Source: Per post at 18th Battalion Facebook Group by David Archer.
Family Search: When Private John Coulson Douglas was born on 4 September 1887, in Owen Sound, Grey, Ontario, Canada, his father, Frederick Gabriel Douglas, was 32 and his mother, Mary Ann Coulson, was 30. He married Ivy Irene Plater on 9 October 1954, in Owen Sound, Grey, Ontario, Canada. He lived in Grey, Ontario, Canada in 1901 and East Linton, Grey, Ontario, Canada in 1915. He registered for military service in 1915. In 1915, at the age of 28, his occupation is listed as farmer in Owen Sound, Grey, Ontario, Canada. He died on 30 August 1971, in Owen Sound, Grey, Ontario, Canada, at the age of 83, and was buried in Greenwood Cemetery, Owen Sound, Grey, Ontario, Canada.
Went by Coulson Douglas and was sometimes identified as Coulson Douglass in the newspapers.
Private John Coulson Douglas, Regimental Number 409113
This man enlisted under the name of Coulson Douglas with the 37th Battalion at Niagara Camp, Niagara-on-the-Lake on 11 June 9`5. He was a farmer and had prior militia experience with the 31st Regiment in the Canadian Militia.
He arrived in England aboard the SS Lapland on 11 December 1915 and was transferred to the 12th Reserve Battalion at Shorncliffe on 15 March 1916.
He was transferred to the 18th Battalion and arrived “in the field” on 2 June 1916.
On 13 April 1917 he was wounded with a GSW to the right hand and returned to England for treatment aboard the H.S> Princess Elizabeth making passage for England on 17 April 1917. He returned to duty on 2 December 1917.
He attended a Machine Gun Course with the 2nd Battalion, Canadian Machine Gun Corps on 15 April 1918.
He suffered from neurasthenia on 8 July 1918 and was classified as B.2 medical classification and assigned to the Canadian Labour Pool.
Returned to Canada aboard the SS Aquitania, arriving in Halifax on 25 January 1919. He was discharged due to demobilization at Toronto, Ontario on 3 June 1919.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 