On the Consideration of the Quintessence

Furthermore, it resists the contraries of the elements:
That it is not hot and moist like air is shown, because air is quickly generated and corrupted, as is evident in dead spiders and flies; but this [quintessence] always remains incorruptible if it has been enclosed in a vessel. That it is not cold and dry like earth is demonstrated from its properties, for it is active and heats in the highest degree. That it is not hot and dry like fire is demonstrated to the eye, for being hot, it cools and diminishes and annihilates hot diseases, as I shall show below. That it is incorruptible and preserves those things which are corruptible, [we] can demonstrate by experience and assign [as a proof]: because if even a few or small [pieces] of flesh are infused into it, they do not corrupt, for the flesh itself will remain in this state, more enlivened, and it will preserve the entire human body from all corruption. This is the quintessence, the heaven of the human being, which alchemists strive for, for the preservation of all qualities of the human body, just as the heaven is for the preservation of the whole universe, setting down a few things which modern philosophy and modern physicians ignore—not only the quintessence and its power. This I, with the help of God, will reveal below, where I have taught you, up to this point, the secret work, the quintessence, which is heaven.