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Poison-Hmlock-art - 8/14/17

"Poison Hemlock - conium maculatum" by Baroness Adelindis filia Gotefridi.

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This article was first published in the Lochac A&S Newsletter "The Cockatrice".

Poison Hemlock - conium maculatum

by Baroness Adelindis filia Gotefridi.

This paper was written as an entry in the Ynys Fawr A&S competition, “Make or Document an Instrument of Assassination”, held at the Assassin’s Ball, September 9^th 2016.

Introduction

Hemlock as a poison has an ancient history. It was known to the Ancient Egyptians, being mentioned in the Ebers papyrus, a compilation of medical and toxicological lore dated to 1500BCE. As well as being the poison of choice for state executions in Ancient Greece (it is generally considered to have been the poison used to kill the philosopher Socrates in 399BCE), hemlock was referenced by a number of Ancient authors as used in suicide or euthanasia, particularly in the elderly[i], and is considered to be one of the more common poisons used in the Ancient world. William Hayes writes of the Romans: "Poisoners preferred plant poisons rather than animal or mineral poisons. Favourites included belladonna, aconite (Wolfbane, monkshood), hemlock, hellebore, colchicum, yew extract, and opium."[ii]

Unlike more violent means, poisoning is a difficult method of assassination to substantiate, due to the absence of forensic science in period and a medical model of knowledge, which was based on very different principles to ours. Deaths were often attributed to poison which may have been from other causes, particularly in periods when the danger of poisoning was considered to be rife, such as Rome in the first two centuries CE. Outside of legally sanctioned or semi-voluntary Greek examples such as Socrates, Theramenes and Seneca, which have come down to us in the works of classical historians, there are no historical deaths I can reliably identify as being directly caused by the ingestion of hemlock. Therefore the evidence I have collected relies on contemporary descriptions of the use of hemlock, both in medicine and in toxicology. There are also literary references which, while they can not be reliably substantiated as referring to historical poisonings or poisoners, still help paint a picture of how hemlock was seen in period.

Description of Conium Maculatum and its Effects

Description: Conium maculatum is a member of the carrot family and closely resembles other species of Apiaceae such as wild carrot, parsley and Queen Anne's Lace. It is usually a biannual, growing to about 45cms tall in the first year, and up to 1.8m in its second season, when it flowers. The root is long, white to pale yellow, and resembles wild carrot or parsley root. The stem is hollow, bright green mottled with purple splotches, and slightly ridged. The leaves are dark green, lacy and fernlike. Both leaves and stem have a strong, unpleasant smell when crushed, often described as being mouselike or resembling cat urine. The flowers are small, white and umbelliferous, and are highly attractive to bees. The seeds are small and slightly ovoid (2-3mm).

Toxicity: All parts of the plant are highly toxic, although the effects are most concentrated in the seeds and root. There have been eight alkaloids identified in poison hemlock, of which two - coniine and gamma-coniceine (the precursor to the other alkaloids) - are most prevalent. Coniine is reportedly up to eight times more potent than gamma-coniceine. The levels of the alkaloids in the plant can fluctuate considerably due to weather conditions, fertility of the soil, soil moisture, and ripeness, and even what time of day the plant is collected. Young green fruits contain more alkaloids than mature fruits, so the toxicity reaches its height as the fruit ripens, then reduces as it dries[iii]. The harmful dosage appears to be variable, but shows that a lethal dose of juices containing coniine is probably not very large:

In man [sic], 3 mg of coniine is said to have produced symptoms, but 150 mg have been tolerated without discomfort. Perhaps 30-60 mg is dangerous and death may occur with doses greater than 100 mg. It has been reported that a lethal dose may be 6 to 8 fresh leaves.[iv]

Effects and Treatment: The International Program on Chemical Safety's Poisons Information Monograph (PIM) on c. maculatum describes the primary effects as follows:

The clinical effects are mainly neurological and when death occurs it is probably secondary to respiratory paralysis with hypoxia. The most prominent signs are due to peripheral paralysis and loss of sensation... Seizures may occur terminally. (Lampe, 1985; Geehr, 1984; Gosselin, 1976; Dreisbach, 1987).[v]

There is still no known antidote to hemlock poisoning, and - then as now - treatment involves inducing vomiting to prevent further absorption in the stomach, and supporting the patient while the toxins already absorbed pass through the body. Modern treatment could also include sedation and artificial respiration, with other treatments administered as needed[vi].

