李士材《读四大家论》一篇，本自王节斋大意，谓三子补仲景之未备，而与仲景并峙也。然仲景医中神圣，德备四
时，三子则伯夷、伊芳尹、柳下惠而已。试观《玉函金匮方》中，黄芩、白虎，已开河间之先也；建中、理中，已开东垣
之先也；复脉、黄连阿胶，已开丹溪之先也。然则谓三于得仲景之一德，而引伸条畅之，则可谓三子补仲景之未备则未
确也。
明季李士材先生，我城人也，所着《医宗必读》一书，固已脍炙人口矣，然余窃有议焉。夫必读者，轩岐之书也，
越人、仲景之书也，下此而《脉经》、《千金》、《外台》，以及近代诸名家书，虽不能尽读，或取其十之六七，或取其十之
三四，不可不读矣。苟守张长沙博闻强识之训，以探本穷源，则是书又为浅医画限之书矣，改其名曰不必读，其庶几乎？
窃观富贵之家，投寒凉则忌，进温补则合，医之喜用温补者，遂有景岳派之名。殊不思《景岳》亦温凉补泻并收之
书也，观其论症，先述古而补以已见，分剂，先古方而补以新方，作者以《全书》名之，读者以《全书》贯之，舍其短
而录其长，则上而溯诸河间、易水、金华诸家，无不合也，更上而溯诸南阳医圣，亦无不合也，而得景岳之益者，岂特
在左归、右归而已哉。
古方自《灵》、《素》至《十金》、《外台》，所集汉、晋、宋、齐诸名方，凡云一两者，以今之七分六厘准之。凡云一
升者，以今之六勺七抄准之。谨考定如左。
凡古方权量，皆赵于律，黄帝律尺九寸，夏尺则加一寸而为十寸，今木工之曲尺是也。
唐孙真人《千金方》论述针穴分寸云∶“其尺用夏家古尺，司马法六尺为步，今江、淮、吴、越所用八寸小尺是也。”
据此知即今曲尺无疑，知此尺即黄帝律尺寸者，以药升之龠积与尺度考得之，详见《律学净闻》。
以曲尺之寸度作方径一寸六分，上下相等，深七分八厘强，共积二千分，即古药升之容积。
《千金》论“药升方作上径一寸，下径六分，深八分。”当作上下径一寸六分，深八分弱。按《管子》云∶“釜 不
得为侈 ”，且计其容积，仅五百廿二分，不应如此之小，故知传写之误也。升口自乘得二百五十六分，以深七分八厘强
乘之，得二千分为容积，云深八分者，举成数言之也。
药升一升，容黄钟两龠之实。以 黍二百四十粒为一两，但 黍之重，今无可考。根据《千金》论蜜一斤，得药升七
合，及《灵台仪象志》，水与蜜同积异重之比例，若二十与廿九，而次第以准测之，古一两，今七分六厘也。
古律龠容一千二百八十 黍，《千金》论“一撮者，四刀圭也（六十四黍为圭，半之为一刀圭）。十撮为一勺，（勺即
龠也），两勺为一合”（“合”为“升”字之误，一升共二千五百六十黍也）。李时珍沿两勺为一合之误，更增十合为一升，
则误以传误矣，幸《千金》及《外台》原文，俱无此五字可证。
黍一稃二米，用以量龠，取基圆滑而齐（见《考工记》轮人条下注疏中）。自刘歆变乱古法，置 用 ，前明郑世
于特觅 黍，权以今平，每龠一千二百粒，重三钱，未足为训也（郑世子《乐书》穿凿附会，其云黍权黍量尽属臆断，
张介宾采入《类经图翼》，殊误后人也）。
知二百四十黍为一两者，《千金》云∶“十黍为一铢（《图翼》谓十黍当作百黍者，非也）。六铢为一分，四分为一两，
十六两为一斤，此则神农之秤也。”
考正古权之法，先作药升满曲尺二千分，中容井水，秤重一两二钱，而推得其同积异重之比例，假如水与蜜各贮一
盏中，容积相等，而水轻蜜重，水若二十两，则蜜必二十九两，以此推算，一药升之水重一两二钱者，则一药升之蜜必
一两七钱四分明矣。
以三率明之∶
水二十，蜜二十九，水一两二钱，相乘得数三十四两八钱，以第一率之二十为法除之，得第四次一两七钱四分。蜜
一两七钱四分。
既得蜜一药升之重，以三率重测之，如法乘除，得蜜七合之重。
药升一升，蜜今重一两七钱四分，药升七合，蜜今重一两二钱一分八厘。
夫此七合之蜜，今重一两二钱一分八厘者，即古蜜十六两之数也，根据上法重测之，得古一两，今若干之数。
古十六两，今重一两二钱一分八厘；古一两，今重七分六厘强。
以古方参之∶
麻黄汤，麻黄三两（准今二钱三分），分三服，中病即止（每服止七分六厘）。
小柴胡汤，柴胡八两（准今六钱），分三服。（每服止二钱）。
承气汤，大黄四两（准今三钱），分再服，中病即止（每服止一钱半）。
白虎汤，石膏一斤（准今一两二钱）。分三服（每服止四钱）。
药升之容积二千分，以今仓斛之积寸推之，古一升，今六勺七抄也。
立方算法，满千分为一寸，曾以仓斛计之，合曲尺之寸度，积一千四百九十七寸为今五斗，则知曲尺二寸，为六勺
七抄。
以古方参之∶
半夏秫米汤，半夏五合（准今三勺三抄半），秫米一升（准今六勺七抄），甘澜水五升（准今三合三勺），煎取升半（准
今一合），分三次，每服饮一小杯（杯如杯饮，约可手掬，今比此尤小，故曰小杯）。
四逆散，每服方寸匕（准今一钱），其泄利下重者，加薤白一升煎服（末药少而一升之薤，其少亦可知）。
方寸匕者，作匕正方一寸，根据曲尺之寸度为之。钱匕者，以五铢钱为之，开元钱亦同。皆抄散取不落为度。
古人用散药，以刀圭抄取之，匕亦刀圭之意也。准前论一刀圭为三十二黍，方寸匕者，十刀圭也。立方一寸积千分
三除之，得三百三十三分为方一寸匕之实，容三百二十黍，准今一钱（药性轻重不等，今但就黍计之，以得其大概）。
《千金》论“钱匕者，以大钱上全抄之；若云半钱匕者，则是一“钱抄取半边耳，井用五铢钱也。钱五匕者，今五
铢钱边五字者以抄之，亦令不落为度。”按五铢钱与开元钱径相同，准曲尺九分，其幂六十三分，以九分乘之，得五百六
十七分，三除之，得一百八十九分为一钱匕之实。乃以三百三十三分为首率，重一钱为次率，一百八十九分为三率，得
重五分六厘为四率，是一钱匕之重也。半钱匕者，准今二分八厘；钱五匕者，准今一分四厘也。
以古方参之∶
五苓散、四逆散等方，每服方寸匕（准今一钱）。
桃花汤，赤石脂末半斤，每服方寸匕，日三服（每方寸匕准今之二钱，石药性重也）。
烧 散，每服方寸匕，日三服（灰性必轻）。
大陷胸汤，甘遂一钱匕，分二服（每服是半钱匕，准今二分八厘）。
十枣汤，强人服一钱匕（准今五分六厘）。
文蛤散，一钱匕（药性较轻）。
一撮者，以三指为度。
《千金》论“一撮者，四刀圭也。”得一百二十八黍，准今四分。
以古方参之∶
泽术糜衔散，药共二十五分（准今四钱七分五厘），以三指撮为后饭（每服四分，日三服，三日后病瘳，而药将尽矣）。
