Three Spoonfuls of Hemlock

On​ my morning commute through Edinburgh I pass a herbalist’s shop opposite the old medical school building. It was established in 1860. The windows are dressed at present with hand-made green paper leaves and a cardboard parrot; there are allergy salves for hay fever, iron tonics for fatigue and slippery elm for heartburn. At the back of one of the windows is a more permanent exhibit: two earthenware jars. The jars are old and empty now, but you can still read their labels. ‘Sennae P.V.’ one says, ‘Pimento’ the other.

Senna is made from the plant Cassia acutifolia which, when swallowed, accelerates the squeezing action of your gut (peristalsis). Your intestine will do all it can to get rid of the stuff – which is particularly helpful if you’re suffering constipation. The shop probably sold bucket-loads of senna to the city’s constipated in the 1860s, and a century and a half later I prescribe bucket-loads of it to their descendants. Pimento is less familiar to me as a drug, but it’s actually a name for allspice, once used as a rubefacient applied to relieve the pain of aching joints. Rubefacients diminish your experience of pain by irritating the skin over the same area: they distract your pain-conveying nerves by giving them an alternative stimulus. They too are still big business, though not in the form of pimento: Tiger Balm and Deep Heat are just two of the rubefacients that you can pick up in any of the modern pharmacies a stone’s throw from the herbalist.

I once knew a woman, a complementary therapist, who thought it hilarious that herbal therapists did business opposite the medical school: ‘They must come out of their respective buildings and shake fists at one another.’ I never saw the incongruity: animosity between herbalism and orthodox medicine is a recent phenomenon; until the 1950s the study of botany was integral to medical training. One study estimates that ten per cent of 21st-century drugs are derived from plants, and when you restrict that inquiry to antibacterial and anticancer drugs, the proportion rises even higher. As the paper leaves in the herbalist’s windows suggest, many of our most effective drugs are derived from tropical plants. Vincristine, a chemotherapy used in leukaemia, comes from a Madagascan flower; the local anaesthetic lidocaine is related to the cocaine of the coca plant. One of my patients – a woman in her eighties – often reminds me that before the NHS came along, poor folk like her went to the herbalist rather than trouble the doctor. Herbal treatments were less effective, she says, but they weren’t ineffective. And they were cheaper, then, than orthodox medicine.

I usually pass the shop without entering, but recently I did go inside. Just by the door was a display stand labelled ‘Belif – believe in truth’. The contents of the Belif products were listed in Korean, and when I asked for a translation, the slip of paper I was given was mostly in Latin. I picked up another package at random, which was advertised as containing ‘organic essential oil of frankincense’. ‘Frankincense has been used for centuries,’ it went on, ‘for a great variety of things including anxiety, coughing and asthma.’ I didn’t need to take the manufacturer’s word for it: the salve had been endorsed by an ‘M.D.’ who has his own television programme. There have been scandals in recent years about the provenance and safety of some herbal treatments – a series of herbal eczema creams imported from the Far East were shown to contain veterinary doses of steroids, far more harmful and ‘allopathic’ than anything that would be prescribed in orthodox Western medicine.

Several kinds of emotional appeal seem to be at work in the promotion of ‘naturopathic’ products. There’s a nostalgia for an age when treatments were less chemically processed, together with an idea that such treatments are in some indefinable way more authentic. There’s a worryingly pseudoscientific mingling of statistics with conjecture. There’s a capitalising on widespread disenchantment with the brevity and perceived indignity of the contemporary clinical encounter. Herbal products have retained some of the mystique they acquired in earlier ages, when medicine was arcane and expensive; perhaps this is alluring to those who hanker for a time in which less was known. Some consumers prefer to believe in the efficacy of a 19th-century apothecarial salve rather than put their trust in drugs approved after randomised, double-blind, placebo-controlled clinical trials.

Placebos are the most tested ‘drugs’ of all; study after study has shown how startlingly effective they can be. For the most part herbal drugs are not placebos, but active pharmaceuticals (the extent to which homeopathic medicines work, on the other hand, has often been understood in terms of the placebo effect). In the 1950s, when botany was still taught in the medical curriculum, Michael Balint wrote that contact with therapists can itself be thought of as a kind of drug, distinct from any treatments therapists actually prescribe. ‘All physicians, therefore, yourselves included, are continually practising psychotherapy,’ Freud said, ‘even when you have no intention of doing so and are not aware of it.’ All of which is a preamble to saying that many of the medieval treatments recounted by Toni Mount in her book Dragon’s Blood and Willow Bark are laughable, or downright dangerous, but that at a time when all physicians had going for them was faith and a few herbs, such treatments could still be remarkably effective.

