Section 1 Concepts and Origin of Chinese Herbology
l. Concepts of Chinese Herbs
Chinese Herbs: The traditional Chinese herbs are of two major characteristics, most of which are produced in China; and they are clinically used to treat diseases according to the basic theory of traditional Chinese medicine and herbology. Chinese herbs reflect traditional cultural features in the Chinese history in certain aspects.
Herbology: The herbology, an important component part of the traditional Chinese medicine, is a special subject for studying the theory on properties of Chinese herbs, their collection, preparation, effects, dosage and administration.
2. The Origin and Development of Chinese Herbology
Chinese herbs originated from productive and medical practice by the laboring people in ancient China. The record of "Shen Nong tasting a hundred herbs came across 70 toxic substances in a single day'' is a vivid description of the discovery and development of Chinese herbs by the laboring people in ancient China at enormous costs in the struggle against diseases.
As early as the primitive times, while looking for food, mankind accidentally discovered that some plants could alleviate or eliminate sufferings from diseases. Since then, people have been actively looking for herbs.
In remote antiquity when written languages were not invented, the knowledge about herbs could only be disseminated and accumulated generation by generation in spoken languages. After the invention of written languages, the knowledge about herbs closely related to birth, senility, illness and death of people was naturally recorded in written languages. Medicinal wine was recorded with inscriptions on bones or tortoise shells in the Shang Dynasty. Herbs were also recorded in early historical books.
With the increase in Chinese herbs, the development of their practical use and the research into theory on their properties, special books on Chinese herbs were published. In the history of the development of Chinese books, there were five herbal classic, namely, Shen Nong's Herbal Classic, Variorum of Shen Nong's Herbal, The Newly Revised Herbology, Classic Classified Herbology for Emergency, Compendium of Herbology, and Supplement to the Compendium of Herbology. Among them, Compendium of Herbology has a relatively enormous influence in the world.

Section 2 Collection and Preparation of Herbs
Part 1 Collection of Herbs
Amount of active ingredients in medicinal parts of animals or plants vary from time to time during their growth, which directly influences their qualities and curative effects. Therefore, it is important to collect in good time when the contents of active ingredients in medicinal parts reach the peak level. The time for collecting different medicinal parts of plants can be summed up as follows:
1. Whole plants, stems and leaves are mostly collected when plants are in full bloom or in early blossom either by cutting off their parts above the ground or by pulling up whole plants with their roots. Seedlings or withered leaves are also used in some herbs, such as oriental wormwood (Yin Chen) and mulberry leaf (Sang Ye).
2. Flowers are generally collected in bud or in early blossom in order to avoid dispersion of their fragrant smell and shedding of their petals. Pollen are collected in full blossom
3. Fruits and seeds are mostly collected when they are ripe. Only a few of fruits are collected when they are unripe, such as black plum(Wu Mei), green tangerine orange peel(Qing Pi) and unripe bitter orange(Zhi Shi). Some kinds of seeds easily shed when they are full ripen. Therefore, these seeds should be collected when they are just nature.
4. Roots and rhizomes are mostly collected in early spring when plants have not sprouted or in late autumn when the stem and leaves start withering. At that time, nutrients stored in roots and rhizomes active ingredients are highest con tents. A small number of herbs can be collected in summer, such as pinellia tuber (Ban Xia) and corydalis tuber (Yan Hu Suo).
5. Bark should be collected in spring and summer when it is thick with adequate fluid and nutrients and easily stripped off. Root-bark should be collected in autumn, such as moutan root-bark (Mu Dan Pi) and wolfberry root-bark (Di Gu Pi).

Part 2 Preparation of Herbs
Herbs should be processed before using or making into various forms. Because most Chinese herbs are used unprepared, besides general handling, quite a few should be specifically processed to meet demands for their clinical use. Preparation, a traditional Chinese pharmaceutical technology, was formed in a long history of practice with its complete theoretical system and strict technique.
1. Aims of Preparation
High effects, low toxicity and convenience for use are the main aims of preparing Chinese herbs.
