The science of conservation has allowed curators at the National Museum of Ireland to discover hidden information in an ancient Irish relic. The technical findings relating to the relic helps solve the mystery of its history and reveal its significance in ancient Irish cultures.
The relic known as the Mias Tighearnin, or the plate of Saint Tighearnin, is a circular bronze and silver disc. It was discovered in the 18th century in the saint's grave lying over his chest in the monastery of Errew, Co Mayo.
Since this discovery, the relic has been in private ownership, both inside and outside the Republic. As a result, the Mias Tighearnin has received little public attention. It was eventually acquired by the National Museum of Ireland earlier this year, and conservators have since been working to unveil its secret past.
"It's a lot more exciting than it looks," stated Mr Anthony Read, who is head of conservation in the National Museum.
Conservation differs from restoration in that it involves gathering as much information as possible without damaging the object, explained Mr Paul Mullarkey, a National Museum conservator working on the Mias Tighearnin. Great care must be taken in cleaning such an object and chemicals must be carefully chosen depending on the reactions they might cause, he said.
The techniques used by the conservators have achieved more than simply removing dirt and grime accumulated through the ages. They have revealed that the Mias Tighearnin is a multi-period object and that its use and significance in people's lives through the ages has also changed.
The relic dates from as far back as the 11th century, Mr Read explained, but several alterations and additions were made to the relic in the 14th, 15th and 19th centuries. "The object itself revealed little in its appearance but conservation has allowed us uncover and piece together its history," said Mr Read.
Another surprise came when the relic was subjected to X-ray study. This showed that the Mias Tighearnin was made up of several layers of plating from different periods. Encapsulated in the outer bronze plating, dated from about the 14th century, there is an older set of plates with studs from the 11th century. The conservators now believe that the object inside is the real relic with the outer casing added later.
Shrines were often used to give protection and enhancement to an important relic or sacred object, according to Mr Raghnall Floinn, of the Department of Irish Antiquities in the National Museum. Such shrines would have given "suitable housing" to valued objects such as books, bells or anything that belonged to a saint.
A second revelation made by the X-ray analysis was the presence of a square metallic object which can be heard rattling in the centre of the Mias Tighearnin. Mr Read believes this object may be made of silver or gold but its significance still remains "an enigma".
The conservators can tell that "curiosity got the better of somebody" as the Mias Tighearnin was opened up in the 19th century, Mr Read said. However, no record of what the then owner saw was made, nor indeed was there word of any changes that might have been made to the relic.
It was possible that the square object could be the most important part of the relic or indeed the primary relic itself, with everything else being secondary additions, Mr Floinn said. However, equally feasible was the possibility that the square was added when the Mias Tighearnin was opened much later in its history.
"Unfortunately it will remain a mystery to us as we cannot now take it apart," he said.
Originally the Mias Tighearnin probably functioned as a paten for holding communion hosts but it is thought that it later functioned as a religious reliquary used for swearing oaths upon and for general good luck, Mr Read said. The alterations made to the object reflected these changes in its use.
The Mias Tighearnin will be on display for viewing in the National Museum in Kildare Street in the new year.