Dragon’s blood was once thought to be just that – the dried and powdered blood of dragons – and was used by medieval physicians as a wound dressing. It’s now known to have been a resin derived from a type of tropical tree, and pharmacologically speaking it is fairly useless (its only common usage now is as a wood varnish). It looks dramatic and powerful though – a deep crimson dust – and that must have been at least partly responsible for people’s faith in its power. Willow bark is a different story: willow contains salicin, a naturally occurring organic compound that is only a couple of steps removed from aspirin. Two and a half thousand years ago the Hippocratic corpus advised chewing on willow bark as an effective remedy to reduce fever and pain. That knowledge wasn’t perfectly inherited in the centuries following Hippocrates: Pliny skated over it, while Hildegard of Bingen dismissed willow as ‘not useful’. But it is useful: salicylates retard the body’s production of chemicals called prostaglandins, which trigger fever and communicate pain. Aspirin also retards the production of thromboxanes, which enhance the clotting of blood. The most widespread use of salicylates today – some of the most common drugs I prescribe – is in blood-thinning regimes to counteract stroke and heart attack.

If you or I were somehow transported back to the Middle Ages we’d be lucky to last even a few days: we would have no resistance to the glut of pathogens in the medieval environment. Some microbiologists recently examined a 15th-century Venetian plague cemetery and found evidence not just of bubonic plague but of typhus, typhoid fever, smallpox, louse-borne trench fever and relapsing fever. Incubation periods vary between different infectious diseases to such a degree that it’s only within the last century or two that we’ve been able to establish cause and effect in the pathogenesis of infection. In the Middle Ages the longest incubation time of any illness was estimated to be forty days: hence ‘quarantine’.

The old idea that miasmas caused disease wasn’t necessarily so silly: Mount tells the story of a butcher in medieval York being ordered by the authorities to remove ‘all that great dunghill’ in his yard, because it was ‘most perilous for infecting the aire’. It was an accurate assessment in many ways: a pile of rotting meat and manure would have been a breeding ground for pathogens spread by flies. Plague can be spread by the fleas that live on rats, and its pneumonic form can be spread between humans by coughing – two mechanisms that escaped medieval understanding. The Great Plague of the 14th century, which killed between twenty and thirty million (a third of Europe’s population), was thought in England to have been caused by miasmas leaking from the earth secondary to a disastrous conjunction of Mars, Saturn and Jupiter in the sign of Aquarius. Leprosy was just as mysterious: it was slow to spread, and its effect on appearance meant that it was considered one of the divine punishments for vanity. Child lepers couldn’t be accused of vanity, and were thought instead to have been conceived during their mother’s menstruation – a heinous sin according to the medieval church. Whooping cough (pertussis), which remains difficult to treat today, was thought to be transmitted by a miasma emitted from dying orchids. Its obstinate ‘hundred-day’ cough inspired some ludicrous treatments, one of which required a caterpillar to be placed in a muslin bag hung around the sufferer’s neck – it was thought that the cough would go when the caterpillar died. Other treatments included breast milk, snail-broth, ‘the hoot of an owl’, the ‘scent of cattle, sheep or horses’, and passing the coughing child over and under a braying donkey, a practice that continued well into the Tudor period.

The schooling of English physicians in the Middle Ages was performed in close conjunction with the Church. Only Oxford and Cambridge had medical schools. The training took between six and nine years, involved placements in Salerno and Paris, and incorporated not just botany, anatomy and pharmacology, but astrology, geometry, music and algebra. Astrology and geometry were essential given the importance of the stars to prognostication, music because according to one Anglo-Saxon leechbook there were diseases that could be cured by the singing of chants. The Church’s influence accentuated the tribalism between physicians and surgeons that persists to this day: physicians were obliged to take holy orders, and the Fourth Lateran Council in 1215 decreed that under no circumstances could they be allowed to spill blood. The council also placed the care of the soul above that of the body: ‘Before prescribing for the sick, physicians shall be bound under pain of exclusion from the Church to exhort their patients to call in a priest.’

One of the earliest known medical treatments is holy water: nearly two thousand years ago, in Roman Alexandria, the engineer Hero created a slot machine that dispensed a set volume of water when a coin was inserted (you had to bring your own bottle). On the shelves in my clinic in Edinburgh I have a collection of vials and bottles of holy water brought by grateful patients from sacred sites as far apart as Lourdes and Mecca (my advice is that if it works for you, carry on). Waters have long been thought to have healing properties, but the pilgrimage to obtain them could also be a cure: a trip to Canterbury or Walsingham, Santiago or Jerusalem, was often prescribed to those hoping to be rid of leprosy, cataract or epilepsy. Richard Esty’s medical manual of 1454 includes a long pilgrim’s travel guide advising on overnight stops, exchange rates and potential routes between England and Jerusalem. Long journeys in unfamiliar circumstances, away from domestic and economic demands, can offer a helpful transformation of perspective; I often wish there was a modern, secular equivalent to the therapeutic pilgrimage. I frequently find myself recommending a holiday somewhere warm.

In​ the 15th century in England there was a short-lived attempt to merge the guilds of physicians and surgeons, but the incompatibilities of approach, difference in numbers (surgeons being far more numerous) and the influence of the Church conspired to stop it. The apothecaries operated under another guild entirely – that of the grocers (because they purchased many of their herbs and luxury imports en gros). Poorer apothecaries made do with herbs gathered in Britain and used only tiny quantities of imported drugs; medicaments included many substances that were considered luxury foodstuffs: cumin, aniseed, fennel, ginger, caraway, nutmeg, mace, cloves and liquorice. Some medications carried the echo of witchcraft: one potion to induce general anaesthesia included the gall of a boar, three spoonfuls of hemlock juice, opium, henbane and vinegar. The text asked for them to be mixed ‘well together, and then let the man sit by a good fire and make him drink of the potion until he falls asleep. Then he may safely be operated upon.’

