Managing the Dose

In the history of European medicine, the awareness of dosage control in the use of toxic substances can be traced back to antiquity, when Greek physicians noted the danger of prescribing medicines in excess. The importance of dosage control was most explicitly expressed by the Swiss physician Paracelsus (1493–1541), who famously wrote that “all things are poison, and nothing is without poison: the dosis alone makes a thing not poison.” Throughout Western medical history, careful administration of doses has been key to the therapeutic use of poisons.⁴

Classical Chinese medicine also recognized the significance of dose early on in history. In its preface, the Han pharmacological treatise The Divine Farmer’s Classic advises, “If one uses a potent drug to cure illness, they should first start with an amount resembling the size of a millet grain, and stop once the illness is eliminated. If not, double the amount. If still not, increase the amount tenfold. Take the measurement according to the elimination of the illness.”⁵ The amount of a potent medicine, in short, has to be carefully calibrated to the response of the patient.

But this terse statement on dose is still too crude; it sketches a general principle without providing concrete treatment guidelines. Tao Hongjing, in his Collected Annotations, further elucidates the passage. He first warns that when using a potent drug on its own, such as croton (badou) and euphorbia (gansui), one should not recklessly take the maximal dose. He then lays out an elaborate scheme of managing the dose with various combinations of drugs, correlating the amount of a potent drug with the total number of ingredients in a given medicine. The more ingredients with which a potent drug is used, the larger the size of the pill and the greater the number of the pills that Tao recommends.⁶ Compared to the discussion of dose in The Divine Farmer’s Classic that only addresses single-drug therapy, Tao adds more scenarios of compound medicines in his commentary, indicating the rise of such formulas during his time. When suggesting larger doses for multi-ingredient medicines, he probably takes into account the dynamic interaction between these ingredients that curbs the power of the one possessing du.

Furthermore, dosage control relies on a stable system of measurement. Elsewhere in the preface, Tao observes that in his time two weight systems coexisted: an ancient system that was coarse, and a more refined one that developed after the Han period. To clear up confusion, he proposes to adhere to the latter system in pharmaceutical preparation to ensure the proper measurement of ingredients.⁷ In the case of measuring potent drugs, Tao offers additional advice. For example, he specifies that when using the du-possessing fruits of croton (badou), an evergreen tree growing in the southwest, one must first remove the pits and skins, and then weigh them using one fen to calibrate sixteen pieces of the fruit. This method bypasses the variations introduced by different sizes of fruit, thereby granting a more precise measurement.⁸

Besides these general guidelines on dosage control, Tao also underscores the danger of overdosing in many of his drug entries. Intriguingly, he points out the risk of taking several hallucinogenic drugs. An herb called “the seed of derangement” (langdang zi, henbane), for instance, could effectively treat mania. Ingested in excess, however, the drug would cause a person to “run madly.” So Tao warns that one must not exceed the suggested doses of the drug. That said, if the drug is taken in small quantities over a long period of time, it could strengthen the body and illuminate the mind. Dose is thus the key factor that could turn the same herb into something curative, harmful, or invigorating.⁹ Moreover, Tao particularly emphasizes the problem of consuming certain foods without restraint. Among many cautionary instructions are that immoderate eating of pork could lead to sudden obesity, too much apricot could injure tendons and bones, and eating salt without limit could harm the lungs and induce coughing. Even for these ostensibly benign substances, the price of neglecting proper doses is high.¹⁰

How should an incident of drug overdose be treated? Tao recommends a list of items that can help to alleviate the symptoms. These include egg yolks, the juice of the indigo plant, mud, water from rinsed rice, and juice from fermented beans, among many others. Notably, most of these substances are ordinary things that could be readily found in a household. Besides treating overdose in general, such commonplace agents could also counter specific types of poisoning, such as spider bites or aconite poisoning. Their easy accessibility probably made them fitting antidotes for handling emergencies.¹¹

Combining Drugs

Aside from dosage control, the combination of drugs was another major technique for the safe use of potent medicines, a concept already discernable during the Han dynasty. The rules for combining drugs depended on the structure in The Divine Farmer’s Classic that has already been discussed. It divides its 365 drugs into three groups, each linked to a specific rank: drugs at the top are the lords; those in the middle are the ministers; those at the bottom are the assistants and envoys. The text then recommends that when combining drugs, one should use one lord, two ministers, and five assistants. One could also use one lord, three ministers, and nine assistants.¹² An effective therapy, like the successful rule of a state, required the cooperation of its constituents.

