古方、汤法 咀，谓锉如麻豆，散法治罗，谓治择捣罗，盖卒病贼邪，须汤以荡涤，久
病痼疾，须散以渐渍，近世一切为散，遂忘汤法，今以锉切 咀，或粗捣筛之类为汤，捣罗
极细者为散，又如丹、丸、膏煎之名，不知异用之实，盖丹者、烹炼而成，有一阳在中之义
，丸者、取其以物收摄而已，膏者、谓摩敷之药，煎者、取其和熟为服食之剂，今以火炼及
色赤者为丹，非炼者为丸，以服食者为煎，涂敷者为膏，审此数者，他可推类而知也。
凡煎药、当取新水，令极清洁，微火小沸，若利汤、欲少水而多取，补汤、欲多水而少
取，此古法也，其汤剂大小，古今升两不同，当根据世俗现行之法，大约每用药三钱匕，以水
一盏煎取七分为率，其余多少增损，当视病之轻重大小。
病在胸膈以上者，先食后服药，病在心腹以下者，先服药后食，病在四肢血脉者，服药
宜空腹而在旦，病在骨髓者，服药宜饱满而在夜，此用药之常法也，若卒病受邪，则攻治宜
速，岂可拘以常法。
凡服利汤，贵在侵早，仍欲稍热，若冷则令人吐呕，又须澄清，若浊则令人心闷，大约
分为三服，初与一服，宜在最多，乘病患谷气尚强故也，次与渐少，又次最少，若其疏数之
节，当问病患，前药稍散乃可再服。
凡服补益丸散者，自非衰损之人，皆可先服利汤，泻去胸腹中壅积痰实，然后可服补药
，应服治风汤散，皆须三五剂，若有久滞风病，即须倍此，乃至百余日可瘥，又当斟酌所宜
，伤寒时气，不拘旦暮，当即亟治，其服药亦不可拘以常法，庶使病易得愈，不致传变，是
以小儿女子得病，益以滋甚者，良由隐忍冀差，不即治之也。
古方与汤剂煎煮方法中，“咀”是指将药材锉碎成如麻子、豆子大小的颗粒；“散法中的‘治罗’”是指经过挑选、捣碎并过筛。这是因为急性病多由贼邪（致病力强之邪气）引起，必须用汤剂来荡涤病邪；而久病形成的痼疾，则需用散剂慢慢浸渍调理。近代人将所有药物都制成散剂，于是忘记了汤剂的用法。现在应当将锉切“咀”的药材，或者粗捣后筛选的药材用于制作汤剂；将捣碎并过筛至极细粉末的药材用于制作散剂。又如丹、丸、膏、煎这些名称，人们不了解它们实际用途的区别。大概来说，“丹”是通过烹炼而成的，蕴含“一阳居于其中”的意义；“丸”是取其用某种物质包裹收摄的意思；“膏”是指用于涂抹敷贴的药物；“煎”是取其调和煮熟后作为服用饮食的制剂。现在有人把用火炼制及颜色赤红的称为“丹”，不是炼制的称为“丸”，把作为服食用的称为“煎”，把涂抹敷贴的称为“膏”，如果仔细审察这几种情况，其他的情况也可以类推而知了。
凡是煎药，应当取用新水，使其极其清洁，用微火加热至微微沸腾。如果是为了通利大便的汤剂，希望用水少而取汁多；如果是为了补益的汤剂，希望用水多而取汁少，这是古代的方法。至于汤剂剂量的大小，古今使用的升、两单位不同，应当依据世俗现行的方法，大致每用药材三钱匕，用水一盏，煎取七分满为限度，其余多少增减，应当视病情的轻重来决定。
病位在胸膈以上的，先吃饭后服药；病位在心腹以下的，先服药后吃饭；病位在四肢血脉的，宜空腹在早晨服药；病位在骨髓的，宜饱腹在夜晚服药，这是用药的一般规律。如果是突发疾病感受邪气，则攻邪治疗应当迅速，怎么可以拘泥于一般规律呢？
凡是服用通利大便的汤剂，贵在清晨服用，并且要稍微温热，如果太冷会让人呕吐；又必须澄清，如果浑浊会让人心闷不适。大约分为三次服用，第一次给的一服量应该最多，因为此时病患的谷气（脾胃之气）还比较强盛；第二次逐渐减少，第三次最少。至于服药间隔的疏密节奏，应当询问病患，前一次药效稍散之后才可以再次服用。
凡是服用补益类的丸剂和散剂，如果不是身体极度衰弱的人，都可以先服用通利汤剂，泻去胸腹中壅积的痰湿和实邪，然后才可以服用补药。凡是服用治疗风病的汤剂和散剂，都需要服用三五剂，如果有久留的风病，就需要加倍剂量，甚至需要一百多天才能痊愈，还应当斟酌适宜的情况。伤寒时行疫病，不拘泥于早晚，应当立即紧急治疗，其服药也不可以拘泥于一般规律，这样才使病情容易痊愈，不导致传变。因此小儿和女子患病，往往更加严重，确实是因为隐忍拖延希望自愈，不及时治疗造成的。
Ancient prescriptions and decoction methods: "Ju" (chewing/crushing) refers to crushing herbs into pieces the size of hemp seeds or beans; "Zhi Luo" (processing and sifting) in powder methods refers to selecting, pounding, and sifting. This is because acute illnesses caused by pathogenic factors require decoctions to purge and cleanse, while chronic stubborn diseases require powders for gradual soaking and treatment. In recent times, all medicines have been made into powders, causing the method of decoctions to be forgotten. Currently, herbs crushed into "Ju" sizes, or coarsely pounded and sifted, are used for decoctions; those pounded and sifted into extremely fine powder are used for powders. Furthermore, regarding the names Dan (elixir/pill), Wan (pill), Gao (paste), and Jian (decoction/concentrate), people do not understand their practical differences. Generally speaking, "Dan" is formed through cooking and refining, symbolizing "one Yang residing within"; "Wan" implies gathering and containing substances; "Gao" refers to medicinal pastes for external application and plastering; "Jian" refers to agents that are harmonized, cooked, and taken as food or drink. Nowadays, some call substances refined by fire and turning red "Dan", non-refined ones "Wan", ingestible concentrates "Jian", and topical plasters "Gao". By carefully examining these categories, one can infer others by analogy.
