THE LESSONS OF SHENNONG
The Basis of Chinese Herb Medicine
Shennong (the Divine Farmer) is the legendary originator of Chinese herbal medicine. It is believed that he was first known as Yan Di (Emperor of Fire), which is why he eventually became known by the full title Yandi Shennongshi (1). His depictions are numerous, mostly appearing as a leaf-draped recluse or a buffalo-horned guardian of the agrarian way of life (the water buffalo was used in virtually all farming activities, especially to pull plows through marshy rice fields; Shennong is credited with developing grain agriculture).
Paintings (left, from India; right from China) of Shennong; typically he has two "horns" at the top of his head, and is adorned with leaves, with a plant in his hand to be tasted.
Giant stone statue of Shennong in Shennongjia, Hubei Province.
Water buffalo pulling a plow through marshy rice fields.
There are two sites in China attributed to the origin of Shennong. The place that seems most likely to be the actual home of Shennong is near the eastern border in what is today Shaanxi Province, along the Jiang River, southwest of the Qi mountains. East and slightly north of the ancient Chinese capital of Xian lies Hua Shan Mountain, where, legend has it, Shennong was conceived, thanks to the intervention of a "divine dragon." In this area (now Fufeng county), an ancient civilization existed, and sophisticated artworks of metal construction have been found dating back nearly 3,000 years (see sample below). The descendents of Shennong have the ancient name Jiang, for the river, and this name is now the 60th most common surname in China. An alternative site for Shennong's home is at Lishan, a mountain in Hubei Province. Hubei is just to the southeast of Shaanxi, and this site is not far from Xian; it is a burial site for the first emperor. There is a cave there, called Shennong Cave, marking the area where he is believed to have lived. It is possible that descendents of Shennong established a home in this area, giving rise to the idea that it was a birthplace of Shennong.
|Left: An artifact at the Shanghai Museum from about 800-900 B.C. found in the area where Shennong is believed to have lived (Fufeng County, Shaanxi).|
Right: A vessel from the same time period and region (Shaanxi Province, Western Zhou Dynasty) for preparing and storing liquids, like those made from herbs.
Shennong is said to have helped people transition from a diet of meat, clams, and wild fruits, to one based on grains and vegetables, and for developing herbal medicine. In addition to promoting agriculture (Shennong is translated as divine farmer), he is recognized for tasting hundreds of herbs-on one day, more than 70 herbs that had medicinal value-selecting those that were suitable as remedies, and describing their properties. As a result of his efforts, numerous herbs became routinely used for health care, and the knowledge was handed down by oral tradition for centuries. When these herbs were described in a formal manner, the book was named after Shennong, known today as the Shennong Bencao Jing (Herbal Classic of Shennong). The earliest mention of a text called Shennong Jing (Classic of Shennong) is by authors who lived during the period immediately following the fall of the Han Dynasty (220 A.D.), suggesting that it might have been compiled during the latter part of the Han Dynasty. Further, the text that comes down to us mentions governmental regulations that applied during the latter Han Dynasty, indicating that this is when it was compiled. It is thought that Shennong lived from 2737 B.C. to 2697 B.C., nearly 5,000 years ago; this is why it is common to hear that Chinese medicine has a history of 5,000 years. However, we are able to access little information about how herbal medicines were used prior to the compilation of the Shennong herbal, about 1,800 years ago.
The original Shennong herbal is long gone, but a version that was four chapters long (the first being general essays; the last three were sets of herb monographs) was used by Tao Hongjing (456-536 A.D.) to produce the Shennong Bencao Jing (published around 500 A.D.) that comes to us in copied form today (2). This text has twice as many herbs as the original, arranged by type of material (e.g., minerals, trees, herbs) and by categories of "upper, middle, and lower" grades (see Appendix 1). Sections copied from the original were in red ink, while new materials and commentaries of various herb authorities were written in a black ink, thus preserving a version of the original. An English language reconstruction of the ancient Shennong Bencao Jing has been published (3).
In addition to having a book named after him, Shennong has been honored by having a region rich in plant resources named after him as well: Shennong Jia (literally, Shennong's Bookshelf or Shennong's Ladder). Legend has it that Shennong carried out his investigation of herbs in this area, which is not far from his birthplace (4).