1.1. To enhance curative effects
For example: corydalis tuber (Yan Hu Suo) can obviously strengthen its analgesic effect by stir-baking with vinegar; ephedra (Ma Huang) can strengthen the effects of alleviating cough, and relieving asthma by stir-baking with honey; and eucommia bark (Du Zhong) can strengthen the effects of calming the liver and reducing blood pressure by stir-baking with salt.
1.2. To reduce toxic effects
Some extremely toxic should not be used orally without preparation for reducing their toxicity. For example: defatted powder of croton seed(Ba Dou Shuang), kansui root (Gan Sui) and knoxia root (Da Jie) boiled with vinegar, Sichuan aconite root (Chuan Wu) and wild aconite root (Cao Wu) boiled for a long time, and pinellia tuber (Ban Xia) and arisaema tuber (Nan Xing) decocted with ginger and alum can all reduce their toxic effects.
1.3. To change properties of herbs and expand their uses
Appropriate preparation can change cold or hot nature and augment effects of herbs. For example, dried rehmannia root (Sheng Di Huang), being cold in nature for removing heat from blood to stop bleeding, can be made into prepared rehmannia root (Shu Di Huang) for warming and tonifying essence and blood. Prepared arisaema (Zhi Nan Xing) being warm and dry in nature for resolving cold phlegm, expelling wind and alleviating spasm, can he made into biled arisaema (Dan Nan Xing) with cool and moist nature for removing heat, resoling phlegm, expelling wind and arresting convulsion. Fleece-flower root (Shou Wu) with its main effects of treating malaria and loosing the bowels can be made into prepared fleece flower root (Zhi Shou Wu) with its special effects of tonifying the liver and kidney and nourishing essence and blood.
In addition, through preparation, herbs become easy to use and store. Also, the abnormal flavor and some un-beneficial ingredients are removed.
2. Methods for Preparation
Methods for preparation of Chinese herbs include purification, preparation with water, preparation with fire and preparation with both water and fire. Methods for preparation of Chinese herbs are closely related to their clinical usage;
2.1. Stir-baking
Herbs are put into a pot over a fire, continually stir-baked to a certain extent and taken out. According to extent of heating, herbs can be stir-baked yellow in color, stir-baked charred or stir-baked carbonized. To be stir-baked yellow or stir-baked charred can moderate herbs' properties or strengthen the effect of invigorating the spleen; and to be stir-baked carbonized can strengthen the effects of stopping bleeding and arresting diarrhea.
2.2. Stir-baking with auxiliary fluid
The common auxiliary fluid includes wine, vinegar, and honey, saline and ginger juice. Herbs stir-baked with auxiliary fluid can strengthen effects, reduce toxicity and remove abnormal flavor. For example: Chinese angelica root stir-baked with wine can strengthen the effects of promoting circulation of blood; corydalis tuber (Yan Hu Suo) stir-baked with vinegar can strengthen its analgesic effect; and kansui root (Gan Sui) stir-baked with vinegar can reduce toxicity. In addition, herbs stir-baked with other auxiliary materials including sand and talc powder can make them crispy and enable their active ingredients to be easily decocted out, such as pangolin scales (Chuan Shan Jia), stir-baked with sand and hedgehog skin (Chi Wei Pi) stir-baked with talc powder.
2.3. Calcination.
Herbs are directly or indirectly calcined over a fierce fire to make them crispy for easily crushing or carbonized. Most of the solid and hard mineral herbs or shells are directly calcined, such as dragon's bone (Long Gu) and oyster shell(Mu Li). Carbonized palm(Zhong Lv Tan) and carbonized hair(Xue Yu Tan) are made by means of calcination in a sealed refractory vessel.
2.4. Roasting
Wrapped in moistened paper or flour paste, herbs are heated in smoldering cinder or roasted in a oven until the coating becomes charred in order to remove oil from herbs or to moderate their properties, such as roasted aucklandia root(Mu xiang), roasted ginger (Sheng Jiang) and roasted nutmeg(Rou Dou Ke).
2.5. Steaming
Herbs are steamed solely or with auxiliary materials to change their proper ties, strengthen their potency and reduce their toxic effects.
