Turba Philosophorum
Assembly of the Philosophers
"Iximidrus saith:—I testify that the beginning of all things is a Certain Nature, which is perpetual, coequalling all things, and that the visible natures, with their births and decay, are times wherein the ends to which that nature brings them are beheld and summoned. Now, I instruct you that the stars are igneous, and are kept within bounds by the air. If the humidity and density of the air did not exist to separate the flames of the sun from living things, then the Sun would consume all creatures.
But God has provided the separating air, lest that which He has created should be burnt up. Do you not observe that the Sun when it rises in the heaven overcomes the air by its heat, and that the warmth penetrates from the upper to the lower parts of the air? If, then, the air did not presently breathe forth those winds whereby creatures are generated, the Sun by its heat would certainly destroy all that lives. But the Sun is kept in check by the air, which thus conquers because it unites the heat of the Sun to its own heat, and the humidity of water to its own humidity.
Have you not remarked how tenuous water is drawn up into the air by the action of the heat of the Sun, which thus helps the water against itself? If the water did not nourish the air by such tenuous moisture, assuredly the Sun would overcome the air. The fire, therefore, extracts moisture from the water, by means of which the air conquers the fire itself. Thus, fire and water are enemies between which there is no consanguinity, for the fire is hot and dry, but the water is cold and moist. The air, which is warm and moist, joins these together by its concording medium; between the humidity of water and the heat of fire the air is thus placed to establish peace.
And look ye all how there shall arise a spirit from the tenuous vapour of the air, because the heat being joined to the humour, there necessarily issues something tenuous, which will become a wind. For the heat of the Sun extracts something tenuous out of the air, which also becomes spirit and life to all creatures. All this, however, is disposed in such manner by the will of God, and a coruscation appears when the heat of the Sun touches and breaks up a cloud. "
— Turba Philosophorum (1896) by unknown author, translated by Arthur Edward Waite
"On the Preparation Of our Mercury, which is a Green Lion devouring the Sun.
He is the Mercury, and you should know that he is cold and moist, and from him God has created all minerals. For he is also an element and is airy, [and] flees from the fire. Therefore, if a portion of him is fixed, he brings great help and is a useful spirit, and there is nothing in the world but him, and nothing else can take his place; he alone penetrates deep into every body and raises it up. Therefore, when he is mixed with the body, he enlightens and transforms it from one disposition and order into another, and from one color into another.
Of the Golden Art Therefore, he is the entire Elixir of the White and the Red, and is a permanent water, and a water of life and death, and Virgin’s Milk (Jungfrauenmilch), a herb of washing, and is a living fountain: whoever drinks of it does not die and takes on its color, being a medicine of the same, making the colors attainable. He is that which kills, dries and moistens, makes warm and clear, and acts in contrary ways according to the measure of his governance. And when he is alive, he has certain effects; and when he is dead, he has other effects; and others still when he is sublimated."