A widely variable name. Francatelli 1867 has a consomme with poultry or game pieces thickened with arrowroot, other versions have vegetable pieces in chicken stock, others add egg or cheese.

Original Receipt from 'A Plain Cookery Book for the Working Classes' by Charles Elmé Francatelli (Francatelli 1846)

No 145 DUCHESS SOUP
Mix two ounces of Bermuda arrowroot with half a tumbler of cold water and pour this into a stewpan containing a quart of good consomme No 4, stir this over the fire until it has boiled gently for about ten minutes and then pour it into a soup tureen containing small neatly cut inch lengths of roasted or boiled poultry or game.