2.6. Boiling
Herbs are boiled in water and auxiliary materials to reduce their toxicity, such as genkwa flower (Yuan Hua) boiled with vinegar, and Sichuan aconite root (Chuang Wu Tou) boiled with bean curd.
2.7. Water-refining
Mineral herbs insoluble in water are crushed, put in a mortar, ground with water into fine powder in suspension, then poured into a vessel for precipitation and dried, such as wet-refined cinnabar (Zhu Sha) then and water-refined talc (Hua Shi).
In addition, there are fermentation, germination, frosting and many other methods for preparation, such as medicated leaven, germinated barley (Mai Ya) and defatted powder of croton seed (Ba Dou Shuang).

Section 3 Theory on Herb Properties
Diseases are caused by pathogenic factors, which affect the human body, resulting in dysfunction of the internal organs and in hyperactivity or hypo-activity of yin, yang, qi and blood. Herbs are used to eliminate pathogenic factors restore normal function of the internal organs and rectify hyperactivity or hypo-activity of Yin, Yang, qi and blood, enable the body to recover from illness.
Curative effects of herbs come from their polarizing properties. Rectification of deviation by polarity is the essence of their curative effects. The theory on herb properties and the law governing applications are pharmacology of Chinese herbs, including four natures and five flavors, effects of lifting, lowering, floating or sinking, meridian tropism and toxicity.
Part 1 Four Natures and Five Flavors
Four natures and five flavors are the main contents of the theory on herb properties. Natures and flavors of herbs are the first principle of all indicated in books on herbology of all ages.
1. Four Natures
1.1. Concept of four natures
Four natures are cold, hot, warm and cool natures of herbs. Cold and cool natures are different in essence form and antagonistic against warm and hot natures, forming the two major properties. Cold nature is the same in essence as but, stronger than cool nature; and hot nature is the same in essence as but stronger than warm nature.
1.2. Determination of four natures
Four natures of herbs are determined by their curative effects on cold and heat syndromes.
For example, patients with extreme heat, extreme thirst and energetic pulse, belonging to heat syndrome of excess type, are treated with gypsum (Shi Gao), anemarrhena rhizome(Zhi Mu) and other herbs. If these heat symptoms are alleviated or eliminated, gypsum and anemarrhena rhizome should belong to cold nature. Warm and hot natures of herbs are determined according to the same principle.
1.3. Effects of four natures
In general, warm and hot herbs have the effects of warming and clearing the meridians, warming the interior to disperse cold, supplementing fire to support yang, warming yang to induce diuresis, and recuperating depleted Yang to rescue patients from collapse. Cold and cool herbs have the effects of clearing heat to purge fire, removing heat from blood to eliminate toxicity, purging heat to relax the bowels, inducing diuresis to treat stranguria, and removing heat from the heart and liver.
"To treat cold syndrome with hot, and to treat heat syndrome with cold herbs'' is the basic principle of using Chinese herbs. That is to say, warm and hot herbs are used to treat cold syndrome, and cold and cool herbs are used to treat heat syndrome. In addition, neutral herbs, such as liquorice, which has mild effects without obvious cold or hot properties, can be used for both cold and heat syndromes.
2. Five Flavors
2.1. Concept of five flavors
Five flavors are pungent, sweet, sour, bitter and salty tastes of herbs, representing their different effects. In addition, tasteless and puckery flavors still belong to five tastes.
2.2. Determination of five flavors
Five flavors are determined by actual tasting and experience of clinical applications. Therefore, five flavors as a theory of herb properties are far beyond the concept of tasting sensations but closely linked to effects of herbs. That is the reason why flavors recorded in books on herbology are sometimes different from actual tasting sensations.
2.3. Effects of five flavors are briefly described as follows:
Pungent flavor herb has the effects of inducing diaphoresis, promoting flow of qi and blood circulation. Pungent herbs include ephedra (Ma Huang), purple perilla (Zi Shu), aucklandia root (Mu Xiang), cyperus tuber (Xiang Fu) and green tangerine orange peel (Qing Pi) as well as chuanxiong rhizome (Chuang Xiong), Chinese angelica root (Dang Gui) and safflower (Hong Hua), etc.