What Killed Socrates? Historical confusion between Conium maculatum and Cicuta virosa

The first difficulty in any investigation into the herb known as cicuta in sources from Rome through to modern times is ascertaining which plant is being talked about. There has been a considerable degree of confusion for many years as to the nature of the poison which Socrates was given - Plato himself did not name it, referring only to "the poison", although Pliny refers to hemlock (disapprovingly) as the judicial poison of the Greeks[vii] - which illustrates the difficulty of tracing references to c. maculatum in the sources.

This confusion is largely linguistic in origin. The Greek name koneion and Latin name cicuta were used by classical authors to refer a highly toxic plant, translated as "hemlock", and most likely what is now known as c. maculatum. The name cicuta continued in that usage in later Islamic and European works drawing on the classical texts, but was increasingly broadly applied. The word "hemlock" itself is from the Old English hemlic or hymlice, and the modern spelling first came into usage with Shakespeare[viii]. The usage of "hemlock" and "cicuta" became increasingly confused after the Romans, and eventually broadened to cover all known members of the hemlock family more or less interchangeably. The authoritative botanical name Cicuta virosa was given (by Gesner) to water hemlock in the 16th century, while poison hemlock was given its current name Conium maculatum (by Linnaeus) in reference to the Greek koneion - doing nothing to decrease the confusion[ix].

Pliny's description of cicuta from the first century CE is worth quoting in full, as the most complete classical reference I have found:

This stem is smooth, jointed like a reed, of a swarthy hue, often as much as two cubits in height, and branchy at the top. The leaves are like those of coriander, only softer, and possessed of a powerful odour. The seed is more substantial than that of anise, and the root is hollow and never used. The seed and leaves are possessed of refrigerating properties; indeed, it is owing to these properties that it is so fatal, the cold chills with which it is attended commencing at the extremities.[x]

Of this, only the description of the root as hollow recalls water hemlock more than poison hemlock. As Bloch argues, the description of the effects as "cold chills...commencing at the extremities" is far more reminiscent of slow peripheral paralysis than the violent "hot" convulsions of water hemlock toxicity. Indeed, the marked differences between the effects of the two plants has been the biggest reason for the confusion as to identification persisting into the 20th century.

Bloch summarises the modern debate, in which authors such as classicist Christopher Gill and pathologist William Ober, writing in the 1970s, and Bonita Graves et. al. in 1991, argued that the description given by Plato was distorted for political and philosophical reasons, in order to provide a picture of a dignified, peaceful death[xi]. However, she argues that this rests on the longstanding linguistic confusion between the various hemlock species contributing to a misunderstanding of the clinical effects of conium maculatum as being similar to that of cicuta virosa and other members of the hemlock family. Of all the hemlock species, c. maculatum is unique in possessing toxic alkaloids. She goes on to argue convincingly that linguistic and cultural evidence from the Greek and Roman sources combined with detailed nineteenth century scientific examination of the effects of c. maculatum paints a remarkably faithful picture of poison hemlock as the poison given to Socrates, and thus as the plant referenced as koneion or cicuta by most Greek and Roman authors[xii]. Because of this confusion, I will confine my discussion to the Greek and Roman sources.

Which Part of the Plant was Used?

As all parts of c. maculatum are toxic, the entire plant could have been utilised by poisoners. However, there are certain drawbacks which mean that some methods of preparation and administration seem more plausible than others. The distinctive acrid smell and bitter, burning taste of the fresh herb must limit its effectiveness as a surreptitious poison in food, since it could be easily detected by a trained taster or a sufficiently paranoid diner. I address the fresh leaves and root in the second section, on methods of ingestion.

