Poison is in everything… by Carolyn Hughes

Paracelsus, the sixteenth century Swiss physician and alchemist, said: “Poison is in everything, and no thing is without poison. The dosage makes it either a poison or a remedy.”

An engraving by Pieter Van Sompel (1600?-1643?) of Swiss physician and alchemist
Paracelsus (born Theophrastus von Hohenheim).
After Pieter Soutman, Public domain, via Wikimedia Commons

Of course, I did know that already, about dosage level making the difference between a killer and a cure, but when I was writing my latest Meonbridge Chronicle, Squire’s Hazard, set in fourteenth century southern England, I needed to know a little more about how plants might be used for good and also for ill.

I refer to plants quite extensively in my novels – gardens are an important theme. I often mention the vegetables grown in peasants’ gardens, especially those used in pottage – onions, turnips, cabbages and the like. Flowers feature too, for the most part those grown in the manor garden. Herbs were undoubtedly grown in the gardens of both rich and poor, to add flavour to food, but also, I imagine, to make remedies for common ailments. As I understand it, ordinary folk – women mostly – would have known something of this therapeutic use of herbs and wild flowers. In one of my novels, I refer to blue scabious (scabiosa) being considered good for curing itchy skin, and to the tiny white flower called eyebright (euphrasia) being used to treat sore eyes.

I’ve also mentioned often the medicinal use of plants, such as in the various salves and lotions used by the Meonbridge barber-surgeon. I’ve imagined him preparing them himself, though he might have acquired them from a different sort of healer, a “wise woman”. There was such a woman in Meonbridge, sought out mostly for her beneficial herbal cures, but also for magic charms and potions, which might be used for good or for ill.

For my most recent book, however, I needed to know more about the less beneficial properties of plants. For one of my characters was wondering how she might silence a lout’s abusive, misogynist tongue. She thought maybe some toxic plant might do the trick, but didn’t know which one, or how to use it, or what effect it might actually have. In truth, at that stage, neither she nor I were even sure how her desire for retribution might unfold, but I thought I’d help her devise a plan with a bit of investigation into the varieties and effects of toxic plants.

My reading led me first to wolfsbane – Aconitum napellus, also known as monkshood or devil’s helmet. I did know already that it was toxic, but not what symptoms it caused. I learned that long-ago hunters of wolves used to dip their spear and arrow heads into a wolfsbane brew and that it acted fast, causing the victims to die “without a struggle”, which is what the Greek word akoniton – ἀκόνιτοv – means. Apparently, it was used also on the battlefield.

Wolfsbane or monkshood (Aconitum napellus) By Walther Otto Müller,
in Flora von Deutschland, Österreich und der Schweiz, 1885.
Public Domain, via Wikimedia commons

But would it do the trick for an unmannerly misogynist? The symptoms of wolfsbane poisoning seemed promising, with laboured breathing and weakening heartbeat, and in particular the numbing of the mouth and tongue. Perfect!  On the other hand, if one got the “dosage” wrong, the odious tongue might well be stilled for ever…

So how much of a hazard was wolfsbane? It seems that most recorded deaths from wolfsbane poisoning have been accidental, but I found a few mentions of its use as a murder weapon. One interesting case was of a man who died after his wife combined boiled-up wolfsbane leaves and stems with crushed sleeping tablets and added the concoction to his wine. She then made his death look like a car accident, but confessed to the murder five years later (why she confessed, the article didn’t say). But, extraordinarily, traces of the aconitine were allegedly still to be found in the poor man’s body. Persistent stuff! And maybe too much of a hazard for my character to contemplate?

So, I looked at other plants that she might use. Three seemed to have potential.

Hemlock. In Atlas der officinellen Pflanzen, O.C. Berg, C.F. Schmidt.
Public domain, via Wikimedia Commons

Eating the bright red berries of the cuckoopint or lords and ladies, Arum maculatum, can apparently cause the lips, mouth, tongue and throat to burn and swell. That sounded useful. But, I read, because the unpleasant sensation begins as soon as the berries touch the lips, they would have to be very well disguised to be effective as a weapon. Hemlock (Conium maculatum) too might work, with respiratory failure and loss of speech listed as symptoms, but it tastes bitter and has an unpleasant smell, so again would need to be heavily disguised. 

