知良甫之时有许多大府秘坚，病气郁塞，
若是之顽浓，可以骤散而大下者耶？亦当开陈时之先后，证之可否，庶乎后人不敢猛浪杀人。
殊不知些小寒热，或者由其气血不和而然，便以为外感而行表散，害人最速。
Danxi stated: There are two variations of the *Che'ao San* (Clam Powder). One uses Qingfen (Calomel) as an adjuvant, and the other uses Dengxincao (Juncus Effusus) as an adjuvant. Both can dissipate toxicity, reduce swelling, and safely purge accumulated pathogens. By carefully assessing the severity and magnitude of the syndrome, one can rely on this formula.
(Jingyao records): Che'ao San (Bencao states: Che'ao is a large clam, also known as Shen. Its nature is cold and non-toxic, capable of treating various sores, carbuncles, and swellings.)
[Ingredients]
Che'ao (Four pieces. Sealed firmly with yellow mud, fired until red-hot, removed from fire, and left overnight to eliminate fire toxicity.)
Gualou (Trichosanthis Fructus, 1 liang. Remove the shell, stir-fry on a tile until fragrant.)
Dengxincao (Junci Medulla, 30 stalks.)
Gancao Jie (Glycyrrhizae Radix et Rhizoma nodes, 2 qian.)
[Preparation and Administration]
First, coarsely powder the Gualou, Dengxincao, and Gancao together as a single dose. Decoct in two cups of wine until reduced to one cup. Strain the dregs, add one large spoonful of honey, and mix evenly. Then, incorporate two qian of finely powdered Che'ao and a small amount of Nifen (Qingfen/Calomel). Take warm on an empty stomach to facilitate the discharge of foul matter.
[Alternative Formula]
Che'ao (1 liang, prepared as above.)
Sheng Gancao (Raw Glycyrrhizae Radix et Rhizoma, 0.5 liang.)
Qingfen (Calomel, 5 fen.)
Grind into a fine powder. For each administration, take 4 qian, mixed with strongly decocted Gualou wine. Administer at Wugeng (the third watch of the night, approx. 3-5 AM). Continue until foul matter is discharged. If not discharged, administer again; this is effective.
In the treatment of carbuncles and sores, replenishing Qi and Blood and promoting dietary intake are truly crucial. Since excessive loss of pus and blood leads to deficiency of both Yin and Yang, this formula can restore life and revive the dead. However, it is regrettable that it does not differentiate by meridians or seasonal timing; it must be applied flexibly by knowledgeable practitioners. Modern physicians, seeing the swelling subside and pain ease, consider the condition stable and neglect further observation. Often, deficiency syndromes manifest two to three months or even half a year after scabbing forms. Physicians who fail to investigate this and instead increase tonifying treatments often cause the condition to transform into other diseases. One case of weak legs is detailed in the following section.
Jingyao states: In general, when treating carbuncles and sores, one should not discard Wuxiang Tang (Five Fragrances Decoction). Danxi said: I do not know if during Liangfu's time there were many cases of severe constipation, stagnant pathogenic qi, and such stubborn and thick conditions where sudden purgation could be used. One must weigh the sequence of timing and the appropriateness of the syndrome, so that future generations dare not recklessly kill patients. Little do they realize that slight chills and fever may result from disharmony of Qi and Blood. Mistaking this for an external contraction and applying diaphoretic methods causes the fastest harm to the patient.