The characteristic odour is at least in part attributable to coniine, which is a volatile a colourless [sic] liquid with a bitter taste (Schvarstman, 1979; Gosselin, 1976; Keelers, 1978).[xiii]

Since the source of the distinctive smell is partly also the source of the toxicity, it must be assumed that most methods of preparation would have to disguise the taste and smell. If not used fresh, there must have been some method used to concentrate and preserve the active compounds for storage and transport. The parts of the plant which will be discussed in this section on preparation are the seeds, juices, leaves and flowers. The primary sources I have found do not always specify what part of the plants were used in poisons (reasonably enough, since, particularly for the Romans, they would be wary of the potential for their work to be misused), so some of my argument will necessarily be conjectural.

Preparing the Poison

Seeds

There are a number of references to hemlock seeds in Celsus' works, but all refer to its medicinal properties rather than as a poison, and do not discuss methods of preparation[xiv]. Pliny describes the use of the plant thus: "It is the seed that is noxious, the stalk being eaten by many people, either green, or cooked in the saucepan."[xv] He goes on to write,

The seed is crushed, and the juice extracted from it is left to thicken in the sun, and then divided into lozenges. This preparation proves fatal by coagulating the blood—another deadly property which belongs to it; and hence it is that the bodies of those who have been poisoned by it are covered with spots.[xvi]

From this, it appears that the ancients understood very well that the seeds contained the highest concentrations of coniine, and that the concentration was highest in the ripe fruits.

Juices

From the linguistic evidence, the poison given to Socrates may have been prepared from fresh hemlock immediately before administration. When Socrates asked if he could offer some of the dose to the Gods, the jailor replied, "we prepare only as much as we think is enough."[xvii] Bloch, examining the original Greek with more facility than I can do, writes,

It is evident that [Socrates' jailor] crushed the hemlock, for when Socrates asked him to 'prepare' the poison, he used a form of the verb tribô, which means to crush, as in a mortar.[xviii]

Not knowing Greek, I cannot judge whether the same word would have been used for crushing a fresh herb and crushing a lozenge into powder to add to a liquid, but it appears that both the juices from the fresh herb and the concentrated and dried juices formed into a lozenge for storage were both used for their lethal properties.

Descriptions of a compound poison containing the juices of hemlock, which may be similar to that given to Socrates (both Bloch and Larsson argue for the likelihood that the hemlock was combined with opium), are given by Theophrastus in his Enquiry into Plants, written some time in the century after Socrates' death:

Thrasyas of Mantineia had discovered, as he said, a poison which produces an easy and painless end; he used the juices of hemlock, poppy and other such herbs, so compounded as to make a dose of conveniently small size, weighing only somewhat less than a quarter of an ounce. For the effects of this compound there is absolutely no cure, and it will keep any length of time without losing its virtue at all...

Now these things seem to have been ascertained far better in recent than in former times. And many things go to shew that the method of using the various drugs makes a difference; thus the people of Ceos formerly did not use hemlock in the way described, but just shredded it up for use, as did other people; but now not one of them would think of shredding it, but they first strip off the outside and take off the husk, since this is what causes the difficulty, as it is not easily assimilated; then they bruise it in the mortar, and, after putting it through a fine sieve, sprinkle it on water and so drink it; and then death is made swift and easy.[xix]

This would appear to indicate that the plant was crushed and the juices were sieved to remove the plant matter and added directly to liquid. The description does not indicate the exact part of the plant from which "they first strip off the outside and take off the husk", but it is possible this refers to the fruit. I'm not entirely certain how you would do this, given how tiny the seeds are, but taken with the reference to "bruising" (rather than grinding to a powder, as with the dried seeds), one interpretation could be removing the green fruits from the flower umbels before crushing.

However, Pliny refers to juices being extracted from the leaves and flowers as well as the seeds:

A juice is extracted from the leaves and flowers; for it is at the time of its blossoming that it is in its full vigour. The seed is crushed, and the juice extracted from it is left to thicken in the sun, and then divided into lozenges.[xx]

This could be read as two separate preparations, or as including the immature fruits as part of the flowers. Dioscorides supports that interpretation in his discussion of hemlock in the Materia Medica. While he notes that hemlock is "one of the venomous herbs", he does not mention lethal uses as an agent for suicide or euthanasia, and like Celsius, speaks only of the use of the juices in various medicinal preparations:

