By Jessica Sequeira

Quina quina (bark of bark, or holy bark), from the cinchona tree, is native to the Amazon rainforest and the Andes of South America. Its properties have been known for hundreds of years to the Quechua people of Peru, Bolivia, Ecuador, Brazil, and other countries of the region, who used the bark as a preventive method and a muscle relaxant against the shivering and fever of the disease later called “malaria”. What is not known is the exact process by which the properties of the tree were introduced to Europe. As Fernando Ortiz Crespo puts it: “The entry of Quina Bark into modern pharmacology has been clouded by unreliable sources, apocryphal ornament and botanical confusion.”

The Spanish physicians Juan Fragoso and Nicolas Monardes wrote about medicinal bark in the New World, but Fragoso didn’t give much detail about the tree in his work Historia medicinal de las cosas que se traen de nuestras Indias Occidentales (Medicinal History of Things Brought from Our West Indies). In the next century, tales circulated about the Countess of Chinchon, wife of the Viceroy of Peru, supposedly cured of “tertian fever” by a local doctor who used an extract from the bark of a Peruvian tree. The facts of this tale cannot be proven, but it captured the European imagination, and Linnaeus named the bark “Cinchona officinalis” after the Countess. The criollo Augustinian friar Antonio de la Calancha also studied the bark, as did the Spanish Jesuit Bernabé Cobo, as well as the Italian Jesuit Agostino Salumbrino, who wrote about its use in Lima to treat shivering. Because it was the Jesuits who brought word of quina quina with them not only back to Europe, but also to other regions of the world such as China where they were involved in missionary work, the bark began to be widely referred to as “Jesuit bark”, “Jesuit’s Powder”, or “Pulvis Patrum”.

Today quinine is often associated with the British empire, a word to be found in a Graham Greene novel or linked to the gin and tonics sipped by colonialists in the tropics. But the drug has a long history before that. The implementation of quina quina in the European context involves overlapping global networks from the 17th to the 21st century with different and at times conflicting aims. South American Jesuits, Portuguese and Spanish conversos, members of London’s Royal Society, merchants and soldiers in Asia and Africa, astronomists, botanists, wartime chemists and a great many more researched or used the tree for medical purposes. And, long before the Europeans, indigenous people lived alongside quina quina without the need for “discovery”, cultivating local knowledge that has still not yet been explored with as much depth and respect as it ought to be.

Jacob de Castro-Sarmento. Mezzotint by R. Houston after R. E. Pine. Wellcome Collection.

One part of this story involves the Portuguese Jews who escaped from the Inquisition and moved to London, where they developed and popularized quinine, a product marketed as quintessentially English under the name agoas de Inglaterra (waters of England). To tell this story in all its complexity would require a structure as delicate and beautiful as that of the cinchona alkaloid, whose synthetization in the 20th century would have been impossible without quina quina.


At the age of 28, the Portuguese doctor Jacob de Castro Sarmento escaped from the Portuguese Inquisition by moving to London. He had studied at Mértola, he matriculated at the University of Evora obtaining a degree in classics and the philosophy of Aristotle, and went on to acquire a medical degree at the University of Coimbra. After completing his studies, he worked with the poor in the region of Alemtejo, where he grew interested in fevers. It was here, however, that he also got involved with underground Jewish practices, and both he and his mother were pursued by guardians of the faith.

It was a common move at the time for Jews like him, averse to converting to Catholicism but even more averse to torture, to make a new life in England, since the two countries enjoyed a political and commercial relationship. Eleven years later, in 1735, Sarmento published his Materia Medica Physico-Historico-Mechanica, reprinted in 1756 under the catchier title Do Uso, e Abuso das Minhas Agoas de Inglaterra (On the Use, and Abuse, of My Waters of England). In the meantime, he continued to experiment and advance his career. By the time the second edition came out, he had had more time to understand the effects of the maravilhoza casca (marvelous bark).

Sarmento heavily criticizes his fellow doctors for writing against his medicine for thirty years, when the bark could have been working its good effects. He also identifies a doctor who vended agoas de Inglaterra with a distinct purposes: “another remedy was circulating with the same name, but with a very different process of invention and preparation; its Author always kept the composition of the remedy secret, and attributed to it virtues or properties other than curing intermittent fevers”.[i] Sarmento repeatedly insists that his version is the correct one, and that great claims which don’t take into account warnings about what the bark can and can’t do, and the specific situations and methods its use requires, are a danger.

