As for the question of how this method of alchemy is practiced, the whole process was explained by the alchemists in a symbolical way. They said gold is made out of mercury:
The nature of mercury is to be ever-moving, but by a certain process the mercury is first stilled,
and once stilled it becomes silver;
then the silver has to be melted,
and the juice of a herb is poured on to the molten silver,