 This interest in mining and geology eventually supplanted his interest in medicine and Douglas embarked on a third career.In the 1860s, his father's financial fiasco investing in the Harvey Hill copper mine, Quebec, Canada, brought to Douglas the opportunity to save the family fortune by finding a way to make the mine profitable (it never was).In 1869, Douglas’ scientific experiments with the assistance of Dr. Thomas Sterry Hunt at Université Laval led him to a discovery that was to change his life.