2 large boiled potatoes.

1 teaspoonful powdered sugar.

1 table-spoonful oil.

1 saltspoonful made mustard.

1 saltspoonful salt, and same of pepper.

1 teaspoonful Harvey's sauce.

1 egg, beaten light - white and yolk separate.

3 table-spoonfuls vinegar.

Boil the potatoes until mealy, drain every drop of water from them; let them dry on the range for an instant, and beat up (not mash) them with a fork, tossing them into lightness and dryness. "When fine and dry, beat in the salt, oil, and egg; the yolk first, then the white, which should be a stiff froth. In another vessel have ready mixed the mustard, sauce, sugar, pepper, and vinegar. Add by degrees to the potato-mixture until it is like thick cream. If not perfectly smooth, rub through a coarse wire sieve or a bit of coarse lace, such as is used for mosquito netting.

This, also, is peculiarly nice with salmon, or halibut mayonnaise, although excellent with chicken or turkey salad.