The tops (or the filaments) are juiced before the seed is dry, pounded, pressed out, and thickened by stirring in the sun. Dried, this is very useful in cures ... The herb and the filaments (pounded into small pieces and smeared on about the testicles) help lustful dreamers and nocturnal emission of sperm; and smeared on, they weaken the genitals.[xxi]

The use of "filaments" is somewhat ambiguous here. The reference to using "the tops (or the filaments)...before the seed is dry" suggests it may refer to the umbelliferous flower clusters and unripe fruits, as suggested by Pliny. "The herb and the filaments" might also refer to the leaves. Without a knowledge of Greek I am unable to judge. However, it does look as though the method of crushing the herb - in whatever combination of leaves, flowers or green fruit - and thickening the resulting juices by evaporation was a common one. The drying of the juices may serve to reduce the acrid smell of the fresh plant, making the powder less noticeable in food or drink, although it might also effect its level of toxicity through evaporation of some of the volatile alkaloids. Larsson writes, "If fresh hemlock was to dry under the sun during seven days an important loss of biological activity occurred."[xxii] It is not clear if the same would apply to the juices, but seems plausible.

In both the cases of Socrates and the citizens of Ceos referred to by Thrasyas, the enforced or voluntary consumption of the extract means that disguising the distinctive taste and smell of hemlock is not an issue. However, an ancient poisoner must have had to find a method of ingestion which is undetectable to the intended victim.

Some Proposed Methods For Use by an Ancient Poisoner

We have very few references to the way in which hemlock could have been administered by a poisoner. The most direct reference to hemlock poisoning I was able to find in the early literature was the hemlock in honey of Horace's Satires.

Hemlock In Honey

The Roman poisoner Canidia, while possibly apocryphal[xxiii], is commonly referenced as one of an infamous trio of female poisoners in the first century AD. The others are Locusta and Martina, both better attested as historical figures. A later commentator, Pomponius Porphyrion, writing in the third century CE) identifies a real life model for Canidia as Gratidia, a perfume woman (unguentaria) from Naples, but this is disputed by modern historians[xxiv]. Canidia is usually given as one of the few examples we have of specific Roman poisons being referenced in the literature, and is associated with honey poisoned with hemlock. In his Satires, Horace writes,

That implacable witch Canidia menaces [her enemies]

with the poison Albucius used on his wife; Turius

imposes a heavy fine if you go to court

while he's on the bench. So everyone would terrify

The ones he most fears by whatever natural means

he can wield. Come now, infer the way of the world

with me, from the following facts: wolves use their teeth,

bulls their horns, to attack. Are they not so instructed

by instinct? Suppose you entrust to the spendthrift Scaeva

An aged mother who keeps living on and on:

his filial hands commit no capital crime-

But what's so amazing? The wolf won't fight with his hoof,

Nor an ox with his teeth. A honey-flavoured cup

of the very best hemlock will fix the old woman up.[xxv]

Neither Albucius and Scaeva are known to correspond to historical figures (although Porphyrion also mentions Albucius as a wife-murderer[xxvi]) and the character of "Scaeva" (presumably from the cognomen scaevola, meaning left-handed, and therefore a play on sinister as evil or unlucky) may be solely a rhetorical device[xxvii].

There are certainly problems in taking the Satires as direct historical evidence of contemporary practices, as is often done, given the likely apocryphal nature of the figures being referenced, and the apparently circumstantial nature of the connection between Canidia's "poison of Albucius" and the hemlock and honey administered to his mother by Scaeva. However, given the pervasiveness of fears of poison in the era in which the Satires were written, the existence of other professional female poisoners such as Locusta and Martina, the discussion in contemporary and earlier sources of hemlock as a method of euthanasia for the elderly, and the toxicological plausibility of the method described by Horace[xxviii], it is certainly suggestive of a method that may have been widely known, enough to make the reference obvious to Horace's readers. The combination of bitter but colourless hemlock juices with honey would certainly disguise the taste. There was certainly no shortage of Roman recipes, which incorporate honey. Fear of poisoning, primarily through food and drink, was also widespread in the Classical world.

