Thesauri et armamentarii medico-chymici appendix [...] Testamentum Hadrianeum

The Testament of Hadrian

Whiteness Albedo follows these colors. It is to be elicited by the power of Vulcan Vulcani the god of fire increased to the third degree. It must be ruled by fire through every stage until it is sublimated to its peak ἀκμὴν.
For not just any whiteness, but only the most perfect, can perform tincting tingit the alchemical transformation of metals. It equals something tinted by Lunar rays. It is the perfect Egg of producing nature, a metal that stands unharmed by fire in constant whiteness.
Finally, the Redness Rubedo succeeds the enclosed whiteness. That is the last of all the colors of our Stone. It is the finishing touch of the undertaking and the desired goal of the labor, if the flame of Vulcan, directed in the right way, successfully completes the divine work.
Therefore, prudent philosopher, proceed here to moderate the fire. Proceed to increase it by degrees, working industriously with the sand placed beneath a sand bath or balneum arenae. Proceed until you see the fruit turn yellow like a citron.
Then further, you must rule your Mulciber fire with prudent reason: until the Queen, most beautiful with a red face and lacking all blemish, offers herself to be seen. She is like the dawn in the glittering sky.
Yet do not allow her to leave her chamber. She must be viewed by you through the shining windows the glass of the vessel, but not until she has put on a perfect, ruddy redness.
Meanwhile, care must be taken lest the Stone, turned to glass by too much fire, disappoint your hope with its virtue burned away. Just as fire promotes the cooking when done in proper stages, so an immoderate heat will destroy the entire work.