After a single session in Glasgow University, at the age of nineteen, Dugald was asked by his father, whose health was beginning to fail, to give his mathematical classes in the University of Edinburgh.
Po jednom semestru v Glasgow, ve věku devatenáct let, byl Dugald povolán otcem, jehož zdraví začalo selhávat, aby vedl matematické třídy na univerzitě v Edinburghu.