The internet has a thing about salacious history. Give the crowd a good old-timey murder, and they will produce 150,000 blog posts and eight true crime podcasts devoted to telling you the real story. While I give them points for enthusiasm, these works often employ some very dodgy research methods. Copy-and-paste is in pretty heavy rotation.

Researched and nuanced history exists even about scandalous subjects, but it seems never to get the same attention as the jazzy stories. Even when they get debunked, these posts soldier on ad infinitum.

The Scented History of the Plague Series:

Prior Posts:

So why do these stories prosper?

I don’t see this writing as historical, sociological or even entirely commercial in its scope. It is, instead, folklore. Folklore fills a different need.

They are tales told around the internet fire that are not meant to be factual. Instead, they convey a moral, some nugget of information about what a community thinks and feels.

I’ve dealt with a few of these less-than-true stories before. The bird-beaked plague doctor costume? (not medieval and rarely used). Were Victorian ladies catching their tears in crystal vials? (that story came about in the 90s to sell perfume bottles for 8x their value).

For the most part, this historical folklore-ing is a relatively harmless distortion of the past. However, sometimes these folkloric narratives are used to justify less-than-sound modern practices. Today we are talking about an aromatic internet myth that has the potential to do physical harm. Let’s talk about the history of Four Thieves.

The Four Thieves Myth

Some of you may be unaware of the aromatic ring of hell that is Essential Oil Tik Tok. For the uninitiated, let me introduce you to the concept of Thieves Oil, also Thieves Vinegar. It’s mostly Four Thieves, but that number can oscillate between Three to Seven Thieves, sometimes Forty.

Look… it’s been hundreds of years, and we haven’t nailed down how many thieves or their preferred mixing medium, but the story goes that there were…some amount of thieves, and they made a magic tonic.

Four Thieves is described as an antibacterial and antimicrobial wonder that will boost your immune system (whatever that means), while simultaneously killing germs, mould, and bacteria. Yet, it is sold as perfectly safe for humans and pets to use in any dosage or application. Plus, it kinda smells like Christmas!

You can find it in room sprays, cleaning products, hand sanitiser, and cosmetics. But most often, it is sold in tiny Boston Rounds for you to make your own concoctions. I have a family member that huffs their dram bottle of Thieves throughout the workday because they swear it helps them with their nerves.

Part of the allure of this wonder product [that the FDA is not a fan of being called medicine] is that it has a long and storied history. A bit of macabre history. The kind of story folks love to tell in breathless tones over the kitchen table. Instead of giving it my spin, here is a version I have seen reproduced nearly verbatim multiple times online. I use this one as I believe this author is the originator of this version of the myth’s copy.

Our favorite rendition dates back to 1413. During the 15th century bubonic plague in Europe and Asia, four European thieves made it a habit to rob the deceased of anything of value. These bodies were highly contagious with the plague, which begins with severe flu symptoms and then continues with the bacteria infecting the blood system, usually ending in death (it is estimated 150 million people passed during this four year pandemic). However, these nasty villains never contracted the plague. It was reported that they wore hats and masks that smelled of vinegar and garlic and herbs and spices, namely cloves, lemons, cinnamon, eucalyptus, and rosemary.

A French version also involves the thieves. These hooligans were caught and jailed for robbing sick or vulnerable people, but never caught the deadly illness. They were to be burned alive for their crimes, but their judge told them he would spare them that if they would share how they avoided the plague. The thieves said that they were perfume and spice merchants who lost their livelihoods because of the thorough devastation of the disease. They combined cloves, lemon, cinnamon, eucalyptus, and rosemary and applied the blend to their hands, ears, feet, temples, and on a mask that they wore over their mouth.

Then they went out and about and committed their crimes, protected from the very infectious illness. Once the judge learned of their secret (and shared it among all he knew), he did spare them the punishment of being burned and he them hung instead. (1)

Now don’t be a jerk to this person. I don’t think they have ill intentions or are deliberately trying to lead people astray. I found nearly identical stories on nine different websites in less than 5 minutes of searching. They were repeating things they had seen duplicated a million times before by sites they trusted.

