Category Archives: Plants and Herbs

Pain, poison, and surgery in fourteenth-century China

Yi-Li Wu

It’s hard to set a compound fracture when the patient is in so much pain that he won’t let you touch him. For such situations, the Chinese doctor Wei Yilin (1277-1347) recommended giving the patient a dose of “numbing medicine” (ma yao).  This would make him “fall into a stupor,” after which the doctor could carry out the needed surgical procedures: “using a knife to cut open [flesh], or using scissors to cut away the sharp ends of bone.” Numbing medicine was also useful when extracting arrowheads from bones, Wei said, enabling the practitioner to “use iron tongs to pull it out, or use an auger to bore open [the bone] and thus extract it.” More generally, Wei recommended using numbing medicines for all fractures and dislocation, for it would allow the doctor to manipulate the patient’s body at will.

Wei’s preferred numbing medicine was “Wild Aconite Powder” (cao wu san), and he detailed the recipe in his influential compendium, Efficacious Formulas of a Hereditary Medical Family (Shiyi dexiao fang), completed in 1337 and printed by the Imperial Medical Academy of the Yuan dynasty (1271-1368). In his preface, Wei affirmed that medical formulas were the foundation of medicine and that a doctor’s ability to cure depended on his ability to use these tools skillfully. Wei’s family had practiced medicine for five generations, and he synthesized their knowledge with that of other doctors to produce a comprehensive treatise encompassing internal medicine; the diseases of women and children; eye diseases; illnesses of the mouth, teeth, and throat; ulcers and swellings; and diseases caused by invasions of “wind” (ailments with sudden onset, including febrile epidemics and paralytic strokes). Numbing medicine appeared in Wei’s chapters on bone setting and weapon wounds.

Wei’s Wild Aconite Powder is the earliest datable recipe that I have found for surgical anesthesia in a Chinese text, and it is a valuable window onto practices that were largely transmitted orally, whether in medical families or from master to disciple.  Dynastic histories relate that the legendary doctor Hua Tuo (110-207) employed a formula called mafeisan  to render his patients insensible prior to cutting them, even opening up their abdomens to excise rotting flesh and noxious accumulations. Some scholars have hypothesized that mafeisan (literally “hemp-boil-powder) may have contained morphine or cannabis (ma), but its ingredients remain a mystery.  A text attributed to the twelfth-century physician Dou Cai (ca. 1146) recommended using a mixture of powdered cannabis and datura flowers (shan qie zi, also called man tuo luo hua) to put patients to sleep prior to moxibustion treatments, which in this text could involve a hundred or more cones of burning mugwort placed directly on the patient’s skin.  Wei Yilin’s recipe provides important additional textual evidence for a tradition of anesthetic formulas based on toxic plants, one that was clearly in circulation long before he wrote it down.

At least as far back as the Divine Farmer’s Classic of Materia Medica (3rd c.), medical authors had described aconite as highly toxic (for contemporary Roman views of aconite, see blogpost by Molly Jones-Lewis). In the right hands, however, aconite was a powerful drug, and part of the Chinese practice of using poisons to cure (see blogpost by Yan Liu).  Warm and acrid, aconite could drive out pathogenic wind and cold from the body, break up stagnant accumulations, and invigorate the body’s vitalities. In the language of Chinese yin-yang cosmology, it nourished yang—all that was active, heating, external, and ascending. The main aconite root was considered more toxic than the subsidiary roots (designated by the separate name fu zi, “appended offspring”), and the wild form was more potent than the cultivated variety.

Images of toxic medicinal plants from China’s most celebrated pharmacological work, Li Shizhen (1518-93), Compendium of Materia Medica (author’s preface dated 1590). Woodblock edition of 1603. Wild aconite is the middle image in the top row. Cultivated aconite (main and subsidiary roots) are in the bottom right corner. Image credit: National Library of China. Posted on-line at the World Digital Library.
Images of toxic medicinal plants from China’s most celebrated pharmacological work, Li Shizhen (1518-93), Compendium of Materia Medica (author’s preface dated 1590). Woodblock edition of 1603. Wild aconite is the middle image in the top row. Cultivated aconite (main and subsidiary roots) are in the bottom right corner. Image credit: National Library of China. Posted on-line at the World Digital Library.

