Snails in medicine – past and present

By Claire Burridge 

A treatment for teary eyes (Ad lacrimas oculorum):

Grind together frankincense, mastic, and snails with their shells. Apply to the forehead in laurel leaves in two parts. It is tried and tested.

(Tus et mastice et cocleas cum testas sua simul teris et in folio lauri in duabus partibus fronte impone probatum est)

Figure 1: A group of recipes for teary eyes (Ad lacrimas oculorum) in St. Gallen, Stiftsbibliothek, Cod. Sang. 44 (p. 359), an early medieval composite manuscript (this section was written in northern Italy in the ninth century) – the snail recipe is the last entry of the group (found on the final two lines). The transcription and translation are my own. A digitised facsimile can be accessed here; full reference below.

Medieval medicine is often assumed to be full of ‘hocus pocus’: irrational magical and religious cures, bizarre potions and lotions. Although the work of many scholars has countered this common perception, the negative stereotypes surrounding medieval medicine remain firmly embedded in the popular imagination. And I must admit that, as a historian of medieval medicine, I can understand how such stereotypes have persisted – despite, of course, disagreeing! At first glance, the treatment for teary eyes listed above – which recommends making a poultice from snails, frankincense, and mastic and applying it to the forehead – may sound more like a potion brewed by the witches of Macbeth than a useful medical prescription. Surely snails are better suited to escargot than medicine, right?

Yet our slimy garden neighbours actually have long been included as ingredients in medical recipes, from classical antiquity to the present day. In fact, a number of other RP posts have already touched on pre-modern snail-based prescriptions, such as Laura Mitchell’s post on amusing charms, Lisa Smith’s post on Mary Napier’s ‘Snaile Milke’, and Jennifer Sherman Roberts’ post on snail waters. While several examples have highlighted the use of snails in cosmetic preparations, including Katherine Allen’s post on animal ingredients in the eighteenth century, in my research on early medieval recipes I have come across snails as ingredients in treatments for all sorts of ailments, from headaches and nosebleeds to diarrhoea, spleen pain, and incontinence. Who knew snails were seen to be such a wonderful panacea?!

I have been particularly struck by the use of snails in a number of different treatments for cuts and open wounds. A recipe in BAV pal. lat. 1088, a ninth-century manuscript written around Lyon, suggests the following to heal ‘cut tendons’ (Ad neruos incisos) on f. 45r:

Burn and pound together live snails with their shells, add an equal amount of frankincense, apply. It heals cut tendons.

(Cocleas uiuas cum testa sua combustas et tonsas adiecto libano paripondere inponis praecisos neruos sanat)

Two other ninth-century manuscripts in the Stiftsbibliothek St Gallen, Cod. Sang. 751 and Cod. Sang. 759, contain nearly identical prescriptions, though the former recommends either slugs (limacis) or snails and the latter specifies that the cut was caused by iron (Ad neruus ferro precisus). Similar recipes can also be found in earlier sources, such as Pliny’s Natural History and its late antique descendent, the Medicina Plinii, as well as Dioscorides’ De materia medica.

Why did this tradition of the wound-healing power of snails catch my eye?

Figure 2: Materia medica on the move (slowly) – photograph by author.

As keen RP readers will know, the use of snails in cosmetics was not limited to pre-modern medicine but is, in fact, growing in popularity today (and you can read more on this in another piece from Katherine Allen). Snail slime, the mucus secreted by snails, has been widely marketed as a great addition to skincare products. You can find it in anti-aging serums, moisturisers, and other restorative cosmeceuticals. Given these uses, could snail slime also have applications in medicine? Indeed, snail slime is a hot topic in modern medical research, with recent work highlighting its many benefits, from helping to treat burns to its antimicrobial properties. With respect to wound healing, there are several significant features to note: first, snail mucus is well known to have agglutinant, adhesive properties. More recently, however, research has shown that it also protects against apoptosis (programmed cell death) and promotes cell migration and proliferation – processes essential to wound repair at the cellular level. The combination of snail mucus’ adhesive qualities, promotion of healing processes, and antimicrobial properties is immensely exciting, especially in the fight against antibiotic resistance.

