Wipe the smelts, empty them through the gills, then salt and flour them over; fry in oil, and drain on a grate until cold. Range them in a flat vessel one closely beside the other. Put some vinegar into a frying pan with a little water and oil, salt, whole peppers, bay leaves, and minced onions; boil the liquid up twice, then remove and when cold pour it over the smelts and leave to macerate for a few hours before using.
Ranhofer's escabeche: small fish fried crisp, then steeped in a hot vinegar marinade and served cold. The recipe gives no quantities at all, so the proportions of the pickle are yours to set.
This is escabeche under a French name: fish fried, then preserved in a vinegar bath, a technique that runs through Spanish, Portuguese and southern Italian cooking and is generally traced to the Arab-influenced kitchens of medieval Iberia, where the acid did the work of refrigeration. Charles Ranhofer, chef at Delmonico's in New York, put it in the cold side dishes of The Epicurean (1894) among the smoked salmon and goose breast, dishes meant to stand on a buffet or open a long meal without last-minute work. American smelt were abundant and cheap in the period, netted in spring runs along the northeastern coast and sold by the basket, which made them a natural candidate for a preparation that improves with keeping.