In a deep soup-plate place the yolks of four eggs, two teaspoonfuls best ground mustard, three-quarters of a teaspoonful of salt, one-half teaspoonful cayenne pepper, and one-half teaspoonful white pepper. With a large fork or spoon stir continually in one direction. With the other hand pour in slowly from time to time, from the bottle, the best olive oil. As soon as it commences to bind and get stringy, add quickly a little lemon juice or vinegar. Keep stirring continually until three-fourths of a pint of oil, the juice of one lemon, and one-half gill of vinegar are used up. Stir up well, then place at once on ice. Some cooks make a big time about mayonnaise, but if everything is properly prepared there is no excuse for failure. Everything should be cold, especially the oil. Should the dressing break in spite of all, add quickly another yolk of egg, and stir, holding back the oil for a minute.