Wei’s numbing recipe consisted of 13 plant ingredients, including the main roots of both wild and cultivated (Sichuanese) aconite, along with drugs known as good for treating wounds:

Young fruit of the honey locust (zhu yao zao jiao)
Momordica seeds (mu bie zi)
Tripterygium (zi jin pi)
Dahurian angelica (bai zhi)
Pinellia (ban xia)
Lindera (wu yao)
Sichuanese lovage (chuan xiong)
Aralia (tu dang gui)
Sichuanese aconite (chuan wu)
Five taels each[1]

Star anise (bo shang hui xiang)
“Sit-grasp” plant (zuo ru), simmered in wine until hot
Wild aconite (cao wu)
Two taels each

Costus (mu xiang), three mace

Combine the above ingredients. Without pre-roasting, make into a powder. In all cases of crushed or broken or dislocated bones, use two mace, mixed into high quality red liquor.

Wei most likely learned this formula from his great-uncle Zimei, a specialist in bonesetting and wounds. Its local origins are also suggested by its use of zuo ru, literally “sit-grasp”, a toxic plant whose botanical identity is unclear. However, according to the eighteenth-century Gazetteer of Jiangxi (Jiangxi tong zhi), sit-grasp was native to Jiangxi, Wei’s home province, and was used by indigenes to treat injuries from blows and falls.  While classical pharmacology focused on the curative effects of aconite, Wei’s anesthetic relied on aconite’s ability to stupefy and numb, while curbing its ability to kill. If an initial dose failed to make the patient go under, Wei said, the doctor could carefully administer additional doses of wild aconite, sit-grasp herb and the datura flower.

Additional images of toxic medicinal plants from Li Shizhen, Compendium of Materia Medica. Sit-grasp herb is in the middle of the top row, and datura flower in the middle of the bottom. Image credit: National Library of China. Posted on-line at the World Digital Library.
Additional images of toxic medicinal plants from Li Shizhen, Compendium of Materia Medica. Sit-grasp herb is in the middle of the top row, and datura flower in the middle of the bottom. Image credit: National Library of China. Posted on-line at the World Digital Library.

In subsequent centuries, as medical texts proliferated, we find additional examples of numbing medicines that employed aconite, datura, and other toxic plants, employed when setting bones and draining abscesses, and to numb injured flesh before repairing tears and lacerations to ears, noses, lips, and scrotums.  Such manual and surgical therapies are an integral part of the history of healing in China.

Yi-Li Wu is a Center Associate of the Lieberthal-Rogel Center for Chinese Studies at the University of Michigan, Ann Arbor (US) and an affiliated researcher of EASTmedicine, University of Westminster, London (UK).  She earned a Ph.D. in history from Yale University and was previously a history professor at Albion College (USA) for 13 years.  Her publications include Reproducing Women: Medicine, Metaphor, and Childbirth in Late Imperial China (University of California Press, 2010) and articles on medical illustration, forensic medicine, and Chinese views of Western anatomical science.  She is currently completing a book on the history of wound medicine in China.

Acknowledgements
This research was funded by the Wellcome Trust Medical Humanities Award “Beyond Tradition: Ways of Knowing and Styles of Practice in East Asian Medicines, 1000 to the present” (097918/Z/11/Z). I am also grateful to Lorraine Wilcox for directing me to the work of Dou Cai.

*****

[1] The weight of the tael (Ch. liang) has varied over time, but during Wei’s lifetime would have been equivalent to 40 grams.  A mace (Ch. qian) is one-tenth of a tael.

True but not Tested: Experimentation in the Apothecary’s Shop

By Valentina Pugliano

Testing and standardization are firmly entrenched in the pharmacological imagination of western biomedicine and its public. Before a new drug can be put on the market, the U.S. Food and Drug Administration demands five rounds of trials. Approximately 70% of new ‘recipes’ fails to pass the first round. Similarly, the European Medicines Agency maintains a database of adverse drug reactions (EudraVigilance) which, growing of one million entries yearly, is used to monitor all pharmaceuticals on sale across the European Economic Area. Meanwhile, the media seizes upon the perils of untested cures as if on morality tales, policing the boundaries of modern science from potential intrusion from the miraculous and the charlatanesque.

