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.