Sweet flavor herb has the effects of tonification, relieving spasm and gentling other herbs, including astragalus root (Huang Qi), prepared rehmannia root (Shu Di Huang) and polise antler (Lu Rong), White peony root (Bai Shao), liquorice (Gan Cao) and malt extract (Yi Tang) as well as Chinese date (Da Zao).
Sour flavor herb has the astringent effect of suppressing sweating, arresting bleeding, relieving diarrhea and controlling nocturnal emission. Sour herbs include white peony root (Bai Shao) and schisandra fruit (Wu Wei Zi), dogwood fruit (Shan Yu Rou), black plum (Wu Mei) and Chinese gall (Wu Bei Zi) etc.
Bitter flavor herb has the effects of eliminating dampness, lowering rebellious qi, purging heat and relaxing the bowels, such as apricot kernel (Xing Ren) and lepidium seed (Ting Li Zi), pinellia tuber (Ban Xia) and tangerine peel (Chen Pi) etc.
Salty flavor herb has the effects of softening and resolving hard lumps to treat scrofula, subcutaneous nodule, mass in the abdomen, and other pathologically formations, such as seaweed (Hai Zao), oyster shell (Mu Li), fresh water turtle shell (Bie Jia) and eupolyphaga (Man Cong). In addition, it is said that "salty herbs act on blood'' and "salty herbs act on the kidney''. Therefore, some herbs with the effects of removing heat from blood and tonifying the kidney taste salty.
In addition, tasteless flavor belongs to sweet with the effect of inducing diuresis to remove dampness. Tasteless herbs include poria (Fu Ling) and lophatherum (Dan Zhu Ye). Puckery flavor belong to sour has the effect of astringency. Puckery herbs include dragon's bone (Long Gu) and cuttlefish bone(Wu Zai Gu).
Natures and flavors reflect properties and the principle of applications in limited aspects. Therefore, only by combining natures with flavors, can the properties be comprehensively grasped. For example, both scutellaria root (Huang Qin) and dried rehmannia root (Di Huang) are cold with the effect of clearing heat. However, scutellaria root, bitter in taste and cold in nature for clearing heat and dampness, is indicated for damp-heat syndrome; while dried rehmannia root, sweet in flavor and cold in nature for clearing heat and nourishing yin, is indicated for yin deficiency and interior heat syndrome. All the herbs for relieving exterior syndrome belong to pungent flavor. However, herbs, pungent in flavor and warm in nature for relieving exterior syndrome, are indicated for wind-cold type of common cold; while herbs, pungent in flavor and cool in nature for relieving exterior syndrome, are indicated for wind-heat type of common cold. It can thus be seen that natures and flavors are inseparably linked to each other.

Part 2 Effects of Lifting, Lowering, Floating and Sinking
Lifting, lowering, floating and sinking refer to curative effects of herbs relative to the tendency of illness. Only by grasping lifting, lowering, floating and sinking effects of herbs and according to different causes and states of illness, can physicians correctly use herbs to eliminate pathogenic factors, restore Qi and purge heat, enable patients to recover from illness.
The tendency of disease development can be downward, upward, inward or outward. For example, downward chronic diarrhea with proctoptosis, upward vomiting with hiccup, inward exopathy with anhidrosis, and outward spontaneous perspiration with night sweating, are all of obvious tendency of illness. Herbs for the above-mentioned syndromes correspondingly have lifting, lowering, floating and sinking effects. For example, astragalus root (Huang Qi) for diarrhea with proctoptosis has lifting effect; pinellia tuber (Ban Xia) for vomiting with hiccup has lowering effect; ephedra (Ma Huang) for inducing sweating and dispel exogenous pathogenic factors has floating effect; and oyster shell (Mu Li)for astringency and hidroschesis has sinking effect.
