Take an ounce and quarter of the best isinglass, cut it into small pieces, and wash them several times in warm water. Put the isinglass into a preserving pan, with five glasses of filtered water, set it on the fire, and, as soon as it boils, place it at the side of the stove, so as to keep up the boiling; take off the scum directly it rises; and when the whole is reduced to three-quarters, strain it through a cloth into a basin for use. Some add, in clarifying isinglass, lemon-peel, to remove its disagreeable taste; but as good isinglass ought to have no flavor, and as the lemon-peel is certain to give a yellow tinge to that, it is much better left out.