While premodern medical practitioners and authors would not have been thinking about snails and their slime on the cellular level or as antimicrobial agents, their repeated use of snails and slugs, especially with respect to skin-related conditions (wound healing, cosmetics, etc.) suggests that they may have recognised that snail mucus had some medical benefits. So, the next time you encounter someone ridiculing the unusual or unpleasant ingredients in a medieval recipe, you can share with them the long history of snails in medicine – from medieval recipes and their ancient antecedents to current, cutting-edge research.

Full reference for manuscript image

St. Gallen, Stiftsbibliothek, Cod. Sang. 44: parchment, 368 pp., 30 x 21 cm; Part I: Bible, consisting of Ezekiel, minor prophets, Daniel, with Prologues and Capitula – given to St. Gall around 780; Part II: collection of medical texts – written in northern Italy in the ninth century.

Brief Academic Biography

Claire Burridge is currently a Residential Research Fellow at the British School at Rome. She completed her PhD at the University of Cambridge in 2019 and will begin a Leverhulme Trust Early Career Fellowship at the University of Sheffield in May 2021. Broadly, Claire works on early medieval health and medicine and is particularly interested in exploring questions of medical practice and the transmission of medical knowledge during the Carolingian period. Her research draws on a range of disciplines, bringing together textual, archaeological, and biocodicological evidence.

Revisiting Laurence Totelin’s Fevers and the Dog Star in Antiquity

Well, the Dog Days of summer are upon us once again…To help us cope with the heat, we revisit Laurence Totelin’s wonderful post from 2018.  In “Fevers and the Dog Star in Antiquity”, Laurence tells us about the origins of the term “Dog Days” and about various ancient remedies for seiriasis a fever whose name evokes the Dog Star Sirius. Keep cool, everyone! Elaine Leong

By Laurence Totelin

Summer this year in the UK has been particularly hot; we have experienced a heat wave for the first time in almost a decade. The hot days between roughly the tenth of July and the fifteenth of August are known as the Dog Days, so called because they are under the astronomical influence of the Dog Star (canicula in Latin, hence the French “canicule”, sometimes also used in English), also known as Sirius. Greek and Latin poets, starting with Homer and Hesiod, sang of the effects of the parching heat on the environment and people:

When the golden thistle blooms and the chirping cicada
Sits in a tree and pours down its shrill song
Continuously from under its wings, it is the season of exhausting heat,
Then goats are fattest, wine is at its best,
Women are most lustful, but men are weakest,
Because Sirius dries up the head and the knees,
And the skin is parched by the burning heat.
[Hesiod, Works and Days 582-588]

The constellation Sirius in the ninth-century manuscript Harley MS 647 . Source: wikipedia

To the Greeks, women were wet and men dry. The heat of the Dog Days caused both men and women to become drier; this brought positive effects to women, who became more like the ideal male, but weakened men. That weakness, however, was not a morbid state; it was not an illness.

Medical texts composed in later antiquity described a disease called seiriasis, which was an inflammation of the meninges accompanied by a burning fever. Its name evoked the Dog Star Sirius, although the physician Soranus of Ephesus suggested that the origin of the word seiriasis might be slightly more complex:

Some people state that the disease is called ‘seiriasis’ after the star [Sirius], because of the fever; but others state that it is thus called after the sunken forehead, because among farmers ‘seiros’ is the name of a hollow object in which they put and keep seeds. [Soranus, Gynaecology 2.55]

Soranus, and other medical writers, recommended the application of various ingredients to the forehead as treatment for the illness: egg yolk mixed with rose oil, the leaf of the heliotrope, grated colocynth, the skin of melon, or the juice of nightshade with rose oil. Most of these products, available in mid-summer, were thought to be cooling, and therefore effective in the treatment of fevers: opposite is a cure for opposite. The heliotrope, however, was not known as a cooling drug. The therapeutic principle at play here seems to be that of homeopathy (similar is a cure for similar): the heliotrope, the plant that follows the heat of the sun, is a remedy for a burning fever.