风引汤，药共五十五两（准今四两一钱八分），取三指撮井水煮服（石药性重，每服八分，以五十余日为度）。
凡丸药如梧子大者，准药末一分。如弹丸及鸡子黄者，准药末一钱。
《千金》论“刀圭者，十分方寸匕之一，准如梧桐子大也。”一方寸匕散以蜜和，得如梧桐子十丸为定。如弹丸及鸡
子黄者，以十梧桐子准之。准前论刀圭容三十二黍，应重一分，方寸匕加十倍，应重一钱。
以古方参之∶
己椒苈黄丸，药共四两（准今三钱，蜜丸如梧子大），饮服一丸，日三服（每日三丸，每丸一分，蜜在外，十日而瘳
可知也）。
薯蓣丸，药共百七十八分（准今三两三钱八分），大枣百枚为膏，和蜜丸如弹子大，空腹酒服一丸，一百丸为剂（每
丸药末当重三分四厘，因有大枣一枚及蜜，故得如弹子大也。弹子大者，或较小于鸡子黄，然亦不甚相远耳）。
理中丸，药共十二两（准今九钱一分），蜜和丸如鸡子黄大，以沸汤数合和一丸，研碎温服之，日三四服，夜二服，
腹中未热，益至三四丸（每丸药末一钱，当得九丸）。然不及汤，汤法以四物根据两数切，用水八升，煮取三升，去滓，温
服一升，日三服（作汤者，即用此九钱一分之药煎之也。寇宗 疑丸药少，汤药多，妄谓古方如鸡子黄者，应是大丸，
李时珍宗之，遂于古法如弹丸及鸡子黄准十梧子者，奋笔增为四十梧子，谬也）。
备急丸，每服大豆许三四丸，未差，更与三丸（按《千金》“十六黍为一大豆”，合七丸计之，不过百十二黍之重，
准今三分半）。
凡药有云大升、大两者，以神农秤三两为一两，药升三升为一升。
《千金》论“隋人以三两为一两。”权三倍，故量亦三倍。
以古方参之∶
《外台》载《广济方》蒜煎，主冷气，用牛乳五升（准今三合四勺），纳剥净蒜肉二升，煎候蒜消尽，下牛膝一大斤
末（准今三两六钱），煎成，酒和两匙服之（乳经煎蒜后，约存二合，配三两六钱煎而调和之，其末必不可复多矣）。
《外台》载《录验方》杏仁煎，疗咳气。杏人一升，捣，以水和研，取三大升汁（准药升九升），煎取一大升，酒服
一匙，日三（以水九升，研杏仁一升，其水亦不可复多矣）。
凡煮汤，大略古药二十两，今一两五钱，用水一斗，今七合，煮取四升，今二合八勺，勺二，三次服之。
上药皆 咀如豆大，必水乘气热，方始透入药中，既而药乘水沸，乃始溢出汁间；然且火欲其微，沸欲其小，绞以
两人，助以尺木，澄去 浊而后服之。全欲得其气之清，而不欲多水以耗其气，读《千金》论自明。
至于《千金》论诸药权量互求之法，往往不合，则古今药性不同故也。即如蜀椒、吴茱萸、地肤子、蛇床子，古取
阴干，今皆晒爆，爆则药性为之轻，轻则各有差等，而权与量不相合矣。又如附子以一枚准半两，古取其土中自养，形
神足者。枣有大小，以三枚准一两。古以八月采爆干，尚皮不尚肉（《别录》云∶枣皮利，肉补虚，惟十枣汤取肥者十
枚用之），今并不如法，宜与古不符也。惟巴豆治净，以一分得十六枚，颇合（《千金》云∶巴豆先去心皮毕秤之，曾如
法修治，其薄衣务尽去之，约十六枚，重分九厘）。苟能于古方中绪论求之，蛛丝马迹，非不可寻也。
以古方参之∶
《千金方》治历节诸风，百节酸疼不可忍，用松脂三十斤（准今三十六两），炼五十遍，少亦须二十遍，服方寸匕，
日三，百日差（方寸匕容三百二十黍，准今一钱，此最足据者。每日服三钱，百日须三十两也。以松脂炼去六两，适合
百日之用，则古一斤为一两二钱，更无疑矣）。
《千金》治结气，冷症积在胁下，及香港脚上入小腹，腹中胀满。大蒜去心，三升，捣令极热，以水三升，和调绞汁，
更捣，以水三升和，绞去滓，更以水三升和之，共成九升，滓可桃颗大，弃却（三升蒜肉研汁后，滓仅如挑颗大，升小
可知）。以微火煎取三升，下牛乳三升，合煎至三升。旦起空腹一顿温服，令尽（三升蒜汁，可以一顿服，升小可知）。
至申时食。三日服一剂，三十日服十剂止（蒜汁最辛劣，全不虑及，而频作服之，升小可知）。
宋·林亿以古三两为今一两，古三升为今一升，庞安常亦云然。此误以汉之权量为凭耳，于古方不相涉也。
古方以二龠为一升，以二百四十 黍为一两，此与刘歆所定二十龠为升，二千四百 黍为两者，大相悬绝，后儒误
信《班志》，遂以新莽刀布之重及铜斛之式断为古律权量，于是以古准今，遂有三两为一两，三升为一升之说，而强合于
医方之权量耳（秦汉之量，每一斗为今之二升，见阎百诗《四书释地》及沈彤《周官禄田考》，附识于此）。
前明张介宾惑于郑世子之《乐书》，定为古方一两，今之六钱，古方一升，今之三合三勺者，尤为大谬。
李时珍云∶古之一两，今之一钱，古之一升，今之二合半，亦非也。
以古方参之∶
《肘后方》治消渴，以黄连三斤（准今三两六钱），纳猪肚中蒸服（根据景岳说，是廿八两八钱矣，猪肚中能容之否？）。
又《肘后方》治中风腹痛，用盐半斤（准今六钱），熬水干，着口中，饮热汤二斤，得吐愈（根据张则四两八钱，能着
口中耶？并能饮如许热汤耶？）。
又《肘后方》治风毒香港脚，用硫黄末一两，牛乳调服，取汗，北方人用此多效（根据张则六钱，可作一顿服耶？）。
又《肘后方》治劳复，用干姜四两，为末（准今三钱），汤调顿服（根据张则为二两四钱之干姜，可一顿服耶？）。
《外台》载《备急方》治五尸，以雄黄、大蒜各一两，捣和如弹丸（准今一钱三分，故适如弹子大），纳热酒中服之
（根据张则一两二钱，能与弹丸相似耶？）。
《千金方》治吞金银 ，用白糖二斤（唐以前方用糖，皆指饴糖，非蔗糖也），一顿（准今二两四钱），渐渐食之，
多食亦佳（根据张则十九两二钱，能作一顿服耶？）。
以上辨古秤。
李士材的《读四大家论》一文，原本依据王节斋的大意，认为这三位医家（指刘河间、李东垣、朱丹溪）弥补了张仲景医学中未完备之处，足以与张仲景并驾齐驱。然而，张仲景在医学界堪称神圣，德行兼备四季之理；而这三位医家则仅相当于伯夷、伊尹、柳下惠那样的贤人罢了。试看《玉函金匮方》中，黄芩汤、白虎汤的使用，已经开启了刘河间学术思想的先河；建中汤、理中汤的运用，已经开启了李东垣学术思想的先河；复脉汤、黄连阿胶汤的应用，已经开启了朱丹溪学术思想的先河。既然如此，如果说这三位医家得出了张仲景的一种医德，并加以引申发挥，那还可以说；但如果说他们弥补了张仲景未完备之处，那就并不准确了。
