Coniunctio sive Coitus

The story

Labeled outright "Coniunctio sive Coitus," this is the sequence’s most explicit plate: Sol and Luna, still crowned, locked in physical embrace on open ground, sun and moon faces floating in the sky beside them. Alchemists used sexual union as their central working metaphor for the chemical combination of opposites — a fixed, "male" sulphur and a volatile, "female" mercury reacting to form a new, third substance. Beneath the image, German verses have Luna and Sol address one another directly, each claiming to need the other’s power to be complete. The plate was frank enough that later, more decorous editions sometimes bowdlerized or cut it; this 1550 Frankfurt printing keeps it intact. It sits at the structural center of the twenty-plate sequence — everything before builds toward this joining, and everything after (death, purification, rebirth) follows directly from it.