Cream of Celery

Boil a trimmed head of celery in one pint of water for thirty or forty minutes;
boil a piece of mace and a large slice of onion in one pint of milk; mix one tablespoonful
of flour with two tablespoonfuls of cold milk, add this to the boiling milk,
and cook for ten minutes. Mash celery in the water in which it has been cooked,
mix it into the boiling milk, add one tablespoonful of butter and season with pepper
and salt to taste. Strain and serve immediately. The flavor may be improved by
adding one teacupful of whipped cream when the soup is in the tureen.