No. 1372 To clarify Isinglass.
Put a quarter of a pound of isinglass in a small stewpan, just cover it with a little clear spring water, and add a piece of lump sugar the size of a walnut, place it upon the fire, shaking the stewpan round occasionally to prevent its sticking to the bottom; when upon the point of simmering add the juice of half a lemon, let simmer about a quarter of an hour, skim and pass it through a fine cloth; if the isinglass is good it will be as clear as crystal, but if it should be a little clouded (which it might be, and yet the isinglass tolerably good) clarify it again thus: pour it into a larger stewpan adding half a gill of water, place it upon the fire, and when on the point of boiling have the white of an egg in a basin, whip well with half a gill of water, pour it into the isinglass, which keep whisking over the fire until boiling, when place it at the corner of the stove, and let reduce to its former consistency, it will keep good some few days if kept in a cool place; if required for crèmes or bavaroises it will not require clarifying, but merely dissolving as at first directed.