Shennong Jia is a high plateau of central China with mountain ridges and rivers crisscrossing the area. The main forested area is in northwest Hubei Province, near Shaanxi, lying between the Yangtze River and the Han River. This area has become famous today as a place where the "bear man" (like "bigfoot" or "yeti," sometimes referred to as abominable snowman) resides. There are six mountain peaks that are about 3,000 meters high, the highest peak being 3,105 meters (nearly 10,000 feet). A large stream running through the area is called Shennong Stream or Shennong River.
Much of Shennong Jia is now a nature preserve, where there are numerous rare plants; it is known for ginkgo trees, gastrodia lily, tremella fungus, codonopsis, and tang-kuei (5). Altogether, there are about 3,000 plant species in the area, with 34 endangered species under government protection.
Today, practitioners of Chinese herbal medicine (outside of China) frequently study the names and properties of herbs, yet have little or no personal experience of the numerous individual herbs or the formulas that are made from them. This book knowledge is quite sterile compared to Shennong's approach of tasting each herb and experiencing its unique taste and discerning its properties. Thanks to Shennong and the many generations of herb doctors that followed him, as well as the input from modern research, we do not have to fear, in trying out the herbs, experiencing highly toxic ones, as Shennong did. The step of tasting each herb (directly, or cooking up a portion with appropriate dosage) and experiencing its effects is an important one, especially for the approximately 100 most commonly used herbs. Similarly, brewing up herbal decoctions or chewing of pills of standard formulas and tasting them would also be a great benefit, as would taking the herbs in small formulations for a short course of therapy to experience the effects. Herbalists who diligently pursue such a path, and who are careful not to have their own limited experience overshadow the vast experience of all those specialists who have gone before them, can be compared to Shennong and might be said to be his students. By contrast, those who only study herbs by name and recited properties are taking chances with their patients, not knowing, at a deep level, what it is they are prescribing and not understanding the basics of taste, nature, and effect of the herbs.
It is common practice for writers today, when describing Chinese herbs, to mention the classification of herbs into three groups, such as upper (or superior), middle, and lower (or inferior). This system was described by Tao Hongjing in his expanded rendition of the Shennong Bencao Jing. He claims, in the introduction, that this system already existed in the original work. Here is his description of the three types of herbs, as rendered by Paul Unschuld (2):
The nature of the drugs in the upper class is quite capable of expelling illnesses. But the strength and function of these substances is gentle; they do not produce hasty results. If these drugs are consumed over years and months, though, a very beneficial effect is inevitable. All illnesses will be overcome and one's existence will be extended. The way of Heaven is characterized by] humaneness and creation. Therefore, it is said that the effect of these drugs corresponds to Heaven. The 120 drugs of this class should be referred to as representing the months yin, mao, chen, and si [note: these are months of spring and early summer]. They correspond to the time when all things come to life and flourish.
The nature of the drugs in the middle class is more closely connected with curing of illnesses; one mentions them less frequently in connection with the liberation of the body from its material weight. If one takes these drugs to eliminate actual suffering, he should use them quickly; if they are supposed to increase one's life span, they should be taken gradually. Mankind harbors feelings and desires. Therefore, it is said that the effects of these drugs correspond to Man. The 120 drugs of this class should be referred to as representing the months wu, wei, shen, and you [note: these correspond to summer and early autumn]. They correspond to the time of completion and maturity of all things.
The nature of the drugs of the lower class is especially suited for attack. The influences of these drugs with their markedly medicinal effectiveness upset the harmony of the organism. They are not to be consumed over an extended period of time. Once an illness is cured, the intake of such drugs must be stopped immediately. The principle of the Earth is to detain and kill. Therefore, it is said that the drugs of the lower class correspond to the Earth. The 125 drugs in this class should be referred to as representing the months xu, hai, zi, and chou [note: these correspond to late fall and winter]…. The drugs of this class correspond to the decay and final concealment of all things. According to the principles of combining, drugs to prescriptions, the drugs of this class must not be employed one-sidedly. They should be blended in accordance withy a patient's suffering and then act collectively….