明代末年的李士材先生，是我们本地人，他所著的《医宗必读》一书，确实已经脍炙人口了，但我私下里对此书有些异议。所谓“必读”的书，应当是黄帝、岐伯的著作，以及扁鹊、张仲景的著作。至于这些书之后的《脉经》、《千金要方》、《外台秘要》，以及近代各位名家的著作，虽然不能全部读完，或者选取其中十分之六七，或者选取其中十分之三四，也是不可不读的。如果死守张仲景（长沙太守）博学强记的教诲，去探求根本源头，那么《医宗必读》这本书就成了限制浅薄医生视野的书了，不如改名为“不必读”，或许更恰当些？
我私下观察富贵人家，遇到寒凉药就忌讳，遇到温补药就喜欢，医生喜欢用温补药的，于是就有了“景岳派”的名声。这些人却不思考，《景岳全书》其实也是一本兼收温凉补泻的书。看他的病症论述，先叙述古人的观点，再补充自己的见解；分列方剂，先列出古方，再补充新方。作者以《全书》命名，读者也以《全书》贯通理解，舍弃其短处而记录其长处，那么向上追溯刘河间、易水学派（李东垣）、金华学派（朱丹溪）等各家，没有不合拍的；再向上追溯医圣张仲景，也没有不合拍的。受益于张介宾（号景岳）的人，哪里仅仅局限于左归丸、右归丸而已呢？
古代方剂自《灵枢》、《素问》至《千金要方》、《外台秘要》，所收集的汉、晋、宋、齐各代名方，凡是说“一两”的，以现在的七分六厘来折算。凡是说“一升”的，以现在的六勺七抄来折算。严谨考证如下：
关于古代方剂的权量标准，都基于律管。黄帝时期的律尺为九寸，夏代的尺则增加一寸变为十寸，就是现在木工使用的曲尺。
唐代孙思邈在《千金要方》中论述针灸穴位分寸时说：“所用的尺是夏代古尺，司马法规定六尺为一步，就是现在江、淮、吴、越地区所使用的八寸小尺。”据此可知这就是现在的曲尺无疑。知道这把尺就是黄帝律尺的标准长度，是通过药物容量单位“升”、“龠”的积累与尺度考证得出的，详见《律学净闻》。
用曲尺的一寸作为边长，制作一个上下相等、深七分八厘多的正方体容器，总体积为二千立方分，这就是古代“药升”的容积。
《千金要方》论述“药升上方径一寸，下方径六分，深八分”，应当理解为上下径均为一寸六分，深略小于八分。按《管子》所说：“釜不得为侈……”且计算其容积，仅有五百二十二立方分，不应该这么小，所以知道这是传写错误。升口自乘得到二百五十六平方分，乘以深七分八厘多，得到两千立方分的容积。说“深八分”，是取整数而言。
药升一升，容纳黄钟律管两龠的实际容量。以二百四十粒黍为一两，但黍的重量，现在已无法考证。根据《千金要方》论述蜜一斤可得药升七合，以及《灵台仪象志》中水与蜜体积相同但重量不同的比例，若为二十比二十九，依次以此为准测量，古代的一两，相当于现在的七分六厘。
古代律龠容纳一千二百八十粒黍。《千金要方》论述：“一撮，等于四刀圭（六十四粒黍为一圭，减半为一刀圭）。十撮为一勺（勺即龠），两勺为一合。”（这里的“合”是“升”字的误写，一升共包含二千五百六十粒黍）。李时珍沿袭了两勺为一合的错误，又增加了十合一升的说法，这就以误传误了。幸好《千金要方》及《外台秘要》的原文中，都没有这五个字，可以证明这一点。
黍有一层外壳和两层米粒，用来量度龠，取其底部圆润光滑整齐（见《考工记》轮人条下的注疏中）。自从刘歆扰乱了古法，放置了用于称重的器具，前明郑世子特意寻找黍，用现在的平秤称重，每龠一千二百粒，重三钱，这不足以作为准则（郑世子的《乐书》穿凿附会，他说用黍称重、用黍量体积完全属于臆断，张介宾将其采入《类经图翼》，严重误导了后人）。
知道二百四十粒黍为一两的，《千金要方》说：“十粒黍为一铢（《类经图翼》说十粒黍应当是一百粒黍，这是不对的）。六铢为一分，四分为一两，十六两为一斤，这就是神农时代的秤。”
考证校正古代权量的方法，先制作装满曲尺两千立方分的药升，中间装入井水，称重一两二钱，从而推导出同体积不同重量的比例。假如水和蜜各装一盏，容积相等，但水轻蜜重，水如果是二十两，那么蜜一定是二十九两，以此推算，一药升的水重一两二钱，那么一药升的蜜一定重一两七钱四分。
用三率法说明：
水二十，蜜二十九，水一两二钱，相乘得数三十四两八钱，以第一率之二十为除数，得到第四率一两七钱四分。即蜜一两七钱四分。
既然得到了蜜一药升的重量，再用三率法称重测量，依法乘除，得到蜜七合的重量。
药升一升，蜜现在重一两七钱四分；药升七合，蜜现在重一两二钱一分八厘。
这七合的蜜，现在重一两二钱一分八厘，也就是古代蜜十六两的数量。根据上面的方法重新测量，得出古代一两相当于现在的多少数量。
古代十六两，现在重一两二钱一分八厘；古代一两，现在重七分六厘多。
参考古代方剂：
麻黄汤，麻黄三两（折合现在二钱三分），分三次服用，病愈即止（每次服用止于七分六厘）。
小柴胡汤，柴胡八两（折合现在六钱），分三次服用。（每次服用止于二钱）。
承气汤，大黄四两（折合现在三钱），分两次服用，病愈即止（每次服用止于一钱半）。
白虎汤，石膏一斤（折合现在一两二钱）。分三次服用（每次服用止于四钱）。
药升的容积为二千立方分，以现在仓斛的积寸推算，古代一升，相当于现在的六勺七抄。
立方的算法，满千分为一寸，曾用仓斛计算过，合曲尺的一寸度量，积一千四百九十七寸相当于现在的五斗，那么就知道曲尺二寸，相当于六勺七抄。
参考古代方剂：
半夏秫米汤，半夏五合（折合现在三勺三抄半），秫米一升（折合现在六勺七抄），甘澜水五升（折合现在三合三勺），煎取半升（折合现在一合），分三次服用，每次喝一小杯（杯子像饮茶的杯子，大约可以手捧起来，现在比这个更小，所以叫小杯）。
四逆散，每次服用方寸匕（折合现在一钱），那些腹泻伴有肛门坠胀感的，加薤白一升煎服（末药很少，而一升的薤白，其量少也可以知道了）。
方寸匕，做成匕首形状，正方形一寸，根据曲尺的一寸度量制作。钱匕，用五铢钱制作，开元钱也相同。都是以舀取散药而不落下为标准。
古人使用散药，用刀圭舀取，匕也有刀圭的意思。根据前面的论述，一刀圭为三十二粒黍，方寸匕则是十个刀圭。立方一寸积千分除以三，得到三百三十三分为方寸匕的实际容量，容纳三百二十粒黍，折合现在一钱（药物性质轻重不等，现在只按黍来计算，以得其大概）。
《千金要方》论述：“钱匕，用大钱全部舀取；如果说半钱匕，那么就是一‘钱’舀取半边而已，都用五铢钱。钱五匕，是用五铢钱边缘的‘五’字来舀取，也让药不落为标准。”按五铢钱与开元钱直径相同，折合曲尺九分，其底面积为六十三平方分，乘以九分，得到五百六十七立方分，除以三，得到一百八十九立方分为一钱匕的实际容量。再以三百三十三立方分为第一率，重一钱为第二率，一百八十九立方分为第三率，得到重五分六厘为第四率，这就是一钱匕的重量。半钱匕，折合现在二分八厘；钱五匕，折合现在一分四厘。
