Tag Archives: robert boyle

“Take Good Syrup of Violets”: Robert Boyle and Historical Recipes

By Rebecca Laroche, in consultation with Steven Turner

Some time ago, Steven Turner of the National Museum of American History and I published our discovery that Robert Boyle’s Experiments and Considerations Touching Colours (1664) reflected knowledge held in historical recipes.[1] In particular, one experiment began with the observation, also recorded in recipes attributed to women, that syrup of violets and syrup of roses changed color when an acid, e.g. lemon juice, was added to it. The juxtaposition of this experiment with historical recipes has led to a second line of questioning, as Boyle begins the experiment with the direction to “take good Syrrup of Violets.” This phrase, coupled with the observations that there were many different recipes for the syrup (two manuscripts at the Wellcome Library have four separate entries),[2] led us to ask what constituted “good syrup of violets” among the many kinds.

Indeed, the basic ingredients—violets, sugar, and water—show very little variation (excepting the addition of acid). One could argue that the recipes differ most notably in the amount of sugar relative to the violets, but the recipe texts also vary in the ordering of the process and the time of boiling the water (sometimes with the sugar). Many pointedly say to “make itt into syrup without boyling.”[3] For example, this recipe held by Elizabeth Jacob (1654-c. 1685) repeats that it is the “best way not to boile the sirup at all,” ending with the direction “leting them come at the fire, w[ith] the flowers in spoiles the colour quite . . . if you will boile it be sure to leaue noe flowers in the Sirrup and boile it a little, though it is not the best way.”[4]

Wellcome MS 3009, image 215.
Wellcome MS 3009, image 215.

Other recipes set flower juices, water, and sugar either in the sun, over low charcoals, or in a waterbath/double boiler, or they add boiling water to the flowers. These are all gentler ways of dissolving the sugar, while boiling the ingredients together would lessen the quality of the syrup.

In looking at the larger record, we observe a tension between preserving efficacy and color and the desire for a longer shelf-life for the syrup. Thus some recipes may attest for it lasting a whole year, but they also require the boiling of the sugar, water, and violet juice together. Two recipes juxtaposed, therefore, may on the left call for boiling all ingredients together, while on the right admonish to “be sure it doe not boyle.”[5] Given an abundance of violets, the recipe maker is left with a choice: to boil or not to boil the flowers.

To anyone who has made preserves, this variation would make sense. Without refrigeration, a solution made with fresh flowers, sugar, and water would have lasted only a month or so,[6] whereas the boiling together of all of the syrup’s ingredients meant a longer shelf-life (if sealed adequately). The downside of this shelf-life, however, would be the loss of freshness, and with that freshness the full medicinal and aesthetic benefits. Syrups infused with fresh flowers tasted better and had a more vibrant hue, i.e. more medically efficacious, thus not boiling the flowers was perceived as “the best way.” Clearly, the unboiled syrup was seen to have qualities special enough to sacrifice longevity. This may not be overtly articulated in every record, but it may be implicit in the juxtaposition of more than one recipe.

When we re-read Boyle’s experiment in this light, we see that it reflects these discernments. In specifying that it is “good Syrrup of Violets,” Boyle points to the syrup made “the best way.” Steve Turner puts the effect this way:

Above 212 degrees (F) some of the liquid inside the cells actually turns into a gas [and] this ruptures the cell walls. The process produces more juice than mashing them in a bowl, . . . But there is also a corresponding loss of flavor, color and chemical sensitivity the longer the Syrup is boiled. The Syrup lasts longer but isn’t as delicious or as sensitive. . . . The Syrup [doesn’t lose] all chemical sensitivity if it is boiled . . . but certainly the longer and more vigorously it is boiled, the more is lost.[7]

The idea that a pre-scientific version of this knowledge is behind Boyle’s experiment is what led us to this juxtaposition in the first place. There are collective observations made in recipe-making that may not be attributed to any one individual but are rather shared in the transmission of one recipe by men and women alike.

[1] This entry builds upon Steven Turner and Rebecca Laroche, “Robert Boyle, Hannah Woolley, and Syrup of Violets.” Notes and Queries 58 (2011): 390­–91. The research was in part made possible through a short-term fellowship from the Chemical Heritage Foundation.

[2] Wellcome MS 7818.

[3] Wellcome MS 7849/0032.

[4] Wellcome MS 3009/215. My thanks to Pamela Spangler for her help in sorting through the Wellcome online database in a timely manner.

[5] See, for example, Wellcome 7892/175.

[6] One non-boiling recipe at the Wellcome states that after “one month, or 6 week,” mold may start to grow. Wellcome MS 2330/4.

