A tablespoonful of mustard, one teaspoonful of salt, the yolk
of three uncooked eggs, the juice of half a lemon, a quarter
of a cupful of butter, a pint of oil, and a cupful of whipped
cream. Beat the yolks and dry ingredients until they are very
light, with a wooden spoon or with a wire beater. The bowl in
which the dressing is being made should be set in a pan of ice
water. Add oil, a few drops at a time, until the dressing
becomes thick and rather hard. After it has reached this stage
the oil can be added more rapidly. When it gets so thick as to
be difficult to beat add a little vinegar, then add the juice
of the lemon and the whipped cream, and place on ice until
desired to be used.