These comments may be summarized as in the following table:
|Principles||humaneness and creation||feelings and desires||detain and kill|
|Correspondence||come to life and flourish||completion and maturity||decay and burial|
|Nature||gentle, not hasty||quick or gradual||marked effect|
|Duration of use||months, years||short or long term||short term|
|Effect||protect health, prolong life||eliminate suffering or prolong life||cure illness|
The grouping of the herbs into three categories has been criticized. For example, in History and Development of Traditional Chinese Medicine (6) the authors note that the three levels have demarcations that are too vague and it is often difficult to grasp the criteria used. Thus, longan (longyanrou), which is a mild tonic herb, was classified in the middle level, while melon pedicle (guadi), which induces vomiting, was listed in the top grade. There are many such examples where the classification of the herb doesn't seem to follow the described pattern for the three categories.
The method of herb preparation is not stated in the original Shennong Bencao Jing herb monographs, though preparation instructions for many of the herbs were added by Tao Hongjing in his publication. Some proponents of Chinese herbal medicine suggest that decoctions are the most appropriate and effective form of herb administration. In fact, throughout the history of Chinese medicine, powdered herbs (usually formed into pills, but also used for brief decoction to make a tea) have been widely used. Tao Hongjing gave some instructions about these forms. Here is a section from the first chapter of his book, translated by Paul Unschuld (2):
All drugs used in the preparation of pills or powders must first be cut up into fine pieces. Then they are dried in the sun and pulverized. Whether a drug is to be pulverized individually or together with the other drugs in a prescription is determined by the prescription. For drugs containing a large amount of moisture, such as ophiopogon and rehmannia, the following is applicable. First, they are cut, dried, and pounded individually into small pieces. Remove the fine parts repeatedly, and tear the remaining portions. Then, they are dried again. If shady weather or rain arrives, they may also be roasted over a weak fire until they are dry. One waits a few moments until they have become cool again before they are pounded.
All drugs containing moisture suffer great weight losses during the drying process. For this reason, the amounts must be carefully increased before drying. Weighed again afterwards, the amounts will be correct. This does not apply to drugs used in decoctions or medicinal wines.
Decoctions are boiled gently over a small fire. The amount of water varies with the volume of the prescription. In general, one dou of water is used with twenty liang of drugs, reduced by boiling to four sheng [note: 1 dou = 10 sheng, so reduced to 40% the original volume]. This should serve as a standard. If one wishes to prepare a laxative decoction, by means of slight processing [note: rhubarb root was usually cooked only a short time to preserve its laxative effects], only a small amount of water should be used but a relatively large quantity of the boiled liquid shall be taken. If a restorative decoction is desired, which needs thorough processing [note: tonic herbs were often cooked for an hour or more], a large volume of water is used, boiled long enough so that only a small amount of liquid remains to be taken as medication.
For the monograph on the herb badou (the purgative croton seed), Tao indicated: "It should be pounded to a pulp separately from other possible ingredients in a prescription, and, finally, it is processed into pills and powders." In his introduction to the book, the preparation and dosage of decoctions is not given much further explanation, but for pills, such as those with strong agents like badou and gansui (this is another purgative, euphorbia) as medicinally effective components, he gave details of dosing, referring to the "scripture" of the original Shennong Bencao Jing:
One ingredient, one medicinally effective drug, take one pill the size of small hemp seeds.
Two ingredients, one medicinally effective drug, take two pills the size of large hemp seeds. Three ingredients, one medicinally effective drug, take three pills the size of small beans.
Four ingredients, one medicinally effective drug, take four pills the size of large beans.
Five ingredients, one medicinally effective ingredient, take five pills the size of hare droppings.
Six ingredients, one medicinally effective drug, take six pill the use of wutong seeds [firmiana]
The preparation of pills is determined by the number [of the ingredients].
The reference to "medicinally effective ingredient" is to a potent herb, usually of the lower class, while the other ingredients, though effective, are milder in nature and used to harmonize the activity of the main ingredient. The term applied in Chinese for these effective ingredients is du, which means toxin or poison. However, this epitaph is used as a contrast to the herbs that can be taken in large quantity and repeatedly, which are said to be free of toxins. In the story of Shennong, it is sometimes translated that he consumed "more than 70 poisonous herbs in one day," which is referring to this concept of medicinally effective herbs.