Yet, can the same be said of premodern drug manufacturing? Was a drug’s efficacy established by testing? And what did ‘testing’ recipes even mean in the sixteenth and seventeenth centuries? When these questions were suggested at Elaine Leong and Alisha Rankin’s Testing Drugs, Trying Cures Workshop in 2013, I began to look for answers among those early modern medical practitioners who most closely resemble the pharmaceutical industry of our times, combining the manufacturing of a Glaxo Smith-Kline and AstraZeneca with the retailing of Boots and Walgreens: apothecaries. [1]

Pharmacy shop, Tacuinum sanitatis, 16th century (BNF, MS Latin 9333, fol. 51v).

While not corporate giants, apothecaries thrived in every large hamlet and town of Italy, reaching spectacular numbers in metropolises like Rome, Naples, and Venice. Unlike free-lance alchemists and empirics, they belonged to the city’s official infrastructure of healthcare: they worked from a licensed shop, trained through formal apprenticeship and, like physicians and surgeons, belonged to a professional association or arte. This ‘trade brotherhood’ gave them bargaining powers but also subjected them to standardization rules and quality controls. As disgruntled masters testify from the archives, in severe cases of infraction the apothecary could see the remedies he had belaboured on for weeks thrown into the gutter or burnt to ashes.

So what did it mean to have ‘correct’ remedies that passed the test of shop inspections and satisfied “God and the public good”? As a historian of artisan knowledge I have learnt that infractions, those occasions when things go (deliberately) wrong, sometimes provide the best clue to understanding which methods of doing things were considered orthodox in the crafts. Apothecaries loved to speak of the abuses supposedly perpetrated by their colleagues. In Florence, for example, they conned customers by mixing expensive guaiac wood with the bark of mulberry trees. In Mantua and Padua, those with a fever and a bad stomach better beware the Lenitive Electuary, regularly adulterated with black sugar (instead of its fine white variety) and counterfeit tamarinds (mimicked by a paste made of old cassia and badly preserved dates ).[2]

Tamarinds

These complaints were not the only ones to be voiced, but they are telling. They are not motivated by protestations from patients, who are remarkably absent from the writings of early modern apothecaries. Nor are they driven by doubts about the method employed to make the remedy from a set of instructions. While household experimenters and professors of secrets were always seeking new formulas and ways to stabilise them, the corpus of remedies sold in sixteenth-century Italian pharmacies was fairly stable, and so were their recipes.

What these criticisms suggested, rather, was that medicinal ingredients possessed a purity, and that this purity had been tainted. The rogue apothecary had played around with the ‘honesty’ of simples, diluting their strength or altogether replacing the ‘sincere originals’ prescribed in the recipe with fraudulent alternatives (often from the kitchen pantry).

With this concern for authenticity in mind, I returned to the apothecaries’ writings, and especially to two bestselling pharmacopoeias, Girolamo Calestani of Parma’s Observations on the Antidotes and Medicaments Most Used in Italy (1562), and Giorgio Melichio of Venice’s Warnings on the Compound Remedies in Use in Pharmacy (1575). Leafing through these texts, I made a curious discovery. Repeatedly, key plant and mineral ingredients in their recipes were referred to according to their reputed truth or falsity: e.g. “true cinnamon”, “true rhaponticum”, “false stibium”, “false balsam”. Repeatedly, apothecaries stressed the importance of sourcing these authentic materials, while their absence was said to ruin the preparation.

Even the use of substitutes began to be criticised. The practice of substituting one ingredient with another possessing similar qualities (quid pro quo), usually a local simple for an exotic import difficult to acquire, had been necessary since antiquity. Yet, the changing attitude to substitutions in the sixteenth century is summarised well by the Neapolitan physician Bartolomeo Maranta: “Substitutes are an abuse.” Never more so than for Theriac, the most celebrated antidote of Italian pharmacy and the toughest to prepare with over sixty ingredients. A Theriac with substitutes instead of true ingredients, Maranta declared, “will be itself in a certain way sick”.[4]

How should we interpret such appeal to the truthfulness of ingredients? At a superficial level, we can understand the apothecary wanting to reassure the public of the genuineness of his wares. After all, practitioners of pharmacy were often portrayed as profiteers and cheats. But, as I argue in my article “Pharmacy, Testing and the Language of Truth in Renaissance Italy,” something else had changed between the medieval period and the 1540s, when this terminology of trues and falses appears: Greek and Roman books on materia medica were reintroduced into western Europe. It is well known that the reappearance of Dioscorides’s On Medicinal Plants, Theophrastus’s On Plants and Pliny’s revised Natural History created as many problems as it solved for those who wished to implement their teachings. Many of the Mediterranean and Levantine simples described in them remained entirely unavailable during the sixteenth century, while many others were plagued by problems of identification and nomenclature.

