From George Whitefield's journal, 'Friends have received me most kindly, and the congregations, I think, are larger than ever. Yesterday (Sunday), besides preaching twice in the field, I preached in the College Kirk, being forced by Mr Gillies. It was a blessed season.'
The College Church was the church of John Gillies the historian, who always welcomed Whitefield and John Wesley.
This is from an 1807 map which can be seen on the National Library of Scotland's website. The old University Church is the southernmost of the four black buildings at the centre of the map.