Lifting is the opposite of lowering; and floating is the opposite of sinking. Lifting means ascending and elevating; lowering means moving downward and lowering the adverse flow of Qi; floating is moving outward and dispersing; and sinking is descending and removing water retention and inducing diuresis. In generally, properties of lifting upward and floating outward have the effects of lifting Yang and arresting diarrhea, inducing sweat and dispelling exogenous pathogenic factors, promoting eruption and inducing vomiting, and may be indicated for deficiency of Qi and sinking of Qi of middle jiao. Properties of Sinking inward and lowering downward have the effects of calming the liver, removing heat from the lung, arresting vomiting, relieving asthma, easing the bowels, and are indicated for hyperactivity of the liver-yang, flaring up of the heart-fire, reversed flow of Qi in the lung and stomach, etc..
Lifting, lowering, floating and sinking effects of herbs are apparently linked to their natures and flavors. Generally, pungent, sweet, warm and hot herbs mostly have lifting and floating effects; sour, bitter, salty and cold herbs mostly have sinking and lowering effects; flowers and leaves being light mostly have lifting and floating effects; and minerals and shells being heavy mostly have sinking and lowering effects. However, there are some exceptions.
In addition, lifting, lowering, floating and sinking effects of herb are also linked to preparation, compatibility and other factors.

Part 3 Meridian Tropism
Herbs have strong affinity to internal organs and meridians. Meridian tropism means what area the herb acts on. A remedy used to treat diseases of one meridian or several meridians is called acting on the meridian or the meridians.
The theoretical basis for meridian tropism of herbs is the theory of zang-fu, and the basis for practice is that the curative effects of meridians and collateral play the role physiologically of linking various organs of the human body from exterior to interior. Therefore, exterior syndrome influences the internal organs, and interior syndrome can be reflected on the exterior. Through synthesis and analysis of the 4ata gained with the four methods of diagnosis, the meridians in the internal organs with pathologic change can be determined. Through the curative effect of a herb, what meridians the herb acts on can be determined. For example, irritability and insomnia, sore in the mouth and on the tongue, and difficulty and pain in urination with dark yellow urine belong to excessive heat in the heart meridian. Coptis root (Huang Lian), lophatherum (Zhu Ye) and fiveleaf akebia (Mu Tong) used to treat the syndrome certainly act on the heart meridian.
The theory on meridian tropism in combination with therapeutic effects enables beginners to grasp properties and practitioners to choose herbs in term of meridians in clinical practice. For example, although scutellaria root (Huang Qin), coptis root (Huang Lian) and phellodendron bark (Huang Bo) have the same effects of purging heat and fire, they act on different meridians: scutellaria root (Huang Qin) on the lung meridian, coptis root (Huang Lian) on the heart meridian, and phellodendron bark (Huang Bo) on the kidney meridian. Therefore, scutellaria root is for cough due to the lung heat, coptis root is for excessive heat in the heart and stomach, and phellodendron bark is for hyperactivity of the ministerial fire.
Meridian tropism of herbs is inseparably linked to their four natures and five flavors as well as lifting, lowering, floating and sinking effects. Remedies acting on the same meridian can have different natures and flavors as well as quite different effects of lifting and lowering. For example, although ephedra (Ma Huang), dried ginger (Gan Jiang), scutellaria root (Huang Qin) and Dang Shen act on the same lung meridian and are used to treat cough. Ephedra being pungent and warm for facilitating the flow of the lung-qi to relieve asthma is used to treat cough and asthma due to wind-cold dried ginger being pungent and hot for warming the lung to reduce watery phlegm is used to treat cough and asthma due to cold-phlegm. Scutellaria root being bitter and cold for removing heat from the lung is used to treat cough due to lung-heat; and Dang Shen being sweet and neutral for supplementing the lung-qi is used to treat chronic cough due to deficiency of the lung. Therefore, meridian tropism should be comprehensively understood in combination with four natures and five flavors as well as lifting, lowering, floating and sinking effects.

Part 4 Toxicity
Toxicity is referred to as harmful effects or toxic effects of herbs on the human body. Attention should be paid to this problem in grasping herb properties of remedies.
