The Herbalist by Benjamin Woolley

Was Nicholas Culpeper a medical rebel who challenged the establishment or simply a quack, asks Scarlett Thomas

Anyone who has ever rubbed dock leaf on a nettle sting, used peppermint tea to ease indigestion or taken chamomile for a good night's sleep has been using herbal medicine. However suspicious some of us may be of a complete system of "alternative" healing, we all know that, for example, vinegar is good on wasp and bee stings, and honey helps a sore throat. When things get more serious, of course, most people rush to the doctor. But what if the doctor gets it wrong? Or what if, for whatever reasons, you wanted to find out how to use other plants to heal yourself or your own family? These are questions which have persisted for centuries. Who has the right to medical knowledge? And, in medical matters, how do you, as Henry VIII wondered in 1512, discern the "cunning from the uncunning"?

It is to the 16th century, with its complex medical system of grandmothers, mothers, aunts, quacks, cunning men and women, midwives, apothecaries and a few physicians, that Woolley first takes us in his immensely readable book. We learn of Henry VIII's answer to the problem of regulation: the creation of the College of Physicians, which was given licensing and fining powers - but not the power to dispense medicines, which was held by the apothecaries. Trade and turf wars seem to have defined the medical system of the next 100 years, until things were shaken up by the plague of 1625 which left London almost empty of doctors, with only apothecaries still providing medical care.

Although the apothecaries were supposed to practise only in accordance with the Pharmacopoeia Londinensis, a huge book of instructions and recipes created by the College of Physicians, most of them did not read Latin and so could not read the book. Perhaps this was fortunate, as the book warned of "a dangerous plague which our book will counteract, namely the very noxious fraud or deceit of those people who are allowed to sell the most filthy concoctions, and even mud, under the name and title of medicaments for the sake of profit". Nevertheless, most apothecaries had some idea of what their medicines did. And despite not understanding the Latin slurs on their characters in the Pharmacopoeia, the apothecaries also knew that the College had it in for them.

In 1634, Nicholas Culpeper, aged 18, arrived in London with £50 in his pocket and a tobacco habit, looking for an apprenticeship. Already something of a rebel (there are stories of childish pranks, an elopement that ended in tragedy and much drinking and smoking) Culpeper soon became an apprentice to an apothecary, becoming familiar with long lists of "simple" ingredients set out in the Pharmacopoeia, including bizarre items like excrement of wolf, human blood, crayfish eyes, sweat, ass milk and "intestines of the earth" (earthworms). Many recipes would also call for opium, which, at the time, cost less than rhubarb. Culpeper did not have a good experience as an apprentice, being "turned over" (assigned a new master) several times. Although perhaps this was not a good time for anyone to be an apprentice, when rules meant you could be summoned to a company "court" for having "stubbornness and long hair".

Culpeper eventually abandoned his apprenticeship and, despite all the rules created by the College of Physicians, set up on his own as an "independent", trading out of a shop on Threadneedle Street. His aim was to provide medical help for anyone who needed it, however poor, and to treat people with simply prepared, locally sourced medicines, not the exotic concoctions favoured by the College, made from "some such thing that drops from Poppies when they weep, and that is somewhere beyond the Sea, I know not where, beyond the Moon". Although very interested in astrology, Culpeper condemned the widespread quack practice of casting horoscopes over chamberpots (ie combining astrological and urinary analysis), calling practitioners "piss prophets". After fighting in the Civil War, and as Levellers called for all legal matters to be conducted in English, so Culpeper's thoughts turned to a similar democratisation of medical texts. These thoughts would be made reality when he was commissioned to produce an English translation of the Pharmacopoeia.

When Culpeper's translation of the Pharmacopoeia appeared, under the title A Physical Directory, it was twice as long as the original, bulging with additions and corrections. It also explained what the recipes were for. "In translating the book," Woolley notes, "Nicholas broke every rule in it." This was not just a medical act but a deeply political one. The College of Physicians was outraged. "College, College, thou art Diseased," Culpeper wrote in his preface to the third edition of his translation. His later book, The English Physitian, better known as Culpeper's Complete Herbal, which outlined not only the uses and features of healing plants but also Culpeper's holistic view of medicine, also upset the establishment but became one of the most popular and enduring books in British history.

Was Culpeper an "arch herbalist and quack salver"? No more so than the medical establishment of the time, argues Woolley. It was the College's Pharmacopoeia after all that recommended the use of the treatments based on ground human skull and gall stones of Persian goats that surely led to King Charles II's demise. Yet Culpeper's legacy - the idea that medicine is not something that should be controlled and administered by the elite but something belonging to everybody - is as important and, perhaps, as revolutionary, now as it was in the 17th century.

One of the reasons this biography is so readable is because of the obvious chemistry between author and subject. In his entry on the herb lesser celandine, or "pilewort", Culpeper notes, "Pilewort being made into an Oil, Ointment or Plaster readily cures both the Piles or the Haemorrhoids, and the King's Evil, if I may lawfully call it the King's Evil now that there is no King." Woolley's text has similar light, humorous touches. Perhaps there is less of Culpeper in this text than there would have been if more biographical material about him had survived, but this book is more than a biography. It is also a profound examination of 17th-century trade practices and monopolies and how the establishment view of who should be allowed to trade and under what conditions affects everything - but especially the health of people denied control over their medical treatment.