Appledore Soup

3 potatoes
1 1/2 teaspoons salt
1 quart milk
1/4 teaspoon celery salt
2 slices onion
1/8 teaspoon pepper
3 tablespoons butter
Few grains cayenne
2 tablespoons flour
3 tablespoons ketchup
1 teaspoon chopped parsley

Cook potatoes in boiling salted water; when soft, rub through a strainer. There should be two cups.

Scald milk with onion; remove onion, and add milk slowly to potatoes. Melt half the butter, and add dry ingredients, stirring until well mixed. Stir into hot soup; boil one minute; strain. Add remaining butter and ketchup. Sprinkle with parsley.