Poisonous is different in their toxic effects. Therefore, herbs are distinguishably marked by "slightly toxic'' or "extremely toxic'' in books on herbology of all ages. In general, the toxic dose of a poisonous herb is close to its therapeutic dose with a relatively small safety coefficient in its clinical use. If used improperly, a poisonous remedy could cause severe damage to tissues and organs of the human body and even lead to death. Therefore, when using a toxic remedy, an extremely toxic one, in order to guarantee its safety dose, physicians should pay attention to the following points:
1. The dose of a poisonous herb should be strictly controlled.
An excessive dose is one of the main causes for intoxication of Chinese herbs. Therefore, when using a toxic herb, physicians should strictly control its dose based on the patient's age, constitution and the state of illness, and stop using it before going too far. Toxic herbs should not be taken in an excessive dose or for a long time in order to avoid excessive or accumulative intoxication of Chinese herbs.
2. Attention should be paid to use the toxic herbs correctly.
The key point to preventing intoxication of herbs is to use different herbs in different way. Some toxic herbs should be taken in pill or powder but not in decoction; some should be externally applied but not be orally taken; and some should be decocted for a long time. Intoxication is often clinically caused by the improper use of a toxic herb. For example, intoxication of Sichuan aconite root or prepared aconite root is mainly attributed to inadequate decoction.
3. Preparation technique should be followed
One of the objects of preparation is to reduce or eliminate the toxic effects of 4rugs. Therefore, strict technology of preparation and scientific standard of quality are important guarantee for safe use of Chinese herbs in clinical practice.
In addition, specific attention should be paid to appropriate compatibility and avoiding incompatibility.
Everything has its duality, and so has herb toxicity. The therapy of attacking toxicity with poisonous remedies is often used to treat scrofula, malignant lump and tumor.

Section 4 Applications of Chinese Herbs
Attention should be paid to the clinical use of Chinese herbs, including compatibility, contraindication, dosage and administration.
1. Compatibility
Compatibility of herbs means the combined use of more than one herb according to treatment needs.
The pathogenesis and development of illness are often complicate and changeable with manifestations that deficiency and excess syndromes are simultaneously seen, cold alternates with heat, and several diseases coexist. It is difficult for various symptoms to be treated with a single herb. Therefore, appropriate compatibility, a main method of the clinical use, can enhance their curative effects, expand the scope of their applications, reduce their toxic effects, to suit the complicate state of illness.
Predecessors summarized six kinds of variations in herb compatibility, which plus that being used alone without combination are called "seven different combination"
Single Remedy Alone: A single herb can be used to cure a disease. For example, Qingjin Powder made from scutellaria root alone can be used to cure hemoptysis due to lung-heat.
Synergism: Herbs with similar effects used together can strengthen their curative effects. For example, atractylodes rhizome (Cang Zhu) and white atractylodes rhizome (Bai Zhu) used together can strengthen the effects of removing dampness and tonifying the spleen.
Assisting: When a main herb is used in combination with another auxiliary herb, the auxiliary herb can strengthen the effect of the main herb. For example, poria can strengthen the effects of astragalus root to strengthen the spleen and induce diuresis. Their combination is called poria assisting astragalus root.
Restraint and detoxication: Restraint and detoxication are two aspects of one combination. For example, fresh ginger can detoxify pinellia tuber(Ban Xia). Their combination is called pinellia tuber (Ban Xia). being restrained by fresh ginger and fresh ginger (sheng Jiang) detoxifying pinellia tuber (Ban Xia).
Antagonism: Herbs used together can reduce their curative effects. For example, when used together, radish seed can weaken the effect of ginseng to supplement Qi.
Increasing Toxicity: Herbs used together can strengthen their toxic effects or produce new toxicity, such as herbs in "eighteen incompatible medicaments''. Among the above-mentioned compatibility, synergism and assisting should he fully used in clinical practice to enhance curative effects; restraint and detoxication can be used to detoxify poisonous herbs; and inhibition and increasing toxicity, belonging to incompatibility of herbs, should be prevented from reducing curative effects or producing toxic reactions.
2. Contraindications
Herbs have their duality of curative effects and toxic effects. To use their curative effects and avoid their toxic side effects are the basic principle for making up a prescription. To avoid toxic effects is called contraindications, including in compatibility of herbs and contraindication in pregnancy.