At this time, all kinds of fevers were grouped as a possible effect of hot weather. Of course, some attributed these ailments to the wrath of God, gleefully pointing toward them as punishments for evil behavior, akin to syphilis. Categories of “heat” and “lax morality” began to overlap, so that regions with hot climates were attributed with dubious ethics. But since epidemics of fever stretched across many 18th-century cities, including Lisbon, this explanation was a troubled one. The King of Portugal himself grew interested in tackling the matter when malaria ravaged the south of his country. While Inquisitors and other religious officials attempted to explain such disease through religion, “natural philosophers”, some of whom were exiled abroad in London, started to provide other explanations in which God was bracketed off at least temporarily, and physiology allowed to take center stage.

Here is where Sarmento offers his services. Notably, he refers to himself as an “Author”, which seems to indicate that medicine is an act as personal as writing a book, one not yet controlled by corporations or laboratory teams. In an uncertain world characterized by an emerging individual self-consciousness, as well as legal precarity regarding brand names, intellectual copyrights, and patents, makers of potions felt very possessive about their recipes and ingredients. Sarmento refers to his potion as minhas Agoas de Inglaterra (my Waters of England) throughout his work, and On the Use, and Abuse, of My Waters of England is a robust defense of “his” medicine, his right to it, and its correct use according to him. For all the talk of Divine Providence, the glory of Portugal, and the benefit to human furthering of Natural History, human ego also plays a role.

Frontispiece of Do uso, e abuso das minhas Agoas de Inglaterra by Jacob de Castro Sarmento (Universidade de Coimbra Digitalis)

Quina quina may have adverse effects, Sarmento admits, but also miraculous ones if used properly, hence the “use and abuse” of the title. Drug use and abuse are familiar ideas in contemporary societies in relation to an individual patient or recreational consumer, but such ideas can apply to the prudent doctor, too. For a man languishing from fever in his bed in some tropical place, the doctor must administer exactly the right combination of ingredients, with the correct dosage. In the edition that I am reading, handwritten notes appear in sepia ink, perhaps marginalia by a medical colleague reading On the Use, and Abuse, of My Waters of England to learn about Sarmento’s techniques, or by a younger man studying to be a physician. Several of the notes are glosses on the prohibitions and warnings about what one should definitely not do. It is as if, in spite of what else could happen, our mysterious note-taker wants to be sure that if his potion does not bring healing, it will at least not usher in death.


Although it was published in England by the Scottish publisher William Strahan, who also published Adam Smith and Edward Gibbon, Sarmento’s work was deeply tied to Portuguese interests. It was dedicated to Diogo de Mendonça Corte-Real, secretary of state to João V of Portugal, and it begins with these resounding words: “In all of natural history, no greater discovery has been made to this day, nor one more interesting to human Nature and public health, than that of quina quina; and it seems to me that in all of Medical history, nowhere are so many astonishing effects of this admirable bark to be found registered, and with such individuality, as in this little book that I offer to Your Excellency.”[ii]

The second edition recalls how the 1731 edition was written on commission for the minister of Portugal, who was “highly inclined to undertake a natural History of our Brazil”[iii], and reminds His Majesty that “in that Dominion, there lies deposited a far greater providence, and a more priceless treasure to discover by means of our natural History, than all of the precious stones or gold that can be extracted from its mines”[iv]. To put it another way, the quina quina bark in Brazil is a greater treasure to Portugal than even its jewels and gold.

Flipping to the end of Sarmento’s book, readers find a picture of quina quina on the last page, its branches laid flat, its thick leaves accompanied by finer ones, its tiny flowers and its stem in cross-section carefully sliced and sorted in preparation for the mixing of the Agoas de Inglaterra. Pictured this way, its every part exposed, the tree is stripped of sacredness and turned into matter, a resource. In the “Dedicatoria”, the language of Providence signals clear human interests: the world is portrayed as having begun as rude and confused, until humanity gradually learned to turn nature to its uses, as destined by Providence. The “happy discovery”[v] of quina quina forms part of this providential history. Such logic was convenient to the Portuguese government, desperate for a cure for both the “fevers” in their country, and the ones suffered by men posted to Brazil and India.

Quina quina, as seen in the end pages of Do uso, e abuso das minhas Agoas de Inglaterra by Jacob de Castro Sarmento (Universidade de Coimbra Digitalis).

