The alchemists paralleled these experiences in their souls as a withdrawal into the darkness of their interior space, a darkness pregnant with possibility. We have to a great extent lost the sense that still lived in the medieval and renaissance alchemists, that this darkness contained all potentialities. Like children we fear the dark, and for twentieth century humanity darkness often holds only an existential dread - philosophers of science have in the last decade brought us this terrible image of the 'Black Hole' which swallows up and annihilates everything that comes into its orbit. Perhaps we do not gaze enough at the blackness of the heavens. For if we look deep into the blackness of space on a clear night, we will sense more stars hidden between the known visible stars, especially in the vast star fields of the Milky Way.
Cosmic space is pregnant with the possibility of other worlds as yet unseen.
It is this image of blackness we must try to recover if we are to become alchemists. In alchemy, to meet with the black crow is a good omen. Thus in the Chymical Wedding of Christian Rosenkreutz, as our hero sets out on his journey of transformation, he meets with a Crow which by a turn of fate decides which among the various paths open to him is the one that will lead him to the Castle of the King. The temporary phase of whitening which followed on the black stage was symbolised by the white eagle or white swan. As the black mass of the calcination was reacted with other substances and heated, it took on a white crust or dusty layer which sometimes puffed up and flew in a cloud in the flask, as heat exploded bubbles of gas out of the black substance below.