My sense is that this ‘Language of Truth’ was an intervention into this state of affairs. It helped the apothecaries get a grip on which was which among rare ingredients, and reflected their aspiration, shared with many contemporaries, of restoring the wisdom of the ancients. It also showed the increasing influence on pharmacy of the contemporary botanical renaissance and the ethos of naturalists who, for the first time, put nature in the foreground, liberating flowers, trees, animals and rocks from the need to be useful.

Crucially, authenticity came to replace experimentation. As ingredients acquired more importance in the apothecary’s mind, the efficacy of the recipe began to be pegged to their presence and quality. Providing the remedy contained the true, correct ingredients its efficacy and fitness for human consumption would be guaranteed, with no need to involve test subjects or pursue the feedback of patients and colleagues. How much this ‘testing by truth’ differed from modern-day trials becomes clear when we turn to the contemporary idiom of the pharmaceutical industry: it is as if the apothecaries’ R&D stopped at the preclinical stage.

 

Notes:

[1] V. Pugliano, “Pharmacy, Testing and the Language of Truth”, Bulletin of the History of Medicine 92/2 (2017): 233-273. See also the other articles in the same issue of BHM.

[2] Ricettario Fiorentino dell’Arte dei Medici e Spetiali di Firenze (Florence, 1574), pp. 45, 74; Giovanni Antonio Lodetto, Dialogo degl’inganni d’alcuni malvagi speciali (Padua, 1572), pp. 21-22.

[3] Giorgio Melichio, Avvertimenti nelle compositioni per uso della spetiaria (Venice, 1601), pp. 27-28.

[4] Bartolomeo Maranta, Della Theriaca et Mithridato libri due (Naples, 1572), p. 33.

 

 

Consumers of the Exotic: summary of a workshop in Cambridge, April 5-6, 2017

By Emma Spary and Justin Rivest

By Reede tot Drakestein, Hendrik van,1637?-1691 [Public domain], via Wikimedia Commons
The project “Selling the Exotic in Paris and Versailles, 1670-1730”, running in the Faculty of History at the University of Cambridge, and funded by Leverhulme Research Grant 2014-289, held its planned workshop in April this year. Its theme, “Consumers of the Exotic: European commerce and the consumption of exotic materia medica, 1670-1730”, brought together a group of international scholars working on these questions in a broad variety of European contexts.

Our goal at the workshop was to produce a comparative picture of the ways in which exotic plant materials were processed, bought and consumed in Europe. Why did European consumers buy—and more significantly ingest—exotic plant materials? What did exoticism mean to them? While recent work has focused on colonial bioprospecting and the appropriation of indigenous knowledge, our aim was to investigate demand within Europe itself, exploring divergences and similarities across contexts. The choice of a restricted timespan—the decades around 1700—provided a baseline for comparison of drug production, sales and consumption in different cultures. Alexandra Cook (University of Hong Kong) kicked off the programme with a study of a proprietary drug, Garcin’s “Maduran pills”, sold around Europe in the early eighteenth century by an entrepreneur whose Protestant faith led to a complex intellectual and commercial itinerary. Cook argued that exotic ingredients were not necessarily a selling point for eighteenth-century patients. Harun Küçük (University of Pennsylvania) provoked us to think about the complexity of defining the exotic, and the importance of a multi-perspectival view of the history of drugs: Ottoman healers associated New World exotica like cinchona bark and ipecacuanha root with French medicine, since these substances often reached them via French commercial and intellectual networks. Continuing the global theme, Samir Boumediene explored the place of drugs in the missionary activities of the Society of Jesus. The decades around 1700 represented a decline in the relative importance of Jesuits in the global drug trade, as new players came to disrupt their initial privileged position.

Šebestián Kroupa (University of Cambridge) offered a counterpoint to the workshop’s focus on European consumption by exploring the supply of European drugs to transplanted European populations—Manila in the Philippines. European drugs were in fact imported in large volumes to this “exotic” locale; little attention was paid to the pursuit of plant substances that might be commodified in the metropole, an exception being the Saint Ignatius bean. Victoria Pickering explored the diverse trajectories, contacts, and exchanges that were necessary to assemble the massive collection of exotic plant substances of Sir Hans Sloane.