The history of poisons and poisonings in Ancient Rome is vividly recorded over some five centuries, from the first allegation of mass poisoning in 331BCE to the heyday of dynastical poisonings in the first and second centuries CE (after which point there are fewer accounts of poisonings, which may or may not equate to a lessening in the frequency with which poisons were employed). "Poisons were usually administered with food or drink – and for this reason official tasters, praegustatores (slaves or freedmen), were employed by the nobility and wealthy. They became so common that they formed a collegium with a procurator praegustatorum."[xxix] Employing a praegustator was no guarantee of safety, however, as this office-holder was in the perfect position to be bribed to poison their employer's food, as may famously have happened in the death of Claudius in 54 CE. His taster, Halotus, was considered to have been at least partly responsible for the Emperor's death, in conspiracy with the Emperor's wife Agrippina and physician Xenophon[xxx].

In Wine

Honey appears prominently in the first two recipes in the collection by Apicius: Fine Spiced Wine and Honey Refresher for Travelers. The translator remarks in a footnote, "Apicius is correct in starting his book with this formula, as all meals were started with this sort of mixed drink."[xxxi] Both recipes are highly spiced, and the combination of wine, honey and spices would presumably hide the bitterness of the hemlock extract successfully. The recipe for Fine Spiced Wine is as follows:

Into a copper bowl put 6 sextarii1 of honey and 2 sextarii of wine; heat on a slow fire, constantly stirring the mixture with a whip. At the boiling point add a dash of cold wine, retire from stove and skim. Repeat this twice or three times, let it rest till the next day, and skim again. Then add 4 ounces of crushed pepper, 3 scruples of mastich, a drachm each of nard or laurel leaves and saffron, 5 drachms of roasted date stones crushed and previously soaked in wine to soften them. When this is properly done add 18 sextarii of light wine[xxxii].

The major drawback to this recipe for a poisoner is that it could not be targeted precisely. Presumably in order not to wipe out the entire household, the poisoner would still have to slip drugged honey or extract into the individual cup, rather than poisoning the entire batch. However the next recipe Apicius provides is made up in convenient single serve portions.

The wayfarer's honey refresher (so called because it gives endurance and strength to pedestrians) with which travelers are refreshed by the wayside is made in this manner: flavor honey with ground pepper and skim. In the moment of serving put honey in a cup, as much as is desired to obtain the right degree of sweetness, and mix with spiced wine not more than a needed quantity; also add some wine to the spiced honey to facilitate its flow and the mixing.

Honey is also mentioned as sweetening or tempering several other recipes for wine in the chapter. That the Romans indeed feared poisoning with hemlock added to wine is seen in Pliny's discussion of the herb:

The great remedy for it [hemlock], provided it has not reached the vitals, is wine, which is naturally of a warming tendency; but if it is taken in wine, it is irremediably fatal.[xxxiii]

It is also possible that the hemlock extract was added to wine directly. The mention of Thrasyas' potion as one that "will keep any length of time without losing its virtue at all" suggests that the problem of preserving the alkaloids for long storage had been addressed somehow, and, like honey, wine is a chemically plausible method[xxxiv]. The delicate alkaloid coniine is soluble in alcohol, so the juice, when extracted, could have been compounded in alcohol to preserve it for storage, and the mixture later added directly to the wine of the victim.

In Food

Honey is mentioned often in the recipes of Apicius, both sweet and savoury, so it would appear that opportunities to use the adulterated honey would have been easy to come by. Any lingering bitterness from the hemlock could have been disguised by other common strong-tasting ingredients. It seems unlikely that fresh parts of the plant could have been directly substituted for similar ingredients. Pliny states that the root of hemlock "is hollow and never used"[xxxv], and I have not found Roman or Greek references to the root. It might also be possible to substitute the leaves as part of a salad or other dish. Despite the unpleasant smell and taste, there are many documented modern cases of poisoning from people mistaking it for parsley, which the young leaves closely resemble. A lethal dose, as mentioned above, can be as small as 6-8 leaves. Parsley (petroselinum) is also referenced frequently by Apicius, and was popular for cooking and medicinal uses in the Ancient world from the time of Alexander the Great onwards[xxxvi]. However, I have found no references to this being a particular fear of the classical authors, and it seems unlikely given the intense paranoia around poisonings in Rome in particular, the widespread use of tasters who would undoubtedly be able to detect the strong taste and odour immediately, and the common knowledge of hemlock and its effects as reflected in Greek and Roman sources. The effects of c. maculatum is no longer as well-known in modern times, resulting in more accidental poisonings. Even so, as Larsson writes, such accidental deaths are still infrequent, due to "the plant's 'mousy' odor, bitter taste and burning sensation of the mouth, throat and abdomen on ingestion" meaning that people who accidentally consume some part of the plant often won't ingest enough for a lethal dose, which supports the idea that the fresh leaves were probably not used by poisoners[xxxvii]. It seems to me that the most likely way to adulterate food or wine would be by using the drugged honey or the extract itself, or a compound poison of some kind containing hemlock, slipped into a dish.