参考古代方剂：
五苓散、四逆散等方，每次服用方寸匕（折合现在一钱）。
桃花汤，赤石脂末半斤，每次服用方寸匕，每天三次（每个方寸匕折合现在的二钱，因为石药性质沉重）。
烧灰散，每次服用方寸匕，每天三次（灰的性质必然轻）。
大陷胸汤，甘遂一钱匕，分两次服用（每次是半钱匕，折合现在二分八厘）。
十枣汤，身体强壮的人服用一钱匕（折合现在五分六厘）。
文蛤散，一钱匕（药性较轻）。
一撮，以三指为标准。
《千金要方》论述：“一撮，等于四刀圭。”得到一百二十八粒黍，折合现在四分。
参考古代方剂：
泽术糜衔散，药共二十五分（折合现在四钱七分五厘），以三指撮为饭后服用（每次服用四分，每天三次，三天后病愈，药也将用完）。
风引汤，药共五十五两（折合现在四两一钱八分），取三指撮井水煮服（石药性质沉重，每次服用八分，以五十多天为限度）。
凡是丸药如梧桐子大小的，折合药末一分。如弹丸及鸡子黄大小的，折合药末一钱。
《千金要方》论述：“刀圭，是方寸匕的十分之一，大小如同梧桐子。”一方寸匕散药以蜜调和，得到如梧桐子大小的十丸为定数。如弹丸及鸡子黄大小的，以十个梧桐子折算。根据前面的论述，刀圭容纳三十二粒黍，应重一分，方寸匕加十倍，应重一钱。
参考古代方剂：
己椒苈黄丸，药共四两（折合现在三钱，蜜丸如梧桐子大），饮水送服一丸，每天三次（每天三丸，每丸一分，蜜在外，十天病愈是可以知道的）。
薯蓣丸，药共一百七十八分（折合现在三两三钱八分），大枣一百枚制成膏，和蜜丸如弹子大，空腹酒送服一丸，一百丸为一剂（每丸药末当重三分四厘，因为有大枣一枚及蜜，所以能得到如弹子大。弹子大的，可能比鸡子黄稍小，但也相差不远）。
理中丸，药共十二两（折合现在九钱一分），蜜和丸如鸡子黄大，用沸水几合和一丸，研碎温服，每天三四次，夜间两次，腹中未觉热，增加到三四丸（每丸药末一钱，应当得到九丸）。但这不如汤剂好，汤法是将四物按照两数切碎，用水八升，煮取三升，去渣，温服一升，每天三次（作汤者，就是用此九钱一分的药煎制的。寇宗奭怀疑丸药少，汤药多，妄称古代方剂如鸡子黄大小的，应该是大丸，李时珍遵从这一说法，于是对古代法如弹丸及鸡子黄准十个梧桐子的，奋笔增加为四十个梧桐子，这是错误的）。
备急丸，每次服用大豆许三四丸，未痊愈，再给三丸（按《千金要方》“十六粒黍为一大豆”，合计七丸，不过一百十二粒黍的重量，折合现在三分半）。
凡是药有说大升、大两的，以神农秤三两为一两，药升三升为一升。
《千金要方》论述：“隋人以三两为一两。”权量三倍，所以量具也三倍。
参考古代方剂：
《外台秘要》记载《广济方》蒜煎，主治冷气，用牛乳五升（折合现在三合四勺），放入剥净的蒜肉二升，煎候蒜消尽，下牛膝一大斤末（折合现在三两六钱），煎成，用酒调和两匙服用（乳经过煎蒜后，约存二合，配三两六钱煎而调和之，其末必不可复多矣）。
《外台秘要》记载《录验方》杏仁煎，治疗咳气。杏人一升，捣碎，用水和研，取三大升汁（折合药升九升），煎取一大升，酒服一匙，每天三次（以水九升，研杏仁一升，其水也不可复多矣）。
凡是煮汤，大致古代药二十两，现在一两五钱，用水一斗，现在七合，煮取四升，现在二合八勺，分勺二，三次服用。
上述药物都要咬碎如豆子大小，必须水乘着热气，才能透入药中，然后药乘着水沸腾，才开始溢出汁液；然而火要微，沸要小，由两人绞汁，借助尺木搅拌，澄清去浊后才服用。全在于获取其气的清纯，而不欲多水以消耗其气，读《千金要方》的论述自然明白。
至于《千金要方》论述各种药物权量互相验证的方法，往往不符合，这是因为古今药性不同所致。就像蜀椒、吴茱萸、地肤子、蛇床子，古代采取阴干，现在都是晒爆，爆了则药性为之变轻，轻则各有差别，而权与量就不相合了。又如附子以一枚准半两，古代取其土中自养，形神充足的。枣有大小，以三枚准一两。古代在八月采摘晒干，尚皮不尚肉（《本草经集注》说：枣皮利，肉补虚，只有十枣汤取肥大的十枚使用），现在都不依法，应该与古法不符。只有巴豆治净，以一分得十六枚，颇为符合（《千金要方》说：巴豆先去心皮毕秤之，曾依法修治，其薄衣务尽去之，约十六枚，重分九厘）。如果能从古代方绪论中寻求，蛛丝马迹，并非不可寻找。
参考古代方剂：
《千金方》治疗历节诸风，百节酸疼不可忍，用松脂三十斤（折合现在三十六两），炼五十遍，最少也要二十遍，服用方寸匕，每天三次，百日痊愈（方寸匕容三百二十粒黍，折合现在一钱，这是最可依据的。每日服三钱，百日须三十两也。以松脂炼去六两，适合百日之用，则古一斤为一两二钱，更没有疑问了）。
《千金要方》治疗结气，冷症积在胁下，及脚气上入小腹，腹中胀满。大蒜去心，三升，捣令极热，以水三升，和调绞汁，再捣，以水三升和，绞去滓，再以水三升和之，共成九升，滓可桃颗大，弃却（三升蒜肉研汁后，滓仅如挑颗大，升小可知）。以微火煎取三升，下牛乳三升，合煎至三升。早晨空腹一顿温服，令尽（三升蒜汁，可以一顿服，升小可知）。到申时进食。三日服一剂，三十日服十剂止（蒜汁最辛辣劣烈，全然不顾忌，而频繁服用，升小可知）。
宋代林亿以古三两为今一两，古三升为今一升，庞安常也这么说。这是错误地以汉代的权量为凭据罢了，与古方不相涉。
古方以二龠为一升，以二百四十粒黍为一两，这与刘歆所定的二十龠为升，二千四百粒黍为两者，相差极大，后世儒生误信《汉书·律历志》，于是以新莽刀布之重及铜斛之式断定古律权量，于是以古准今，就有三两为一两，三升为一升的说法，而强行合于医方的权量罢了（秦汉的量，每一斗为现在的二升，见阎百诗《四书释地》及沈彤《周官禄田考》，附识于此）。
前明张介宾被郑世子的《乐书》迷惑，定为古方一两，现在的六钱，古方一升，现在的三合三勺，更是大错特错。
李时珍说：古之一两，今之一钱，古之一升，今之二合半，也不对。
参考古代方剂：
《肘后备急方》治疗消渴，以黄连三斤（折合现在三两六钱），纳猪肚中蒸服（根据景岳说，是廿八两八钱矣，猪肚中能容之否？）。
又《肘后备急方》治疗中风腹痛，用盐半斤（折合现在六钱），熬水干，着口中，饮热汤二斤，得吐愈（根据张则四两八钱，能着口中耶？并能饮如许热汤耶？）。
