Читать книгу The Greatest Benefit to Mankind: A Medical History of Humanity - Roy Porter - Страница 47

The archetypal system of Indian medicine is called Ayurveda – the knowledge (Sanskrit: veda) needed for longevity (ayus). Ayurvedic teachings amount to a code of life and consist of practical advice concerning all aspects of life, from washing to diet, from exercise to regimen, within a wider Hindu religious philosophy of rebirth, renunciation, and the maintenance of the balance of the soul. Their theoretical foundation lies in the notion of three basic bodily humours (dosas) – wind, bile, and phlegm – which reflect the macrocosmic forces of wind, sun and moon. There are also seven fundamental bodily constituents: chyle, blood, flesh, fat, bone, marrow and semen. The Ayurvedic pharmacopoeia is mainly herbal, prescribing an assortment of therapies including ointments, enemas, douches, massage, sweating and surgery. Though metallic compounds came into medical use from around AD 1000, these remained marginal; opium too was brought in, apparently from Islamic sources, to relieve dysentery. For achieving health, the canonical texts stress temperance in all matters – food, sleep, exercise, sex and medicines themselves. The healthy life is to be consonant with the harmonies of the universe and true religious teachings.

Written in Sanskrit, the earliest surviving Ayurveda texts date from the early centuries of the Christian era; traditional claims among practitioners that Ayurveda dates back thousands of years are pious. Of the various Sanskrit writings that expound the Ayurveda, the earliest are the Caraka Samhita [Caraka’s Compendium] and the Susruta Samhita [Susruta’s Compendium], supposedly the work of the sages Caraka and Susruta. Very substantial in bulk, they form the cornerstone of Ayurveda. A third early text, the Bhela Samhita, survives only in a single damaged manuscript.

The Caraka Samhita tradition is connected with north-western India, and in particular the ancient university of Taksasila; the Susruta Samhita was supposedly composed in Benares on the River Ganges. Their original composition date is a matter of speculation: earlier versions may derive from as far back as the time of the Buddha (early fourth century BC). Caraka may date to around AD 100; Susruta to the fourth century. The Sanskrit texts which became canonical represent the works in the form they had attained around AD 1000.

There are other subsequent prominent Brahminic texts. These include the Astangahrdaya Samhita of Vagbhata (AD C. 600), which includes midwifery, the Rugviniscaya of Madhavakara (AD C. 700), the Sarngadhara Samhita of Sarngadhara (c. fourteenth century AD), and the Bhavaprakasa of Bhavamisra (sixteenth century). Madhavakara’s work broke new ground through rearranging medical topics according to pathological categories, thereby establishing the model of thematic grouping followed by almost all later works. Sarngadhara was the first Sanskrit author to introduce new foreign elements, including opium and metallic compounds, into the materia medica, and the use of pulse lore in diagnosis and prognosis.

The Caraka Samhita and the Susruta Samhita stem from a common intellectual tradition. The Caraka Samhita is marked by long reflective and philosophical passages, including discussions of causality and so forth. The Susruta Samhita for its part contains extensive descriptions of sophisticated surgical techniques: eye operations, plastic surgery, etc., which do not appear in the Caraka Samhita at all or only in less detail. Both are huge compendia of medical teachings on subjects such as a balanced diet; the powers of plants and vegetables; the causes and symptoms of various maladies; epidemic diseases; the right techniques for examining patients; the parts of the body; conception, pregnancy and the way to take care of foetuses; diagnosis and prognosis; stimulants and aphrodisiacs; the nature and treatment of fever, heated blood, swellings, urinary and skin disorders, consumption, insanity, epilepsy, dropsy, piles, asthma, coughs and hiccups and scores of other conditions; cupping, blood-letting, the use of leeches, and many other treatments; the right use of alcohol; the properties of vegetables, nuts, and other materia medica; the use of enemas – and all alongside incantations, omens and fears of sorcery.

The medicines described in the Caraka Samhita and the Susruta Samhita comprise a rich menu of animal, vegetable, and mineral substances. For dealing with the 200 diseases and 150 other conditions mentioned, the Caraka Samhita refers to 177 materials of animal derivation, including snake dung, the milk, flesh, fat, blood, dung, or urine of such animals as the horse, goat, elephant, camel, cow and sheep, the eggs of the sparrow, pea-hen and crocodile, beeswax and honey, and various soups; 341 items of vegetable origin (seeds, flowers, fruit, tree-bark and leaves), and 64 substances of mineral origin (assorted gems, gold, silver, copper, salt, clay, tin, lead and sulphur). The use of dung and urine are standard; since the cow is a holy animal to orthodox Hindus, all its products are purifying. Cow dung was judged to possess disinfectant properties and was prescribed for external use, including fumigation; urine was to be applied externally in many recipes.