An altogether more colourful remedy for seiriasis is recorded in Pliny the Elder’s Natural History:

The inflammation of infants which is called seirasis is improved by the bones that are found in dog excrement, worn as amulets. [Pliny the Elder, Natural History 30.135]

Girl playing with a dog on a Greek funerary stele, second century BCE. Credit: British Museum

Bone shards are sometimes found in dog poop, and these might be what Pliny was referring to here. This ingredient was most certainly chosen because of the perceived link between seiriasis and the Dog Star Sirius. One can only imagine the despair that would lead the sleep deprived parents of a sick child to put their trust in such an amulet.

Revisiting He Bian’s Fetch Me at Pearl Nest Street: Rhubarb Pills as Panacea in Qing China

Today we revisit He Bian’s fascinating post from 2018. Here, He tells us about the global trade in Chinese rhubarb (dahuang) roots, panaceas and notions of difference in premodern theories of the body. Fascinated by this post and want to learn more about drugs in early modern China? You’re in luck as He’s monograph Know your Remedies: Pharmacy and Cultures in Early Modern China is now out with Princeton University Press. Have you ordered your copy? Elaine Leong

He Bian

In the late eighteenth century, American ginseng opened up a new niche market in Qing China. At the same time, Chinese rhubarb (dahuang) roots, harvested from the northwest regions of the empire, were transported by Chinese traders all the way to the southeast coast and sold off to foreign customers in Canton (Figure 1). Part of these transactions took place in the Ryukyu Kingdom (present-day Okinawa Islands), a vassal state of the Qing but also an important node of global trade that crisscrossed the West Pacific. At some point in 1789, the Qing court issued an edict to the Ryukyu king that explicitly forbade him from selling rhubarb to Russians, with whom the Qing was then engaging in an all-out trade war. Rhubarb featured prominently in the Qing strategy because they believed that Europeans imported so much of this drug that they could not live a day without it.[1]

Figure 1. Chinese or Turkish rhubarb (Rheum palmatum): flowering and fruiting stem with leaf. Coloured zincograph after M. A. Burnett, c. 1842. Credit: Wellcome Collection,
Figure 1. Chinese or Turkish rhubarb (Rheum palmatum): flowering and fruiting stem with leaf. Coloured zincograph after M. A. Burnett, c. 1842. Credit: Wellcome Collection,

Yet is it really true that pharmacological visions in early modern China and Europe were so different that they could not possibly reach a consensus over rhubarb’s properties ? Classical Chinese pharmaceutical literature listed rhubarb as a drug with a “very cold” nature, and generations of physicians were taught not to use the cold drug in curing cold-natured diseases. This suggested that Russians (and other Westerners, as seen in this post on rhubarb in early modern England) had different bodies than the Qing Chinese, as they depended on rhubarb as an all-round cure. Pharmacological theories, in other words, engendered a vision of difference that seemed insurmountable.

During my recent reading of Qing medical recipe books, however, I discovered that rhubarb in fact functioned as nothing short of a panacea for Qing Chinese. This is evident in the text Bianyong liangfang (Excellent Recipes for Expedient Use), which appeared in the Jiaqing reign (1796-1820). Compact (only 2-juan in length) and very nicely printed (with carved woodblocks), it arranges pills, powders, tinctures, and decoctions by symptom. The book has about 120 pages, and most recipes are merely a few lines in length. What surprised me was that one very long recipe at the end of the text takes up the entirety of 13 pages. The remedy in question, mi shou Qingning wan (Secretly transmitted pill of purity and tranquility), calls for “several dozen pounds” of good quality rhubarb roots as the principal ingredient. Rubbed clean and steeped in rice water, the rhubarb was sliced, sun-dried, processed with “ash-less good rice liquor” for three days, and then put through a lengthy, elaborate protocol of fifteen rounds of steaming. Each steam involved a different set of herbs. Finally, makers took the resultant rhubarb paste, mixed it with “yellow ox milk” (using cooked honey as substitute if there was no milk), boy’s urine, ginger juice, and rolled it into tiny pills. The recipe listed hundreds of common illnesses that could be treated with this pill, ranging from headache and hemorrhage to gynecological disorders.