又《肘后备急方》治疗风毒脚气，用硫黄末一两，牛乳调服，取汗，北方人用此多效（根据张则六钱，可作一顿服耶？）。
又《肘后备急方》治疗劳复，用干姜四两，为末（折合现在三钱），汤调顿服（根据张则为二两四钱之干姜，可一顿服耶？）。
《外台秘要》记载《备急方》治疗五尸，以雄黄、大蒜各一两，捣和如弹丸（折合现在一钱三分，故适如弹子大），纳热酒中服之（根据张则一两二钱，能与弹丸相似耶？）。
《千金方》治疗吞金银异物，用白糖二斤（唐以前方用糖，皆指饴糖，非蔗糖也），一顿（折合现在二两四钱），渐渐食之，多食亦佳（根据张则十九两二钱，能作一顿服耶？）。
以上辨析古秤。
Li Shicai's essay "Reading the Discourse on the Four Great Masters" is originally based on the main idea of Wang Jiezhai, stating that these three masters (referring to Liu Wansu, Li Dongyuan, and Zhu Danxi) made up for what was incomplete in Zhang Zhongjing's medicine and stood shoulder to shoulder with him. However, Zhang Zhongjing is considered divine and holy in medicine, possessing virtues that correspond to the four seasons; whereas these three masters are merely like Bo Yi, Yi Yin, and Liu Xiahui—noble men of their time. Observe the *Yukan Jingui Fang* (Jade Box and Golden Cabinet Formulas): the use of Huangqin Tang (Scutellaria Decoction) and Baihu Tang (White Tiger Decoction) had already paved the way for Liu Hejian's (Liu Wansu's) academic thought; the application of Jianzhong Tang (Middle-Builder Decoction) and Lizhong Tang (Spleen-Regulating Decoction) had already paved the way for Li Dongyuan's thought; and the use of Fumai Tang (Pulse-Replenishing Decoction) and Huanglian Ejiao Tang (Coptis and Donkey-Hide Gelatin Decoction) had already paved the way for Zhu Danxi's thought. Therefore, if one says that these three masters derived one aspect of Zhang Zhongjing's virtue and expanded upon it, that might be acceptable; but to say they made up for what was incomplete in Zhang Zhongjing's work is inaccurate.
Mr. Li Shicai of the late Ming Dynasty was a native of our city. His book *Yizong Bidu* (Essential Readings for Medical Students) is indeed well-known and popular. However, I have some private reservations about it. The books that must be read are those of Huangdi (Yellow Emperor) and Qibo, as well as those of Yue Ren (Bian Que) and Zhang Zhongjing. As for works after them, such as *Maijing* (Pulse Classic), *Qianjin Yaofang* (Essential Prescriptions Worth a Thousand Gold), *Waitai Miyao* (Secret Essentials from the Outer Cabinet), and various modern masters' writings, although one cannot read them all, selecting sixty or seventy percent, or thirty or forty percent, is still indispensable. If one strictly adheres to the teachings of Zhang Changsha (Zhang Zhongjing) to explore the root and source, then this book (*Yizong Bidu*) becomes a text that limits the vision of shallow physicians. It would be better to rename it "Books Not Necessarily to Be Read," which might be more appropriate.