[7] Steve Turner, e-mail to Rebecca Laroche, February 6, 2011.

Mistletoe: Not just for kissing?

By Jennifer Munroe

As the holiday season draws near, mistletoe might come to mind, since the tradition of kissing under this otherwise culturally-absent plant prevails today. Native to North America, mistletoe grows in the west as well as in areas of the east. The first time I saw mistletoe growing high in the tree canopy as I was driving down the highway here in North Carolina, it seemed somehow out of place, with its wispy tendrils, quite unlike the version I’d seen in stores over the years. In England, mistletoe, or viscum album, grows as a shrub, with its small, yellow flowers and white, sticky berries. It seems that today, the extracts of European mistletoe has been used for seizures, headaches, and even to treat cancer. And to think: I thought it was just for kissing.

Imagine my surprise, then, when I came across the following references to mistletoe from correspondence between Katherine Jones, Lady Ranelagh, and her brother, Robert Boyle. Both letters express Jones’s concern for her sister-in-law, Margaret Boyle, as she suffers from frequent bouts of “scurbitical humour,” or fits related to scurvy.

In the first letter, Jones refers to a quantity of mistletoe that she has found in the recently-deceased Lady Clarendon’s “case”:

“Nature being soe farr weakened as to be unable to worke together wth ye remedys ye Dr had upon consulte agreed to give her. None of all which had so visible an operation as to wakening and rousing her as a large bottle of very quick spirit of Hartshorne that I procured for he held under her nose which ye Dr confesed was as proper as any thing that could be use to her (& which I give you notice of to invite you to put yourselfe into a good stock of it for my Dearest Sisters use which how you may doe, one that I know having lately stilled it in good quantity & selling it for 5s an ounce. Halfe a pinte would be enough for you at once which was about what we now had for this poore Lady … I intend this night if I can get Dr Cox to discourse with him about her, & then send you wt he directs his power he thinks rather better than ye Misselto I found in my Lady Claringdons case that ye Dr [saw her] foaming & puking at ye mouth differing things in these fits he she did ye later at least…” (BL Add 75354, ff. 101-104: Letter from Katherine to Robert 10 Aug, 1667?).

In the second letter, dated a week later, mistletoe is prescribed as a possible remedy for Margaret Boyle’s fits, but an alternative remedy, a “hartshorn spirit” of Jones’s making, figures as again as an arguably superior treatment:

“The misselto may be given about ye changes of ye moone if it could be got in quantities enough to be so employed but because its so great a raretie its seldome given but in a fit or upon discovery of ye approach of one. My Lady Warwicke is not yet come home when she does I shall god wiling make her send you some but my Lord Dretzwel can furnish you for he has one growing. Ye Hartshorne spirit I have spoken for as you [requested] but know not how to send a halfe pint bottle by ye post & therefore shal desire Mr Graham to send it as fast as he can” (BL Add 75354, ff. 107r-110v, dated  17 Aug 1667?).

While there is much that could be said about these letters, what’s curious to me is the way that mistletoe and hartshorn spirits function as competing treatments for scorbitical fits [related to scurvy] (and earlier in the first letter, ironically, the doctor insisted that Margaret Boyle not eat raw fruit when she began to feel unwell). Jones seems not quite to want to contradict the doctor’s prescription of mistletoe, but she certainly suggests her hartshorn might be more effective. In the first letter, that is, she makes it clear that even the doctor “confesed” that her hartshorn spirits, waved under the nose (which she can sell to interested parties for 5s an ounce, by the way…) vivified the ailing Lady Clarendon more effectively than other applications; and it seems the “foaming & puking at ye mouth” that Lady Clarendon experienced may well have stemmed from her use of the mistletoe in her case, as mistletoe ingestion induces vomiting. In both recipes, the references to mistletoe as a treatment are followed almost immediately by those for Jones’s own (and obviously preferred) hartshorn spirits, made from the shavings from a hart’s antlers, which produces ammonium carbonate. And while it seems that such a remedy would likely be an irritant to its user, Jones swears by it. Or at least she swears by her spirit of hartshorn. Maybe it is better, though, to leave the hartshorn on the hart and the mistletoe for kissing and just eat some fruit—or some fruitcake.

On the “Oil of Swallows”, Part 1: Did anyone actually use these outrageous remedies?