The correspondence between drug combination and bureaucratic organization is a clear example of the strong influence of political thought on medical writing in early China.¹³ In particular, the Han empire established an ideology rooted in the resonance between the cosmos, the state, and the body of the ruler. In this correlative system, a monarch should properly align his body with and model his ways of governance on the patterns of the cosmos. This microcosm-macrocosm resonance promised not just the vitality of the physical body but also the stability of the political body.¹⁴ As a result, medical works during the Han period are replete with political associations. The Yellow Emperor’s Inner Classic, for instance, assigns an office to each of the twelve organs: the Heart is the office of the lord, the Lungs the office of the minister, the Liver the office of the general, and so forth. When these offices work in harmony, a healthy body is sustained.¹⁵ Drug combination in Han materia medica writings provides another example of this correlative thinking. When the body is in disarray, properly coordinated drugs/officers are dispatched to restore health.

Political alignment, however, was not the only way of perceiving drug relationships during the Han dynasty. Another scheme that stood out was “the seven dispositions” (qiqing), which used the analogy of human interaction to define drug relations. The Divine Farmer’s Classic presents the seven scenarios as follows: drugs that act on their own, ones that need each other, ones that assist each other, ones that fear each other, ones that hate each other, ones that oppose each other, and ones that kill each other.¹⁶ Except for the first type, which refers to single-drug therapy, all the other six dispositions characterize drug combinations with distinct effects, ranging from mutual facilitation to mutual annihilation. The word “disposition” (qing) merits our attention. In contrast with political organization discussed above, it points to interpersonal relationships. Qing was an important concept in early Chinese thought as disparate definitions emerged out of intellectual debates during the Han period. Some literati understood qing to describe the passions or emotions of an individual that required proper control; others took qing to be the ways in which one spontaneously responded to specific situations in order to align the self with the natural patterns of the universe.¹⁷ Qing in The Divine Farmer’s Classic meant something still different: rather than referring to sentiments or natural reactions at the individual level, it described the ways people interacted with each other. Qing was thus a relational concept in the Han pharmacological treatise. That is, a given medicine had no fixed character; its effect would vary greatly depending on the other medicines with which it worked in tandem.

Let us take a closer look at these relationships. In his Collected Annotations, Tao Hongjing offers further explanations of them, together with a list of 141 drugs, each with its combinatorial scenarios.¹⁸ The first two dispositions—mutual need (xiangxu) and mutual assistance (xiangshi)—concern the relationship of two drugs that each enhance the power of the other. In the case of mutual need, the second substance is absolutely required to make a drug work. Tao often identifies these necessary agents as fire, water, or alcohol, indicating the importance of preparing a drug to release its power. In the case of mutual assistance, the second drug could boost the activity of the first one, though it was not essential for efficacy. Sometimes, this involved the use of two potent drugs, such as the combination of gelsemium (gouwen) and pinellia (banxia). In other cases, ordinary substances were harnessed as “assistants,” such as the use of soybeans to activate stellera (langdu), an herb possessing great du.¹⁹ Tao comments that drugs combined according to mutual need or mutual assistance need not necessarily be of the same type. The combinations resemble cooking, where fish, meat, scallion, and fermented beans are mixed together to bring out the qualities of one another.²⁰

The last four types of relationship—mutual fear (xiangwei), mutual hatred (xiangwu), mutual opposition (xiangfan), and mutual killing (xiangsha)—seek to constrain a drug’s power, with varying degrees of inhibition offered by the second drug. Although The Divine Farmer’s Classic discourages the use of mutual hatred and mutual opposition in combining drugs because they diminish the power of medicines to the degree that they are not efficacious anymore, Tao does not consider this an absolute rule. If two generals dislike each other, he muses, they can still jointly support the same kingdom. Similarly, although the power of two drugs is reduced, they can still collectively benefit the body.²¹ Tao also points out the subtle differences between these two types of combination. For mutual hatred, the inhibition is one-way only—dragon’s bone (longgu)²² suppresses bovine bezoar (niuhuang), yet the latter enhances the former. Tao explains this using a human analogy: “Although a person hates me, I have no resentment.” Mutual opposition, by contrast, is bidirectional—the two “people” are enemies. For example, when orpiment (cihuang) and barbarian powder (hufen)²³ meet, they become “gloomy and jealous.” As a result, barbarian powder blackens, and orpiment also changes color.²⁴ In the case of potent drugs, the scenario of mutual fear, in which a second drug is required to assuage the potent one without neutralizing its power, is most relevant. For example, whenever using pinellia, Tao stresses that one must add fresh ginger to curb its potency.²⁵ Without this strategy, the herb is simply too dangerous to ingest.