The Caraka Samhita praises the virtuous healer: ‘Everyone admires a twice-born [brahmin] physician who is courteous, wise, self-disciplined, and a master of his subject. He is like a guru, a master of life itself.’ Quacks, by contrast, are roundly condemned: ‘As soon as they hear someone is ill, they descend on him and in his hearing speak loudly of their medical expertise.’ In respect of the true physician, the Caraka Samhita tenders an Oath of Initiation, comparable to the Hippocratic Oath. A pupil in Ayurvedic medicine had to vow to be celibate, to speak the truth, to adhere to a vegetarian diet, to be free of envy, and never to carry weapons. He was to obey his master and pledge himself to the relief of his patients, never abandoning or taking sexual advantage of them. He was not to treat enemies of the king or wicked people, and had to desist from treating women unattended by their husbands or guardians. The student had to visit the patient’s home properly chaperoned, and respect the confidentiality of all privileged information pertaining to the patient and his or her household.

The diagnostic and therapeutic aspects of Ayurveda depended on knowledge of the canonical Sanskrit texts. The good physician (vaidya) memorized material consisting largely of verses which specified the correlations between the three humours (wind, bile and phlegm), and the various symptoms, complaints and treatments. He conducted an examination of his patient which took into account the symptoms, in the process recalling verses applicable to the patient’s condition. These would trigger remembrance of further verses containing the same combinations of humoral references, all of which would lead to a prognosis and a proposed therapy.

The Ayurvedic schemes of substances, qualities and actions offered the vaidya an effective combination of solid learned structure and freedom to act. The practice of Ayurveda depended heavily upon oral traditions, passed down from master to pupil, in which a huge magazine of memorized textual material was recreated to fit particular circumstances, while remaining faithful to the fundamental meaning of the text. (The role of precedent within English Common Law offers a parallel.)

The Susruta Samhita is distinctive for its wide-ranging section on surgery, which describes how a surgeon should be trained and the various operations he should perform. There are, among other things, descriptions of cutting for stone, couching for cataract, the way to extract arrowheads and splinters, suturing, and the examination of human corpses as part of the study of anatomy. The text maintains that surgery is the oldest and most useful of the eight branches of medical knowledge, and elaborate surgical techniques are described. However, there is little evidence to confirm that these practices persisted. A description of the couching operation for cataract exists in the ninth-century Kalyanakaraka by Ugraditya, and texts based on the Susruta Samhita copy out the sections on surgery with other material. But medical texts give no evidence of any continuous development of surgical thinking; no ancient or even medieval surgical instruments survive; nor is surgery described in literary or other sources. A parallel may be found in the apparent fate of surgery within the Islamic tradition.

One possible explanation for this apparent waning of surgery is that, as the caste system grew more rigid, taboos concerning physical contact became stronger and, a little like Hippocratic doctors, vaidyas may have shunned therapies which involved applying the knife to the body, transferring their attention to less intrusive approaches, including examination of the pulse and the tongue. Whatever the reasons, the early sophistication of surgical knowledge seems to have been an isolated phenomenon in the development of the Indian medical tradition.

There is, however, one well-documented historical event which suggests that surgery akin to the Susruta Samhita remained widely known. In March 1793, an operation was undertaken in Poona of significance for the later course of plastic surgery. A Maratha named Cowasjee, a bullock driver with the English army, having been captured by Tipu Sultan’s forces, had his nose and one hand cut off – a customary punishment for adultery. He turned to a man of the brickmakers’ caste to have his face repaired. Thomas Cruso (d. 1802) and James Trindlay, surgeons in the Bombay Presidency, witnessed this operation, publishing in 1794 an account of what they had seen, with an engraving of the patient and diagrams of the skin-graft procedure. The obscure brick-maker, reported the English surgeons, had performed a superb skin-graft and nose reconstruction using a technique superior to anything they had ever seen. It was taken up in Europe and became known as the ‘Hindu method’.

This may seem to be proof of the persistence of Susruta’s surgery during the course of well over a thousand years, but there are puzzling elements to the tale – notably the fact that rhinoplasty of this kind is not delineated in any detail in the Susruta Samhita. Furthermore, as a member of the brickmakers’ caste, the surgeon who performed the Poona operation was not himself a vaidya. He probably knew no Sanskrit: his skill lay in his hands, not in his head. It is conceivable that this represents a survival of a procedure from Susruta’s time, but if so it seems to have been passed down independently of the practice of educated physicians. There is no evidence from other written sources of the practice of such operations in the intervening period.

