Parchments in the laboratory: How can the natural sciences be applied to Ecclesiastical Latin?

Medieval texts, a treasure for the scholars of humanities, are now also being studied using chemistry, protein studies and carbon dating.

In the very centre of Helsinki, under the Unioninkatu street, a centuries-old treasure lies hidden. Even many Helsinki residents are not aware that the basement of the National Library of Finland holds the second most extensive collection of medieval parchment fragments in the world.

The texts written on these parchments, which are made of skin, led humanities scholars at the University of Helsinki to form an alliance with natural scientists. One of their goals is to increase the accuracy of the age determinations of the texts.

“The parchments include burnt sections, with dirt and soot from historical fires. These impurities hinder any radiocarbon dating attempts,” says Tuomas Heikkilä, professor of church history.

Heikkilä and his colleagues have spent years exploring the collection which includes roughly 20,000 pages of text from at least 1,400 individual books. The majority of the parchments are related to church services in Catholic Finland, but in addition to liturgical writings, there are also texts on science and law.

“The topics were imported, but a unique northern twist originating in Finland can be seen in the texts,” Heikkilä explains.

Skin has a story to tell

The content of the parchments has been investigated by specialists in the humanities, as have different handwriting styles, page layout and other aspects. However, this does not mean that the professor considers the topic exhausted and intends to close the archives – or the Fragmenta membranea database, which his research group created on the basis of the collection.

On the contrary, Heikkilä is getting ready to take advantage of equipment used in the natural sciences to help in his research. Techniques based on molecular biology and biochemistry, from DNA analysis to paleoproteomics, or the study of ancient proteins, are under development in the sphere of science.

The tools already in use around the world include chemical analysis of pigments, in relation to which the researchers working in Helsinki have heeded the teachings of Maria João Melo, a professor from Lisbon and guru of the field.

“Pigments too have something to tell us about local choices and international contacts.”

With the means of natural sciences, details pertaining to animals, skin processing, book making and trade routes can be deduced.

“Being aware of the type of parchment used, we can draw conclusions pertaining to trade and cultural contacts, economic conditions and literary ideals. We gain knowledge that might not necessarily be available from any single source.”

Typically, the material for parchment came from calves, sheep and goats, of which calves were the most common in the north. Often, the animal used for the parchment can be determined by the hair follicles visible in the skin, in addition to which the bulges of the spine and other bones stand out when studying parchments on a light table.

“This helps to determine the species, size and age of the slaughtered animal. Calves had to be no more than six weeks old at the time of slaughtering,” Heikkilä says.

Help from old bills of sale

At the moment, radiocarbon dating is the area where the parchment scholars of Helsinki have progressed the farthest. For this, Heikkilä has included in his group Markku Oinonen, who heads the Laboratory of Chronology on the natural sciences campus in Kumpula, Tuuli Kasso from the University of Copenhagen and Jaakko Tahkokallio from the National Library of Finland.

Ideally, a parchment can be dated with the precision of a few decades. The bigger the parchment specimen extracted for analysis, the better the results. At the same time, moderation is necessary when handling treasures.

“At best, specimens only need to be three square millimetres in size.”

Some dating findings have closely matched the hypotheses made by scholars in the humanities, but there have also been peculiarly see-sawing figures.

“Even though the fragment collection was conserved in its entirety roughly 10 years ago, impurities that affect dating still remain in the parchments. Next, we will use an FTIR infrared spectrometer to investigate whether the state of the collagen contained in the skin offers an explanation for the dating difficulties.”

The traditional study of handwriting known as paleography typically reveals the chronological order in which texts have been written, but linking them to a precise moment in the past is often impossible by using the methods of this field. For such calibration, Heikkilä’s group has also looked to other medieval documents.

“Alongside the Finnish fragments, we have dated old Italian bills of sale, which have dates on them. They help us confirm that our methods are reliable, in addition to which we are conducting control dating with recently manufactured parchments.”

Rage or a blessing?

The fragments studied by Tuomas Heikkilä became fragments when the founder of the City of Helsinki, King Gustav I of Sweden with his collaborators seized books and had them destroyed during the Reformation. However, the professor insists this destruction was not carried out in a blind rage.

“Instead of obliterating any signs of the papal religion, the actions were founded on practical reasons. Parchment skin was well suited to be used as covers for the Crown’s ledgers, and their production grew after the Reformation, starting in the 1530s.”

The pages of the ledgers were made of paper, while sections of text could be scratched off of the recycled parchment skins to make room for new titles in a prominent place. Other than that, the old texts were not tampered with.

In the end, this destruction proved to be a blessing for historical research. As a result of the reuse of fragments, pieces of functional church writings ended up safe and sound in the archives, while in the parts of Europe that remained Catholic they were completely used up or otherwise lost. Compared to the abundance of these parchment fragments, only very few complete books have been preserved in Finland.

The texts which evolved into the Fragmenta membranea database have been catalogued for decades, and they were published online for everyone to access in conjunction with a project on medieval literary culture in Finland headed by Heikkilä.

“National heritage belongs to everyone. If you want to browse the digitised writings for a favourite section and print it out for a pattern for your dress, go for it!”

From the Middle Ages to the future

After having the opportunity to establish links with natural scientists, Tuomas Heikkilä finds himself lucky to have such a vantage point.

“It’s rewarding to have my former students advance so far, such as the manuscript guru Jaakko Tahkokallio and Tuuli Kasso, who is writing her doctoral dissertation in a big international project based at the University of Copenhagen and Cambridge University.”

In addition to parchments and radiocarbon dating, Kasso’s repertoire includes beeswax studies, and the topic of her dissertation is the biomolecular analysis of cultural heritage.

Heikkilä also witnessed the first time that humanities scholars in Finland became interested in digital research methods and extensive datasets. In the early 2000s, he contributed to the development of stemmatology, the study of the transmission of old texts, changes made to them and their different versions.

“The same spirit of advancement seems to now prevail in this new kind of parchment research. Science has to renew itself, and church history cannot cling to techniques invented in the Middle Ages.”

The article has been published in Finnish in the 4/2020 issue of the Yliopisto Magazine.