1.l. Incompatibility of Herbs:
Antagonism and increasing toxicity belong to contraindication. Incompatible drugs are differently recorded in books on herbology of all ages and generally recognized in later ages as "eighteen incompatible medicaments" and "nineteen medicaments of mutually increasing toxicity'' which have great influence. In "eighteen incompatible medicaments'' it says that: Sichuan aconite root (Wu Tou) is incompatible with pinellia tuber (Ban Xia), trichosanthes fruit (Gua Lou), fritillary bulb (Bei Mu), ampelopsis root (Bai Lian) and heacintbletilla (Bai Ji); liquorice (Gan Cao) is incompatible with seaweed (Hai Zao), knoxia root (Da Ji), kansui root (Gan Shui) and genkwa flower (Yuan Hua); and veratrum root (Li Lu) is incompatible with ginseng (Ren Shen), ladybell root (Sha Shen), red sage root (Dan Shen), scrophularia root (Xuan Shen), flavescent sophora root (Ku Shen), asarum herb (Xi Xin) and peony root (Shao Yao). In "nineteen medicaments of mutually increasing toxicity'' it says that: sulphur (Liu Huang) is antagonistic to crude mirabilite (Mang Xiao); mercury (Shui Yin) to white arsenic (Pi Shuang); langdu root (Lang Du) to litharge (Mi Tuo Shen); croton seed (Ba Dou) to morning glory seed (Qian Niu Zi); cloves (Ding Xiang) to curcuma root (Yu Jing); Sichuan aconite root (Chuan Wu Tou) and wild aconite root (Cao Wu) to rhinoceros horn (Xi Jiao); crystalized mirabilite (Ya Xiao) to burreed tuber (San Leng); cinnamon bark (Rou Gui) to red halloysiie (Chi Shi Zhi); and ginseng (Ren Shen) to trogopterus dung (Wu Ling Zhi). "Eighteen incompatible medicaments'' and "nineteen medicaments of mutually increasing toxicity'' are recorded in books on herbology of all ages. Chinese Pharmacopeia stipulates that incompatible herbs should not be used together. However, judged by actual conditions, either ancient use or modern researches of Chinese herbs, there has been no unified recognition on whether incompatible herbs can be used together or not. This problem needs further clinical and experimental studies. At present, it will be better to not use Chinese herbs together blindly.
1.2. Contraindications in Pregnancy:
Some herbs can damage the primordial Qi of fetus and even cause mis-carriage. Therefore, women in pregnancy should be careful to use pungent and dry herbs with the effects of relieving Qi and blood stasis, such as unripened bitter orange (Zhi Shi), peach kernel (Tao Ren), rhubarb (Da Huang), prepared aconite root (Fu Zhi) and Chinese cassia bark (Rou Gui). And they should be prohibited to use herbs with strong toxicity or drastic effect, such as croton seed (Ba Dou), kansui root (Gan Shui), nux-vomica seed (Ma Qian Zi) and burreed tuber (San Leng).
Contraindicated herbs should absolutely be prohibited; and carefully used herbs should not be used unless obliged and safety is guaranteed.
In addition, there are contra-syndromes for herb applications and food taboo under which patients should be prohibited to eat certain food during the herb taking period.
3. Dosage
The dosage indicated in this book refers to the amount of a dry raw herb in a decoction orally taken by an adult per day.
Whether the dosage of an herb is proper or not directly influences its curative effect and safety use. For example, it is difficult for small dosage to cure severe illness; and in light illness the vital qi is prone to be damaged. The excessive dosage is one of the common causes for intoxication of Chinese herbs.
Therefore, reasonable dosage is important. How to determine the dosage of herbs is related to the following factors:
3.1. Properties: Neutral, heavy and non-toxic herbs (minerals and shells) should be used in large dosage; drastic, light and toxic herbs should be used in small dosage. In addition, some rare and expensive herbs, such as rhinoceros horn, cow bezoare and musk, should be used in small dosage.
3.2. State of illness, Age and Constitution of the Patients:
In general, large dosage should be used for the patients with acute and heavy illness; and small dosage for the patients with mild and light illness. For old and weak patients, tonifying herbs should be used in large dosage; and for eliminating pathogenic factors in small dosage.
