Cut and pull out the gills, then open the belly and take out the inside; wash it in spring water; if this fish is required crimped, you must clean it before it is quite dead (that is to say, whilst life remains in the muscles of the fish); cut it up in slices three inches in thickness, and lay them in spring water for a quarter of an hour; or if the fish is wanted to be served whole, merely cut incisions upon each side to the bone, about two inches apart, and lay it in spring water three quarters of an hour.
Whitings.
Cut out the gills, and open the belly; wash them and cut off the fins; if for frying, cut off the flaps under the neck of the fish, then pass your knife lightly from the head to the tail, down the back, merely cutting through the skin; then detach the skin at the head, and pull it all off one side together, and then the other; then put the tail into the mouth, and run a peg through the nose and tail, to keep it in that position.
Haddocks.
Are cleaned in the same manner as whitings, but not skinned or trussed, as they are seldom fried.
Salmon.
Cut out the gills, open the belly, and take out the inside, which wash lightly; scrape off the scales, and cut it in slices, or serve whole; if it is to be crimped, you must let the scales remain; crimp it in the same manner as cod-fish. Clean salmon-trout in the same way as salmon.
Soles.
Take out the gills, and make a small opening in the belly of the fish; take out the interior, leaving the roe; then detach the skin of the back at the head; pull it all off the fish together, and cut off the fins.
Mackerel.