On Use and Abuse reads in part as a cookbook, with descriptions of situations given along with specific mixtures required, the fruit of Sarmento’s experience of three decades. Quina quina bark must be ground and combined with other substances and liquids, which vary depending on the specific case. Ingredients include malva, cream of tartar, tamarind pulp, flaxseed oil, sal ammoniac, spirit of hartshorn, vinegar, strawberry syrup, juice of oranges from China, lemon juice, green wine or “the best white wine of Lisbon”, lemonade, rhubarb, valeriana silvestre, pure opium, cinnamon water, spiritus mindereri and Mynsicht’s elixir of vitriol. Some are familiar to us, some less so. It is organized into sections focusing on the different ailments that can be treated with quina quina, from varieties of fever (“intermittent”, “ardent” and “nervous”) to other unexpected situations such as “hysterical affects”, “matrimony” (i.e. sex life), constipation, stomachs cheo de flatos depois de comer (full of flatulence after eating), miscarriages, gangrene following surgical operations and amputations, and bullet wounds. The book ends with two testimonials, a common genre similar to today’s book blurbs, attesting to the efficacy of the medicines and once again reinforcing the “Authorship” of Sarmento. The first is by a physician in the Roman curia, Dr Gaspar Rodrigues de Payva, the second by a physician to the King of Angola, Dr Euzebio Catela de Lemos.

Quina quina is truly portrayed as a miracle drug. It seems that the Agoas can be used for nearly everything, diced and dissolved into different recipes. The trick is to determine the correct combination and timing. Rather than immediately prescribing the Agoas, the prudent doctor will often let the fever run its course for a time first, to avoid the patient’s relapse. Specific ingredients are also recommended as complements, such as contrayerva to slow or retard the effect of quina quina, or else as purgatives to help expel noxious substances prejudicial to the patient’s health. Medicine comes to mirror human activity itself, requiring great circumspection and the equanimity to move backward a bit before one can advance.

Although nominally about medicine, the book displays concern about the human being in general. Sarmento’s experience as a doctor shines through, both in his first-person references and in his vivid allusions to others, such as his story of a feverish patient tucked away in bed next to an open window, afflicted by frights and terrors. In the section about bullet wounds, we also read: “I remember noticing the bullet wound in my Father’s leg, which he received in his youth, and which could clearly be seen; many times I heard him declare that even after he was cured, he continued to suffer, or that even the slightest inconvenience bothered him in the place in his leg where the bullet had lodged, and when he died, at 86 years old, he took it with him to the grave”[vi].

In the 18th century, autobiography was not the stand-alone genre it is today, and it is startling to find such first-person accounts in unexpected places such as this medical manual. It might perhaps fit into an alternate tradition of medical writing that includes works by figures such as Gerolamo Cardano and Leonardo da Vinci, and before them many Greeks and Romans, for whom the health of the soul and the health of the body are bound up, and the life of the doctor is connected to that of the patient.


As a muscular relaxant, quina quina had many uses to tranquilize a body overstimulated by heat, mosquitos or the many other undesirable influences which might persecute a poor human organism from the outside. But it had some undesirable internal effects as well, of the kind doctors warn about even today, should they prescribe tablets to patients. Vomiting is a risk. But even more dangerous is an excessive dose, or one taken at the wrong stage of fever, which could relax the body too much, especially the central organ in charge of distributing blood and life to the rest of the system: the heart. Cardiac arrhythmia is the name for an irregular pulse that reaches the extreme of stopping the body entirely, and quina quina is an antiarrhythmic agent. In such cases, it is not unusual for the patient in question to die.

The dose makes the poison, Paracelsus is said to have remarked, implying that medicine improves life in small quantities but turns to poison in larger ones. Quina quina, like other powerful medicines, is also a poison. During the unstable time of experimentation with its effects, 18th-century amateur scientists occasionally inflicted illness when experimenting with the bark, possibly even death. Many untold stories haunt this period when political and medical interests preferred not to notice the invisible hand that gently closed victims’ eyes.

Sarmento assumed a position of importance in the Royal Society when his predecessor, Isaac de Sequeira Samuda, died at the age of 48. Sequeira, another exile from the Portuguese Inquisition, had also been studying quina quina thanks to his contact with Dr Fernando Mendes, another member of the erudite diaspora committed to battling the new strains of fever, with the added experience of having survived England’s Great Plague. On 25 August 1728, Joseph Israel Carrillo, physician to the King of Tunis, sent Sequeira a long letter about the verbascum flower, also mentioning the “arbor Exotica Indica Melancholica”. Just a couple months later, on 22 November 1729, Sequeira passed away under mysterious circumstances linked to his study. The report of his death describes him as having “stopped”.

