These 1888 and 1889 newspaper articles from the Qu'Appelle Progress state that he was a Methodist minister.
http://peel.library.ualberta.ca/search/?search=follow&qi...Rev Septimus E. Colwill, 1853 - 1938
http://boards.ancestry.com/thread.aspx?mv=flat&m=2&p..."Reverend Septimus E. Colwill was born near Charlottetown, PEI the 26th of August 1852. He received his academic traiing at Acadia University and was ordained in 1879. He retired in 1902. He died on 11th January 1938.
This information was supplied to me by the United Church Archives in Toronto. I have additional information about his postings with the ministry if you are interested."
http://www.genealogy.com/forum/surnames/topics/colwill/6/