Finally, the scenario of mutual killing signals the annihilation of the activity of both drugs. This combination, evidently, does not carry therapeutic value. Instead, the goal is to use an antidote to counter a poison. In addition to identifying the medical benefits of poisons, classical Chinese pharmacy recognizes many types of poisoning and offers cures. In fact, Tao provides a list of antidotes in his work to treat cases of poisoning that are derived either from animal attacks (snakebite, beesting, etc.) or from the inept use of powerful medicines.²⁶ Small wonder that the substances that make potent drugs “fear” overlap with those that “kill” poisons. Examples include licorice, soybean, fresh ginger, ginseng, and the juice of the indigo plant. Dosage is probably the key factor that allows the same substance to work in these two distinct fashions.

Other than dosage control and drug combination, early works of materia medica in China discuss two more factors that condition the use of drugs. First, the method of delivery mattered. According to The Divine Farmer’s Classic, drugs could be made into pills, powders, decoctions derived from boiling in water or from soaking in alcohol, and pastes formed by pulverizing the ingredients. Each drug could be prepared in one or several of these forms, following strict rules.²⁷ In general, the liquid forms were thought to deliver the effect of a drug faster than the solid forms, because the former could be easily assimilated into the body. For this reason, drugs possessing du were often taken as pills or powders to forestall too vehement a blow to the body. Consistent with this rationale, Tao offered a list of drugs, many of them potent, that he deemed inappropriate for use in decoction.²⁸

Second, the effect of a given drug could vary with the state of a particular body. In his Collected Annotations, Tao notes that, although a drug’s properties were the foundation for its healing power, physicians should also pay attention to the specific condition of a patient’s body. For example, they needed to take into account whether a person was deficient, thus requiring replenishment, or replete, thus requiring draining;²⁹ whether a person was male, female, old, or young; whether a person was sad, happy, vigorous, or exhausted. They should also consider the place where the patient lived and their way of life. All these individual traits could affect the working of drugs. To support this view, Tao offered the example of Chu Cheng, an eminent physician of his time, who treated widows and nuns differently from wives and concubines. In this case, the sexual activity of a woman changed her body to the degree that it required a modified therapy.³⁰

Processing Aconite

Many drugs were often subject to various degrees of processing before they were used. A specific term arose in early pharmaceutical sources that designates this set of techniques: paozhi (roast and broil).³¹ As a result, we find two major types of drugs in Chinese pharmacy: the raw (unprocessed) and the cooked (processed). The latter group included many potent drugs that relied on these techniques to attenuate their power.

How did drug processing in China begin? The etymology of the term paozhi offers a clue. Both characters contain the radical for fire, indicating the involvement of heating. According to the Han dictionary Explaining Characters, zhi means placing meat on fire. The meaning of pao is similar but more specific, referring to roasting meat that still has hairs.³² Evidently, both characters denote ways of cooking. The sense of pao as a roasting method can already be found in the first poetry collection in China, The Book of Odes (Shijing, ca. 1000 to ca. 600 BCE), in which one poem depicts a host roasting the head of a rabbit to welcome his guests.³³ This early source already considers pao and zhi to be two distinct cooking techniques: the former refers to the roasting of a newly killed rabbit that still has hairs on its flesh, while the latter designates the broiling of cut rabbit meat that is still soft.³⁴ Later, pao also acquired the meaning of roasting meat coated with a mixture of mud and reed.³⁵ By the time of the Warring States (476–221 BCE), pao had become such a significant method for cooking that it was used interchangeably with its homophone pao 庖, which means the person who cooks. The borrowing of this word in labeling drug processing suggests a sharing of culinary and pharmaceutical techniques in early China.³⁶

What were the specific techniques and procedures of drug processing? The term paozhi implies the use of fire, an essential component in cooking, yet heating constituted only part of the rich repertoire of techniques for drug preparation. For example, The Divine Farmer’s Classic mentions two ways of drying an herb, under the sun and in the shade, which presumably preserve different levels of moisture in the drug.³⁷ In his Collected Annotations, Tao Hongjing offers more elaborate explanations of these pharmaceutical techniques, including cutting, pounding, grinding, sifting, rinsing, soaking, boiling, and roasting, among others. He pays keen attention to potent drugs, giving detailed instructions on how to prepare croton, pinellia, and aconite.³⁸ Skillful preparation was central to taming these poisons for medical use.