Sometimes studying the past can feel like detective work, and I still do not know what the exact links between events might be. Certainly, the brief account given of Sequeira’s death matches the medical description of a stopped heart from quina quina. Or perhaps it was the verbascum he was inquiring about in his letter, also used by indigenous peoples as a poison. Upon Sequeira’s death, Jacob de Castro Sarmento published his book about quina quina, alluding to its tragic consequences if not used correctly. He quickly took over Sequeira’s role as a physician and scientific adviser, and life at the Royal Society went on. In his spare time, out of friendship or guilt, he also made the effort to complete an epic poem about the Lusitanian leader Viriatus which Sequeira had begun.

Having escaped the horrors of the Inquisition, a Portuguese exile might find a subtler arena of human sacrifice in London, where oblations were contextualized in terms of a greater good, if not God’s Providence, than the advancement of natural philosophy. In the early 18th century, as the world opened up with new global networks, scientific discoveries were frequently decontextualized from their original circumstances. A plant held sacred by Quechua people, in the context of an indigenous culture that was aware of its power, respectful of its healing properties, and conscious of its potentially dangerous effects as a poison, was transformed into pure matter, a resource for the Europeans desperate for a cure for the diseases ravaging their nations and empire.

The quina quina plant was used to advance solutions and careers as part of larger accounts of Catholic providential history and Progress. Stories about it often assumed a kind of parasitism and mimesis similar to that of the malaria that it sought to cure. By erasing Quechua knowledge and claiming its “discovery”, the story of modern European pharmacology often became one of narrative parasitism that unfolded in parallel with bodily disease. And ironically, it was many of those who had been victims themselves — the Portuguese who suffered from the Inquisition, for instance — who assumed important roles in these processes.

[i] De Castro Sarmento, Jacob. Do Uso, e Abuso das Minhas Agoas de Inglaterra, ix. “corria outro remedio com o mesmo nome, mas na invençam, e preparaçam muito differente; nem seu Autor, que fez sempre segredo de dizer, o de que se compunha o tal remedio, lhe atribuio ja mais ontras virtudes, ou propiedades, que a de curar as febres intermittentes”

[ii] Ibid., iii-iv. “Em toda a Historia natural, se naō tem feito mayor descobrimento ate este dia, nem mais interessante à Natureza humana, e saude publica, do que o da quina quina; e pareceme a mim, que em toda a Historia Medica, se naõ acharàm registrado tantos, e com tanta individuaçam, os pasmozos effeitos desta admiravel casca, como neste pequeno livro que offereço a V. Exa.”

[iii] Ibid, xii. “muito inclinado a entreprender numa Historia natural do nosso Brasil”

[iv] Ibid., xii. “na quelle Dominio, tem depozitado a providencia muito mayor, e mais inextimavel thezouro, a descobrir por meyo de numa Historia natural, do que todas as pedras preciozas e o ouro que das suas minas se podem extrahir”

[v] Ibid., vi. “feliz descobrimento”

[vi] Ibid., 257. “me lembro, que havendo recebido meu Pay hum tiro de bala, em huma perna, na sua mocidade, e ficandolhe nella, como manifestamente lhe percebia; muitas vezes lhe ouvi declarar, que depois da cura que se lhe fez, ja mais padecera o menor inconveniente ou molestia, no lugar, ou perna, donde lhe ficou a tal bala, sendo que morreo de oitenta e seis annos, e a levou consigo a sepultura”

Jessica Sequeira has published the novel A Furious Oyster, the story collection Rhombus and Oval, the essay collection Other Paradises: Poetic Approaches to Thinking in a Technological Age and the hybrid work A Luminous History of the Palm. She has translated many books by Latin American authors, and in 2019 was awarded the Premio Valle-Inclán. Currently she lives between Chile and the UK, where she is based at the Centre of Latin American Studies at the University of Cambridge.

Featured Image: Quina quina, as seen in the end pages of Do uso, e abuso das minhas Agoas de Inglaterra by Jacob de Castro Sarmento. (Detail). Courtesy of Universidade de Coimbra Digitalis.