Take a quantity of clarified sugar in that state that on dipping the
finger into the pan the sugar which adheres to it will break with a
slight noise; this is called _crack_. When the sugar is near this,
put in two or three drops of lemon juice, or a little vinegar to
prevent its graining. When it has come to the _crack_, take it off
instantly, and dip the pan into cold water, to prevent its burning;
let it stand a little, and then pour it on a marble which must be
previously rubbed with oil. Cut the sugar into small pieces, when it
will be ready for use. One drop of citron will flavour a considerable
quantity.