Sheepskin may have been the preferred parchment for use in legal documents in Britain between the 16th and 20th century based on its utility in detecting fraud, according to research publish in the open-access journal Heritage Science.
By the late 16th century in Britain, deeds - legal documents concerning the ownership and occupation of property - were primarily handwritten on parchment made from animal skin. It has not been clear which species were used to make them.
Researchers at the Universities of Exeter, York and Cambridge, UK found that, of 477 British legal documents dating from the 16th to 20th century, most were written on sheepskins.
Sean Doherty, at the University of Exeter, the corresponding author said: "We were surprised to discover that the deeds were made almost exclusively from sheepskin, as previous research has indicated that other non-legal documents were written on skins from a range of species. This potential preference for sheepskins could indicate that there was something particularly important about their use."
The authors suggest that sheepskins may have been the preferred choice for parchment, due to the higher prevalence of sheep compared to goats and calves in Britain and the resulting low cost of sheepskins compared to goat and calfskins. Additionally, the authors found passages of text in 12th and 17th century documents which indicated that sheepskins may have been preferred because they allowed for the detection of fraudulent changes to legal documents. The high fat content of sheepskins may have enabled this fraud detection, according to the authors.
Sean Doherty said: "Removing fat during the parchment making process can cause the layers within sheepskins to separate more easily than those of other animals. To make fraudulent changes to documents after signing, the original text would have to be scraped off. This could cause the layers within sheepskin parchment to separate and leave a visible mark on the document, resulting in the fraud being easily detectable."
The authors investigated which species of animal were used to make parchments for legal documents using 645 samples taken from 477 British property deeds dating from 1499 to 1969. They performed mass spectrometry on proteins extracted from the samples to identify if proteins characteristic of species commonly used to make parchments were present in the deeds.
All 645 samples contained proteins characteristic of animals from the Bovidae family, which includes sheep, goats and cattle. 622 of the samples contained proteins characteristic of sheep, indicating that they were made from sheepskins. The remaining 23 were made from either sheep or goatskins but the individual species could not be identified due to a lack of characteristic proteins.
The authors caution that the presence of goatskin parchment in the documents studied cannot be ruled out as proteins characteristic of goats in the samples may have been degraded during storage, potentially affecting their analysis.
Sean Doherty said: "Historic legal deeds are one of the most abundant resources in British archives but are often considered to be of limited historic value. Our research demonstrates that, as physical objects, historic legal deeds can be used to explore centuries of craft, trade and livestock economies."
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Notes to editor:
1. Scratching the surface: the use of sheepskin parchment to deter textual erasure in early modern legal deeds
Doherty et al.
Heritage Science 2021
For an embargoed copy of the research article please contact Deborah Kendall-Cheeseman at Springer Nature.
After the embargo lifts, the article will be available here: https://heritagesciencejournal.springeropen.com/articles/10.1186/s40494-021-00503-6
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2. Heritage Science is an open access journal publishing original peer-reviewed research covering:
- Understanding of the manufacturing processes, provenances, and environmental contexts of material types, objects, and buildings, of cultural significance including their historical significance.
- Understanding and prediction of physico-chemical and biological degradation processes of cultural artefacts, including climate change, and predictive heritage studies.
- Development and application of analytical and imaging methods or equipments for non-invasive, non-destructive or portable analysis of artwork and objects of cultural significance to identify component materials, degradation products and deterioration markers.
- Development and application of invasive and destructive methods for understanding the provenance of objects of cultural significance.
- Development and critical assessment of treatment materials and methods for artwork and objects of cultural significance.
- Development and application of statistical methods and algorithms for data analysis to further understanding of culturally significant objects.
- Publication of reference and corpus datasets as supplementary information to the statistical and analytical studies above.
- Description of novel technologies that can assist in the understanding of cultural heritage.