The true science of Alchemy is of transmutating other metals into gold, for just one principle. And Sir Isaac Newton practiced it, we now know.
What Alchemy is spirtually is refining ourselves into gold, going through the fire, in a spiritual, not a physical sense.
The gold, or best parts of us, will come to the top of the pot. The dross, or waste, will be skimmed away. Until we are perfection.
Of course, on this earth, we will never be perfect.
And most of us now think it is not what we are supposed to try to be.
Better to be just human, with good ideals.