It seems rather ironic to be writing about ‘heat’ in the middle of a heatwave. I’m not sure anyone in Britain at the moment is keen to increase their level of heat any further! However, according to humoral theory, which underpinned many medical recipes throughout the medieval and early modern periods, heat could be a very good thing when men and women wanted to reproduce. Heat, in the humoral sense, was believed to aid both sexual performance and fertility, and ‘hot’ foods and medicines were recommended as aphrodisiacs and fertility aids in many ancient, medieval and early modern medical texts. Jennifer Evans has set this out very nicely for the early modern period – see her book and her post on the Recipes blog from 2013. But heat wasn’t always a good thing: in some circumstances too much heat could also be a problem for fertility, and in that situation ‘cold’ foods and medicines might be suggested.

In my own work on the medical recipe books of the fourteenth and fifteenth centuries, then, I would expect to find a range of recipes to aid conception which include ingredients designed to raise or reduce a person’s heat. Although recipes were written in less complex language than Latin medical texts, and focused on treatment rather than theory, the recipes in these collections were often drawn from longer Latin medical works and so were often based on humoral theory even when this was not made explicit. Nevertheless, my initial survey of recipe manuscripts in the Wellcome Library, British Library and Cambridge University Library suggests that the picture was more diverse than this. I haven’t made a comprehensive search – and, given the number of unpublished medieval recipe manuscripts, I probably won’t be able to – but the recipes to aid conception that I’ve found so far work on a variety of principles.

Some do seek to adjust a person’s heat in order to correct a perceived humoral imbalance. For example, a series of recipes in Latin in Wellcome Library MS 541, a fifteenth-century medical miscellany of unknown provenance, is explicit about this.

In a chapter on ‘Impediment of Conception’ it includes recipes for:

If the sterility is because of cold humours… (Si sterilitas fuerit propter humores frigidos…)

If conception is impeded because of too much moisture… (Quod si propter nimiam humiditatem conceptio impediatur…)

If there is a distemper of heat or dryness in the woman which impedes conception… (Quod si caliditate aut siccitate fuerit distemperancia in muliere impediens conceptionem…)

In each case the first stage is to purge the excess humours, and then a selection of baths, plant remedies and suppositories is recommended. (Wellcome Library MS 541, ff. 137r-v)

The whole manuscript is digitized on the Wellcome Library website here.

Similarly British Library MS Harley 2378, quoted by Henslow in an edition of fourteenth-century medical recipes, also mentioned lack of heat as a cause of women’s infertility and suggested a cure to raise her heat:

‘For a womman þat may not bere no chyld for colde blode: Take and let hire blode, and take trisandali and diapendion, and take and ley þem to-gedere with hony, and ete iche day þer-of, and haue blode bothe hote and gode.’ (G. Henslow, Medical Works of the Fourteenth Century (London, 1899). p. 104.)

However, in many other cases the recipes found in fourteenth- and fifteenth-century manuscripts are not obviously heat-related. Instead many of them require the man, woman or both to ingest animal parts, particularly genitalia. These recipes work on another theoretical framework with a long history going back to the ancient world: the idea that certain substances were able to stimulate the reproductive organs because of a certain sympathy with them. For example several fourteenth- and fifteenth-century manuscripts of the Liber de Diversis Medicinis, a collection of recipes in English, include a series of recipes involving animal genitalia. To help a woman conceive a male child, ingredients such as the womb and vagina of a hare; the testicles of a hare; and the liver and eyes of a pig (see Catherine Rider, ‘Men’s Responses to Infertility in Late Medieval England’, in The Palgrave Handbook of Infertility in History, ed. Gayle Davis and Tracey Loughran (Basingstoke, 2017), p. 281).

All of these recipes derive – directly or indirectly – from the Trotula, the twelfth-century Latin compendium of women’s medicine edited by Monica Green, although there were some changes in the process of transmission: the Trotula recommends the liver and testicles of the pig, rather than liver and eyes (see p. 77 in Green). These recipes from the Trotula appear frequently in recipe collections from medieval England: the pig’s testicles appear again in Wellcome Library MS 407 (f. 61r), ‘Against sterility’.

As Green has shown, numerous manuscripts of the Trotula circulated in England, and the treatise had several Middle English translations, so perhaps it is not surprising that its remedies turn up frequently in recipe collections. Recipes based on animal parts have also featured on the recipes blog before: to take just one example, Laurence Totelin mentioned the use of a deer’s penis as an aphrodisiac in ancient Greece back in 2015. The Trotula did also discuss the ways in which too much or too little heat might make men or women infertile (see Green’s translation, pp. 85-7). Nevertheless, its influence and the popularity of its genitalia-related remedies means that treatments based on heat and humoral theory were not the only fertility aids available to readers of medieval English recipe collections. In the future I’m hoping to look in more detail at which aids to conception were particularly popular in English medical texts, and what that might tell us about the transmission of information from earlier Latin medical works. But at the moment the picture – as regards heat – is looking rather diverse.