Take some bitter oranges, and double their weight of sugar; cut the rind of the fruit into quarters and peel it off, and if the marmalade be not wanted very thick, take off some of the spongy white skin inside the rind. Cut the chips as thin as possible, and about half an inch long, and divide the pulp into small bits, removing carefully the seeds, which may be steeped in part of the water that is to make the marmalade, and which must be in the proportion of one quart to one pound of fruit. Put the chips and pulp into a deep earthen dish, and pour the water boiling over them; let them remain for twelve or fourteen hours, and then turn the whole into the preserving pan, and boil it until the chips are perfectly tender. When they are so, add by degrees the sugar (which should be previously pounded), and boil the marmalade until it jellies. The water in which the seeds have been steeped, and which must be taken from the quantity apportioned to the whole of the preserve, should be poured into a hair sieve, and the seeds well worked into it with the back of a spoon; a strong, clear jelly will be obtained by these means, which must be washed off them by pouring their own liquor through the sieve in small portions over them. This must be added to the fruit when it is first set on the fire.