Moving to early modern Russia, Clare Griffin suggested that its unique geographical connections—in the form of a land route between Europe and the Far East—led commentators to represent distant substances and peoples as subject to incorporation into the Empire, rather than “exotic” in the sense of “foreign”, as the case of rhubarb showed. Paula De Vos concluded the first day with an account of Palacios’ prominent 1706 pharmacopoeia. Early modern Western pharmacy was indebted, for its materia medica, to the Indo-Mediterranean world rather than the continent of Europe. The slow appropriation of new drugs spread outwards from this Indo-Mediterranean core to the Silk Roads, the Indian Ocean, and eventually the Atlantic world.

On day 2, Laia Portet explored the architecture of exoticism in printed French materia medica. Where familiar European plants tended to be classified alphabetically, unfamiliar exotics were classified by parts (roots, barks, leaves) since this was the form in which they entered the European marketplace. Emma Spary used a case history of an exotic aromatic, cinnamon, to point up the disjuncture between textual, material and empirical knowledge of drugs, a conundrum for medical experts, market regulators and individual consumers. Hjalmar Fors provocatively suggested that for early modern Europeans, “the exotic” primarily evoked traded material goods, including spices and drugs, rather than foreign peoples or distant geographies. Lack of knowledge about the places of origin of drugs was critical to a substance remaining “exotic” in European eyes.

Justin Rivest spoke of the encounter between political power, the emerging state and the large-scale administration of drugs in France, looking at how personal trialling of drugs by successive ministers of war led to a centrally administered programme of dispensing exotic drugs like tobacco, quinquina and ipecacuanha to French troops. In a very different take on the end-user, Wouter Klein introduced us to the uses of print culture as a research tool for relating newspaper advertising and ships’ cargoes of drugs in the Dutch republic after 1700.

Several common themes emerged from the papers. It seemed that “colonial bioprospecting” had its limits as a way of understanding European engagement with non-European materia medica. Most substances discussed did not reach Europe thanks to state intervention, but rather were trafficked by a heterogenous set of actors: missionaries, trading company officials, entrepreneurial merchants and court physicians. Many papers also showed that “exoticism” was not necessarily inherently desirable. A drug’s value was established through consensus-building over time. Furthermore, “exoticism” was a relative, context-specific category, subject to change, not solely a feature of geographic origin, or of a core-periphery relation between European metropoles and their colonies. The papers demonstrated that exoticism was also, perhaps largely, a product of degrees of familiarity and unfamiliarity, which varied widely across different European contexts. In sum, rather than being inherently valuable objects of appropriation, exotic drugs were socially constructed goods.

Distilling and Deflowering

A friar in an apothecary
Credit: Wellcome Library, London.

By Peter Murray Jones

Between 1416 and 1425, English friars put together a Latin medical handbook. This handbook, called the Tabula Medicine (‘Table of Medicine’), mostly consisted of remedies, arranged alphabetically by name of ailment, instead of the head to toe order of the standard medical Practica. The friars seem to have assembled the text by accumulating remedies in a sort of medieval Wikipedia. Some copies preserve the ‘open’ format by leaving room for additional remedies under each heading.[1]

Many remedies are medicinal recipes culled from books. Most often they cite the works of Avicenna, Galen and native authorities, Gilbertus Anglicus, Bernard de Gordon, John of Gaddesden, and John Arderne. But a lot of other remedies are attributed to English friars who flourished c.1370-1420.[2] The friars mentioned were identified as authorities (expressed as “per fratrem Peter Russell”, for example) for recipes of all kinds. But they had a particular fondness for distillations. Under the heading “Gutta arthetica” (Gout of the joints), we find:

King’s MS 16, fol.1. The opening of the Tabula medicine

“According to brother William Holme, for cold gout take the dregs of a pottle (two quarts) of beer; boil down a pennyweight of boar’s flesh for a day, stirring it with a ladle; and take a handful each of chamomile, pellitory, cowslip, lavender, honeysuckle, and marjoram. Cut up the cooked meat and the herbs into tiny pieces and distill together with the dregs in an alembic. The water collected in a glass can be kept and used as wanted.  Apply it warm, and it is called flesh-water.”