This concoction would have been very dangerous if made up wrongly: herbalism was and is still bedevilled by the difficulty of estimating the strength of its constituents. The levels of pharmacologically active substance in herbal products vary according to the age of the plant, when it was gathered, where it was grown, and whether leaves, stems, roots or flowers are used, not to mention how long the product has stood on the shelf and under what conditions it had been stored. Overdose in these circumstances occurred frequently, and was treated either by induced vomiting, or with powerful laxatives like bryony. In medieval medicine, as much as its modern equivalent, it was necessary to find a practitioner one could trust.

The 14th-century French physician Guy de Chauliac was unusual in being surgically trained, and was preoccupied with this issue of trust. In his seven-volume Chirurgia Magna he wrote that ‘a doctor should be willing to learn, be sober and modest, charming, hard-working and intelligent. He should care for rich and poor alike for medicine is required by all. If payment is offered he should accept it; but if it isn’t offered, he shouldn’t demand it.’ Mount explains how the relationship between physicians and their apothecaries was often close, and could be corrupt: Chaucer’s contemporary John Gower wrote of how the crooked double act of apothecary and physician could devise rip-offs a hundred times more dastardly than either could manage alone. The modern version of such practices is rampant in today’s private healthcare market; I have known private clinics do ‘deals’ with adjacent pharmacies that increase the price the patient has to pay, and as far as the indications for surgery go, there’s often one rule for an NHS practice, and another for the fee-paying customer.

Mount begins a chapter on medieval obstetrics and gynaecology with a quotation from Hildegard of Bingen, who believed that the woman’s pleasure was of primary importance in conception, and that it was her delight – ‘a sense of heat in her brain’ – that brought forth seed from her male partner. The Salernitan writers collectively known as Trotula wrote several texts on fertility, pregnancy and neonatal care: the baby’s mouth should be anointed with honey ‘so that it might talk the sooner’; a baby ‘should be bathed and massaged daily after breast-feeding, and its facial features straightened’; ‘according to the retention of the umbilical cord the male member will be greater or smaller’; ‘swaddle most of the time but not always.’ The texts reveal a concern over a new baby’s sensory environment that prefigures Donald Winnicott: ‘There should be different kinds of pictures, cloths of diverse colours and beads put in front of the child’; a new baby should be spoken to gently, ‘using neither rough nor harsh words’. Abortion was forbidden by both the Hippocratic writers and the Church, so recipes for abortifacients were laced in euphemistic and circumlocutory language. Trotula advises ‘an excellent powder for provoking the menses: take some yellow flag [iris], hemlock, castoreum, mugwort, sea wormwood, myrrh, common centaury and sage. Let a powder be made and let her be given to drink one dram of this with water in which savin and myrrh are cooked, and let her drink this in the bath.’ Savin, a kind of juniper, was used to kill intestinal parasites and is still recognised as an effective abortifacient.

That physicians had to take holy orders was effectively a ban on women, although Italy was more lax than the northern European states in this regard. Surgery was a little more open: even where women practitioners were proscribed they often continued to practise by calling themselves apprentices. In the early 15th century, Bologna had a long-serving female professor of medicine and philosophy, Dorotea Bocchi, and in the wills and testaments of English surgeons Mount finds several instances of master-surgeons leaving money and books to their female protégées.

Towards the end of the book, Mount gallops through Tudor medicine – hardly medieval, but her survey does illustrate the incremental way that medical knowledge has advanced over the past thousand years. The medical revolutions of the Enlightenment were only possible because of the insights of the early modern period, which in turn emerged from the reflections of Tudor-era physicians. Without Trotula, Esty and de Chauliac’s mistakes, the revolution brought on by Paracelsus is unthinkable. Every age has drawn on the texts of classical antiquity. Mount’s tour of medieval medicine is breezy, not to say breathless. I counted a few mistakes which could easily have been avoided, and every time I went to the index, the entry I was looking for wasn’t there. But gripes aside the main pleasure of the book is the way it shows just how intimately the treatments and tenets of modern medical practice are related to the herbalism and hocus-pocus of the past.

Medicine is no longer taught in Edinburgh’s old medical school, opposite the herbalist’s shop. The school has been moved, along with the city’s main hospital, to a new glass and steel building, a PFI project, swamped by car parks in the suburbs. The old hospital, with its parkland views and Nightingale wards, has been sold off for conversion into luxury flats. The corridors where I was taught biochemistry and pathology, pharmacology and microbiology, now house departments of literature and social science. There’s no one left for the herbalists to shake their fists at. I like to think that proximity to the physicians kept the herbalists from the worst nonsense, and that proximity to the herbalists kept Edinburgh’s physicians respectful and open-minded. Physicians, surgeons and pharmacists, we were all herbalists once.