We tend to believe what we see multiple times, and just as there is such a thing as a Health Halo that gives a false impression that a food is good for us, repetition creates a History Halo. It must be true if so many people are saying the same thing. Also, by framing it as a story, you get to opt-out of proving anything, hence folklore. Yet one plays the story both ways when one uses folklore to justify purchasing a modern product, as is done above.

So, let’s look at this story critically and address some of the facts presented. Our task isn’t to skewer the author or the thousands of other versions of this story floating around. Let’s instead look critically and give context to what we know about the past.

1413 AD…The Black Death?

The author of the above quote caught a mistake that most other re-tellers of this tale didn’t. The story almost always begins during the Black Death, with the date listed as 1413. I think this author, too, is referencing the Black Death, though they don’t name it. Here’s the problem, the Black Death was from 1346 – 1352. It started in the 14th-century in Europe, not the 15th. This frequent error seems to come straight from EO marketing materials that have been disseminated widely online.

This matters because the Black Death was the first volley in Europe’s war with the Second Global Pandemic of yersinia pestis (plague). The Black Death is the name for the initial outbreak, not the whole pandemic (2). The totality of the Second Pandemic lasted in Europe from 1346 to 1835. It matters because those first few years were exceptionally terrible.

The author gives a reasonable estimation of the death toll for 1346-1352 (not 1413-1417 as the copy states). We will never know for sure how many died. All of these numbers are statistical guesses and vary wildly. I put the most credence in historian Philip Daileader’s estimation that 45%-50% of Europe’s population died in just the first four years (Black Death) (3). Ole Benedictow puts that number closer to 60% (4). Either way, pretty awful. Major cities like Florence were nearly depopulated at that time by death and those fleeing for the countryside (5).

Miniature by Pierart dou Tielt illustrating the Tractatus quartus bu Gilles li Muisit (Tournai, c. 1353). The people of Tournai bury victims of the Black Death.

The story of perfumers and spice merchants taking to a life of crime in desperation might have sort of made sense 67 years earlier when Europe essentially imploded for half a decade or so, but that wasn’t the case in 1413.

The plague was still in Europe, and infections were episodic (they were called visitations). By 1413, however, the European economy was well versed in dealing with plague times, and the trade in spices was booming. Skilled labour was at a premium. While a visitation of the plague was always harrowing, it was only totally economically devastating during the opening years of the Black Death and Great Plague outbreaks. The periods in between saw enormous economic growth (6).

There was a visitation (a smaller outbreak) from 1413-1416, but the epicentres were in Sweden and the UK, not France. Is it possible there was a plague visitation in an unnamed French town in 1413? Yes, but it doesn’t fit the economic devastation of the story.

Marseille is often named the site of this drama, but Marseille didn’t have a visitation in 1413 or during the Black Death. They did in 1377 and 1476 but not in 1413 (7). Plus, there are no original documents yet found in Marseille confirming this tale. No records, no court documents.

The 19th-century telling of the Thieves’ story seems to be mixing up events that happened during the Great Plague of Marseille in 1720 with the earlier outbreaks. So from our oldest to newest source, we don’t have a set date or location. Not a great sign, fam.

Robbing Plague Victims

Robbing plague victims was pretty common, but the thieves were most often people who already had access to the house; servants, family members, neighbours, plague guards, and doctors. Municipal guards often restricted access to plague homes. However, the guards were there to keep people in, not out. Also, people were legitimately terrified of catching the plague and avoided even walking near plague-infected homes.

Still, there is sufficient surviving evidence that thefts did occur (8). Plague doctors, in particular, had a bad reputation for unscrupulous behaviour. This was primarily due to the enormous amount of power they held. A plague doctor could witness someone’s will, be an executor of their estate, and in some circumstances give last rites. As I’ve written about on this blog before, some truly heroic physicians did this work. There were also a lot of very shady dudes that took up the job as the years went on.

Could strangers burgle a plague house? Yes, though a band of perfumers wouldn’t be my first suspects.

Plague Preservatives

Did people use smelly stuff to protect themselves from the plague? Yes, but enterprising thieves were not the inventors of these items. People employed a Plague Preservative or Counter-corruptive, which consisted of a strong aromatic material kept in the house or worn on the body as a prophylactic to disease. This was standard medicine of the era. It was employed personally and communally, with cities paying considerable sums to have their streets fumigated.

