Black Bean Soup

1 pt. black beans
2 qts. water
1 small onion
2 stalks celery, or
¹⁄₄ teaspoon celery salt
2 teaspoons salt
¹⁄₈ teaspoon pepper
¹⁄₄ teaspoon mustard
Cayenne
3 tablespoons butter
1¹⁄₂ tablespoons flour
2 [hard-cooked eggs]
1 lemon

Soak the beans over night, drain them and add the two quarts of water. Cook the onion in one-half of the butter; add onion and celery to the beans, and, when boiling, put them into a cooker for from eight to twelve hours. Rub the soup through a strainer, add the seasonings, bind it, and when it has boiled for five minutes pour it over the sliced eggs and lemon in a soup tureen.

Serves eight or ten persons.