Boiled Haddock with Lobster Sauce

Wash the fish, then place it in a fishkettle with boiling water to cover, add one
tablespoonful of salt, and boil gently for about half an hour. Pick out the flesh of a
small lobster and cut it into little pieces; put the coral in a mortar with one ounce of
butter, and pound it. Place three ounces of butter in a small saucepan, with two
tablespoonfuls of flour, and mix together over the fire until well incorporated; then
put in the pounded coral, and season with two tablespoonfuls of lemon juice and a
small quantity of cayenne. Pour in gradually one pint of boiling water, and stir it
over the fire for ten minutes. Strain the sauce, return it to the saucepan, put in the
pieces of lobster, and boil it up once. When cooked drain the fish, being careful not
to break it; place it on a hot dish, baste with a little of the sauce, and serve the
balance in a sauceboat.