Why were aromatics such a big part of Medieval and Early Modern medicine? Miasma Theory. The generally held belief was that the plague was caused by rotting bits of matter called miasmata, which become airborne and infect people through their breath. This rotting matter, it was believed, would cause the infected person to rot from the inside out, which wasn’t a stretch to think, given what the plague does to the human body (9).

The idea behind the Plague Preservatives was that if you could occupy your nose with pleasant or strong odours, they would keep the rotting bits from getting in (10). That is Miasma Theory in a nutshell. It existed before the plague but became the predominant modality of medicine during the Middle Ages and for hundreds of years until the 19th-century when Germ Theory definitively debunked it. Even still, miasmic thought lingered on in folk remedies and patent medicine.

Was it effective on any level? Maybe it inadvertently helped thwart the bacteria a little? I think if we are talking about 40%-60% of a continent’s population dying in less time than it took me to finish my 1st degree, we can call that the most abysmal therapeutic failure of all time.

Queen Elizabeth holding her aromatic pomme d’ambre

Many people were using some kind of aromatics to protect themselves from plague in the Middle Ages and Early Modern periods. Queens commissioned extremely expensive and luxurious pomme d’ambre. Ordinary folks had their pocket full of posey. So if someone were going into a plague house, they would have their Counter-Corruptive with them for sure. However, 67 years into the plague, the idea was not novel. Maybe people would have been interested in a Counter-Corruptive that was rumoured to be failsafe. Still, if the Four Thieves formula was common knowledge, we would have historical evidence of it at the time, and there is no mention I could find for Four Thieves before the early 19th-century.

Medieval Essential Oils Weren’t Really a Thing

Modern formulas for Four Thieves vary, but five ingredients are the most often cited; cloves, lemon, cinnamon, eucalyptus, and rosemary essential oils. Firstly we need to remember that Europeans had just figured out how to distil at this time. Essential oils and hydrosols were rare and super expensive. Distillation slowly starts in Europe in the 12th-century in the School of Salerno (11). It would take another century before Tadeo Alderotti’s fractional distillation was perfected, which is needed to make essential oils (12). It would take until the 16th-century and the publication of Hieronymus Brunschwig’s work before distillation became widespread in Europe (13). Could they make essential oils in the 14th-century? Yes, but they would have been in very limited supply, found mostly in monasteries and very costly.

Hieronymus Brunschwig, Liber de arte distilandi de compositis

So the OG Four Thieves are unlikely to contain essential oil concentrates. They just didn’t have the technology readily available for commercial use at that time. However, macerations of aromatic materials in fat or acid were available, which jives with the earliest versions of this story talking about an aromatic vinegar.

However, aromatic vinegar also wouldn’t become readily available until after the late 15th-century (14).

I suspect that all of this commotion derives from a 19th-century story. Aromatic vinegars were incredibly common by then, as was the creation of essential oils. If someone is looking to their own material culture to fill out a story, these inconsistencies make sense.

Putting On Gucci To Steal From Target

Let’s talk about these ingredients and their availability during the Middle Ages. Clove is native to Indonesia. Cinnamon is native to India, Sri Lanka, Bangladesh, and Myanmar. These were insanely expensive imports in Medieval Europe. Most people would never smell these products.

Only royalty would have access to them before the late 16th-century. Cinnamon as a word wouldn’t even enter the English language until the 14th-century.

Eucalyptus is from Australia, which was a continent that Europeans did not know existed until 1606. Eucalyptus was introduced to Europe in the 18th-century (15). Lemons were first introduced to Europe during Roman times but weren’t widely cultivated. They would be reintroduced to the Mediterranean in the Early Medieval period through contact with Levantine and North African cultures. They were particularly prized for ornamental gardens and domestic use. Lemons were not cultivated as a cash crop until the middle of the 15th-century and then only in Genoa (16). Access to lemons outside of the Mediterranean was rare and would have been insanely expensive before the 17th-century.

