Have two fine, medium-sized, sound salt mackerel. Let them soak in plenty of cold water for at least eighteen hours, changing the water two or three times. Take out and thoroughly dry; remove the back bone of each. Arrange them on a well-oiled fish-broiler, split part upward, and then with a hair brush gently oil the surface. Place them on a very brisk fire for five minutes, on the split side, and two minutes on the skin side. Remove them from the broiler, dress on a hot dish, pour half a gill of drawn butter over, decorate the dish with one lemon cut in quarters and some parsley greens, and send to the table.