3.3. Compatibility and Combination:
A single herb should be used in large dosage; and herbs in a complex prescription in small dosage. Herbs in decoction should be used in larger dosage than in pill and in powder.
The dosage of Chinese herbs is calculated mainly in weight. In the past, an obsolete system of weight was used in China with 1 Jin equal to 16 Liang and 1 Liang equal to 10 Qian. At present, the metric system of weight has been introduced with gram as the unit. The obsolete system of weight can be approximately converted into the metric system of weight: 1 Liang is equal to 30 grams; 1 Qian is equal to 10 grams; and 1 Fen is equal to 0.3 gram. For children over 6 months and under 5 years old, herbs can be used in a half and a quarter of an adult dosage respectively. Smaller dosage should be used for babies and infants.

4. Administration
The administration of Chinese herbs mainly refers to the methods of making a decoction, points for attention and specific methods of making a decoction for some herbs.
4.1. Methods of Making a Decoction: It is appropriate to use an earthenware pot for making a decoction. Before decocted, herbs should be soaked in cold water in the pot for half an hour with water just submerging the Chinese medicines. A dose of Chinese herbs is generally decocted two times, and 250-300 milliliters of strained herbal tea is taken each time.
The decocting time varies with herbal properties. For example, diaphoretics and aromatics should be decocted with a strong fire for a short time, boiling for 35 minutes; and tonics should be simmered, boiling for 30-60 minutes.
Because of their different properties, some herbs should be decocted with specific methods:
To be decocted ahead:
Some minerals and shells with their active ingredients difficult to dissolve in water, such as talc (Hua Shi), dragon's bone (Long Gu), oyster shell (Mu Li) and pearl shell (ZhengZhu Mu), should be kept boiling for 20-30 minutes before other herbs are added.
To be decocted later:
Some aromatics with their active ingredients easy to volatilize, such as peppermint (Bo He), amomum fruit (Sha Ren) and sweet wormwood (Qing Hao), should be added after other herbs have been kept boiling for 5-10 minutes, in order to prevent their active ingredients from escaping.
To be wrapped for decoction:
Some herbs in fine powder or with fine hair, such as talc(Hua Shi), plantain seed (Che Qian Zi) and inula flower (Xuan Fu Hua), should be wrapped in a piece of cloth before decocted with other herbs in order to prevent stimulation of the throat by turbid herbal tea to cause cough.
To be decocted alone:
Some expensive herbs, such as ginseng (Ren Shen), American ginseng (Xi Yang Shen) and rhinoceros horn(Xi Jiao), should be decocted alone. Their herbal tea should be taken alone or after mixed with other herbal tea.
To be taken following infusion with warm boiled water:
Some herbs with their active ingredients difficult to dissolve in water or easy to be destroyed after decocted, such as omphalia(Lei Wan), hairy vein agrimony(He Cao Ya) and cinnabar (Zhu Sha), should be made into fine powder for oral taken following infusion with warm boiled-water or with hot decoction. Some expensive herbs are often ground into powder for oral taken following infusion with warm boiled-water in order to save medicinal materials.
To be melted:
Gluey herbs, such as donkey-hide gelation, tortoise-plastron glue and malt extract, should be dissolved in boiling water or in a decoction before oral administration in order to prevent them from sticking on the pot and turning charred when decocted with other herbs.
4.2. Methods of Taking:
For decoction, generally one dose is decocted and take two times each day. Patients with acute and heavy illness can take two doses a day, and those with chronic diseases can take a dose in two days or every other day.
Time for taking herbs:
In general, tonics should be taken before meals; Irritant to the stomach and intestine should be taken after meals; anthelmintics and cathartics (purgatives) should be taken when stomach is empty. Antimalarial herbs should be taken two hours before the patient has a fit of malaria; sedatives should be taken before going to bed; patients with acute diseases take at any time; and patients with chronic diseases take herbs on time or drink decoction instead of tea.
Besides decoction of Chinese herbs, there are pill, powder, soft extract, granule or powder to be taken after infused in warm boiled water, and syrup. In recent years, tablet and injection of Chinese herbs have been developed. Their characteristics and administrations are shown in detail in Pharmacology of Traditional Chinese Medical Formulae.