PLAIN MAYONNAISE DRESSING
Put 2 chilled egg-yolks in a cold soup plate, and stir into them 1 teaspoon of salt and ½ teaspoon of mustard, using a silvered spoon, and after these are well mixed in begin to add oil, actually drop by drop, from 1 scant cup of cool olive oil, and do this until the eggs are so thickened that it is not possible to make them more so; then the remaining oil may be added less slowly. If this first process is not properly done, no amount of stirring will ever thicken the sauce. A fork or whisk may be used to finish the stirring. When the oil is added, beat in slowly 1 tablespoon of vinegar, and 1 of lemon juice, and ½ saltspoon of cayenne pepper. Put on the ice until wanted.
Tarragon mayonnaise is made by substituting tarragon vinegar for plain vinegar.