Jacob Fopsen Van Es, Still Life with Lemons, Oranges, and Pomegranates, CA. 1660

Rosemary, however, is both native to most of Europe and widely cultivated since the Roman empire. If the original Four Thieves was a preparation of rosemary, that was no innovation; it already existed as Queen of Hungary Water (17). Queen of Hungary Water is another legendary product rumoured to have been created in the 14th-century for one of possibly three queens of Hungary named Elizabeth. However, as Queen of Hungary Water requires brandy, and commercial production of brandy didn’t begin until the 16th-century, it is unlikely to be a 14th-century product. At least Queen of Hungary Water is a product we have evidence for in the Early Modern, unlike our Four Thieves.

Back to our thieves, If these nogoodniks had access to these materials, they might as well have dipped themselves in gold.

There is no way this is a Medieval or Early Modern European formula, in my opinion. It is inconsistent with every Medieval or Early Modern preparation I have seen. If these gents had such fine aromatics, they would have sold them instead of using them for crime. It’s like putting on Gucci to go shoplifting at Target to make money. Just sell the Gucci that everyone thinks will save their lives!

Some modern tellers list other materials such as wormwood and marjoram that would have been more available. Still, there are no original sources in these cases and no provenance I can confirm older than the early 1800s. The oldest Marseilles vinegar I could find is from 1825 and includes camphor and garlic (18). If the combo of aromatics is what makes the magic, then why so loose with the recipe? Medicines aren’t keen on substitutions normally.

Out Of Work Perfumers…In This Economy?

That takes us to the claim of the down and out perfumers and spice traders. There are two issues with this part of the story. Firstly, very few people called themselves perfumers in Europe in the Middle Ages in general because perfume didn’t exist as a commercial product the way we understand it today. There was no Ye Olde Perfumer Shoppe serving a middle-class clientele with disposable income in the Middle Ages, that came later. There were spice merchants, but again they were not selling little bottles of pumpkin spice mix. They commanded sophisticated trade routes that got the most costly materials in the world to the people that could afford them (19).

Compounded fragrance was either an expensive luxury reserved for the wealthy or used as medicine. The functions of a perfumer would have been attached to royal kitchens, most likely in the spicery. The spicer would have watched over all the exotic ingredients used for both food and aromatics in the household. The spicer would make the nobleman’s aromatic waters, vinegar, pomme d’ambre and fumigating incense (20).

But it wasn’t just the spicer that did the perfumer’s job. Physicians and apothecaries also worked heavily with aromatics as a form of medicine or prophylactic. In fact, the first seat of perfumery in France wasn’t the famed Grasse (which in the Middle Ages was a leatherworking town). It was Montpellier (21). Montpellier was famous for its ancient medical school, its renowned medical garden, and its apothecaries.

Many of what we now think of as traditional European aromatics, like potpourri and pomanders, came out of medical aromatics, not consumer products. Santa Maria Novella, 4711, and Jean-Louis Fargeon, some of the oldest names in European perfumery directly connect to aromatic patent medicines and pharmacies that turned into perfumeries centuries after the end of the Middle Ages (22).

Perfumery, as a profession similar to today’s perfumer, came to Europe in the 16th-century. The trade was almost always tied to the creation of another commercial good. Venice was one of the first seats of European perfumery because of the glass trade. Glass works, famed in Venice, uses a lot of the same equipment as early perfumery (23). Also, Venice was already the centre for importing the vastly superior scented products from the Islamicate, and the glassmakers wanted to cut in on that action.

From there, leather workers picked up perfumery as a way to add value and reduce the malodours associated with leatherworking. We don’t see a stand-alone perfumer’s guild until the 18th-century. Most are Glove Makers and Perfumers guilds (24). Indeed the perfume shop of the Regency included scented gloves and stationary, soaps, hair tonics, fans, and even millenary. The perfumer had to be multi-talented.

But back to our Medieval perfumers, because of the prominence of Miasma Theory in the Middle Ages and Early Modern, spicers, physicians, apothecaries, importers and later the nascent perfumers were all in high demand during the whole of the Second Pandemic. People wanted these items and paid enormous prices because they thought it would save them from the plague. It is hard to believe four skilled labourers in the aromatics trade couldn’t find patronage.

If this is a later story, set during a later visitation, it still doesn’t make sense. If 17th and 18th-century perfumers had a product that they thought could help with the plague (and it had a scandalous story attached) they wouldn’t have shut up about it. We see aromatic vinegars from that time, but not the Four Thieves marketing.

