Remove all the fat from the stock. If it is in a jelly, take off as much as possible with an iron spoon, and remove the remainder by washing the top of the stock with a cloth dipped in very hot water.
Scrape the beef finely and soak it in two tablespoonfuls of cold water to loosen the juices.
Put the stock in a stewpan and add the beef to it, the white and shell of the egg, and a very tiny piece of each kind of vegetable used in making the stock.
Whisk over the fire until the stock begins to simmer.
Then leave off stirring and let it well boil up.
Remove it from the fire and put it on one side for a crust to form.
Tie a clean cloth to the four legs of a chair turned upside down.
Pour some boiling water through it into a basin, to ensure it being perfectly clean.
Then put a clean basin underneath and pour all the contents of the stewpan on to the cloth. The first time the soup runs through it will be cloudy, because the filter made by the beef and egg will not have settled at the bottom of the cloth.
Take the soup away; put a clean basin under the cloth, and pour the soup slowly through.
If this is carefully done the soup will be quite brilliant the second time of straining, and will not require to go through the cloth again.