Figure 2. Luo Benli ed. Bian yong liang fang. Vol. 2b, p. 50b. c. 1796-1820. Princeton University Library. Downloadable PDF available at
Figure 2. Luo Benli ed. Bian yong liang fang. Vol. 2b, p. 50b. c. 1796-1820. Princeton University Library. Downloadable PDF available at

I have tried to look up this recipe in earlier Chinese medical texts, and my preliminary findings suggest that it probably came into existence no earlier than the seventeenth century. It became wildly popular in the eighteenth century, and recipe books serve as evidence of its widespread consumption. On the last page of Bianyong liangfang (Figure 2), the compiler, Luo Benli, announced that he had a batch of rhubarb pills prepared during his tenure in Guizhou – a southwestern province of China – and that, in case of emergency, readers could “call upon my house on Pearl Nest Street” and look for the “residence of Mr. Luo of the Ministry of Defense (bingbu Luo zhai).” Pearl Nest Street (zhuchaojie), a neighborhood in Qing Beijing not far from the Forbidden City, featured prime real estate. As a military official who had served in the frontier provinces, Luo was less bound by medical norms of the day and possessed the financial and political capital to manufacture elaborate pills like these. Was there, in other words, a sub-culture of health and medication championed by military elites such as Luo, which stood distinct from classical prescriptions?

One last word about this recipe that hints at a hidden connection between different cultural realms in early modern China: Sun Xingyan (1753-1818), a prominent scholar who combed through medieval sources for fragments of ancient texts, published the same recipe for Pill of Purity and Tranquility in his scholarly series. The inclusion of this Qing text alongside ancient monographs so bewildered modern bibliographers that they mistakenly attributed the recipe’s author to a seventh-century figure. In fact, Sun Xingyan made it clear that it was a contemporary remedy and provided an elaborate scholarly argument to defend rhubarb’s all-around efficacy to cure both hot and cold-natured illnesses. He also suggested that “vulgar physicians” despised the pill because if everyone had access to this remedy then their businesses would be lost. Therefore it does appear that, when it comes to rhubarb, Qing Chinese scholars and military commanders were no less enthusiastic than what they imagined about the Russians.

[1] I recommend this excellent essay by Chang Che-Chia (translated by Penelope Barrett) for more on this curious episode.

Revisiting Chelsea Clark’s The Wonders of Unicorn Horns: Preventions and Cures for Poisoning

Editor’s note: Today, we revisit a wonderful post from Chelsea Clark in 2012 on the intersection of magic and medicine from Early Modern England. Drawing on the seventeenth century  manuscript ascribed to the herbalist Johanna St. John, Clark examines the symbolic power remedies to unwind magical forces.  In this case, the remedy for the malicious magic of poison rests on unicorn, bezoar stones, and the bones of stag hearts.  Magical ailments, after all, would necessitate magical cures.  R.A. Kashanipour

By Chelsea Clark

Johanna St John’s Book, Credit: Wellcome Library, London

In Johanna St. John’s recipe book, the mysterious “Banister’s Powder by Dr Bates” lay nestled between the equally intriguing “Mrs Archers way of makeing My Lady Kents Powder” and the beginning of the letter “R” section of St. John’s efficiently organized recipe book. There is no indication what type of recipe this “Banister’s Powder” was, besides a powder, or what it’s intended use was. Following several pages of recipes for “pox” and “pills” this “Powder” is the tail end of St. John’s letter “P” section, however, even knowing this context offers little information. An analysis of the “Banister’s Powder” ingredients suggests a link between St. John’s early modern medicinal recipes and the presence of magical beliefs associated with medicine in the early modern period.

The first three ingredients required to make the “Banister’s Powder” are: powdered Unicorn horn, east bezoars, and the “bones” of a stag’s heart. Each of these ingredients had longstanding associations with the belief they were capable of preventing or countering the effects of poisoning. To a modern eye, these appear strange items to reside alongside many complicated recipes which rely on an expansive knowledge of medicinal, rather than magical, properties. These ingredients indicate that magical beliefs remained acceptable practices among home practitioners in the early modern period. This is possibly because the science to disprove them was not advanced and medical practitioners were only beginning to be skeptical and move away from such unreliable remedies.