Aconite presents an excellent example to illustrate the importance of drug processing. Touted in Tao’s text as “the lord of the hundred drugs,” it possessed great du and hence required careful preparation. The celebrated medicine encompassed a group of herbs of the Aconitum genus that Chinese sources refer to by a variety of names (fuzi, wutou, tianxiong, cezi, wuhui, jin). It is difficult to precisely identify these plants with species in modern botany given the diverse, sometimes conflicting accounts of them and their shifting referents across disparate sources.³⁹ In general, these names correspond to different parts of the tubers of the plant collected in different seasons of the year. For example, wutou, which literally means “black head,” refers to the main tubers of the herb, harvested in the spring when the side tubers have not yet developed, whereas fuzi, which literally means “attached offspring,” depicts the side tubers that grow in the summer. Tianxiong, which literally means “heavenly champion,” designates a particular kind of main tuber that never produces side tubers (figure 2.1). Accordingly, these different types of aconite were understood to possess varied levels of potency: tianxiong, a plant that consolidated all its medicinal power in its main tubers, was the strongest type, whereas the fuzi side tubers were substantially weaker. Classical Chinese pharmacy attributed distinct medicinal uses to each of these varieties of aconite.⁴⁰

More than fifty species of aconite are used in Chinese medicine today, with Aconitum carmichaelii from northern Sichuan being the most produced.⁴¹ According to modern pharmacology, the main toxic component in aconite is aconitine-type alkaloid: 0.2 mg of it, taken orally, suffices to poison a person, with symptoms of dizziness, nausea, and numbness of the limbs; 3–5 mg may cause death through cardiovascular and neurological failure. When administered in smaller doses, however, aconitine and other alkaloids in the herb can relieve pain, reduce inflammation, and strengthen the heart. The use of aconite today, therefore, hinges on the techniques of moderating the herb’s toxicity while preserving its therapeutic power.⁴²

Evidence for the early medical use of aconite comes from a collection of formulas excavated from Mawangdui in southern China (ca. 168 BCE). Among over two hundred substances that appear in these formulas, aconite, called wuhui, is the second most-used drug (twenty-one times), only surpassed by cinnamon (gui), another du-possessing plant.⁴³ In most cases, aconite is applied externally, often mixed with other drugs, to treat wounds, abscess, scabies, and itching. When taken internally, it acts as a tonic to replenish qi, boost sexual energy, and prolong life. Several formulas also employ aconite to attain the capacity of running with fast speed, evincing its magical power.⁴⁴

Aconite remained popular in the following centuries, with diversified types and altered medical uses. It appears frequently in another set of medical formulas excavated from an unmarked tomb in Wuwei (in present-day Gansu) dating to the early Eastern Han period (25–220). Prominently, among the one hundred substances included in the thirty-six formulas, aconite stands out as the most often used drug (eighteen times in sixteen formulas). Unlike the Mawangdui formulas, which only employed a strong type of aconite (wuhui), the Wuwei formulas primarily used the weaker variety of the plant (fuzi), indicating the rising awareness of the drug’s power during the Eastern Han period. Subsequently, the herb in the latter collection was often ingested to treat internal disorders such as coughing, “cold damage,” and paralysis, whereas its tonic and magical activities receded.⁴⁵ That being said, the Wuwei formulas also prescribed tianxiong, the most powerful type of aconite, to treat male genital disorders.⁴⁶ Consistent with the regular use of aconite in medical manuscripts, wuhui and fuzi also appear in a list of essential drugs from a first-century BCE primer wordbook for children, indicating that the medicinal use of the herb was common knowledge during the Han period.⁴⁷ The drug was fairly affordable at the time, on par with the price of silk products.⁴⁸

Why was aconite so popular in early China? One fundamental guideline of drug therapy in classical Chinese medicine, as established in The Divine Farmer’s Classic, is the principle of opposites, namely, using warming drugs to treat cold maladies and using cooling drugs to treat hot maladies.⁴⁹ Tellingly, aconite is characterized as a substance of great heating power that aims to cure cold conditions such as wind-induced coldness, blood conglomerations, and pain in the joints.⁵⁰ The frequent use of the potent herb during the Han dynasty suggests a prevalent concern among healers about the easy loss of the body’s vital heat. The warming nature of aconite, therefore, enabled it to powerfully dissipate cold and revive the body.