Privately observing wealthy families, they avoid cold-natured herbs and favor warm-tonic ones. Physicians who prefer using warm tonics have thus acquired the name of the "Jingyue School." These people fail to realize that *Jingyue Quanshu* (Complete Works of Jingyue) is actually a book that collects both cold/warm and tonifying/reducing methods. Looking at his discussions on symptoms, he first cites ancient views and then supplements them with his own opinions; regarding formulas, he lists ancient formulas first and then adds new ones. The author named it *Quanshu* (Complete Book), and readers should understand it as such, discarding its shortcomings and recording its strengths. In doing so, tracing back to masters like Liu Hejian, Yishui School (Li Dongyuan), and Jinhua School (Zhu Danxi), there is no inconsistency; tracing further back to the Medical Sage Zhang Zhongdong, there is also no inconsistency. Those who benefit from Zhang Jiabin (courtesy name Jingyue) are not limited to Zuo Gui Wan (Left Restoring Pill) and You Gui Wan (Right Restoring Pill).
Ancient formulas, from *Lingshu* (Spiritual Pivot) and *Suwen* (Basic Questions) to *Qianjin Yaofang* and *Waitai Miyao*, collected famous formulas from the Han, Jin, Song, and Qi dynasties. Whenever it says "one liang" (tael), it is equivalent to 0.76 qian (mace) today. Whenever it says "one sheng" (peck/liter unit), it is equivalent to 6 shao (spoonfuls) and 7 chao (small spoonfuls) today. The rigorous verification is as follows:
Regarding ancient weights and measures, they were based on pitch-pipes. The pitch-pipe ruler of the Yellow Emperor era was nine cun (inches); the Xia dynasty ruler added one cun to make ten cun, which is the carpenter's square used today.
Sun Simiao in *Qianjin Yaofang* discussed the measurement for acupuncture points: "The ruler used is the ancient Xia ruler. The Sima Fa states that six chi (feet) make one bu (pace). This is the eight-cun small ruler used in Jiang, Huai, Wu, and Yue regions today." Based on this, it is undoubtedly the current carpenter's square. Knowing this ruler corresponds to the standard length of the Yellow Emperor's pitch-pipe ruler was verified by correlating the volume accumulation of medicinal sheng and yue with linear measurements, detailed in *Lvxue Jingwen*.
Using the carpenter's inch as the side length, a cube with equal top and bottom sides and a depth of slightly over 0.78 cun has a total volume of 2,000 cubic fen. This is the volume of the ancient "medicinal sheng."
*Qianjin Yaofang* discusses the "medicinal sheng" as having an upper diameter of one cun and lower diameter of six fen, with a depth of eight fen. It should be understood as having a top and bottom diameter of 1.6 cun and a depth slightly less than eight fen. According to *Guanzi*: "The fu (cooking pot) must not be too large..." Calculating its volume yields only 522 cubic fen, which is too small. Thus, it is known to be a transcription error. Squaring the mouth of the sheng gives 256 square fen. Multiplying by a depth of slightly over 0.78 cun yields 2,000 cubic fen. Saying "depth eight fen" is taking the round number.
One sheng of the medicinal sheng holds the actual volume of two yue of the Huangzhong pitch-pipe. Taking 240 grains of millet as one liang, the weight of millet cannot be verified today. Based on *Qianjin Yaofang* stating that one jin of honey yields seven he of medicinal sheng, and the ratio of water to honey in *Lingtai Yixiangzhi* where volumes are equal but weights differ (ratio 20:29), measuring sequentially, one ancient liang equals 0.76 qian today.
The ancient law yue holds 1,280 grains of millet. *Qianjin Yaofang* states: "One cuo (pinch) equals four daogui (knife-point measure). Sixty-four grains of millet make one gui; half makes one daogui. Ten cuo make one shao (spoon/yue). Two shao make one he." ("He" here is a typo for "Sheng"; one sheng contains 2,560 grains of millet). Li Shizhen followed the error of two shao making one he, and added ten he making one sheng, thereby spreading the error. Fortunately, the original texts of *Qianjin Yaofang* and *Waitai Miyao* do not contain these five characters, proving this point.
Millet has a husk and two layers of grain. It is used to measure yue because its base is round, smooth, and even (see commentary on *Kaogongji*, Wheelwright section). Since Liu Xin disrupted ancient methods, placing weights for weighing, the Prince of Zheng in the late Ming specifically sought millet and weighed it with modern scales. Each yue contained 1,200 grains, weighing three qian. This is not a valid standard (The Prince of Zheng's *Yueshu* is far-fetched; his claims about weighing and measuring with millet are purely speculative. Zhang Jiabin included this in *Leijing Tuyi*, severely misleading later generations).
Knowing that 240 grains of millet equal one liang, *Qianjin Yaofang* says: "Ten grains of millet make one zhu. Six zhu make one fen. Four fen make one liang. Sixteen liang make one jin. This is the scale of Shennong."
To verify and correct ancient weights: First, fill a medicinal sheng (volume 2,000 cubic cun of the carpenter's ruler) with well water and weigh it at 1.2 qian. From this, deduce the ratio of same-volume different-weight substances. For example, if water and honey are stored in identical vessels, water is lighter and honey heavier. If water weighs 20 liang, honey weighs 29 liang. Using this ratio, if one medicinal sheng of water weighs 1.2 qian, then one medicinal sheng of honey weighs 1.74 qian.
Explained by the rule of three:
Water 20, Honey 29, Water 1.2 qian. Multiply to get 34.8 liang-qian. Divide by the first rate (20) to get the fourth rate: 1.74 qian. So, honey weighs 1.74 qian per sheng.
Having obtained the weight of honey in one sheng, use the rule of three again to find the weight of seven he of honey.
One sheng of honey weighs 1.74 qian today; seven he of honey weighs 1.218 qian today.
This seven he of honey, weighing 1.218 qian today, corresponds to sixteen liang of ancient honey. Recalculating based on the above method, we determine the modern equivalent of one ancient liang.
Sixteen ancient liang = 1.218 qian today.
One ancient liang = slightly over 0.76 qian today.
Referencing ancient formulas:
Mahuang Tang (Ephedra Decoction): Mahuang (Ephedrae Herba) 3 liang (equivalent to 0.23 qian today), divided into three doses. Stop when the illness is cured (each dose stops at 0.76 qian).
Xiaochaihu Tang (Minor Bupleurum Decoction): Chaihu (Bupleuri Radix) 8 liang (equivalent to 0.6 qian today), divided into three doses (each dose stops at 0.2 qian).