A similar puzzle is posed by smallpox. Before the nineteenth century, inoculation was popular knowledge and widely used for protection against the disease, with the expectation that a mild episode would follow. After the graft the patient was kept quarantined in a controlled environment. A detailed account by an English surgeon, dating from 1767, describes the practice and states that it was widespread in Bengal. No trace of inoculation appears, however, in any Sanskrit medical text. The disease was undeniably identified in Ayurvedic writings, where it is called the ‘lentil’ disease, but again the link between theory and practice is tenuous. It seems that techniques recorded in texts, though still related in the learned tradition, fell into disuse, while new developments were widely practised without being inscribed in approved medical learning.

In this light it is easy to fall into the trap of assuming that the Ayurvedic tradition was static and ‘timeless’ – that later texts did no more than to elaborate a coherent and comprehensive set of teachings set out, once and for all, in the Caraka Samhita and the Susruta Samhita. This supposition is given some support by the fact that these two texts do present themselves as unchanging bodies of knowledge; moreover, it is in line with native and foreign stereotypes of India as the fountain-head of eternal truths. But while the canonical texts present the appearance of homogeneity, research into the development of Sanskrit Ayurvedic literature has revealed that numerous authors dissented from orthodox viewpoints. In the course of time new diseases were reported and identified. From the sixteenth century syphilis (known as ‘foreigners’ disease’ in Sanskrit) was described in texts (mercury, brought to India by Islamic physicians, was used to treat it); and from the eighteenth century writings embraced disease descriptions evidently borrowed from western medicine.

There were also innovations in diagnostics. Close attention to urine, and techniques for its inspection, stem from the eleventh century. Before the thirteenth century there is no mention of pulse examination in Sanskrit texts, but it subsequently developed into a key diagnostic method. A technique called ‘examination of the eight bases’ (astasthanapariksa) – the routine diagnostic method for examining the patient’s pulse, urine, faeces, tongue, eyes, general appearance, voice and skin – emerged in the sixteenth century. Novel prognostic techniques also came into use. For example, from about the same time, a procedure was taught whereby a bead of oil was dropped on the surface of a patient’s urine. The remaining span of his life was read from the way the oil spread.

In therapy, a discernible shift lay in the rise of standardized compound medicines (yoga). Consisting of a large number of ingredients, yoga is regularly described in terms of its specific effectiveness against a particular ailment; this brings into question the conventional western view that Ayurvedic medicine was invariably holistic.

Though Ayurveda is the most familiar tradition of indigenous Indian medicine, others have flourished in the subcontinent, notably the Siddha system of the Tamils and the Yunani medicine of Islam. Other assorted therapies are also visible, from folk medicine and shamanism to faith-healing and astrology.

In south India, the form of medicine evolved in the Tamil-speaking areas was dissimilar in certain aspects to Ayurveda. Known as Siddha medicine (Tamil: cittar), this was basically an esoteric magical and alchemical system, presumably heavily influenced by tantric ideas. It was characterized by a greater use of metals, in particular mercury, than in Ayurveda, and prized a substance called muppu, credited with possessing great powers for physical and spiritual transformation. Pulse taking was highly valued for diagnosis. The semi-legendary founders of Siddha medicine include Bogar, who is said to have journeyed to China, teaching and learning alchemical lore, and Ramadevar, who supposedly travelled to Mecca, teaching the Arabs the arts of alchemy.

From earliest times, Ayurvedic medicine handled and treated a range of children’s maladies, blaming them on the evil influence of celestial demons (graha, seizer), believed to attack children. The Sanskrit term graha was subsequently used to mean ‘planet’, and although grahas are clearly described as celestial beings in the Susruta Samhita, later rites for planetary propitiation are targeted at the same types of influence. Indian astrology and religious ordinances contain texts for placating heavenly bodies, as well as astrological prognostications regarding such matters as pregnancy and the sex of unborn children, dream interpretation, sickness and death. According to an early and significant legal work, ‘one desirous of prosperity, of removing evil or calamities, of rainfall [for farming], long life, bodily health and one desirous of performing magic rites against enemies and others should perform sacrifice to planets.’

A work exemplifying the close relationship between medicine and astrology as therapeutic systems is the Virasimhavaloka by Virasimpa, written in AD 1383, probably in Gwalior. It deals with diseases from three points of view: astrology, religion, and medicine. The body parts are matched to the constellations and planets in an intricate scheme of influences and associations, and it is the astrologer’s task to read this pattern of symbols to understand the patient’s problem before advising remedies such as charms, expiations, prayers and herbs.

The Bower manuscript, one of the oldest surviving Indian works, contains a text on divination by dice. It reveals the outlook of a fifth-century healer interested in the therapeutic powers of garlic, in elixirs for eternal life, in the treatment of eye diseases, herbal medicines, butter decoctions, aphrodisiacs, oils, the care of children, and spells against snake-bites, as well as divination.