Boil two calf's feet in two quarts of water, till the liquid is
reduced one half, and the meat has dropped to pieces. Then strain
it into a deep dish or pan, and set it by to get cold. When it has
congealed, take all the fat carefully off; put a tea-cupful of the
jelly into a sauce-pan, and set it on hot coals. When it has
nearly boiled, stir in by degrees the beaten yolk of an egg, and
then take it off immediately. You may add to it a little sugar,
and some grated lemon-peel and nutmeg.