Carp.
Have a sharp-pointed kitchen knife, put the point carefully under the scales (between the scales and the skin); at the tail of the fish pass the knife gently up the back to the head, dividing the scales from the skin carefully; you may then take off the whole of the scales in one piece from each side, and your fish will look very white; (most cooks are acquainted with this mode, but should it be too difficult for some, they can scrape it in the common way; it will not look so white, but will eat equally good;) then make a small incision in the belly, close to the bladder; pull out the gills with a cloth, and the inside with them; but if any remains, take it out of the incision, but be careful not to disturb the roe or break the gall; lay it in spring water half an hour to disgorge; dry it with a cloth.
Pike.
Take off the scales as you would a carp; make two incisions in the belly, a small one close to the bladder, and a larger one above; pull one of the gills at the time with a strong cloth, and if the inside does not come with them, take them out of the incisions, and wash it well; the cutting of the fins is a matter of taste, but it is usually done.
Trout
Are sometimes served with the scales on, but they are usually taken off; clean like salmon.
Tench
Are very difficult fish to clean; the best way is to form them in the shape of the letter S, and instead of scraping them from the tail to the head, like other fish, scrape upwards from the belly to the back with an oyster knife, the scales running that way, take out the gills, open the belly, take out the inside, and wash it clean.
Perch
Are very difficult to scrape; they must be done almost alive: form the fish like an S, and scrape it with an oyster-knife; open the belly and take out the inside; pull out the gills, and wash well; when large, they are often boiled with the scales on, and they are taken off afterwards, which is much easier; but it depends upon how they are to be cooked.