Burning Thieves At The Stake?

The most common punishment for theft in the Middle Ages was a fine. I know we like to think of the past as brutal, but it wasn’t nearly as game-of-thrones-y as you might think. Though I will say, they did have divorce-by-combat in Medieval Germany. That was pretty rad.

If you got caught doing something wrong and it didn’t involve bodily harm to another person, the king, your landowner, or the church, the stakes were pretty low. Theft as we know it wasn’t really criminalised until the rise of the middle-class centuries later, who insisted on protection for their property (25). One could certainly be executed for stealing from the crown or the church, but the absolute most in France at the time would be hanging.

In 1532 the Holy Roman Empire amended its legal code to include death by burning for those that committed aggravated theft of sacred objects from churches (26). That is the only circumstance I have seen of burning being the prescribed punishment for theft, which doesn’t fit our story.

You might get beat up by your neighbours and be a social outcast. Serial thieves could have their ears or hands cut off. In 1413 burning at the stake would have been highly unorthodox for the crime of burgling a plague house.

Burning at the stake was a punishment deeply associated with actions viewed as religious heresy and sexual deviancy (27). So unless these perfumers and spicers were gay Cathers, I don’t think they were at risk of burning.

So Where Did The Story Come From And Why Is It An Internet Myth?

The story is most certainly a folktale, and probably a relatively recent one. It is unlikely that this trial happened. Aromatic Plague Preservatives were around in the Middle Ages, but four dudes didn’t invent them. Most of the recipes we have for Four Thieves today would have been impossible to create in the Middle Ages. Also, what little history is available is disconnected from the products on the market today. These modern preparations have little connection to the 19th-century recipes of vinegar, camphor, and garlic. They are purely 20th and 21st-century inventions.

However, aromatic vinegars with the ingredients found in Four Thieves were ordinary in the 19th century. Likely, the vinegar and the story began then or shortly before; either way centuries after the Black Death, the Middle Ages, and the Early Modern.

There were many aromatic cure-all products like Four Thieves in the 19th-century, and many of them had tales associated with them. Those tales wanted to market the effectiveness of the product by recalling an ancient past (28). Such and such queen used this tonic. That vinegar was a formula made by Galen himself!

Nothing says Tutonic valour like Pabst ‘tonic’

It was marketing, patent medicine, but these stories ended up in the marginalia of a few pharmacopoeias as well (29). Not all the marginalia was positive. In 1846 Pereira called Four Thieves useless and corrosive to the skin (30). We also can see as early as 1828 Four Thieves is the butt of jokes. The joke below, published in The Mirror of Literature, Amusement, and Instruction plays on the name and the perceived duplicity of the chemist selling patent medicine during an epidemic (31). So this product was far from widely beloved or even widely known.

However, since the 1960s, proponents of alternative medicine have used these side notes in the pharmacopoeias to give credence to their ends. They weren’t concerned with verifying the effectiveness of 19th-century products. Instead, they used it by claiming a historical legacy that provided their work legitimacy outside of science-based medicine (32). If what I’m doing has historical precedence, it must have value. This worldview relies on a bias towards historical knowledge over modern modalities.

I’ve found recipes to turn lead into gold and transmute a frog to a cat in old pharmacopoeias. I’ve also seen Assyrian cuneiform tablets that swear you need to sacrifice four animal embryos to make glass (33). Y’all, I’m just saying, not all information written down is gospel truth just because it survived a long time.

So if this was most likely 19th-century marketing, where did the name come from? We aren’t 100% sure. There are theories, but none will be truly definitive because trying to disprove a folktale is like trying to catch mist.

What is clear is an obscure bit of marginalia was written down about 200 odd years ago, and some folks wrote about it in the 60s. It lingered in aromatherapy, and holistic medicine circles in the 80s and the 90s and then the internet and multilevel marketing came.

A particular MLM likes this story very much and uses it in their marketing; others followed. An apocryphal tale gets duplicated like mad. Some tell it like a story. Some point out flaws. But a concerning amount describes it as straight facts and embeds the tale in product copy. These pages talk about how this remarkable history proves quality and all the glorious things it can do for you!

Why We Make Modern Myths

When I talk to loved ones in the US, the conversation usually turns to essential oils. I’m a perfumer, after all, and they swear by X oil for their sciatica and Y oil for depression. They aren’t using these products to achieve a vibe or for personal enjoyment. They are using them as medicine. Treatment, they believe, will cure genetic conditions, infectious diseases, and the fall out of years of literal back-breaking agricultural labour. We can talk about whether EOs affect mood, if they have some topical benefits, or if inducing the placebo effect is beneficial in the long term. They don’t change your genetics, though. They can’t heal a fractured vertebra. It is like Medieval miasmata booked a trip to Florida.

These are hard conversations for me because I love these people, and I can see that they blindly put their faith in literal snake oil. It fills me with rage. At the same time, I know their options are limited. If you are more afraid of Covid because it may mean missing work rather than it may mean dying; the world is already on its head, so why not try something crazy?

That $45 bottle of condensed plant juice isn’t a cure. It is a talisman, a wish, a way of saying, “Hey, I haven’t given up yet.”

While the use of essential oils as pseudo-medicine is global, this phenomenon has a special place in the US landscape. Firstly, essential oils for this use are often sold in multilevel marketing schemes in the US. While the well-meaning hippies at the health food store have done their share of spreading these tales, it’s in the MLMs where they breed.

For those not associated with the US, MLMs are a form of business heavily regulated or outlawed in most other developed countries. They are regulated because, according to the US Federal Trade Commission, 99% of independent distributors lose money.

The big companies in this field over the years have claimed that essential oils can cure Ebola, AIDs, Autism, Covid-19 and cancer. Even if the head office is savvier today, many local untrained distributors are not. I don’t have a problem if you like the way they smell or you like a fun little story. My issue is with the use of history to ground unfounded health claims. The companies and the distributors both appeal to a historical application of these products as evidence of effectiveness. They sell millions of units based on this appeal to history. They don’t have to prove a thing, and people put their faith that maybe this would help. This is the insidiousness of the Four Thieves myth.

But why do these products sell?

In my opinion? More and more Americans are disconnected from the healthcare system. Needed treatment is unaffordable. Folks are fearful a diagnosis could lead to an increase in their rates. With that disconnection comes deep distrust and a desire for an alternative.

In my own family, I see how effective that appeal to an alternative is. It is an appeal to a gentler, softer medicine than the cold and heartless system they find themselves in. Unburdened by scientific rigour, it has the weight of ‘history’ instead and with that a nostalgia for a bygone era. A world they can understand.

These products rely heavily on a system of folklore creation both about their pasts and what they can do for you today. Purity, wholeness, and wellness, these terms are never defined but are accepted as states of mind in contrast to the feeling of creeping toxicity and unwellness many Americans feel.

The Four Thieves story isn’t about the facts of the case, which I hope I’ve been able to at least throw into doubt. It’s about the unsayable feelings of a community. A community that hurts and finds no relief. That craves a deeper understanding of their medicine. That feels isolated from modern systems, so seeks other claims to knowledge, even if deep down they know it isn’t true.

They hope there can be a panacea. They want one so bad. A wonder potion that will protect all of us from what avails us. I can extend grace for those blinded by hope, but those that make millions off their suffering, how very dare you. I hope one day you are held accountable for the harm you have done.

References

Quote source,
Byrne, Joseph Patrick. Encyclopedia of the black death. Vol. 1. ABC-CLIO, ISBN 9781598842531 2012.
Daileader, Philip. The Late Middle Ages, Great Courses. ISBN 9781598033434. 2007
Benedictow, Ole. The Black Death 1346–1353: The Complete History, Boydell Press. ISBN 9780851159430 2012.
Tignor, Robert; Adelman, Jeremy; Brown, Peter; Elman, Benjamin; Liu, Xinru; Pittman, Holly; Shaw, Brent. Worlds Together, Worlds Apart, Volume 1: Beginnings to the 15th Century. W.W Norton & Company. ISBN 978-0-393-92208-0. 2014
Braid, Robert. “Behavioural Economics, the Black Death and the Labour Market.” Living with the Black Death. ISBN 9788776743895. 2009.
Barbieri, R, and M Drancourt. “Two thousand years of epidemics in Marseille and the Mediterranean Basin.” New microbes and new infections vol. 26 S4-S9. 2018, doi:10.1016/j.nmni.2018.08.009
Atlas, Jerrold. “The Black Death: An Essay on Traumatic Change.” The Journal of psychohistory 36.3.2009.
Kannadan, Ajesh. “History of the Miasma Theory of Disease.” ESSAI 16.1. 2018.
Herring, Francis. Preservatives Against the Plague: Published at the Request of the City of London, in the Year 1665, when They Were Visited. By Francis Herring,…... T. Waller, 1757.
Kockmann, Norbert. “200 years in innovation of continuous distillation.” ChemBioEng Reviews 1.1. 2014.
Holmyard, Eric John. Alchemy. Courier Dover Publications. p. 53. 1990. ISBN 0-486-26298-7.
Hermann Fischer. Mittelalterliche Pflanzenkunde. p. 109-113: Das kleine Destillierbuch des Hieronymus Brunschwig. 1929.
Bourgeois, Jacques. Bar, François. The history of vinegar and of its acetification systems. ARCHIVES DES SCIENCES. 62. 2009.
Silva-Pando, F. Pino Pérez, R. Introduction of Eucalyptus into Europe. Australian Forestry 79(4):283-291. 2017. DOI:10.1080/00049158.2016.1242369
Ramon-Laca, Luís. “The introduction of cultivated citrus to Europe via Northern Africa and the Iberian Peninsula.” Economic Botany 57.4. 2003.
Herz, Rachel S. “Perfume.” (2012).
Ayrton Paris, John. Pharmacologia: Corrected and Extended, in Accordance with the London Pharmacopoeia of 1824, and with the Generally Advanced State of Chemical Science, Volume 2. S. Wood, R. Lockwood, S.B. Collins. p18. 1825.
Turner, Jack. Spice: the History of a Temptation. Vintage, 2008.
Carlin, Martha, and Joel T. Rosenthal. Food and eating in medieval Europe. Bloomsbury Publishing, 1998.
Guibert, Marie-Sophie. “One place, a lot of people. The apothecary companions in Montpellier between 1574 and 1654.” Revue D’histoire de la Pharmacie 54.351. 2006.
De feydeau, Elisabeth. “A Scented Palace: The Secret History of Marie Antoinette’s Perfumer. Translated by Jane Lizop. IB Tauris. 2008.
Artico, Chiara Isadora, and Michele Tamma. “Culture-based products: integrating cultural and commercial strategies.” Entrepreneurship in Culture and Creative Industries. Springer, Cham, 2018.
Martin, Morag. Selling Beauty: Cosmetics, Commerce, and French Society, 1750–1830. Vol. 2. JHU Press, 2009.
Ireland, Richard W. “Law in action, law in books: the practicality of medieval theft law.” Continuity and Change 17.3 .2002.
Sumner, William Graham . Folkways. New York : Arno Press. 1979.
Goodrich, Michael. “Sodomy in medieval secular law.” Journal of Homosexuality 1.3.1976.
Albert, Michael R. “Nineteenth-century patent medicines for the skin and hair.” Journal of the American Academy of Dermatology 43.3. 2000.
-Ibid. Ayrton Paris 1825 -Pereira, Jonathan. The elements of materia medica and therapeutics: Pereira’s materia medica and therapeutics. V2 ed Carson, Joseph. p. 946. Lea and Blanchard, 1846. NLM 101507075 -Hopkins, The Scientific American Encyclopedia of Formulas. p. 878. 1910.
Ibid. Pereira p.946
Limbird, J. ed. The Mirror of Literature, Amusement, and Instruction. V 10. London. P. 163. 1828. https://books.google.co.il/booksid=9mcJAAAAQAAJ&printsec=frontcover#v=onepage&q&f=false 
Kaptchuk, Ted J. Eisenberg, David. “The persuasive appeal of alternative medicine.” Annals of Internal Medicine 129.12, 1998.
Levey, Martin. “Babylonian Chemistry: A Study of Arabic and Second Millenium B.C. Perfumery.” Osiris, vol. 12, 1956

The Death Scent Project

The Sketchy History of Four Thieves Oil