You may know when the lard or dripping is hot enough, by dipping in the tail of one of the fish. If it becomes crisp immediately, the lard is in a proper state for frying. Or you may try it with a piece of stale bread which will become brown directly, if the lard is in order.
There should always be enough of lard to cover the fish entirely. After they have fried five minutes on one side, turn them and fry them five minutes on the other. Skim the lard or dripping always before you put in the fish.
Having cleaned the fish, and cut off the fins, dredge them with flour. Have ready some beaten yolk of egg, and in a separate dish some grated bread crumbs. Dip each fish into the egg, and then strew them with bread crumbs. Put some butter or fresh beef-dripping into a frying-pan, and hold it over the fire till it is boiling hot; then, (having skimmed it,) put in the fish and fry them.
Prepare some melted butter with a spoonful of mushroom-catchup and a spoonful of lemon-pickle stirred into it. Send it to table in a sauce-boat to eat with the fish.
You may fry carp and flounders in the same manner.
Put a handful of salt into the water. When it boils put in the trout. Boil them fast about twenty minutes, according to their size.
For sauce, send with them melted butter, and put some soy into it; or flavour it with catchup.