Chengqi Tang (Order the Qi Decoction): Dahuang (Rhei Radix et Rhizoma) 4 liang (equivalent to 0.3 qian today), divided into two doses. Stop when cured (each dose stops at 0.15 qian).
Baihu Tang (White Tiger Decoction): Shigao (Gypsum Fibrosum) 1 jin (equivalent to 1.2 qian today). Divided into three doses (each dose stops at 0.4 qian).
The volume of the medicinal sheng is 2,000 cubic fen. Estimating from modern granary hu units, one ancient sheng equals 6 shao and 7 chao today.
Calculation of cubes: A full thousand fen equals one cun. Having calculated using granary hu, combining with the carpenter's inch measurement, a volume of 1,497 cubic cun equals five dou today. Thus, two carpenter's inches equal 6 shao and 7 chao.
Referencing ancient formulas:
Banxia Shumi Tang (Pinellia and Sorghum Decoction): Banxia (Pinelliae Rhizoma) 5 he (equivalent to 3.35 chao today); Shumi (Sorghei Fructus Glutinosis) 1 sheng (equivalent to 6.7 chao today); Ganlan Shui (Ganlan Water/Water Stirred Vigorously) 5 sheng (equivalent to 3.3 shao today). Decoct to obtain half a sheng (equivalent to 1 he today). Divide into three doses. Drink one small cup each time (a cup like a tea cup, roughly hand-held; today's cups are smaller, hence 'small cup').
Sini San (Four Reversal Powder): Each dose uses one fangcun bi (square-inch spatula measure) (equivalent to 0.1 qian today). For those with diarrhea and heaviness in the anus, add Xiebai (Allii Macrostemonis Bulbus) 1 sheng to decoct and take (the amount of powder is small, so the quantity of one sheng of Xiebai indicates a small volume).
Fangcun bi is shaped like a square-inch spatula, made according to the carpenter's inch. Qianbi is made using a Wuzhu coin; Kaiyuan Tongbao coins are similar. The standard is to scoop loose herbs without spilling.
Ancients used loose herbs, scooping with daogui. Bi also implies daogui. According to previous discussion, one daogui equals 32 grains of millet. Fangcun bi is ten daogui. One cubic inch (1,000 fen) divided by three gives 333 fen, the actual capacity of a fangcun bi, holding 320 grains of millet, equivalent to 0.1 qian today (herbs vary in density; this calculation uses millet for approximation).
*Qianjin Yaofang* states: "Qianbi: scoop fully with a large coin. Half-qianbi means scooping half the coin. Use Wuzhu coins. Qianwubi: scoop using the character 'Wu' (five) on the edge of the Wuzhu coin, ensuring no spillage." Wuzhu and Kaiyuan coins have the same diameter, approximating 0.9 cun. Area is 63 square fen. Multiplied by 0.9 cun depth, it is 567 cubic fen. Divided by three, 189 cubic fen is the actual capacity of one qianbi. Using 333 fen as the first rate, 0.1 qian as the second rate, and 189 fen as the third rate, the fourth rate is 0.056 qian. This is the weight of one qianbi. Half-qianbi equals 0.028 qian today; Qianwubi equals 0.014 qian today.
Referencing ancient formulas:
Wuling San (Five-Ling Powder), Sini San, etc.: Each dose uses one fangcun bi (0.1 qian today).
Taohua Tang (Peach Blossom Decoction): Chishizhi Mo (Red Stone Lip Powder) 0.5 jin. Each dose uses one fangcun bi, three times daily (Each fangcun bi equals 0.2 qian today because stone drugs are heavy).
Shao Tan San (Burned Ash Powder): Each dose uses one fangcun bi, three times daily (Ash is light).
Da Xianxiong Tang (Major Chest-Stagnation Decoction): Gansui (Kansui Radix) one qianbi, divided into two doses (Each dose is half-qianbi, 0.028 qian today).
Shizao Tang (Ten-Jujube Decoction): Strong adults take one qianbi (0.056 qian today).
Wenge San (Clam Shell Powder): One qianbi (Drug is light).
One cuo is measured by three fingers.
*Qianjin Yaofang* states: "One cuo equals four daogui." This equals 128 grains of millet, equivalent to 0.04 qian today.
Referencing ancient formulas:
Zeshu Mixian San: Total medicine 25 fen (0.475 qian today). Take one pinch (cuo) after meals (Each dose 0.04 qian, three times daily. After three days, illness resolves, medicine finishes).
Fengyin Tang: Total medicine 55 liang (4.18 qian today). Take three-finger pinch boiled in well water (Stone drugs are heavy; each dose 0.08 qian, duration over 50 days).
For pills the size of wutong seeds, equivalent to 0.01 qian of powder. For pills the size of bullet pellets or egg yolks, equivalent to 0.1 qian of powder.
*Qianjin Yaofang* states: "Daogui is one-tenth of fangcun bi, size like wutong seeds." Mixing one fangcun bi of powder with honey yields ten wutong-sized pills. Bullet/egg-yolk sized pills are ten times wutong seeds. Daogui holds 32 grains, weighing 0.01 qian; fangcun bi is ten times that, weighing 0.1 qian.
Referencing ancient formulas:
Jifeng Lihuang Wan: Total medicine 4 liang (0.3 qian today), honey pills wutong-sized. Take one pill with water, three times daily (Three pills daily, 0.01 qian each, excluding honey. Cure in ten days).
Shuyu Wan: Total medicine 178 fen (3.38 qian today). 100 jujubes made into paste, mixed with honey, pills bullet-sized. Take one pill with wine on empty stomach. 100 pills constitute one course (Each pill contains 0.034 qian of powder. With one jujube and honey, it reaches bullet size. Bullet size may be slightly smaller than egg yolk, but close).
Lizhong Wan: Total medicine 12 liang (0.91 qian today). Mixed with honey, pills egg-yolk-sized. Dissolve one pill in boiling water, crush, and take warm. Three to four times daily, two times at night. If abdomen feels not warm, increase to three to four pills (Each pill contains 0.1 qian of powder, requiring nine pills). However, decoction is better. Decoction method: Cut four ingredients according to liang amounts. Use 8 sheng water, boil to 3 sheng, remove dregs, take 1 sheng warm, three times daily (Decoction uses the 0.91 qian of medicine. Kou Zongshi doubted pill dosage vs decoction, wrongly claiming egg-yolk-sized pills were large. Li Shizhen followed this, erroneously increasing the conversion of bullet/egg-yolk pills from 10 to 40 wutong seeds).
Beiji Wan: Take 3-4 pills the size of soybeans. If not improved, give 3 more pills. (*Qianjin* states 16 millet grains = one soybean. Seven pills weigh 112 grains, equivalent to 0.035 qian today).
When medicines specify "large sheng" or "large liang," it refers to Shennong's scale where 3 liang = 1 liang, and 3 sheng = 1 sheng.
