An hour before you intend to dress them, wash them dioroughly, and wrap them in a clean cloth, to make them perfectly dry, or the bread-crumbs will not stick to them.
Prepare some bread-crumbs, by rubbing some stale bread through a colander; or, if you wish the fish to appear very delicate and highly finished, through a hair sieve; or use biscuit powder.
Beat the yolk and white of an egg well together, on a plate, with a fork; flour your fish, to absorb any moisture that may remain, and wipe it off with a clean cloth; dip them in the egg on both sides all over, or, what is better, egg them with a paste-brush; put the egg on in an even degree over the whole fish, or the bread crumbs will not stick to it even, and the uneven part will burn to the pan. Strew the bread crumbs all over the fish, so that they cover every part, take up the fish by the head, and shake off the loose crumbs. The fish is now ready for the frying-pan, into which put a quart or more of fresh sweet olive oil, or clarified butter, dripping, lard, or clarified drippings; be sure that they are quite sweet and perfectly clean (the fat ought to cover the fish): what we here order is for soles about ten inches long; if larger, cut them into pieces the proper size to help at table; this will save much time and trouble to the carver: when you send them to table, lay them in the same form they were before they were cut, and you may strew a little curled paisley over them: they are much easier managed in the frying-pan, and require less fat: fry the thick part a few minutes before you put in the thin, you can by this means only fry the thick part enough, without frying the thin too much. Very large soles should be boiled, or fried in fillets. Soles cut in pieces, crossways, about the size of a smelt, make a very pretty garnish for stewed fish and boiled fish.
Set the frying-pan over a sharp and clear fire; watch it, skim it with an egg-slice, and when it boils, i. e. when it has done bubbling, and the smoke just begins to rise from the surface, put in the fish: if the fat is not extremely hot, it is impossible to fry fish of a good color, or to keep them firm and crisp.
The best way to ascertain the heat of the fat, is to try it with a bit of bread as big as a nut; if it is quite hot enough, the bread will brown immediately. Put in the fish, and it will be crisp and brown on the side next the fire, in about four or five minutes; to turn it, stick a two-pronged fork near the head, and support the tail with a fish-slice, and fry the other side nearly the same length of time. Fry one sole at a time, except the pan is very large, and you have plenty of fat.
When the fish are fried, lay them on a soft cloth (old table-cloths are best), near enough the fire to keep them warm; turn them every two or three minutes, till they are quite dry on both sides; this common cooks commonly neglect. It will take ten or fifteen minutes, if the fat you fried them in was not hot enough; when it is, they want very little drying. When soles are fried, they will keep very good in a dry place for three or four days; warm them by hanging them on the hooks in a Dutch oven, letting them heat very gradually, by putting it some distance from the fire for about twenty minutes, or in good gravy, as eels, Wiggy's way.
There are several general rules in this receipt which apply to all fried fish: we have been very particular and minute in our directions; for, although a fried sole is so frequent and favorite a dish, it is very seldom brought to table in perfection.