The union of the King and Queen symbolizing the reunification of opposites is shown. The is the mystic marriage of the Sun and Moon. The sun represents sulfur (the fiery, active, masculine principle) conjoined with the moon representing mercury (the passive). Like many other aspects illustrating the process, these two agents (mercury and sulfur) are elemental. Though they contain completely different natures, the idea is to unite them as opposites to create one. The alchemist on the right signifies the need to keep the furnace fire at a constant temperature.