The prevention and cure of poisoning was a genuine concern before and throughout the early modern period. It was quite common to be bitten or stung, to consume poisonous berries, roots, or herbs, or to believe a spell had been cast by a witch (Jackson, 96). It was also common for physicians to diagnose poison as the cause when they could not determine the source of an ailment (Auble, 17). This led to the necessity for remedies to detect, prevent and cure poisoning.

Rhinoceros Horn Vessel, Credit: Wellcome Library, London


Pharmacy sign, Credit: Wellcome Library, London

Unicorn horns were actually believed to come from the mythical creature and possess its symbolic purity and strength, though they were most often a narwhal tooth or powdered rhinoceros horn. The horns were commonly powdered and used in poison antidotes or as vessels to drink from before or after ingesting poison (Jackson, 97). Unicorn horns were also believed to have properties which allowed them to detect poison (Knight, 245). In addition to being thought to detect, prevent or cure the effects of poison, the horns were also thought to strengthen your heart, relieve headaches, resist the plague and pestilence, expel measles and small pox, and cure “falling sickness” in children (Brockbank, 3) all of which were reoccurring ailments in the early modern period.


Bezoar stones were solid masses from the intestines of goats, sheep or deer that were primarily believed to detect poisons but also, in some cases thought to provide a cure if small amounts of the stone were consumed. “Oriental” or “East” Bezoars, as St. John called for, were the most valuable type which came from a Persian wild goat (Jackson, 97). It was occasionally consumed, but more commonly mounted on a chain and dipped in to drinks to nullify the effects of poison if there was any (Jackson, 97). Queen Elizabeth I reportedly kept one “sett in golde hanging at a little Bracelett … The most parte of this stone being spent” indicating the Queen mounted and consumed her stone (Auble, 18).

Mounted Bezoar Stone, Credit: Wolfgang Sauber

The belief in the magical powers of the “bones” from a stag’s heart originates from a folk tale. The tale is that stags ate poisonous snakes by sniffing them out of holes and then after which they rushed to drink water. The “bones” in their heart were believed to be what protected the stags from being poisoned. The “bones” were actually caused by the degeneration of arteries into flat, oblong bone like objects. Powdering and consuming this “bone” was seen as a preventative measure to protect against the effects of poisoning (Jackson, 97).

Unicorn horn, bezoars and “bones” from a stag’s heart, were the key ingredients to the “Banisters Powder” in St. John’s recipe book. Because of the longstanding beliefs about these ingredients and their associations with poisoning detection, prevention and cures, this recipe was perhaps intended to cure or prevent poisoning. One can imagine the remedy would have been thought to be fool-proof against poison because it combined the powers of each of these ingredients. Although there was a movement away from magical remedies and cure-alls among physicians in the Early Modern period, belief in the curing power of magical objects was still present in the lives of home practitioners such as Johanna St. John. What we would consider scientifically impossible, they were only beginning to discover.

A strong belief in unexplainable phenomenon was common practice and popular beliefs are difficult to dispel, especially when they hold significant symbolic value. Just the other day the North Korean state media associated the discovery of a Unicorn Lair with their new young leader. It is hoped this association would strengthen the nation’s confidence in their young leader because of the symbolic meaning of the Unicorn and its ties to the state’s history. This example illustrates that a belief in the symbolic power of an object, like a Unicorn or its horn, bezoars, or “bones” from a stag’s heart can transcend both time and logic, persisting even when its truth is questionable.

Works Cited:

Auble, Cassandra. “The Cultural Significance of Precious Stones in Early Modern England.” Dissertations, Thesis, & Student Research, Department of History, University of Nebraska Paper 39 (2011).

Brockbank, William. “Sovereign Remedies: A Critical Depreciation of the 17th-Century London Pharmacopoeia.” Medical History 8.01 (1964): 1-14.

Jackson, William A. “Antidotes” Trends in Pharmacological Sciences 23.2 (2002): 96-98.

Knight, Katherine. “A Precious Medicine: Tradition and Magic in Some Seventeenth-Century Household Remedies” Folklore 113.2 (2002): 237-247.