By Michelle DiMeo, with Rebecca Laroche

Part of the appeal of old medical remedies is that many are filled with seemingly outrageous ingredients. A recipe “For deaffnesse” attributed to Sir Kenelm Digby, Fellow of the Royal Society, required one to “Take a hare new killed, Take out the bladder in which you will still find some urine … soe pouer into each eare by degrees”. The recipe concludes by suggesting one continue to do this “for several dayes with new hares”.[1] The chemist Robert Boyle’s medical remedy book includes plenty of unsavory ingredients, including wood lice and earth worms, as well a treatment for dysentery that involves drinking baked pig’s dung.[2] This, coupled with the fact that many early modern recipe books do not show all the burns, spills and edits one would expect to find in a heavily used book, leads to the question:  did anyone actually make these recipes? If so, how’d they accomplish it?

The “Oil of Swallows” is one such remedy. An early version may be found in Thomas Dawson’s The Good Husvvifes Ievvel [Housewife’s Jewel] from 1587, which begins “Take eight Swallowes readie to flie out of the nest, driue away the breeders when you take them out, and let them not touch the earth, stampe them vntill the Fethers can not be perceiued” (fols. 50r-50v). It also requires the addition of approximately five herbs to be mixed with butter, and it eventually produces an oil that should be externally applied to aches and bruises.

The recipe continues to evolve over the next 100 years and seems increasingly less believable. By the mid-seventeenth century, “Oil of Swallows” is almost ubiquitous in recipe books; however, the number of swallows greatly increases, as do the number of additional ingredients. This may be due to certain print versions of the recipe, such as that found in Gervase Markham’s The English House-vvife (1615), which requires more than two dozen separate ingredients and as many as 20 live swallows. This example from an anonymous manuscript compiled over the late-seventeenth and early-eighteenth centuries requires over twenty ingredients and “twenty Young Quick Swallows”, showing just how complicated the recipe became:

Late-17th-Century Recipe for "Oil of Swallows"
Wellcome Library, Western MS 1795, fol. 222v 

A historian’s first instinct might be to dismiss this as a remedy that was never actually tried. After all, how did they catch 20 live birds, and how did they beat them all in a mortar without the birds flying away? However, a closer reading of how the recipe language evolved over time shows contemporaries trying to sort through these complicated issues, providing tips for how and when to capture the birds, and what to do if you can’t get enough. Dawson’s recipe, quoted above, is an early example of this.[3]

But perhaps the best evidence that the “Oil of Swallows” was used is an undeniable reference to the final product in Elizabeth Isham’s autobiographical “Rememberance”, written around 1639. Isham recalls having a recurring pain in her thigh in her early adulthood. In her closet, she found a glass jar, which, upon opening, she “thought it to be by the smell oiles of swallowes”. She deduced that it must be about 40 years old and that it was made by her great grandmother “Who was … very skillful in Surgery”. Isham’s aunt “thought it might have some virtue because it retained the sent [scent]. Being close stoped.” So Isham applied the ointment to her aching thigh and found some relief, noting that “it [came] foorth in a rednes and after weared away by de grees”.[4]

Isham’s “Rememberance” makes it impossible for us to deny that the “Oil of Swallows” was actually made, and it provides contextual information to help us better understand the recipe.  If we continue to read recipes against other available archival material, including letters, diaries, and account books, we might continue to find surprising evidence that these seemingly outrageous remedies really were tried and approved. But while Isham testifies to the use of “Oil of Swallows”, we still don’t know exactly which ingredients comprised the final product she tried. And as Rebecca Laroche will explain in Part 2 of this blog post on Thursday, the ingredients in this remedy were sometimes even stranger than just swallows and herbs…


This blog entry has been from adapted research used in the essay Michelle DiMeo and Rebecca Laroche, “On Elizabeth Isham’s ‘Oil of Swallows’: Animal Slaughter and Early Modern Women’s Medical Recipes” in Ecofeminist Approaches to Early Modernity, ed. Jennifer Munroe and Rebecca Laroche (New York: Palgrave Macmillan, 2011) pp. 87-104.

[1] British Library, Sloane MS 1367, fol. 19v. Contractions have been silently expanded.

[2] Robert Boyle, Medicinal Experiments (London, 1692), p. 7.

[3] For more examples, and for a more detailed analysis of the language, see the original essay on which this blog post was based: Michelle DiMeo and Rebecca Laroche, “On Elizabeth Isham’s ‘Oil of Swallows’: Animal Slaughter and Early Modern Women’s Medical Recipes” in Ecofeminist Approaches to Early Modernity, eds. Jennifer Munroe and Rebecca Laroche (New York: Palgrave Macmillan, 2011) pp. 87-104.

[4] Elizabeth Isham, “My Booke of Rememberance”, Princeton University Library, Robert H. Taylor Collection RTC01 no.62, fols. 26v-27r. For an open-access modern spelling edition, see Constructing Elizabeth Isham, dirs.. Elizabeth Clarke and Erica Longfellow, http://www2.warwick.ac.uk/fac/arts/ren/projects/isham/