“This figure is found in the Museum Hermeticum. The athanor and the principal symbolic animals of Hermeticism are shown. This athanor has a somewhat fanciful shape, but its main parts can still be recognized: the tower topped with a dome, the sand bath, and the philosophical egg. The serpent enclosed in the egg represents the material of the stone. The lion is the symbol of fixed Sulfur, the eagle symbolizes the volatile, Mercury. The serpent and the dragon are symbols of Matter. The raven represents the color black, the swan the color white, the peacock the colors of the rainbow, and finally, the phoenix symbolizes the color red."
— Théorie & Symboles Des Alchimistes, c. 1891 by Albert Poisson
"We will now speak of our Furnace, but it will be very unfortunate for us to report here the secret of our Furnace, which the ancient Philosophers hid so much; for we have depicted in our Books various Furnaces: nevertheless I sincerely declare to you that we only use one Furnace, which is called Athanor, the meaning of which is to be an immortal fire, because it always gives the fire equally and continual in the same degree, vivifying and nourishing our compound from the beginning to the end of our Stone. O children of doctrine, listen to our words, and hear; our Furnace is composed of two parts, they must be well sealed in all the joints of its enclosure; such is the nature of this Furnace; whether the furnace is made large or small, according to the quantity of matter requires a large Furnace, the small one small; it must be made in the manner of a distilling furnace with its lid, that it be well closed and closed; so when the Furnace has been composed with its lid, make sure that there is a ventilator at the bottom, so that the heat of the lighted fire can breathe there; for Furnace this nature of fire requires and demands this only Furnace, and not another; and the closure of the joints of our Furnace is called the Seal of Hermes, as it was known only to the Sages, and is in no place expressed by any of the Philosophers; for it is reserved in Wisdom, especially as it guards it by a common power." — Elucidation or Clarification of the Will of Raymond Lulle