Conclusion

As we have seen, conium maculatum was a well-known ingredient in poisons used for execution, suicide or euthanasia in the Greek and Roman world. Its use as a surreptitious poison is also referenced in the literature, often with very little detail. The documented methods I have found of using c. maculatum for more nefarious purposes such as assassination by poisoning are an extract of the seeds, leaves and flowers, or some unspecified part of the plant added directly to honey. I have also explored some more commonly feared avenues for administration of poisons, such as adulterating wine or food, or slipping the fresh parts of the plant directly into a dish as a substitute for a similar ingredient. While poisoning is one of the most difficult methods of assassination to substantiate before the advent of modern toxicology, I have attempted to trace some ways in which hemlock may have been used for this purpose.

Primary Sources

Apicius, De Re Coquinaria, in Vehling, Joseph Dommers (trans), Cookery and Dining in Imperial Rome, 1936, translation found at http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Apicius/home.html, accessed 2 July 2016

Celsus, De Medicina, Book 5, translation found at http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Celsus/5*.html, accessed 5 July 2016

Dioscorides, De Materia Medica, http://panaceavera.com/BOOKFOURROOTS.PDF, accessed 17 May 2016

Horace, Satires, in Bovie, Smith Palmer (trans), Horace: Satires and Epistles, Chicago, 2002

Plato, Phaedo, in Fowler, Harold North (trans), Plato in Twelve Volumes, Vol. 1, Cambridge, MA, 1966. pp. 117-8 (death of Socrates) found at http://www.perseus.tufts.edu/hopper/text?doc=urn:cts:greekLit:tlg0059.tlg004.perseus-eng1:117, accessed 5 July 2016 (there is no title page for this work)

Pliny the Elder, Naturalis Historia, translation found at http://www.perseus.tufts.edu/hopper/text?doc=Plin.+Nat.+25.95, accessed 24 June 2016

Suetonius, The Lives of the Twelve Caesars: Life of Claudius, 5:44, translation found at http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Claudius*.html, accessed 2 July 2016

Theophrastus, Historia Plantarum, translation found at https://www.loebclassics.com/view/theophrastus-enquiry_plants/1916/pb_LCL079.305.xml, accessed 17 May 2016

Secondary Sources

Anagnostakis, Ilias, "Makedonisi(on): Parsley, the Macedonian Herb", in Anagnostakis (ed.) Flavours and Delights, 2013, pp. 37-42

Bevan-Jones, Robert, Poisonous Plants: A Cultural and Social History, Oxford, 2009

Bloch, Enid, Hemlock Poisoning and the Death of Socrates: Did Plato tell the truth?, Plato 1 (2001), online: posted January 2008, https://gramata.univ-paris1.fr/Plato/article9.html, accessed 23 June 2016

Cilliers, L. and F. P. Retief, "Poisons, Poisoning and the Drug Trade in Ancient Rome", Akroterion 45 (2000) 88-100

Hayes, A. Wallace, Principles and Methods of Toxicology, New York, 2008

International Program on Chemical Safety, Poisons Information Monograph "Conium maculatum L.", found at http://www.inchem.org/documents/pims/plant/conium.htm, accessed 24 June 2016

Larsson, Thomas, Some History and Effects of Conium Maculatum L., Uppsala, 2004

Miller, Paul Allen, Latin Verse Satire: An Anthology and Reader, 2005

Raia, Ann R., "Quintus Horatius Flaccus, Sermo I. 8: Canidia", found at http://www2.cnr.edu/Home/araia/Horace_canidia.html, accessed 17 May 2016

Footnotes: