Category Archives: Medieval Science

Five Things To Do With Urine In The Middle Ages


This post has been a long time in the making. It has taken so long because I wanted to find proper sources for everything, but I’ve had to accept that if a respected historian says something in a television documentary it will have to do.

The respected historian I’m referring to is Ruth Goodman. She was in all of the historical farm series on BBC Two, but the series that I’m using are The Secrets of the Castle (about building a castle in the thirteenth century), Tudor Monastery Farm (set in 1500) and Tales from the Green Valley (set in 1620), all of which I watched for the third or fourth time in the last few weeks.  Although the last two are not strictly speaking about the Middle Ages, some of the uses people had for urine then were the same as they were in the fourteenth century.  I was originally inspired to write this post by something Ruth Goodman said in the Secrets of the Castle. She said that people in the Middle Ages used urine for everything. Whilst that’s an exaggeration, it isn’t much of one.

Urine was a valuable resource and it was collected. In the fourteenth century there were no indoor toilets, unless you lived in a castle or a monastery, and nobody who needed to get up in the night was going to go outside to the midden (the most basic form of toilet) or the necessary house (a slightly more sophisticated toilet, with walls and a roof). Even if it wasn’t icy, raining or snowing outside, the toilet facilities would be some distance away from the house and the darkness of night was considered dangerous. Instead of going out they used a chamber pot. This was emptied each morning into a storage pot, which was also kept as far away as possible from the house. The pot was covered and the urine left to ferment,  becoming amonia. I’m a bit shaky on the science, so that  might not be quite what happens. Whatever it is that goes on in the storage pot, there is a usable, but very smelly,  product after three weeks.

We saw one of the uses when we were looking at the production of cloth. Stored urine was used in the fulling and bleaching processes. Urine was pounded into the cloth, with with the feet or wooden paddles. The cloth was rinsed and then spread out to dry in the sun. Something similar was done on a domestic scale on washday. Contrary to popular belief, medieval people in general did wash their clothes and bedlinen. It was their underclothes that they washed, however. The outer layer was usually made from woollen cloth, which can be washed, but takes forever to dry, even in the summer. It made sense, therefore, to protect the woollen garments from things that could make them dirty, such as sweat, by not wearing them next to the skin. Garments that touched the skin tended to be made of linen, which could be washed frequently.  These were put into a tub and had the stale urine poured over them. After a bit of of a soak, they were taken to the river where they were rinsed, then beaten with a paddle to get the dirt out. When they were clean they were dried in the sun.

I wrote last week that tanning was such a malodorous process that tanneries were usually built beyond a town’s walls. One of the reasons why it was so bad was that this was another process that used urine. It was one of the substances used to remove hair from the leather. The leather was soaked in a vat of urine until the hairs could be scraped off. Thankfully, the later processes removed the smell, but being a tanner could not have been pleasant.

Urine was also used in dying, where it was a mordant: a substance that fixes the dye to the fibre so that it doesn’t wash out. Woad, for example,  was picked, chopped finely and moulded into balls. Once the balls were dry, they were ground into a powder, to which urine was added. The threads were dipped into the resulting mixture, which was green. When they removed from the liquid, they turned blue. The technique is still used today by some people who use natural dyes.

Medicine also made use of urine for diagnosing illnesses. Much as you can tell today from your urine whether you’re hydrated or not, or that you’ve been eating beetroot or asparagus, a medieval physician could learn much from the colour, smell or taste of his patient’s urine. That’s why you knew without thinking too much about it that the monk at the top of the post is a physician. His patients are bringing him flasks of urine for him to make diagnoses. Just as kings are always depicted wearing their crowns in medieval art (even if they’re in bed) so physicians are depicted with urine flasks.

Last, but by no means least, urine was used in alchemy. In the fourteenth century alchemy was a respectable science and it wasn’t always about turning lead into gold. In this case, however, it was. One path towards turning one metal into another was to turn one metal into the facsimile of another. The theory was that if you could imitate something you would understand more about how to create it.  Urine, specifially urine from a youth, was used in a process to create an imitation of gold. Just in case you want to give it a go, the recipe is one dram of lime and one dram of ground sulphur. They’re mixed together, then the urine is added and the mixture heated. When it looks like blood, it should be filtered. If you dip a piece of silver into the clear liquid, will take on the appearance of gold.

Medieval and Early Renaissance Medicine by Nancy G Siraisi
Tudor Monastery Farm by Peter Ginn, Ruth Goodman and Tom Pinfold
The Secrets of Alchemy by Lawrence M. Principe


April Munday is the author of the Soldiers of Fortune and Regency Spies series of novels, as well as standalone novels set in the fourteenth century.

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Filed under Fourteenth Century, Medieval Family, Medieval Life, Medieval Medicine, Medieval Science

Medieval Bodies by Jack Hartnell – A Review


Medieval Bodies is not what you might expect from the cover or from the title. Based on a podcast I heard in which Jack Hartnell was interviewed about his book, I was expecting something about medieval medicine and medieval illnesses. I was wrong, but in a good way.

It’s a book that looks at the parts of the body (head, hands, feet, skin etc.) and asks how such things were thought about in the Middle Ages. Each chapter is about a different part of the body, starting with the head and ending with the feet. Within each chapter, there’s a look at what medieval medical science thought about that particular body part and then there’s a consideration of what that part meant to people at the time, both physically and spiritually. The chapter on genitals, for instance, talks about medieval childbirth in reality and in art. I enjoyed the chapter on feet, which talks about some of the odd fashions in footwear in the fourteenth and fifteenth centuries.

