Dr. Campbell donated an extensive collection of 2765 sheets to the McGill University herbarium. He was the minister of the Scottish Presbyterian Church of St. Gabriel’s in Montreal and moderator of the Presbyterian church of Canada. An amateur naturalist, he collected avidly wherever he went in North America and Europe. He was the author of several papers dealing with the Flora of the Island of Montreal, the Rocky Mountains, and North American goldenrods. The latter appeared in the Canadian Record of Science circa 1900.