A potent medicine like aconite could easily turn into a lethal poison. This brings us back to the court murder at the opening of this chapter where the herb figured prominently. Although aconite was a versatile drug, the unprocessed tuber was rarely used due to its extreme toxicity. It is quite possible that the physician introduced some raw aconite into a medicine that was supposed to nourish the empress postpartum but ultimately led to her premature death. An intriguing detail of the story is that the empress complained about feeling dizzy after taking the “medicine,” which for us modern readers suggests an alarming sign. Yet medical writings at the time often deemed the strong sensations induced by a potent drug as a marker of its efficacy.⁵¹ This interpretation probably added weight to the words of the physician, who eased the doubts of the empress. The line between medicine and poison is thin; so is that between life and death.⁵²

Because of its potency, aconite must be carefully processed prior to medical use. The Mawangdui and Wuwei manuscripts already mention a variety of methods of preparing the plant, including pulverizing (ye), soaking in alcohol (jiuzi), boiling (zhu), decocting (jian), roasting (zhi), and mincing (fuju), although these Han sources offer no technical details.⁵³ To better understand these pharmaceutical techniques, I now turn to a text that emerged during the Era of Division and offers more detailed accounts. Titled Treatise on Drug Processing from Lord Thunder (Leigong paozhi lun; hereafter, Treatise on Drug Processing), it is the first book devoted to the discussion of drug preparation in China. The dating of the text is debatable—some scholars have considered it to be a work of the fifth century, while others have argued for later dates, during the Sui or Tang dynasty.⁵⁴ The title offers a hint, in that “Lord Thunder” has two possible referents. The name could point to a legendary figure of high antiquity who received the teachings of the Yellow Emperor and became a master in drug processing: this image of Lord Thunder as the founder of Chinese pharmaceutics persisted throughout the imperial era. Alternatively, the name could refer to a historical figure named Lei Xiao, who lived in the fifth century. We know almost nothing about him, except that he was an official in the Liu-Song dynasty established in the south (420–479). He may have written the text based on the teachings of a certain alchemist called Master Yan, as he mentions this name several times in his work.⁵⁵ However, particular drugs discussed in the text, such as refined arsenic (pishuang), were unlikely to have been available in China during the Era of Division.⁵⁶ Most likely, the work took shape over a long period of time, containing a fifth-century core with sections that were added later during the Sui-Tang period.

The treatise contains three scrolls and discusses three hundred drugs altogether.⁵⁷ In each entry, the text elucidates the methods of processing the drug, often combined with guidance on how to properly identify the substance in nature. In the case of aconite, the text distinguishes six different types of the plant (wutou, wuhui, tianxiong, cezi, mubiezi, fuzi), each with a unique morphology. This is followed by a depiction of two techniques of processing the plant:

To process ten liang [about seven ounces] of aconite, roast it in a gentle fire and an intense fire alternately. Eliminate the wrinkles and cracks on the surface of the tuber. Use a knife to scratch off the hairs at the top and eliminate the fine tip at the bottom. Split the tuber. Dig a pit at the southern ground of wu underneath a house, the depth of which could be one chi [about one foot].⁵⁸ Place the aconite inside overnight. Take it out the next morning. Dry it by baking before use. If one intends to roast aconite, do not use fire generated from impure wood. It is most wonderful to use willow wood. To prepare aconite without heating, eliminate the bottom tip of the tuber. Cut it into thin pieces. Use east-flowing water and black beans to soak the pieces for five days and five nights. Then take them out and drain off the water. Dry them under the sun before use. Whenever one uses aconite, one needs to prepare it without heating. Eliminate the tip of the tuber. For every ten liang of aconite, use five liang of raw black beans and six sheng [about 1.8 liters] of east-flowing water.⁵⁹

Aconite can be prepared in two distinct manners: roasting and soaking. They differ in the time consumed and in the level of technical sophistication. Roasting is faster (one day and one night) but requires delicate manipulation of fire and the use of fine resources (willow wood). It also requires the understanding of a divination system that guides the proper positioning of the tuber for its cooling. Soaking takes longer (five days and five nights) but is easier to execute, given that east-flowing water and black beans were not hard to obtain. The text recommends the latter technique for processing aconite, probably because of its simplicity.

But what is east-flowing water (dongliu shui)? Literally, it is water collected from a stream flowing eastward. Such water was deemed to possess the power of purification, an idea that can be traced back to the Han period. According to The History of the Later Han (Hou Hanshu, fifth century), each year in the spring, Han officials and common people went to a river that flowed eastward and performed a cleansing ritual to eliminate the filth accumulated over the preceding year.⁶⁰ This idea was later adopted by Daoist adepts during the Era of Division, especially those interested in alchemy, who valued the purity of the sites where they compounded elixirs. They often built their alchemical chambers deep in the mountains along a stream flowing eastward, and used its water to ingest the prepared medicines.⁶¹ Certainly easy access to water was important for alchemical exercises, yet we cannot ignore its ritual significance, which aimed to cleanse the site, the alchemical products, and the body of the adept. The water likely served a similar function in the preparation of aconite, that is, to cleanse the herb and eliminate its impurities. It is one of the many examples in Treatise on Drug Processing where the text not only discusses material practice in detail but also incorporates ritual thinking prevalent at the time.