Hartnell doesn’t just cover thoughts about bodies from Europe, but he also includes Jewish and Islamic writings and illustrations. Islamic works were being translated into Latin from the twelfth century, bringing long-forgotten Greek learning and philosophy into countries north of the Mediterranean. This wider knowledge is reflected in a change of ideas about medicine, while the church had to consider whether or not physicians and surgeons should be allowed to follow the teachings of the pagan Greeks.

There are colour illustrations on almost every other page, making this a book to be browsed as well as read. I enjoyed it very much, although it, of necessity, deals with each subject superficially. Any book with ‘medieval’ in its title already has to spread itself thin, since the Middle Ages lasted more than a thousand years. Medieval Bodies compounds the problem by going beyond the bounds of Europe.


April Munday is the author of the Soldiers of Fortune and Regency Spies series of novels, as well as standalone novels set in the fourteenth century.

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Filed under Book Review, Medieval Life, Medieval Medicine, Medieval Science

The Humours

D for Dentist

The female protagonist of my current novel is a bit of a healer. She has learned all she can about medicine from people who are willing to share what they know and from the books she has to hand. Since she’s betrothed to the son of an earl, she lives in a large household and can see how the sick are looked after. She can also practise on them if the circumstances allow.

In reality, however, physicians were unlikely to share what they knew beyond their families and apprentices, and a woman who was to be married to the son of an earl would see very little of the father-in-law’s household.

There was a vast gulf between those who studied medicine in the universities and those who practised it in towns and villages. Universities trained up men to serve in royal and noble households. They read and discussed ancient and modern writings about medicine as part of their studies, but it’s questionable how much practical training they received.

Practical medicine was left to physicians, midwives, surgeons, apothecaries, dentists and barbers. You didn’t have to be literate to be a good physician. All you had to do was to watch and learn from someone who knew more than you did.

A physician’s main aim in caring for the sick would have been to ensure that their humours were in balance with one another.

The skin wasn’t considered to be an impenetrable barrier to the natural elements: earth, air, water and fire. These four interacted with the body. Each of them also had properties relating to heat and moisture. Earth was dry and cold, air hot and wet, water wet and cold, and fire hot and dry. As well as the external agents, the body was affected internally by blood, phlegm, yellow bile and black bile. These were the humours and a person could only be well if they were kept in balance. There were four of them to match the number of external elements, not because it made any real sense medically.

If someone was thought to have too much of a particular humour, they would be purged. Excessive heat could be removed by the use of cooling herbs. Fiery spices could drive out the cold. The idea of the humours came from Ancient Greece. Aristotle particularly valued hot, thin, clear blood, which he said led to courage and intelligence.

Phlegm was any colourless or white secretion that wasn’t semen or milk. It was mostly associated with the brain, but it was also connected with blood.

Yellow and black bile were said to come from the gall bladder, but were essentially the same thing. They were believed to purify the blood when they were functioning properly.

Blood was considered to be both a single substance and something that was mixed with the other three humours.

It’s not surprising, then, that blood-letting could be considered a cure for certain conditions. Nor is it surprising that the patient’s blood, urine or faeces were examined more closely than the patient himself. The only way a physician could discover what was wrong with his patient was by looking at what the patient secreted to learn what he could about the balance of the humours.



Medieval Bodies by Jack Hartnell

Medieval and Early Renaissance Medicine by Nancy G. Siraisi


April Munday is the author of the Soldiers of Fortune and Regency Spies series of novels, as well as standalone novels set in the fourteenth century.

Available now:













Filed under Medieval Medicine, Medieval Science

The British Museum in Thirteen Objects – The Chaucer Astrolabe

The Chaucer Astrolabe

The Chaucer Astrolabe, British Museum

The astrolabe was a multi-purpose scientific instrument in the Middle Ages. When the illegitimate child of Abelard and Héloise was born in the early twelfth century, he was named Astrolabe in its honour.

An astrolabe, according to James Robinson in Masterpieces of Medieval Art, is a two-dimensional map of the three-dimensional celestial sphere. In much the same way that an Ordnance Survey map can help you find your way through a wood, up hills and over streams you’ve never seen before, so an astrolabe can you to find your way through the heavens. It was, as you can see, a sophisticated instrument.


The Chaucer astrolabe is dated 1326, 16 years before Chaucer was born, and is the earliest dated European astrolabe. Although it didn’t belong to Chaucer, the poet wrote a treatise on the astrolabe, the first in English, and described an instrument very like this. Dedicated to his son Lewis, it was written by 1391. There are more than thirty surviving manuscript copies of the treatise.

Most texts about the construction and use of astrolabes were written in Latin. They were used to tell the time in the many different time systems that existed in fourteenth-century England. It could be used to work out angles and the height of objects. It could also be used while casting horoscopes.

Saints’ days in English and the latitude for Oxford are written on the back, indicating that it was principally for use in England. There are also inscriptions relating to Jerusalem, Babylon, Montpellier and Paris.

It’s just over 5 inches in diameter and less than half an inch thick. The star pointers are shaped like birds.

On the left in my photograph is Richard II’s quadrant. The raised piece that you can see is his emblem: the white hart. It’s a timepiece, enabling its user to tell the time from the angle of the sun. It’s dated 1399, the year of the king’s death.


Masterpieces of Medieval Art


Filed under Fourteenth Century, Medieval Science