Q. Why is the rarefaction of the waters confined to the first heaven? A. Because it is in the nature of rarefied substances to ascend, and because God, in His eternal laws, has assigned its proper sphere to everything.Q. Why does each celestial body invariably revolve about an axis? A. It is by reason of the primeval impetus which it received, and by virtue of the same law which will cause any heavy substance suspended from a thread to turn with the same velocity, if the power which impels its motion be always equal.Q. Why do the superior waters never descend? A. Because of their extreme rarefaction. It is for this reason that a skilled chemist can derive more profit from the study of rarefaction than from any other science whatsoever.Q. What is the matter of the firmament? A. It is properly air, which is more suitable than water as a medium of light.Q. After the separation of the waters from the dry earth, what was performed by the Creator to originate generation? A. He created a certain light which was destined for this office; He placed it in the central fire, and moderated this fire by the humidity of water and by the coldness of earth, so as to keep a check upon its energy and adapt it to His design.Q. What is the action of this central fire? A. It continually operates upon the nearest humid matter, which it exalts into vapour; now this vapour is the mercury of Nature and the first matter of the three kingdoms.Q. How is the sulphur of Nature subsequently formed? A. By the interaction of the central fire and the mercurial vapour.Q. How is the salt of the sea produced? A. By the action of the same fire upon aqueous humidity, when the aerial humidity, which is contained therein, has been exhaled." Ali Sani Amir Saiyid Ali of Hamadan observes: