Salad Dressing

2 teaspoonfuls sugar, 1 teaspoonful cornflour, 1 tea- spoonful butter, ½ teaspoonful mustard, salt, pepper, ½ cupful vinegar, ½ cupful milk, 1 egg. Put milk and vinegar on to boil; mix other ingredients with little cold milk, then pour into boiling liquid and stir till thick cream. This dressing will keep for a long while.