Drug Sellers and Medical Markets

Who were the people involved in processing and administering drugs during the formative age of Chinese pharmacology? The History of the Later Han recounts a story of a drug seller named Han Kang, who came from a noble family. He harvested drugs in famous mountains and sold them at the market of Chang’an. For more than thirty years, he was unusual in being totally unwilling to negotiate the set price of any of his drugs. This peculiar behavior had made him famous: when he refused to alter the price of a drug that a woman was trying to buy, she immediately recognized who he was.⁶² If Han refused to haggle at all, what was his motivation for selling drugs?

The key to this puzzle lies in his prestigious family background, which qualified him for government service. Emperor Huan (132–168) sent envoys with lavish gifts as an invitation to Han to serve at court, but he declined the offer and eventually fled to the mountains to avoid worldly duties altogether. Hence, drug-selling became a façade behind which Han could hide his identity and enjoy his eremitic life. Tellingly, this story appears in a collection of biographies under the category of recluses, people who possessed great talents but had no interest in politics. Besides Han Kang, two other hermits in the section also engaged in harvesting drugs in the mountains to support themselves and escape political burdens.⁶³ Picking and selling herbs, in other words, was associated with unconventional ways of living.

Other stories from the Han period depict drug sellers as people possessing extraordinary powers. A person named Ji Zixun sold drugs when he was young and after a century, his facial complexion remained unchanged.⁶⁴ A healer named Duan Yi offered his disciple an ointment for treating a head injury before the incident occurred, revealing his divinatory power.⁶⁵ In another story, an old man hung a gourd in front of his shop when he was selling his drugs at the market. Once the market concluded, he jumped into the gourd. The man later revealed himself to be a master of many kinds of magical arts.⁶⁶ Notwithstanding the fantastic aura of these episodes, they disclose an important feature of drug handlers during the Han dynasty: instead of being devoted specialists, they cultivated multiple skills, often of a magical or occult nature. All these stories appear in a section of The History of the Later Han that offers vivid narratives about a group of people generally referred to as fangshi, who were technical adepts practicing a variety of magical and esoteric arts, including astrology, divination, exorcism, physiognomy, alchemy, and drug therapy.⁶⁷ In comparison to scholars versed in classical learning, these wonder-workers assumed an inferior position in society—standard Han histories treat them as unorthodox and thus less reputable figures, while still depicting their arts with respect. The connection between the preparation of drugs and alchemy was particularly strong, as both activities involved the material practice of transformation.⁶⁸ It is possible that certain fangshi, such as Han Kang, became hermits and prepared drugs not just to shun politics but also as part of their alchemical practices to prolong their lives. Managing drugs during the Han period was thus linked to a marginalized group of adepts who possessed occult knowledge.

The situation changed during the Era of Division, when we see increasing separation of labor between the different aspects of drug harvesting, selling, and usage. In the preface of his Collected Annotations, Tao Hongjing devotes a lengthy section to various methods of preparing drugs. At the beginning of this section, he laments that during his time many drugs were collected from regions south of the Yangzi River instead of from the best sites in the western and northern regions. Due to their inferior quality, these drugs could not effectively cure illness. Tao then remarks:

Furthermore, the marketmen do not understand the properties of drugs; they only pay attention to their shape and adornment. They no longer sell ginseng from Shangdang,⁶⁹ and discard asarum from Huayin like grass.⁷⁰ They each follow certain trends, compete with each other, and comply with formulas, accommodating what is needed [in society]. They cannot extensively provide all types of drugs, hence often leave some out. What remains today is about two hundred types. Many physicians do not recognize drugs upon seeing them, so they only listen to the marketmen. Nor are the marketmen able to discriminate among drugs, so they all rely on those who harvest and deliver drugs. Those who harvest and deliver drugs transmit and learn clumsy methods of managing drugs. Thus, it is hard to distinguish the authentic from the fake, the superior from the inferior.⁷¹