Holme, like Hieronymus Brunschwig, held that distillation ensured your remedy did not go off.

More ambitious distillations aimed at producing the heavenly quintessence, or at the very least aqua ardens (burning water). The friars must have had a copy of John of Rupescissa, Liber de consideratione quintae essentie to hand, for they quote from it accurately under headings for “Cor” (Heart), “Demon,” “Facies” (Face), “Frenesis” (Frenzy), “Melancholia,” “Spasmum” [Convulsion] and “Venenum” (Poison). They never identify him by name, although Rupescissa was a Franciscan friar, writing from prison in France c.1350. Under the heading “Facies”, they tell us that wild strawberries are a hundred times more powerful against outbreaks of pustules on the face if administered as a quintessence. Rupescissa uses exactly the same words at two points in his text. We are not told in the ‘Table of Medicine’ how to extract a water from wild strawberries and combine it with quintessence, although Rupescissa does give a recipe.

The only heading in the ‘Table of Medicine’ that names a remedy instead of an ailment is “Balsamum” (Balsam). Native balsam was extraordinarily rare and expensive in late medieval Europe, in all its three forms, and friar William Holme is credited with two different recipes for making an ‘Artificial Balsam.’ One simply requires powdered exotic spices to be put successively into hot but not boiling oil. The second requires small quantities of natural balsam, as well as twenty-five other ingredients. They are mixed and pulped in a mortar before distillation. This distillate comes in three degrees of strength, and is said to be just as effective as the native kinds in treating a long list of ailments. Holme is the only one of the friars mentioned in the ‘Table of Medicine’ who can now be identified as author of a surviving text, De simplicibus medicinis (‘On medicinal simples’) of 1415. This was “deflowered” as the bibliographer John Bale later put it, by Holme “from twelve doctors of medicine”. The ‘Table of Medicine’ itself went in for “deflowering”, though it also credited experienced friar practitioners.

King’s MS 16, fol. 144. Wistanton’s recipe for distilling blood and Forman’s hand in the margin.

Friar Robert Wistanton gives a recipe to make use of distilled human blood in surgery. The blood is kept for forty days in a glass vessel under dung, then cooked in a copper pot for a day, cooled, then skimmed. Afterwards it is distilled with a filter, mixed with aqua ardens, then distilled again with an alembic, and that distillate is the best of all waters. It will consolidate a wounded limb within three days and heal the sick. What remains in the bottom of the vessel should be kept, cooled and dried, and the resultant powder is best for fractured bones. Friars were not supposed to dabble in alchemy and surgery, but that does not seem to have stopped Wistanton and his brothers.

King’s MS 16, fol. 8b. Insert in Forman’s hand on Catalepsis.

In 1574 Simon Forman, astrologer and alchemist, purchased a manuscript of the ‘Table of Medicine’ in Oxford. He added recipes drawn from his own experience, or from Andrew Boorde’s Breviary of Healthe (1557), in the margin opposite the entries for particular illnesses. He also interleaved the manuscript to add remedies for illnesses not covered in the ‘Table of Medicine’. In this enhanced form the text continued in use into the seventeenth century.[3]

[1] Peter Murray Jones, “The ‘Tabula medicine’: an Evolving Encyclopedia,” English Manuscript Studies 1100–1700, vol. 14, Regional Manuscripts 1200-1700, ed. A. S. G. Edwards (2008), 60-85.

[2] Peter Murray Jones, “Mediating Collective Experience: the Tabula Medicine (1416–1425) as a Handbook for Medical Practice,” in Between Text and Patient: The Medical Enterprise in Medieval & Early Modern Europe, ed. Florence Eliza Glaze and Brian K. Nance (Florence: SISMEL-Edizioni del Galluzzo, 2011), 279-307.

[3] Cambridge, King’s College MS 16. See Lauren Kassell, Medicine and Magic in Elizabethan London. Simon Forman: Astrologer, Alchemist and Physician (Oxford: Clarendon Press, 2005).

Peter Murray Jones: I am Fellow Librarian of King’s College, Cambridge and a historian of medieval medicine. I have a particular interest in relations between knowledge and practice as expressed through recipes. My current project is on the contribution of friars to practical medicine and science in late medieval England.