William Morison was the son of Roderick Morison, from Strathglass, who became minister of Kintail in 1781, and Jane Fraser of Culduthel. His date of birth is given as 10th May 1790 in Fasti Ecclesia Scoticanae, two years earlier than the age on his parents gravestone.
Sacred to the memory of Revd Roderick Morison Minister of Kintail who died on 14th April 1826 in the 75th year of his age and 45th of his ministry and of his beloved spouse Jane Fraser daughter of Alexander Fraser of Culduthel who died on the 29th January 1830 in the 65th year of her age and of their children Alexander who died at Java on 20th July 1812 aged 25 years William who died at Demerara on the 15th May 1814 aged 22 years and Mary, Mrs Mackenzie of Kernsary who died on the 27th May 1847 aged 59 years.
William's nephew, Roderick Mackenzie, also died in Demerara [Alexander Mackenzie, History of the Mackenzies]. He was the son of William's sister, Mary (named on the gravestone), and Alexander Mackenzie of Kernsary.