Celery and Button-Onions Soup

Having cleansed three heads of celery, cut them into inch lengths; boil them in water for five minutes, and when drained, place then in a soup-pot with half a pint of button onions, a little tarragon and chervil, a piece of sugar, and a pinch of mignionette pepper; fill up with game stock; boil gently until the celery is thoroughly done, and serve.