When decocting medicine, fresh water should be used, ensuring it is extremely clean, and heated over a low flame until slightly boiling. For laxative decoctions, less water should be used to obtain more liquid; for tonic decoctions, more water should be used to obtain less liquid. This is the ancient method. Regarding the dosage of decoctions, the units of Sheng and Liang differ between ancient and modern times; one should follow current secular practices. Approximately, for every three Qianbi (a small measure of herbs) of medicine, use one Zhan (a cup measure) of water, decoct until seven-tenths remains. The increase or decrease of other amounts should depend on the severity of the disease.
For diseases located above the chest and diaphragm, take medicine after eating; for diseases located below the heart and abdomen, take medicine before eating; for diseases in the limbs and blood vessels, take medicine on an empty stomach in the morning; for diseases in the bone marrow, take medicine when full at night. These are the general rules of medication administration. However, for sudden illnesses caused by pathogenic invasion, aggressive treatment should be swift, and one cannot rigidly adhere to general rules.
When taking laxative decoctions, it is best to take them early in the morning, and they should be slightly warm; if cold, they may induce vomiting. They must also be clear; if turbid, they may cause胸闷 (chest stuffiness). Generally, divide the dose into three servings. The first serving should be the largest, as the patient's Gu Qi (Grain Qi/Spleen-Stomach energy) is still strong. Subsequent servings should be gradually smaller, with the last being the smallest. The frequency and intervals of dosing should be determined by consulting the patient; the next dose should only be given after the effect of the previous dose has somewhat dissipated.
When taking tonifying pills and powders, unless the person is severely depleted, one should first take a laxative decoction to drain accumulated phlegm and excess from the chest and abdomen, and only then take tonifying medicine. When taking decoctions or powders for treating wind diseases, three to five doses are usually required. For chronic lingering wind diseases, the dosage must be doubled, potentially requiring over a hundred days for recovery. One must also consider what is appropriate. For Shang Han (Cold Damage) and epidemic febrile diseases, do not restrict treatment to morning or evening; immediate urgent treatment is necessary. Medication administration should not be restricted by general rules, so that the disease may heal easily without transmitting. Therefore, illnesses in children and women often become more severe, largely due to enduring symptoms in hope of spontaneous recovery rather than seeking immediate treatment.