History of Scottish Gaelic
All surviving dialects are Highland and/or Hebridean dialects. Dialects of Lowland Gaelic have become defunct since the demise of Galwegian Gaelic, originally spoken in Galloway, which seems to have been the last Lowland dialect and which survived into the Modern Period. By the 18th century Lowland Gaelic had been largely replaced by Lowland Scots across much of Lowland Scotland. According to a reference in "The Carrick Covenanters " by James Crichton, the last place in the Lowlands where Scottish Gaelic was still spoken was the village of Barr in Carrick: only a few miles inland to the east of Girvan, but at one time very isolated. Crichton gives neither date nor details.
Gaelic-speaking congregations in the Church of Scotland
There is a shortage of ministers able to speak Gaelic. Continuity of Gaelic worship in Edinburgh has been maintained since 1704. It began when a provision was made by the General Assembly of the Church of Scotland for services for Gaelic-speaking soldiers stationed at Edinburgh Castle. Today, this Gaelic tradition continues at the 12.30 Gaelic-language service at Greyfriars Kirk. Glasgow still has a weekly Gaelic service at St Columba's Church, Glasgow on St Vincent Street at 10am.