*Qianjin Yaofang* states: "Sui dynasty people took 3 liang as 1 liang." Weight tripled, so volume tripled.
Referencing ancient formulas:
*Waitai Miyao* records Guangji Fang Garlic Decoction for cold qi: Use 5 sheng cow milk (3.4 shao today). Add 2 sheng peeled garlic meat. Boil until garlic dissolves. Add 1 big jin Niuxi (Achyranthis Bidentatae Radix) powder (0.36 qian today). Boil, mix with wine, take two spoons. (After boiling garlic, milk reduces to ~2 he. Mixed with 0.36 qian powder, the residue cannot be much).
*Waitai Miyao* records Lu Yan Fang Almond Decoction for cough: 1 sheng almonds. Pound, mix with water, grind, extract 3 large sheng juice (9 medicinal sheng). Boil to 1 large sheng. Take one spoon with wine, three times daily. (Grinding 1 sheng almond with 9 sheng water leaves little water remaining).
General decoction: Roughly 20 ancient liang of medicine equals 1.5 qian today. Use 1 dou water (7 he today). Boil to 4 sheng (2.8 shao today). Divide into three doses.
All above medicines should be chewed/crushed to bean size. Water must absorb heat to penetrate the drug. Then drug boils water, extracting juice. Fire should be low, boiling gentle. Strain with help of wooden ruler. Clarify and remove turbidity before taking. Goal is pure qi, avoiding excess water diluting qi. *Qianjin* explains this clearly.
Discrepancies in *Qianjin*'s weight/measure verification arise because ancient and modern drug properties differ. For instance, Shujiao, Wuzhuyu, Difuzi, Shechuangzi were dried in shade anciently, but sun-dried/baked today. Baking lightens the drug property, causing discrepancies in weight/volume ratios. Regarding Fuzi, one piece equaled half a liang anciently, selected from soil-grown, full-shape pieces. Jujubes varied in size; three pieces equaled one liang. Ancient harvest was August, drying skin-on, flesh-off (*Bencao Jing Jizhu*: Skin benefits flow, flesh tonifies deficiency. Only Shizao Tang uses plump jujubes). Modern practices don't follow this, differing from ancient methods. Only Badou (Croton Seed), cleaned, where 1 fen equals 16 seeds, aligns well (*Qianjin*: Remove heart/skin, weigh. Fully processed, thin skin removed. ~16 seeds weigh 0.09 fen). Tracing ancient formula theories reveals clues.
Referencing ancient formulas:
*Qianfang* treats Lijie wind/pain with 30 jin Songzhi (Pine Resin) (36 liang today). Refine 50 times (min 20). Take fangcun bi, three times daily, 100 days for cure (Fangcun bi holds 320 millet grains = 0.1 qian. Daily 0.3 qian x 100 days = 30 liang. Refined pine resin loses 6 liang, fitting 100-day use. Thus, 1 ancient jin = 1.2 qian today, undeniably).
*Qianjin* treats Jieqi, cold accumulation in hypochondrium, Hongjiao (podagra) entering lower abdomen, bloating. Garlic 3 sheng, pound hot. Mix with 3 sheng water, squeeze juice. Pound again, add 3 sheng water, squeeze. Repeat once more. Total 9 sheng. Residue like peach pit size, discard (Residue tiny after squeezing 3 sheng garlic, indicating small sheng volume). Simmer gently to 3 sheng. Add 3 sheng cow milk. Boil together to 3 sheng. Take warm on empty stomach morning. Finish in one go (3 sheng garlic juice taken at once confirms small sheng). Eat at Shen hour. One dose every 3 days, 10 doses over 30 days stop (Garlic juice is pungent/harsh; frequent dosing confirms small sheng).
Song dynasty Lin Yi stated 3 ancient liang = 1 modern liang, 3 ancient sheng = 1 modern sheng. Pang Anchang agreed. This error relied on Han dynasty weights, irrelevant to ancient formulas.
Ancient formulas: 2 yue = 1 sheng; 240 millet grains = 1 liang. This differs greatly from Liu Xin's 20 yue = 1 sheng, 2,400 grains = 1 liang. Later scholars mistakenly believed *Han Shu*, using Xin Mang knife/coin weights and bronze hu shapes to define ancient standards. Thus, converting ancient to modern led to the claim 3 liang = 1 liang, 3 sheng = 1 sheng, forced to fit medical formulas. (Qin/Han volume: 1 dou = 2 modern sheng. See Yan Baishi *Sishu Shidi* and Shen Tong *Zhouguan Lutian Kao*).
Ming dynasty Zhang Jiabin, confused by Prince of Zheng's *Yueshu*, defined 1 ancient liang = 0.6 qian today, 1 ancient sheng = 3.3 shao today. This is a major error.
Li Shizhen said: 1 ancient liang = 1 qian today; 1 ancient sheng = 2.5 he today. Also incorrect.
Referencing ancient formulas:
*Zhouhou Beiji Fang* treats Xiao Ke (Wasting-Thirst) with 3 jin Huanglian (Coptidis Rhizoma) (3.6 qian today). Steam in pig stomach. (According to Jingyue, this is 28.8 qian. Can a pig stomach hold this?)
*Zhouhou Beiji Fang* treats Windstroke abdominal pain with 0.5 jin Yan (Salt) (0.6 qian today). Boil dry, place in mouth, drink 2 jin hot water to induce vomiting and cure. (According to Zhang, this is 4.8 qian. Can one place this in mouth? Drink such hot water?)
*Zhouhou Beiji Fang* treats Feng Du Hongjiao (Wind-Toxin Podagra) with 1 liang Huangshi (Sulfur) powder, mixed with cow milk to induce sweat. Northerners use this effectively. (According to Zhang, 0.6 qian. Can this be taken in one dose?)
*Zhouhou Beiji Fang* treats Lao Fu (Labor Relapse) with 4 liang Ganjiang (Zingiberis Rhizoma) powder (0.3 qian today). Mix with water, take in one dose. (According to Zhang, 2.4 qian. Can this be taken in one dose?)
*Waitai Miyao* records Beijifang treating Wushi (Five Corpse Diseases) with 1 liang Xionghuang (Realgar) and 1 liang Dasuan (Garlic). Pound and mix into bullet-sized pill (0.13 qian today, fitting bullet size). Take in hot wine. (According to Zhang, 1.2 qian. Can this resemble a bullet?)
*Qianfang* treats swallowing gold/silver with 2 jin Baixiang (Sugar) (Pre-Tang sugar refers to maltose, not sucrose). Take in one meal (2.4 qian today). Eat gradually, more is fine. (According to Zhang, 19.2 qian. Can this be taken in one meal?)
Above distinguishes ancient scales.