Sauce Hollandaise

4 table-spoons vinegar
1 blade mace
1 tea-spoon flour
Yolks of 4 eggs
3 ozs. butter

Season the vinegar, add to it the flour and mix perfectly smooth. Add the mace. Bring to the boil and boil for two or three minutes. Take off the fire, and take out the mace. Add the butter cut in small pieces, and the well-beaten yolks. Stir continually, in one direction, over a bain marie. Serve directly the butter is melted.