Tasting the glossy black berries of Atropa belladonna (deadly nightshade or devil’s cherries) can result in a dry mouth, confusion and incoherent speech. And, more usefully, the berries apparently taste sweet, so ground up in something also sweet, like cake or wine, might make their presence relatively easy to conceal…

Belladonnna. In Köhler's Medizinal-Pflanzen, Franz Eugen Köhler.
Public domain, via Wikimedia Commons

I read all this and shared it with my character, through the medium of Meonbridge’s wise woman. Despite the woman’s reputation (amongst some of Meonbridge’s populace) of being a witch – a common enough problem for medieval wise women – she in fact gives sound and cautious guidance about the pros and cons of using wolfsbane, belladonna and the others, essentially employing Paracelsus’s dictum (albeit that physician would not be born for another 130 years): dosage is everything.

What my character decided to do with the information given to her is not relevant to this article. But I read a little more about how some of these “poisons” can indeed also be “cures”, provided they are administered in appropriate amounts.

In herbal medicine, wolfsbane has been used as a treatment of joint and muscle pain, as a diuretic, for reducing fever and inflammation, and also as a means of slowing the heart rate in people with cardiac problems. However, it is not used today in conventional medical practice.

Deadly nightshade, on the other hand, is used in modern medicine. Apparently, its constituent compounds can help with nausea, acid reflux, controlling the heart rate and the treatment of other conditions, and is an ingredient, in tiny quantities, in many medications. It is also of course well known historically as a cosmetic. The name belladonna alludes to the “beautiful women” of sixteenth century Italy, who used an extract of it to enlarge their pupils and flush their cheeks, which was considered attractive at the time. Those ladies presumably considered their cosmetic “beneficial”, but I imagine it often led to most undesirable consequences…

In my novels, the Meonbridge barber-surgeon uses belladonna for remedial purposes in the form of “dwale”, an anaesthetic used when performing surgery. Although I’ve read elsewhere that dwale was made, not from belladonna, but from a combination (again, presumably in small quantities) of hemlock, opium (poppy, Papaver somniferum) and henbane (Hyoscyamus niger, another member of the nightshade family), mixed with lettuce (perhaps surprisingly!), vinegar and other substances. It was apparently mixed with a great deal of wine before being given to the patient to drink. I wonder if a surgeon would have mixed the dwale himself? With those ingredients, it sounds a risky thing to do! However, dwale was widely known about in medieval times, and I’ve read that recipes for it might have been found in domestic herbals, and could have been administered by housewives. Extraordinary, if true!

One last thing. Again, for my latest Chronicle, as the story progressed, it turned out that I needed to know how a housewife might treat her precious cows’ mastitis. I delved into the sources once again, looking for what medication medieval people might have used. I came across no specific historical reference, but did discover – and was not at all surprised to learn – that, in modern homeopathy, belladonna is yet again the answer, as a remedy for easing inflammation, including mastitis. Whether my housewife, who owns a great book of herbs, would really have known of its use, I don’t know. But I can guess that, if women like her knew of “dwale”, they would probably also know about belladonna as a treatment for inflammation. And, of course, once more I have her understanding the principle of suitable dosage when she explains to her prying servant: “It is poisonous, but only in large measures. The scant amount I put in here is curative.”

Anyway, what is the point of this post of mine? I hope it’s been of some interest, this talk of poisons, but I’m sharing it as just one of many fascinating subjects that I’ve found myself exploring over the past few years. It’s a reminder of the joy of writing fiction, and especially perhaps historical fiction, when your imagination takes you in unexpected – and unfamiliar – directions, and you then find yourself diving down a veritable warren of research rabbit holes, to bring illumination and fascination to your story, but also – in my case anyway – for the sheer pleasure of discovery.