Applying science to medieval manuscripts with Dr Kate Nicholson.
Words by Josh Duncan, edited by Clare Fearon
Science and religion are occasionally viewed by some as rivals but in October’s SciBar, Kate Nicholson, Senior Lecturer at Northumbria University, showed us how the two have come together to help shed light on the past. Kate spoke of how, in 2013, a gathering of the Lindisfarne Gospels (a collection of four religious texts written by Eadfrith dating back to the 8th century) sparked the creation of ‘Team Pigment’, a collaboration between scientists and historians from Northumbria, Durham and Cambridge universities.
So how exactly does a chemist find themselves delving into history and flicking (very carefully!) through books that are usually reserved for a historian’s eye?
First, a bit of a recap…
Religion has long been of interest to historians in the United Kingdom. Up and down the country you can find relics of the past, in ancient Abbeys, remnants of Henry VIII’s rulings over the Catholic Church and the Dissolution of the Monasteries in the 16th century. Some nine centuries earlier however, there had been another, lesser known, upheaval. In 597 Pope Gregory tasked St. Augustine, a Benedictine monk, with spreading Christianity across the British Isles. Despite successfully converting the then King of Kent to Christianity, it wasn’t until the conversion of Edwin, King of Northumbria, in 625 that Christianity began to take hold in Britain, overthrowing Paganism.
In the decades and centuries that followed, the North East of England became an important ‘cradle’ of English Christianity and indeed Holy Island has been dubbed the ‘birthplace of English Christianity’. And so with Eadfrith’s writings of the 8th century we are back to answering the question of ‘what does this have to do with science?’
After giving us all the opportunity to hold a piece of history in our hands – a 15th century ‘Book of hours’, it was time to learn about the work of Team Pigment. Kate and her team are interested not in the words written in the gospels, or even the language they are written in, but the ink they are written with. We perhaps don’t think about it now, living in an age where everything we could want or need is commercially available, but in times gone by dyes and inks were a valuable commodity, and varied from region to region. Understanding how they evolved over time can therefore help us understand advances in technologies, the availability of local resources and can even tell us about international trade routes.
By investigating the composition of the inks used in texts such as the famed Lindisfarne Gospels, Team Pigment can unravel history and perhaps even uncover some long lost secrets. Had Eadfrith and his fellow monks been kind enough to write down the recipes used to produce the inks they used, Kate’s work would have been a lot easier! However, the earliest recorded pigment recipe dates back to the 12th century, meaning Kate and her team have to uncover the past…
For a chemist, analysing materials and substances to determine their composition is an everyday task, so this should be a doddle right?
Of course, it’s not so simple…
The Lindisfarne Gospels are old, really old, and as Kate is interested in the ink used to write the books, only the originals will do. They’re also quite big. And valuable.
This posed a couple of challenges for Team Pigment:
- How do we analyse the ink without damaging the Gospels?
- How do we bring our equipment and the Gospels together?
The Gospels themselves of course could not be transported to the lab and so this meant the lab had to be transported to the books. Miniaturising their spectroscopes (more on what one of those is in a minute) was no mean feat, but once complete, it meant that Kate and her team were the only group capable of travelling anywhere in the country in order to analyse a sample and so the scope of their investigations exploded.
To understand why the analysis might damage the Gospels, we need to first understand what the analysis is, what is spectroscopy?
Spectroscopy is widely used in science, whether it is to measure the amount of toxic chemicals in a blood sample, or to investigate the habitability of a distant planet. Put simply, spectroscopy can be used to tell us more about a substance (on a chemical level) than we can glean with the naked eye, or even a very good microscope. Kate described two of the main techniques used in her investigations.
Raman spectroscopy takes advantage of the idea that molecules are like ‘antsy little kids’, they move around alot- they vibrate. More importantly, they vibrate differently from molecule to molecule. By shining a light onto the sample (usually near-infrared) and analysing the radiation that is emitted, Kate can determine which compounds are present in a sample. Each compound has its own tell-tale signature, a spike (or several) on a graph, which is enough to confirm the chemicals used in the ink. Thankfully, this is a non-destructive method, so the books could be safely returned after the analysis!
Reflectance spectroscopy, another technique utilised by Kate, works in much the same way as our eyes. The principle is very much the same, a light is shone on the sample, and the radiation (photons) reflected is analysed. These techniques can allow Kate to tell apart two seemingly identical inks by quantifying the amount of any given chemical compound.
The painstaking process of analysing the ink used throughout these ancient religious texts has uncovered much of interest, starting with the fact that the chemistry knowledge of those in the 7th century is nothing to be sniffed at! The prevalence of Minium, a bright orange-red pigment containing lead was quite remarkable, given the fact that it requires a furnace kept at a precise 585C to be produced – just quite how this level of control was possible remains a mystery. What is certain however, is that you should never be tempted to lick the paintbrush – especially if it is red.
Kate was also able to shed light on the thrifty-ness of monks in the North East, by analysing the purple inks that were used. Purple is often seen as a colour of royalty, deemed so because of the cost and difficulty in producing the Tyrian purple dye. ‘Scaring 5000 sea snails’ (the sea snails in question secrete a bromine based substance to subdue their prey, and it is from this the purple dye was usually made) for 1g of dye can be quite an arduous process. Thankfully, for the sake of all that is purple, monks in the North East were able to take advantage of a local species of lichen to produce their purple inks – quite how they discovered that the lichen produced the purple pigmentation only when left to soak in stale urine however is anyone’s guess…
As well as highlighting the technical prowess – and ingenuity – of local monks, mapping the use of inks can also be used to confirm significant historical events and developments in international trading. The Norman Conquest, for example, is marked by the appearance of Lapis Lazuli, a blue dye originating from Afghanistan, whilst increased trading ties with Spain brought Vermillion, a scarlet-red pigment produced from Cinnabar. However, one mystery, the presence of Egyptian blue on a manuscript has puzzled the team. The recipe for the dye was lost sometime in the 4th century, so how did a monk come to be in possession of it? Was it perhaps ‘borrowed’ from an ancient Egyptian relic?
It is questions like this, that have inspired Kate and her team to extensively map the use of inks from the 5th to the 15th century in what is now the largest study of its kind. Who knows what further secrets can be uncovered?