Rule of Thumb
19 December, 2013
This is blog number 50 from me (although there have been one or two posts from colleagues along the way!) so that’s a wee celebration for me. But it also coincides with Historic Scotland becoming the 50th signatory to Scotland’s Geodiversity Charter.
The charter sets out to recognise the importance of Scotland’s very diverse geology. It has contributed to Scotland’s historical and cultural development, intellectual growth and creative expression and is fundamental to the wonderfully diverse wildlife.
Past blogs have explored how Historic Scotland’s sites and monuments are inextricably linked with the geology of the area. In May I explained how the towns of Melrose and Jedburgh are located on the only sandstone outcrops in the area.
Other posts looked at Arthur’s Seat in Edinburgh and Dumbarton Rock, recognised for their historical importance as defensive sites. They are both the remains of extinct volcanoes and designated as Sites of Special Scientific Interest (SSSIs).
Many of Historic Scotland’s monuments correspond with important geological sites: examples include Edinburgh Castle, Tantallon Castle in East Lothian, Inchcolm Priory in the Firth of Forth and St Ninian’s Cave in Galloway, all of which lie within geological SSSIs.
But my particular favourite is Eileach an Naoimh (‘Rock of the Saint’) in the Inner Hebrides, which holds the ruins of an early Christian monastery with beehive cells, a chapel and a tiny graveyard.
The island lies at the southern end of the Gavellachs, a 4-mile (6km) long island chain in the Firth of Lorn, lying between Jura and Mull. Geologically it is important as an unusual limestone outcrop with related limestone ‘pavement’. Limestone gives rise to an unusual, base-rich soil with associated distinctive plant communities.
In addition to the naturally occurring plants, there are many species that were probably introduced for medicinal purposes by the monks who lived here. These include St John’s wort, wild angelica and purple loosestrife.
St John’s wort contains a powerful anti-depressant, hypericin. It is associated with St Columba, who reportedly cured the illness of a young boy by placing it under his armpit. This is the origin of its colourful Gaelic name achlasan Chaluim-chille, (‘armpit package of St Columba’).
Wild angelica was used as a sedative and painkiller; while purple loosestrife was a traditional remedy used to control bleeding.
Another plant found on the island is the small white grassland flower, the grass of Parnassus. This flower is the plant badge of the Clan Maclae and is associated with another figurehead of Celtic Christianity, St Moulag.
Moulag was a contemporary of Columba and it seems that some rivalry existed between them. The story goes that the two missionaries were racing to reach the Isle of Lismore, having agreed that the first to set foot there could claim ownership. Realising he was lagging behind, Moulag is said to have cut off his thumb and thrown it onto the shore, sneakily – if painfully – gaining control of the island. According to tradition, he is buried on Lismore.
What became of his severed thumb is another matter.