In this passage, Tao identifies three groups of people who act in a chain to handle drugs: those who harvest and deliver drugs (cai song zhi jia), the marketmen (shiren) who sell drugs, and the physicians who prescribe drugs. We know little about the first group, except that their skills are inferior in Tao’s eyes. Besides harvesting drugs, they were probably also involved in processing them, as suggested by the word “manage” (zhi), which also appears in Treatise on Drug Processing.⁷² In his Collected Annotations, Tao also uses another term, “drug specialist” (yaojia), whose work probably overlapped with that of the first group. Tao holds a critical attitude toward them, claiming that in many cases where a drug proved ineffective, it was due to the incompetence of these drug specialists, not the fault of physicians.⁷³ Even worse, these suppliers sometimes produced ersatz drugs to make money. Tao writes down a list of ways to produce these counterfeits: whitening stalactite by boiling it in vinegar, straightening the root of asarum by soaking it in water, sweetening astragalus by steaming it in honey, moistening angelica by sprinkling it with alcohol, gluing the eggshells of the mantis to the branches of mulberry trees,⁷⁴ and dyeing the legs of centipedes red.⁷⁵ What stands out from these examples is Tao’s concern about authenticity: the deceptive behavior of the drug suppliers compromised the medical practice of physicians, a situation he tried to rectify by providing reliable pharmaceutical knowledge in his work.

The marketmen, unlike the sagacious, skilled, and somewhat mysterious drug sellers depicted in Han sources, are cast in a negative light in Tao’s work, perceived as incompetent and greedy. The competition between these men indicates the booming of the drug market in fifth-century China that drove them to attract consumers by cunning strategies—their attention to the look of drugs suggests that the medical uses of these commodities were not necessarily their primary concern. Tao’s attitude toward the drug sellers is mixed. On the one hand, he relies on them to obtain pharmaceutical knowledge. In several cases, he points out the obscurity of a drug based on the fact that even the sellers were not able to recognize it.⁷⁶ On the other hand, Tao criticizes them for their neglect of drug quality, especially for their selling substitute drugs for profit.⁷⁷

The situation was partly an offshoot of the political turmoil during Tao’s days, when the regimes of northern nomadic origin confronted a succession of southern dynasties that Tao was affiliated with. This long-lasting political division impeded the circulation of drugs, leading to the use of ersatz drugs in the south. That being said, markets along the border of the opposing powers allowed a limited exchange of drugs. Previous studies have demonstrated that at least three such markets existed during the fifth century, two in the west—in Liangzhou (present-day Hanzhong in Shaanxi) and Yizhou (present-day Chengdu in Sichuan)—and one on a small island off the east coast, Yuzhou (present-day Lianyungang in Jiangsu). Trade was legal when the two sides were at peace; when political tensions increased, smuggling took the place of open trade.⁷⁸ It is conceivable that the marketmen in Tao’s account visited similar trading centers and brought valuable drugs from afar back to their local customers.

Sitting at the end of the chain of drug flow, finally, were the physicians. Although Tao himself never practiced medicine, he came from a family that had been involved in healing for generations. By compiling Collected Annotations, he hoped to continue his family’s engagement in medical enterprise.⁷⁹ In this context, Tao’s comments on the first two groups of people evince the sentiment of physicians during his days who were concerned about the quality of drugs due to the growth of the market, which distanced them from the source of the medicines they prescribed. By offering elaborate guidelines on the identification and preparation of drugs in his work, Tao sought to clarify the pharmaceutical knowledge that was often opaque to physicians so they would be able to accurately discriminate among drugs and achieve their intended cures.

Tao’s observations were echoed by Xu Zhicai (ca. 492–572), an eminent physician and medical officer during his time. Xu came from an aristocratic family that originated from the area of Donghai (in present-day Shandong) and had practiced medicine continuously for eight generations from the fourth to the sixth century. This exceptionally long medical lineage not only brought social prestige to the family but also gained them political capital; several members of the Xu clan served at the courts of both southern and northern dynasties. Xu Zhicai, for his part, was appointed the “director of palace drugs” (shangyao dianyu) at the court of the Northern Qi dynasty (550–577), a new position that oversaw the administration of medicines for the imperial house.⁸⁰ Among several medical works he compiled, one is titled Drug Correspondences from Lord Thunder (Leigong yaodui), a treatise that describes the rules of drug combination. In the preface, Xu notes that in the past, people who were skilled medical practitioners all harvested drugs by themselves. Those healers examined the properties of the drugs and collected them in the right seasons. If a drug was picked too early, its medicinal power would not yet have developed; if harvested too late, its power would have already diminished. Yet nowadays, he complains, those who practice medicine do not harvest their own drugs. Without knowing in which season a drug should be harvested, they use it indiscriminately. Furthermore, they lack the proper understanding of the cooling and warming properties, administration, and dosage of drugs. As a result, they only desire to cure illness but can never actually obtain the intended results. This is, Xu laments, truly a confusing situation.⁸¹

