The Cockerel and the Brooding Hen (Aurora Consurgens)

This illumination shows a black rooster with a prominent tail standing on an elevated grey-green mound; it is leaning forward to peck at a cluster of red organic material near the ground. Below and to the left, a tan-colored hen with a red comb sits patiently within a circular, flat wooden basket containing a clutch of five white oval eggs. The background is a plain, neutral parchment tone with traces of marginalia visible to the left.

This image originates from the 'Aurora consurgens', a 15th-century alchemical treatise attributed to pseudo-Aquinas, where avian imagery is frequently used to allegorize stages of the transmutation process, such as putrefaction or the whitening of the stone.