Cook together two tablespoons of butter and the same of flour until they bubble, stirring constantly. Use the blazer of the chafing dish. Add a cup of milk and half a cup of oyster liquor to the bubbling butter and flour; stir until thick and smooth and put in a pint of oysters which you have turned into a colander to free them from as much of the juice as possible. In any event there will be a good deal of liquid from them. Cook them until the gills begin to curl and the oysters to plump, and then season to taste with salt and pepper, and serve at once on toast or crackers.