Xu attributes his colleagues’ insufficient knowledge of drugs partly to their diminished involvement in harvesting, which was likely a result of the separation of labor between collecting, selling, and deploying drugs, as discussed earlier. The distancing of physicians from the sources of their medicines compromised their practice; without knowing the time of a drug’s harvest, they missed a crucial piece of information about its power. Yet Xu was not suggesting his readers should go back to the old days. Given the mushrooming of drugs in Xu’s time and the sophistication of the techniques of preparation, it had become simply impossible for a physician to know how to do everything. To deal with the new challenge, he established a set of standards for the preparation and administration of drugs to guide physicians’ practice. As a court medical officer, he might have produced the text as an institutional response to the chaotic situation of drug usage at the time. Alternatively, considering his family background, it is also possible that he established these pharmaceutical guidelines to assist medical practice in his clan, similar to Tao Hongjing’s efforts. Regardless of his motivation, it is evident that fifth- and sixth-century China witnessed increasing concern among physicians about their alienation from the activities of harvesting and preparing drugs and associated therapeutic knowledge. The emergence of the works of Tao and Xu, then, reflects physicians’ endeavors to retrieve and standardize that knowledge in order to clear up confusions and improve therapeutic outcomes.

Conclusion

Techniques of preparation and usage were essential in transforming medicines, especially potent ones, from the earliest inception of Chinese pharmacology. Rather than being fixed entities with stable functions, these drugs were malleable substances whose effects varied considerably with the adjustment of dosage, with their interaction with other drugs, and with the methods of processing them. Other factors, such as the form of drugs, the place and time of their harvest, and the constitution of an individual body, mattered too. These diverse techniques were pivotal aspects of drug materiality that constituted a central characteristic of pharmaceutical practice in premodern China: physicians were keenly aware of how the effect of any given medicine changed according to the way in which it was prepared and deployed. Technical interventions were particularly important for the medical use of poisons, such as aconite, as it mitigated their potency yet still preserved their therapeutic efficacy.

This fluid materiality of medicines in classical Chinese pharmacy is in sharp contrast to the concept of “active ingredient” or “active principle” in modern biomedicine, where a specific chemical ingredient isolated from a substance is responsible for its effects. Originating in nineteenth-century Europe, the idea has become the gold standard for drug development in modern pharmacology.⁸² In early Chinese pharmaceutical history, however, drugs were not understood to contain such a pure and invariant material core; it was the context of a drug—its interplay with other drugs, its preparation, its mode of acting upon a particular body—that shaped its therapeutic outcome. In this regard, the concept of “drug assemblage” proposed by philosophers Gilles Deleuze and Félix Guattari is relevant. When discussing the function of psychoactive drugs, they challenge the idea of reducing these substances to definitive molecules, and contend that, through dynamic interaction with a fluid body, drugs can produce varied effects that alter a person in myriad ways.⁸³ Similarly, it is better to consider any given medicine in Chinese pharmacy not as an independent, self-sufficient entity but rather as something working in an assemblage, in which its actions are always relational.

These understandings of materiality were put into practice against the backdrop of significant change that took place in the makeup of pharmaceutical practitioners in early China. During the Han period, various aspects of drug management were attended to by fangshi, an eclectic group of adepts who possessed occult knowledge and magical power. Although occasionally summoned by the court to offer their expertise, they largely lingered on the margins of the society, living as hermits. In the fifth and sixth centuries, with the expansion of drugs, we see a growing specialization of pharmaceutical activity that separated the collection and selling of drugs from their usage in medical practice. Concurrently, physicians from aristocratic families with strong political connections dominated the production of medical texts, which often reveal their concerns about the new situation. The proliferation of guidelines on how to identify, collect, and prepare drugs during this period manifested their efforts to standardize pharmaceutical knowledge and improve remedies, thereby securing social and political prestige.

The altered landscape of Chinese pharmaceutics in the fifth and sixth centuries was in addition a partial outcome of political conditions, as hostile regimes in the north and south impeded the circulation of medicines. The situation started to change toward the end of the sixth century, when the unified dynasties of the Sui (581–618) and the Tang (618–907) facilitated empire-wide production and dissemination of drug knowledge. Unlike the preceding centuries, when medical works were compiled by capable and concerned individuals, the state became more involved in medicine during the Sui and early Tang periods, resulting in new institutions, legal codes, and pharmacological texts that oversaw the preparation and use of drugs. In this new era, the therapeutic logic of deploying poisons resonated with political rulings, leading to powerful repercussions in society.